Commit Graph

1526 Commits

Author SHA1 Message Date
David Howells
c8070b7875 mm: Don't pin ZERO_PAGE in pin_user_pages()
Make pin_user_pages*() leave a ZERO_PAGE unpinned if it extracts a pointer
to it from the page tables and make unpin_user_page*() correspondingly
ignore a ZERO_PAGE when unpinning.  We don't want to risk overrunning a
zero page's refcount as we're only allowed ~2 million pins on it -
something that userspace can conceivably trigger.

Add a pair of functions to test whether a page or a folio is a ZERO_PAGE.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Christoph Hellwig <hch@infradead.org>
cc: David Hildenbrand <david@redhat.com>
cc: Lorenzo Stoakes <lstoakes@gmail.com>
cc: Andrew Morton <akpm@linux-foundation.org>
cc: Jens Axboe <axboe@kernel.dk>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: Matthew Wilcox <willy@infradead.org>
cc: Jan Kara <jack@suse.cz>
cc: Jeff Layton <jlayton@kernel.org>
cc: Jason Gunthorpe <jgg@nvidia.com>
cc: Logan Gunthorpe <logang@deltatee.com>
cc: Hillf Danton <hdanton@sina.com>
cc: Christian Brauner <brauner@kernel.org>
cc: Linus Torvalds <torvalds@linux-foundation.org>
cc: linux-fsdevel@vger.kernel.org
cc: linux-block@vger.kernel.org
cc: linux-kernel@vger.kernel.org
cc: linux-mm@kvack.org
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20230526214142.958751-2-dhowells@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-31 09:48:15 -06:00
Linus Torvalds
22b8cc3e78 Add support for new Linear Address Masking CPU feature. This is similar
to ARM's Top Byte Ignore and allows userspace to store metadata in some
 bits of pointers without masking it out before use.
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Merge tag 'x86_mm_for_6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 LAM (Linear Address Masking) support from Dave Hansen:
 "Add support for the new Linear Address Masking CPU feature.

  This is similar to ARM's Top Byte Ignore and allows userspace to store
  metadata in some bits of pointers without masking it out before use"

* tag 'x86_mm_for_6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/iommu/sva: Do not allow to set FORCE_TAGGED_SVA bit from outside
  x86/mm/iommu/sva: Fix error code for LAM enabling failure due to SVA
  selftests/x86/lam: Add test cases for LAM vs thread creation
  selftests/x86/lam: Add ARCH_FORCE_TAGGED_SVA test cases for linear-address masking
  selftests/x86/lam: Add inherit test cases for linear-address masking
  selftests/x86/lam: Add io_uring test cases for linear-address masking
  selftests/x86/lam: Add mmap and SYSCALL test cases for linear-address masking
  selftests/x86/lam: Add malloc and tag-bits test cases for linear-address masking
  x86/mm/iommu/sva: Make LAM and SVA mutually exclusive
  iommu/sva: Replace pasid_valid() helper with mm_valid_pasid()
  mm: Expose untagging mask in /proc/$PID/status
  x86/mm: Provide arch_prctl() interface for LAM
  x86/mm: Reduce untagged_addr() overhead for systems without LAM
  x86/uaccess: Provide untagged_addr() and remove tags before address check
  mm: Introduce untagged_addr_remote()
  x86/mm: Handle LAM on context switch
  x86: CPUID and CR3/CR4 flags for Linear Address Masking
  x86: Allow atomic MM_CONTEXT flags setting
  x86/mm: Rework address range check in get_user() and put_user()
2023-04-28 09:43:49 -07:00
Linus Torvalds
7fa8a8ee94 - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of
switching from a user process to a kernel thread.
 
 - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj Raghav.
 
 - zsmalloc performance improvements from Sergey Senozhatsky.
 
 - Yue Zhao has found and fixed some data race issues around the
   alteration of memcg userspace tunables.
 
 - VFS rationalizations from Christoph Hellwig:
 
   - removal of most of the callers of write_one_page().
 
   - make __filemap_get_folio()'s return value more useful
 
 - Luis Chamberlain has changed tmpfs so it no longer requires swap
   backing.  Use `mount -o noswap'.
 
 - Qi Zheng has made the slab shrinkers operate locklessly, providing
   some scalability benefits.
 
 - Keith Busch has improved dmapool's performance, making part of its
   operations O(1) rather than O(n).
 
 - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
   permitting userspace to wr-protect anon memory unpopulated ptes.
 
 - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive rather
   than exclusive, and has fixed a bunch of errors which were caused by its
   unintuitive meaning.
 
 - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
   which causes minor faults to install a write-protected pte.
 
 - Vlastimil Babka has done some maintenance work on vma_merge():
   cleanups to the kernel code and improvements to our userspace test
   harness.
 
 - Cleanups to do_fault_around() by Lorenzo Stoakes.
 
 - Mike Rapoport has moved a lot of initialization code out of various
   mm/ files and into mm/mm_init.c.
 
 - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
   DRM, but DRM doesn't use it any more.
 
 - Lorenzo has also coverted read_kcore() and vread() to use iterators
   and has thereby removed the use of bounce buffers in some cases.
 
 - Lorenzo has also contributed further cleanups of vma_merge().
 
 - Chaitanya Prakash provides some fixes to the mmap selftesting code.
 
 - Matthew Wilcox changes xfs and afs so they no longer take sleeping
   locks in ->map_page(), a step towards RCUification of pagefaults.
 
 - Suren Baghdasaryan has improved mmap_lock scalability by switching to
   per-VMA locking.
 
 - Frederic Weisbecker has reworked the percpu cache draining so that it
   no longer causes latency glitches on cpu isolated workloads.
 
 - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
   logic.
 
 - Liu Shixin has changed zswap's initialization so we no longer waste a
   chunk of memory if zswap is not being used.
 
 - Yosry Ahmed has improved the performance of memcg statistics flushing.
 
 - David Stevens has fixed several issues involving khugepaged,
   userfaultfd and shmem.
 
 - Christoph Hellwig has provided some cleanup work to zram's IO-related
   code paths.
 
 - David Hildenbrand has fixed up some issues in the selftest code's
   testing of our pte state changing.
 
 - Pankaj Raghav has made page_endio() unneeded and has removed it.
 
 - Peter Xu contributed some rationalizations of the userfaultfd
   selftests.
 
 - Yosry Ahmed has fixed an issue around memcg's page recalim accounting.
 
 - Chaitanya Prakash has fixed some arm-related issues in the
   selftests/mm code.
 
 - Longlong Xia has improved the way in which KSM handles hwpoisoned
   pages.
 
 - Peter Xu fixes a few issues with uffd-wp at fork() time.
 
 - Stefan Roesch has changed KSM so that it may now be used on a
   per-process and per-cgroup basis.
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Merge tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of
   switching from a user process to a kernel thread.

 - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj
   Raghav.

 - zsmalloc performance improvements from Sergey Senozhatsky.

 - Yue Zhao has found and fixed some data race issues around the
   alteration of memcg userspace tunables.

 - VFS rationalizations from Christoph Hellwig:
     - removal of most of the callers of write_one_page()
     - make __filemap_get_folio()'s return value more useful

 - Luis Chamberlain has changed tmpfs so it no longer requires swap
   backing. Use `mount -o noswap'.

 - Qi Zheng has made the slab shrinkers operate locklessly, providing
   some scalability benefits.

 - Keith Busch has improved dmapool's performance, making part of its
   operations O(1) rather than O(n).

 - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
   permitting userspace to wr-protect anon memory unpopulated ptes.

 - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive
   rather than exclusive, and has fixed a bunch of errors which were
   caused by its unintuitive meaning.

 - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
   which causes minor faults to install a write-protected pte.

 - Vlastimil Babka has done some maintenance work on vma_merge():
   cleanups to the kernel code and improvements to our userspace test
   harness.

 - Cleanups to do_fault_around() by Lorenzo Stoakes.

 - Mike Rapoport has moved a lot of initialization code out of various
   mm/ files and into mm/mm_init.c.

 - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
   DRM, but DRM doesn't use it any more.

 - Lorenzo has also coverted read_kcore() and vread() to use iterators
   and has thereby removed the use of bounce buffers in some cases.

 - Lorenzo has also contributed further cleanups of vma_merge().

 - Chaitanya Prakash provides some fixes to the mmap selftesting code.

 - Matthew Wilcox changes xfs and afs so they no longer take sleeping
   locks in ->map_page(), a step towards RCUification of pagefaults.

 - Suren Baghdasaryan has improved mmap_lock scalability by switching to
   per-VMA locking.

 - Frederic Weisbecker has reworked the percpu cache draining so that it
   no longer causes latency glitches on cpu isolated workloads.

 - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
   logic.

 - Liu Shixin has changed zswap's initialization so we no longer waste a
   chunk of memory if zswap is not being used.

 - Yosry Ahmed has improved the performance of memcg statistics
   flushing.

 - David Stevens has fixed several issues involving khugepaged,
   userfaultfd and shmem.

 - Christoph Hellwig has provided some cleanup work to zram's IO-related
   code paths.

 - David Hildenbrand has fixed up some issues in the selftest code's
   testing of our pte state changing.

 - Pankaj Raghav has made page_endio() unneeded and has removed it.

 - Peter Xu contributed some rationalizations of the userfaultfd
   selftests.

 - Yosry Ahmed has fixed an issue around memcg's page recalim
   accounting.

 - Chaitanya Prakash has fixed some arm-related issues in the
   selftests/mm code.

 - Longlong Xia has improved the way in which KSM handles hwpoisoned
   pages.

 - Peter Xu fixes a few issues with uffd-wp at fork() time.

 - Stefan Roesch has changed KSM so that it may now be used on a
   per-process and per-cgroup basis.

* tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
  mm,unmap: avoid flushing TLB in batch if PTE is inaccessible
  shmem: restrict noswap option to initial user namespace
  mm/khugepaged: fix conflicting mods to collapse_file()
  sparse: remove unnecessary 0 values from rc
  mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area()
  hugetlb: pte_alloc_huge() to replace huge pte_alloc_map()
  maple_tree: fix allocation in mas_sparse_area()
  mm: do not increment pgfault stats when page fault handler retries
  zsmalloc: allow only one active pool compaction context
  selftests/mm: add new selftests for KSM
  mm: add new KSM process and sysfs knobs
  mm: add new api to enable ksm per process
  mm: shrinkers: fix debugfs file permissions
  mm: don't check VMA write permissions if the PTE/PMD indicates write permissions
  migrate_pages_batch: fix statistics for longterm pin retry
  userfaultfd: use helper function range_in_vma()
  lib/show_mem.c: use for_each_populated_zone() simplify code
  mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list()
  fs/buffer: convert create_page_buffers to folio_create_buffers
  fs/buffer: add folio_create_empty_buffers helper
  ...
2023-04-27 19:42:02 -07:00
Longlong Xia
4248d0083e mm: ksm: support hwpoison for ksm page
hwpoison_user_mappings() is updated to support ksm pages, and add
collect_procs_ksm() to collect processes when the error hit an ksm page. 
The difference from collect_procs_anon() is that it also needs to traverse
the rmap-item list on the stable node of the ksm page.  At the same time,
add_to_kill_ksm() is added to handle ksm pages.  And
task_in_to_kill_list() is added to avoid duplicate addition of tsk to the
to_kill list.  This is because when scanning the list, if the pages that
make up the ksm page all come from the same process, they may be added
repeatedly.

Link: https://lkml.kernel.org/r/20230414021741.2597273-3-xialonglong1@huawei.com
Signed-off-by: Longlong Xia <xialonglong1@huawei.com>
Tested-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:53:52 -07:00
Liu Shixin
1cb9dc4b47 mm: hwpoison: support recovery from HugePage copy-on-write faults
copy-on-write of hugetlb user pages with uncorrectable errors will result
in a kernel crash.  This is because the copy is performed in kernel mode
and in general we can not handle accessing memory with such errors while
in kernel mode.  Commit a873dfe103 ("mm, hwpoison: try to recover from
copy-on write faults") introduced the routine copy_user_highpage_mc() to
gracefully handle copying of user pages with uncorrectable errors. 
However, the separate hugetlb copy-on-write code paths were not modified
as part of commit a873dfe103.

Modify hugetlb copy-on-write code paths to use copy_mc_user_highpage() so
that they can also gracefully handle uncorrectable errors in user pages. 
This involves changing the hugetlb specific routine
copy_user_large_folio() from type void to int so that it can return an
error.  Modify the hugetlb userfaultfd code in the same way so that it can
return -EHWPOISON if it encounters an uncorrectable error.

Link: https://lkml.kernel.org/r/20230413131349.2524210-1-liushixin2@huawei.com
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:30:09 -07:00
Aneesh Kumar K.V
0b376f1e0f mm/hugetlb_vmemmap: rename ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
Now we use ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP config option to
indicate devdax and hugetlb vmemmap optimization support.  Hence rename
that to a generic ARCH_WANT_OPTIMIZE_VMEMMAP

Link: https://lkml.kernel.org/r/20230412050025.84346-2-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Tarun Sahu <tsahu@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:30:09 -07:00
Aneesh Kumar K.V
87a7ae75d7 mm/vmemmap/devdax: fix kernel crash when probing devdax devices
commit 4917f55b4e ("mm/sparse-vmemmap: improve memory savings for
compound devmaps") added support for using optimized vmmemap for devdax
devices.  But how vmemmap mappings are created are architecture specific. 
For example, powerpc with hash translation doesn't have vmemmap mappings
in init_mm page table instead they are bolted table entries in the
hardware page table

vmemmap_populate_compound_pages() used by vmemmap optimization code is not
aware of these architecture-specific mapping.  Hence allow architecture to
opt for this feature.  I selected architectures supporting
HUGETLB_PAGE_OPTIMIZE_VMEMMAP option as also supporting this feature.

This patch fixes the below crash on ppc64.

BUG: Unable to handle kernel data access on write at 0xc00c000100400038
Faulting instruction address: 0xc000000001269d90
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
Modules linked in:
CPU: 7 PID: 1 Comm: swapper/0 Not tainted 6.3.0-rc5-150500.34-default+ #2 5c90a668b6bbd142599890245c2fb5de19d7d28a
Hardware name: IBM,9009-42G POWER9 (raw) 0x4e0202 0xf000005 of:IBM,FW950.40 (VL950_099) hv:phyp pSeries
NIP:  c000000001269d90 LR: c0000000004c57d4 CTR: 0000000000000000
REGS: c000000003632c30 TRAP: 0300   Not tainted  (6.3.0-rc5-150500.34-default+)
MSR:  8000000000009033 <SF,EE,ME,IR,DR,RI,LE>  CR: 24842228  XER: 00000000
CFAR: c0000000004c57d0 DAR: c00c000100400038 DSISR: 42000000 IRQMASK: 0
....
NIP [c000000001269d90] __init_single_page.isra.74+0x14/0x4c
LR [c0000000004c57d4] __init_zone_device_page+0x44/0xd0
Call Trace:
[c000000003632ed0] [c000000003632f60] 0xc000000003632f60 (unreliable)
[c000000003632f10] [c0000000004c5ca0] memmap_init_zone_device+0x170/0x250
[c000000003632fe0] [c0000000005575f8] memremap_pages+0x2c8/0x7f0
[c0000000036330c0] [c000000000557b5c] devm_memremap_pages+0x3c/0xa0
[c000000003633100] [c000000000d458a8] dev_dax_probe+0x108/0x3e0
[c0000000036331a0] [c000000000d41430] dax_bus_probe+0xb0/0x140
[c0000000036331d0] [c000000000cef27c] really_probe+0x19c/0x520
[c000000003633260] [c000000000cef6b4] __driver_probe_device+0xb4/0x230
[c0000000036332e0] [c000000000cef888] driver_probe_device+0x58/0x120
[c000000003633320] [c000000000cefa6c] __device_attach_driver+0x11c/0x1e0
[c0000000036333a0] [c000000000cebc58] bus_for_each_drv+0xa8/0x130
[c000000003633400] [c000000000ceefcc] __device_attach+0x15c/0x250
[c0000000036334a0] [c000000000ced458] bus_probe_device+0x108/0x110
[c0000000036334f0] [c000000000ce92dc] device_add+0x7fc/0xa10
[c0000000036335b0] [c000000000d447c8] devm_create_dev_dax+0x1d8/0x530
[c000000003633640] [c000000000d46b60] __dax_pmem_probe+0x200/0x270
[c0000000036337b0] [c000000000d46bf0] dax_pmem_probe+0x20/0x70
[c0000000036337d0] [c000000000d2279c] nvdimm_bus_probe+0xac/0x2b0
[c000000003633860] [c000000000cef27c] really_probe+0x19c/0x520
[c0000000036338f0] [c000000000cef6b4] __driver_probe_device+0xb4/0x230
[c000000003633970] [c000000000cef888] driver_probe_device+0x58/0x120
[c0000000036339b0] [c000000000cefd08] __driver_attach+0x1d8/0x240
[c000000003633a30] [c000000000cebb04] bus_for_each_dev+0xb4/0x130
[c000000003633a90] [c000000000cee564] driver_attach+0x34/0x50
[c000000003633ab0] [c000000000ced878] bus_add_driver+0x218/0x300
[c000000003633b40] [c000000000cf1144] driver_register+0xa4/0x1b0
[c000000003633bb0] [c000000000d21a0c] __nd_driver_register+0x5c/0x100
[c000000003633c10] [c00000000206a2e8] dax_pmem_init+0x34/0x48
[c000000003633c30] [c0000000000132d0] do_one_initcall+0x60/0x320
[c000000003633d00] [c0000000020051b0] kernel_init_freeable+0x360/0x400
[c000000003633de0] [c000000000013764] kernel_init+0x34/0x1d0
[c000000003633e50] [c00000000000de14] ret_from_kernel_thread+0x5c/0x64

Link: https://lkml.kernel.org/r/20230411142214.64464-1-aneesh.kumar@linux.ibm.com
Fixes: 4917f55b4e ("mm/sparse-vmemmap: improve memory savings for compound devmaps")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reported-by: Tarun Sahu <tsahu@linux.ibm.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:30:09 -07:00
ZhangPeng
c0e8150e14 mm: convert copy_user_huge_page() to copy_user_large_folio()
Replace copy_user_huge_page() with copy_user_large_folio(). 
copy_user_large_folio() does the same as copy_user_huge_page(), but takes
in folios instead of pages.  Remove pages_per_huge_page from
copy_user_large_folio(), because we can get that from folio_nr_pages(dst).

Convert copy_user_gigantic_page() to take in folios.

Link: https://lkml.kernel.org/r/20230410133932.32288-6-zhangpeng362@huawei.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:29:55 -07:00
ZhangPeng
e87340ca5c userfaultfd: convert copy_huge_page_from_user() to copy_folio_from_user()
Replace copy_huge_page_from_user() with copy_folio_from_user(). 
copy_folio_from_user() does the same as copy_huge_page_from_user(), but
takes in a folio instead of a page.

Convert page_kaddr to kaddr in copy_folio_from_user() to do indenting
cleanup.

Link: https://lkml.kernel.org/r/20230410133932.32288-4-zhangpeng362@huawei.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:29:55 -07:00
Arnd Bergmann
5f300fd59a mm: make arch_has_descending_max_zone_pfns() static
clang produces a build failure on x86 for some randconfig builds after a
change that moves around code to mm/mm_init.c:

Cannot find symbol for section 2: .text.
mm/mm_init.o: failed

I have not been able to figure out why this happens, but the __weak
annotation on arch_has_descending_max_zone_pfns() is the trigger here.

Removing the weak function in favor of an open-coded Kconfig option check
avoids the problem and becomes clearer as well as better to optimize by
the compiler.

[arnd@arndb.de: fix logic bug]
  Link: https://lkml.kernel.org/r/20230415081904.969049-1-arnd@kernel.org
Link: https://lkml.kernel.org/r/20230414080418.110236-1-arnd@kernel.org
Fixes: 9420f89db2 ("mm: move most of core MM initialization to mm/mm_init.c")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: SeongJae Park <sj@kernel.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:29:42 -07:00
Kefeng Wang
8cbc82f3ec mm: memory-failure: Move memory failure sysctls to its own file
The sysctl_memory_failure_early_kill and memory_failure_recovery
are only used in memory-failure.c, move them to its own file.

Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
[mcgrof: fix by adding empty ctl entry, this caused a crash]
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-13 11:49:35 -07:00
Raghavendra K T
d46031f40e sched/numa: use hash_32 to mix up PIDs accessing VMA
before: last 6 bits of PID is used as index to store information about
tasks accessing VMA's.

after: hash_32 is used to take of cases where tasks are created over a
period of time, and thus improve collision probability.

Result:
The patch series overall improves autonuma cost.

Kernbench around more than 5% improvement and system time in mmtest
autonuma showed more than 80% improvement

Link: https://lkml.kernel.org/r/d5a9f75513300caed74e5c8570bba9317b963c2b.1677672277.git.raghavendra.kt@amd.com
Signed-off-by: Raghavendra K T <raghavendra.kt@amd.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Cc: Bharata B Rao <bharata@amd.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Disha Talreja <dishaa.talreja@amd.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 20:03:03 -07:00
Raghavendra K T
20f586486b sched/numa: implement access PID reset logic
This helps to ensure that only recently accessed PIDs scan the VMAs.

Current implementation: (idea supported by PeterZ)

 1. Accessing PID information is maintained in two windows. 
    access_pids[1] being newest.

 2. Reset old access PID info i.e.  access_pid[0] every (4 *
    sysctl_numa_balancing_scan_delay) interval after initial scan delay
    period expires.

The above interval seemed to be experimentally optimum since it avoids
frequent reset of access info as well as helps clearing the old access
info regularly.  The reset logic is implemented in scan path.

Link: https://lkml.kernel.org/r/f7a675f66d1442d048b4216b2baf94515012c405.1677672277.git.raghavendra.kt@amd.com
Signed-off-by: Raghavendra K T <raghavendra.kt@amd.com>
Suggested-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Bharata B Rao <bharata@amd.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Disha Talreja <dishaa.talreja@amd.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 20:03:03 -07:00
Raghavendra K T
fc137c0dda sched/numa: enhance vma scanning logic
During Numa scanning make sure only relevant vmas of the tasks are
scanned.

Before:
 All the tasks of a process participate in scanning the vma even if they
 do not access vma in it's lifespan.

Now:
 Except cases of first few unconditional scans, if a process do
 not touch vma (exluding false positive cases of PID collisions)
 tasks no longer scan all vma

Logic used:

1) 6 bits of PID used to mark active bit in vma numab status during
   fault to remember PIDs accessing vma.  (Thanks Mel)

2) Subsequently in scan path, vma scanning is skipped if current PID
   had not accessed vma.

3) First two times we do allow unconditional scan to preserve earlier
   behaviour of scanning.

Acknowledgement to Bharata B Rao <bharata@amd.com> for initial patch to
store pid information and Peter Zijlstra <peterz@infradead.org> (Usage of
test and set bit)

Link: https://lkml.kernel.org/r/092f03105c7c1d3450f4636b1ea350407f07640e.1677672277.git.raghavendra.kt@amd.com
Signed-off-by: Raghavendra K T <raghavendra.kt@amd.com>
Suggested-by: Mel Gorman <mgorman@techsingularity.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: Disha Talreja <dishaa.talreja@amd.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 20:03:03 -07:00
Mel Gorman
ef6a22b70f sched/numa: apply the scan delay to every new vma
Pach series "sched/numa: Enhance vma scanning", v3.

The patchset proposes one of the enhancements to numa vma scanning
suggested by Mel.  This is continuation of [3].

Reposting the rebased patchset to akpm mm-unstable tree (March 1) 

Existing mechanism of scan period involves, scan period derived from
per-thread stats.  Process Adaptive autoNUMA [1] proposed to gather NUMA
fault stats at per-process level to capture aplication behaviour better.

During that course of discussion, Mel proposed several ideas to enhance
current numa balancing.  One of the suggestion was below

Track what threads access a VMA.  The suggestion was to use an unsigned
long pid_mask and use the lower bits to tag approximately what threads
access a VMA.  Skip VMAs that did not trap a fault.  This would be
approximate because of PID collisions but would reduce scanning of areas
the thread is not interested in.  The above suggestion intends not to
penalize threads that has no interest in the vma, thus reduce scanning
overhead.

V3 changes are mostly based on PeterZ comments (details below in changes)

Summary of patchset:

Current patchset implements:

1. Delay the vma scanning logic for newly created VMA's so that
   additional overhead of scanning is not incurred for short lived tasks
   (implementation by Mel)

2. Store the information of tasks accessing VMA in 2 windows.  It is
   regularly cleared in (4*sysctl_numa_balancing_scan_delay) interval. 
   The above time is derived from experimenting (Suggested by PeterZ) to
   balance between frequent clearing vs obsolete access data

3. hash_32 used to encode task index accessing VMA information

4. VMA's acess information is used to skip scanning for the tasks
   which had not accessed VMA

Changes since V2:
patch1: 
 - Renaming of structure, macro to function,
 - Add explanation to heuristics
 - Adding more details from result (PeterZ)
 Patch2:
 - Usage of test and set bit (PeterZ)
 - Move storing access PID info to numa_migrate_prep()
 - Add a note on fainess among tasks allowed to scan
   (PeterZ)
 Patch3:
 - Maintain two windows of access PID information
  (PeterZ supported implementation and Gave idea to extend
   to N if needed)
 Patch4:
 - Apply hash_32 function to track VMA accessing PIDs (PeterZ)

Changes since RFC V1:
 - Include Mel's vma scan delay patch
 - Change the accessing pid store logic (Thanks Mel)
 - Fencing structure / code to NUMA_BALANCING (David, Mel)
 - Adding clearing access PID logic (Mel)
 - Descriptive change log ( Mike Rapoport)

Things to ponder over:
==========================================

- Improvement to clearing accessing PIDs logic (discussed in-detail in
  patch3 itself (Done in this patchset by implementing 2 window history)

- Current scan period is not changed in the patchset, so we do see
  frequent tries to scan.  Relaxing scan period dynamically could improve
  results further.

[1] sched/numa: Process Adaptive autoNUMA 
 Link: https://lore.kernel.org/lkml/20220128052851.17162-1-bharata@amd.com/T/

[2] RFC V1 Link: 
  https://lore.kernel.org/all/cover.1673610485.git.raghavendra.kt@amd.com/

[3] V2 Link:
  https://lore.kernel.org/lkml/cover.1675159422.git.raghavendra.kt@amd.com/


Results:
Summary: Huge autonuma cost reduction seen in mmtest. Kernbench improvement 
is more than 5% and huge system time (80%+) improvement from mmtest autonuma.
(dbench had huge std deviation to post)

kernbench
===========
                      6.2.0-mmunstable-base  6.2.0-mmunstable-patched
Amean     user-256    22002.51 (   0.00%)    22649.95 *  -2.94%*
Amean     syst-256    10162.78 (   0.00%)     8214.13 *  19.17%*
Amean     elsp-256      160.74 (   0.00%)      156.92 *   2.38%*

Duration User       66017.43    67959.84
Duration System     30503.15    24657.03
Duration Elapsed      504.61      493.12

                      6.2.0-mmunstable-base  6.2.0-mmunstable-patched
Ops NUMA alloc hit                1738835089.00  1738780310.00
Ops NUMA alloc local              1738834448.00  1738779711.00
Ops NUMA base-page range updates      477310.00      392566.00
Ops NUMA PTE updates                  477310.00      392566.00
Ops NUMA hint faults                   96817.00       87555.00
Ops NUMA hint local faults %           10150.00        2192.00
Ops NUMA hint local percent               10.48           2.50
Ops NUMA pages migrated                86660.00       85363.00
Ops AutoNUMA cost                        489.07         442.14

autonumabench
===============
                      6.2.0-mmunstable-base  6.2.0-mmunstable-patched
Amean     syst-NUMA01                  399.50 (   0.00%)       52.05 *  86.97%*
Amean     syst-NUMA01_THREADLOCAL        0.21 (   0.00%)        0.22 *  -5.41%*
Amean     syst-NUMA02                    0.80 (   0.00%)        0.78 *   2.68%*
Amean     syst-NUMA02_SMT                0.65 (   0.00%)        0.68 *  -3.95%*
Amean     elsp-NUMA01                  313.26 (   0.00%)      313.11 *   0.05%*
Amean     elsp-NUMA01_THREADLOCAL        1.06 (   0.00%)        1.08 *  -1.76%*
Amean     elsp-NUMA02                    3.19 (   0.00%)        3.24 *  -1.52%*
Amean     elsp-NUMA02_SMT                3.72 (   0.00%)        3.61 *   2.92%*

Duration User      396433.47   324835.96
Duration System      2808.70      376.66
Duration Elapsed     2258.61     2258.12

                      6.2.0-mmunstable-base  6.2.0-mmunstable-patched
Ops NUMA alloc hit                  59921806.00    49623489.00
Ops NUMA alloc miss                        0.00           0.00
Ops NUMA interleave hit                    0.00           0.00
Ops NUMA alloc local                59920880.00    49622594.00
Ops NUMA base-page range updates   152259275.00       50075.00
Ops NUMA PTE updates               152259275.00       50075.00
Ops NUMA PMD updates                       0.00           0.00
Ops NUMA hint faults               154660352.00       39014.00
Ops NUMA hint local faults %       138550501.00       23139.00
Ops NUMA hint local percent               89.58          59.31
Ops NUMA pages migrated              8179067.00       14147.00
Ops AutoNUMA cost                     774522.98         195.69


This patch (of 4):

Currently whenever a new task is created we wait for
sysctl_numa_balancing_scan_delay to avoid unnessary scanning overhead. 
Extend the same logic to new or very short-lived VMAs.

[raghavendra.kt@amd.com: add initialization in vm_area_dup())]
Link: https://lkml.kernel.org/r/cover.1677672277.git.raghavendra.kt@amd.com
Link: https://lkml.kernel.org/r/7a6fbba87c8b51e67efd3e74285bb4cb311a16ca.1677672277.git.raghavendra.kt@amd.com
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Raghavendra K T <raghavendra.kt@amd.com>
Cc: Bharata B Rao <bharata@amd.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Disha Talreja <dishaa.talreja@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 20:03:03 -07:00
Suren Baghdasaryan
c7f8f31c00 mm: separate vma->lock from vm_area_struct
vma->lock being part of the vm_area_struct causes performance regression
during page faults because during contention its count and owner fields
are constantly updated and having other parts of vm_area_struct used
during page fault handling next to them causes constant cache line
bouncing.  Fix that by moving the lock outside of the vm_area_struct.

All attempts to keep vma->lock inside vm_area_struct in a separate cache
line still produce performance regression especially on NUMA machines. 
Smallest regression was achieved when lock is placed in the fourth cache
line but that bloats vm_area_struct to 256 bytes.

Considering performance and memory impact, separate lock looks like the
best option.  It increases memory footprint of each VMA but that can be
optimized later if the new size causes issues.  Note that after this
change vma_init() does not allocate or initialize vma->lock anymore.  A
number of drivers allocate a pseudo VMA on the stack but they never use
the VMA's lock, therefore it does not need to be allocated.  The future
drivers which might need the VMA lock should use
vm_area_alloc()/vm_area_free() to allocate the VMA.

Link: https://lkml.kernel.org/r/20230227173632.3292573-34-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 20:03:02 -07:00
Suren Baghdasaryan
0d2ebf9c3f mm/mmap: free vm_area_struct without call_rcu in exit_mmap
call_rcu() can take a long time when callback offloading is enabled.  Its
use in the vm_area_free can cause regressions in the exit path when
multiple VMAs are being freed.

Because exit_mmap() is called only after the last mm user drops its
refcount, the page fault handlers can't be racing with it.  Any other
possible user like oom-reaper or process_mrelease are already synchronized
using mmap_lock.  Therefore exit_mmap() can free VMAs directly, without
the use of call_rcu().

Expose __vm_area_free() and use it from exit_mmap() to avoid possible
call_rcu() floods and performance regressions caused by it.

Link: https://lkml.kernel.org/r/20230227173632.3292573-33-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 20:03:02 -07:00
Suren Baghdasaryan
55324e46eb mm: add FAULT_FLAG_VMA_LOCK flag
Add a new flag to distinguish page faults handled under protection of
per-vma lock.

[surenb@google.com: document FAULT_FLAG_VMA_LOCK flag]
  Link: https://lkml.kernel.org/r/20230301022720.1380780-2-surenb@google.com
  Link: https://lore.kernel.org/all/20230301113648.7c279865@canb.auug.org.au/
Link: https://lkml.kernel.org/r/20230227173632.3292573-26-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Laurent Dufour <laurent.dufour@fr.ibm.com>
Cc: Dan Carpenter <error27@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 20:03:00 -07:00
Suren Baghdasaryan
50ee325372 mm: introduce lock_vma_under_rcu to be used from arch-specific code
Introduce lock_vma_under_rcu function to lookup and lock a VMA during page
fault handling.  When VMA is not found, can't be locked or changes after
being locked, the function returns NULL.  The lookup is performed under
RCU protection to prevent the found VMA from being destroyed before the
VMA lock is acquired.  VMA lock statistics are updated according to the
results.  For now only anonymous VMAs can be searched this way.  In other
cases the function returns NULL.

Link: https://lkml.kernel.org/r/20230227173632.3292573-24-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 20:03:00 -07:00
Suren Baghdasaryan
457f67be59 mm: introduce vma detached flag
Per-vma locking mechanism will search for VMA under RCU protection and
then after locking it, has to ensure it was not removed from the VMA tree
after we found it.  To make this check efficient, introduce a
vma->detached flag to mark VMAs which were removed from the VMA tree.

Link: https://lkml.kernel.org/r/20230227173632.3292573-23-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 20:02:59 -07:00
Suren Baghdasaryan
55fd6fccad mm/khugepaged: write-lock VMA while collapsing a huge page
Protect VMA from concurrent page fault handler while collapsing a huge
page.  Page fault handler needs a stable PMD to use PTL and relies on
per-VMA lock to prevent concurrent PMD changes.  pmdp_collapse_flush(),
set_huge_pmd() and collapse_and_free_pmd() can modify a PMD, which will
not be detected by a page fault handler without proper locking.

Before this patch, page tables can be walked under any one of the
mmap_lock, the mapping lock, and the anon_vma lock; so when khugepaged
unlinks and frees page tables, it must ensure that all of those either are
locked or don't exist.  This patch adds a fourth lock under which page
tables can be traversed, and so khugepaged must also lock out that one.

[surenb@google.com: vm_lock/i_mmap_rwsem inversion in retract_page_tables]
  Link: https://lkml.kernel.org/r/20230303213250.3555716-1-surenb@google.com
[surenb@google.com: build fix]
  Link: https://lkml.kernel.org/r/CAJuCfpFjWhtzRE1X=J+_JjgJzNKhq-=JT8yTBSTHthwp0pqWZw@mail.gmail.com
Link: https://lkml.kernel.org/r/20230227173632.3292573-16-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 20:02:58 -07:00
Suren Baghdasaryan
c732293331 mm: mark VMA as being written when changing vm_flags
Updates to vm_flags have to be done with VMA marked as being written for
preventing concurrent page faults or other modifications.

Link: https://lkml.kernel.org/r/20230227173632.3292573-14-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 20:02:57 -07:00
Suren Baghdasaryan
5e31275cc9 mm: add per-VMA lock and helper functions to control it
Introduce per-VMA locking.  The lock implementation relies on a per-vma
and per-mm sequence counters to note exclusive locking:

  - read lock - (implemented by vma_start_read) requires the vma
    (vm_lock_seq) and mm (mm_lock_seq) sequence counters to differ.
    If they match then there must be a vma exclusive lock held somewhere.
  - read unlock - (implemented by vma_end_read) is a trivial vma->lock
    unlock.
  - write lock - (vma_start_write) requires the mmap_lock to be held
    exclusively and the current mm counter is assigned to the vma counter.
    This will allow multiple vmas to be locked under a single mmap_lock
    write lock (e.g. during vma merging). The vma counter is modified
    under exclusive vma lock.
  - write unlock - (vma_end_write_all) is a batch release of all vma
    locks held. It doesn't pair with a specific vma_start_write! It is
    done before exclusive mmap_lock is released by incrementing mm
    sequence counter (mm_lock_seq).
  - write downgrade - if the mmap_lock is downgraded to the read lock, all
    vma write locks are released as well (effectivelly same as write
    unlock).

Link: https://lkml.kernel.org/r/20230227173632.3292573-13-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 20:02:57 -07:00
Lorenzo Stoakes
28d8b812e9 mm: remove unused vmf_insert_mixed_prot()
Patch series "Remove drm/ttm-specific mm changes".

Functionality was added specifically for the DRM TTM driver to support
mapping memory for VM_MIXEDMAP VMAs with customised protection flags,
however this has now been rolled back as issues were found with this
approach.

This series removes the mm changes too, retaining some of the useful
comments.


This patch (of 3):

The sole user of vmf_insert_mixed_prot(), the drm ttm module, stopped
using this in commit f91142c621 ("drm/ttm: nuke VM_MIXEDMAP on BO
mappings v3") citing use of VM_MIXEDMAP in this case being terribly
broken.

Remove this now-dead code and references to it, but retain the useful
description of the prot != vma->vm_page_prot case, moving it to
vmf_insert_pfn_prot() instead.

Link: https://lkml.kernel.org/r/cover.1678661628.git.lstoakes@gmail.com
Link: https://lkml.kernel.org/r/a069644388e6f1593a7020d15840e6fc9f39bcaf.1678661628.git.lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Aaron Tomlin <atomlin@atomlin.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: "Russell King (Oracle)" <linux@armlinux.org.uk>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 19:42:55 -07:00
Mike Rapoport (IBM)
eb8589b4f8 mm: move mem_init_print_info() to mm_init.c
mem_init_print_info() is only called from mm_core_init().

Move it close to the caller and make it static.

Link: https://lkml.kernel.org/r/20230321170513.2401534-12-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 19:42:54 -07:00
Mike Rapoport (IBM)
f2fc4b44ec mm: move init_mem_debugging_and_hardening() to mm/mm_init.c
init_mem_debugging_and_hardening() is only called from mm_core_init().

Move it close to the caller, make it static and rename it to
mem_debugging_and_hardening_init() for consistency with surrounding
convention.

Link: https://lkml.kernel.org/r/20230321170513.2401534-10-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 19:42:54 -07:00
Mike Rapoport (IBM)
4cd1e9edf6 mm: call {ptlock,pgtable}_cache_init() directly from mm_core_init()
and drop pgtable_init() as it has no real value and its name is
misleading.

Link: https://lkml.kernel.org/r/20230321170513.2401534-9-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Sergei Shtylyov <sergei.shtylyov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 19:42:53 -07:00
Mike Rapoport (IBM)
b7ec1bf3e7 init,mm: move mm_init() to mm/mm_init.c and rename it to mm_core_init()
Make mm_init() a part of mm/ codebase.  mm_core_init() better describes
what the function does and does not clash with mm_init() in kernel/fork.c

Link: https://lkml.kernel.org/r/20230321170513.2401534-8-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 19:42:53 -07:00
Kirill A. Shutemov
428e106ae1 mm: Introduce untagged_addr_remote()
untagged_addr() removes tags/metadata from the address and brings it to
the canonical form. The helper is implemented on arm64 and sparc. Both of
them do untagging based on global rules.

However, Linear Address Masking (LAM) on x86 introduces per-process
settings for untagging. As a result, untagged_addr() is now only
suitable for untagging addresses for the current proccess.

The new helper untagged_addr_remote() has to be used when the address
targets remote process. It requires the mmap lock for target mm to be
taken.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Alexander Potapenko <glider@google.com>
Link: https://lore.kernel.org/all/20230312112612.31869-6-kirill.shutemov%40linux.intel.com
2023-03-16 13:08:39 -07:00
Linus Torvalds
3822a7c409 - Daniel Verkamp has contributed a memfd series ("mm/memfd: add
F_SEAL_EXEC") which permits the setting of the memfd execute bit at
   memfd creation time, with the option of sealing the state of the X bit.
 
 - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset()
   thread-safe for pmd unshare") which addresses a rare race condition
   related to PMD unsharing.
 
 - Several folioification patch serieses from Matthew Wilcox, Vishal
   Moola, Sidhartha Kumar and Lorenzo Stoakes
 
 - Johannes Weiner has a series ("mm: push down lock_page_memcg()") which
   does perform some memcg maintenance and cleanup work.
 
 - SeongJae Park has added DAMOS filtering to DAMON, with the series
   "mm/damon/core: implement damos filter".  These filters provide users
   with finer-grained control over DAMOS's actions.  SeongJae has also done
   some DAMON cleanup work.
 
 - Kairui Song adds a series ("Clean up and fixes for swap").
 
 - Vernon Yang contributed the series "Clean up and refinement for maple
   tree".
 
 - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series.  It
   adds to MGLRU an LRU of memcgs, to improve the scalability of global
   reclaim.
 
 - David Hildenbrand has added some userfaultfd cleanup work in the
   series "mm: uffd-wp + change_protection() cleanups".
 
 - Christoph Hellwig has removed the generic_writepages() library
   function in the series "remove generic_writepages".
 
 - Baolin Wang has performed some maintenance on the compaction code in
   his series "Some small improvements for compaction".
 
 - Sidhartha Kumar is doing some maintenance work on struct page in his
   series "Get rid of tail page fields".
 
 - David Hildenbrand contributed some cleanup, bugfixing and
   generalization of pte management and of pte debugging in his series "mm:
   support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap
   PTEs".
 
 - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation
   flag in the series "Discard __GFP_ATOMIC".
 
 - Sergey Senozhatsky has improved zsmalloc's memory utilization with his
   series "zsmalloc: make zspage chain size configurable".
 
 - Joey Gouly has added prctl() support for prohibiting the creation of
   writeable+executable mappings.  The previous BPF-based approach had
   shortcomings.  See "mm: In-kernel support for memory-deny-write-execute
   (MDWE)".
 
 - Waiman Long did some kmemleak cleanup and bugfixing in the series
   "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF".
 
 - T.J.  Alumbaugh has contributed some MGLRU cleanup work in his series
   "mm: multi-gen LRU: improve".
 
 - Jiaqi Yan has provided some enhancements to our memory error
   statistics reporting, mainly by presenting the statistics on a per-node
   basis.  See the series "Introduce per NUMA node memory error
   statistics".
 
 - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog
   regression in compaction via his series "Fix excessive CPU usage during
   compaction".
 
 - Christoph Hellwig does some vmalloc maintenance work in the series
   "cleanup vfree and vunmap".
 
 - Christoph Hellwig has removed block_device_operations.rw_page() in ths
   series "remove ->rw_page".
 
 - We get some maple_tree improvements and cleanups in Liam Howlett's
   series "VMA tree type safety and remove __vma_adjust()".
 
 - Suren Baghdasaryan has done some work on the maintainability of our
   vm_flags handling in the series "introduce vm_flags modifier functions".
 
 - Some pagemap cleanup and generalization work in Mike Rapoport's series
   "mm, arch: add generic implementation of pfn_valid() for FLATMEM" and
   "fixups for generic implementation of pfn_valid()"
 
 - Baoquan He has done some work to make /proc/vmallocinfo and
   /proc/kcore better represent the real state of things in his series
   "mm/vmalloc.c: allow vread() to read out vm_map_ram areas".
 
 - Jason Gunthorpe rationalized the GUP system's interface to the rest of
   the kernel in the series "Simplify the external interface for GUP".
 
 - SeongJae Park wishes to migrate people from DAMON's debugfs interface
   over to its sysfs interface.  To support this, we'll temporarily be
   printing warnings when people use the debugfs interface.  See the series
   "mm/damon: deprecate DAMON debugfs interface".
 
 - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes
   and clean-ups" series.
 
 - Huang Ying has provided a dramatic reduction in migration's TLB flush
   IPI rates with the series "migrate_pages(): batch TLB flushing".
 
 - Arnd Bergmann has some objtool fixups in "objtool warning fixes".
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Merge tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Daniel Verkamp has contributed a memfd series ("mm/memfd: add
   F_SEAL_EXEC") which permits the setting of the memfd execute bit at
   memfd creation time, with the option of sealing the state of the X
   bit.

 - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset()
   thread-safe for pmd unshare") which addresses a rare race condition
   related to PMD unsharing.

 - Several folioification patch serieses from Matthew Wilcox, Vishal
   Moola, Sidhartha Kumar and Lorenzo Stoakes

 - Johannes Weiner has a series ("mm: push down lock_page_memcg()")
   which does perform some memcg maintenance and cleanup work.

 - SeongJae Park has added DAMOS filtering to DAMON, with the series
   "mm/damon/core: implement damos filter".

   These filters provide users with finer-grained control over DAMOS's
   actions. SeongJae has also done some DAMON cleanup work.

 - Kairui Song adds a series ("Clean up and fixes for swap").

 - Vernon Yang contributed the series "Clean up and refinement for maple
   tree".

 - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It
   adds to MGLRU an LRU of memcgs, to improve the scalability of global
   reclaim.

 - David Hildenbrand has added some userfaultfd cleanup work in the
   series "mm: uffd-wp + change_protection() cleanups".

 - Christoph Hellwig has removed the generic_writepages() library
   function in the series "remove generic_writepages".

 - Baolin Wang has performed some maintenance on the compaction code in
   his series "Some small improvements for compaction".

 - Sidhartha Kumar is doing some maintenance work on struct page in his
   series "Get rid of tail page fields".

 - David Hildenbrand contributed some cleanup, bugfixing and
   generalization of pte management and of pte debugging in his series
   "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with
   swap PTEs".

 - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation
   flag in the series "Discard __GFP_ATOMIC".

 - Sergey Senozhatsky has improved zsmalloc's memory utilization with
   his series "zsmalloc: make zspage chain size configurable".

 - Joey Gouly has added prctl() support for prohibiting the creation of
   writeable+executable mappings.

   The previous BPF-based approach had shortcomings. See "mm: In-kernel
   support for memory-deny-write-execute (MDWE)".

 - Waiman Long did some kmemleak cleanup and bugfixing in the series
   "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF".

 - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series
   "mm: multi-gen LRU: improve".

 - Jiaqi Yan has provided some enhancements to our memory error
   statistics reporting, mainly by presenting the statistics on a
   per-node basis. See the series "Introduce per NUMA node memory error
   statistics".

 - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog
   regression in compaction via his series "Fix excessive CPU usage
   during compaction".

 - Christoph Hellwig does some vmalloc maintenance work in the series
   "cleanup vfree and vunmap".

 - Christoph Hellwig has removed block_device_operations.rw_page() in
   ths series "remove ->rw_page".

 - We get some maple_tree improvements and cleanups in Liam Howlett's
   series "VMA tree type safety and remove __vma_adjust()".

 - Suren Baghdasaryan has done some work on the maintainability of our
   vm_flags handling in the series "introduce vm_flags modifier
   functions".

 - Some pagemap cleanup and generalization work in Mike Rapoport's
   series "mm, arch: add generic implementation of pfn_valid() for
   FLATMEM" and "fixups for generic implementation of pfn_valid()"

 - Baoquan He has done some work to make /proc/vmallocinfo and
   /proc/kcore better represent the real state of things in his series
   "mm/vmalloc.c: allow vread() to read out vm_map_ram areas".

 - Jason Gunthorpe rationalized the GUP system's interface to the rest
   of the kernel in the series "Simplify the external interface for
   GUP".

 - SeongJae Park wishes to migrate people from DAMON's debugfs interface
   over to its sysfs interface. To support this, we'll temporarily be
   printing warnings when people use the debugfs interface. See the
   series "mm/damon: deprecate DAMON debugfs interface".

 - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes
   and clean-ups" series.

 - Huang Ying has provided a dramatic reduction in migration's TLB flush
   IPI rates with the series "migrate_pages(): batch TLB flushing".

 - Arnd Bergmann has some objtool fixups in "objtool warning fixes".

* tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits)
  include/linux/migrate.h: remove unneeded externs
  mm/memory_hotplug: cleanup return value handing in do_migrate_range()
  mm/uffd: fix comment in handling pte markers
  mm: change to return bool for isolate_movable_page()
  mm: hugetlb: change to return bool for isolate_hugetlb()
  mm: change to return bool for isolate_lru_page()
  mm: change to return bool for folio_isolate_lru()
  objtool: add UACCESS exceptions for __tsan_volatile_read/write
  kmsan: disable ftrace in kmsan core code
  kasan: mark addr_has_metadata __always_inline
  mm: memcontrol: rename memcg_kmem_enabled()
  sh: initialize max_mapnr
  m68k/nommu: add missing definition of ARCH_PFN_OFFSET
  mm: percpu: fix incorrect size in pcpu_obj_full_size()
  maple_tree: reduce stack usage with gcc-9 and earlier
  mm: page_alloc: call panic() when memoryless node allocation fails
  mm: multi-gen LRU: avoid futile retries
  migrate_pages: move THP/hugetlb migration support check to simplify code
  migrate_pages: batch flushing TLB
  migrate_pages: share more code between _unmap and _move
  ...
2023-02-23 17:09:35 -08:00
Linus Torvalds
1f2d9ffc7a Scheduler updates in this cycle are:
- Improve the scalability of the CFS bandwidth unthrottling logic
    with large number of CPUs.
 
  - Fix & rework various cpuidle routines, simplify interaction with
    the generic scheduler code. Add __cpuidle methods as noinstr to
    objtool's noinstr detection and fix boatloads of cpuidle bugs & quirks.
 
  - Add new ABI: introduce MEMBARRIER_CMD_GET_REGISTRATIONS,
    to query previously issued registrations.
 
  - Limit scheduler slice duration to the sysctl_sched_latency period,
    to improve scheduling granularity with a large number of SCHED_IDLE
    tasks.
 
  - Debuggability enhancement on sys_exit(): warn about disabled IRQs,
    but also enable them to prevent a cascade of followup problems and
    repeat warnings.
 
  - Fix the rescheduling logic in prio_changed_dl().
 
  - Micro-optimize cpufreq and sched-util methods.
 
  - Micro-optimize ttwu_runnable()
 
  - Micro-optimize the idle-scanning in update_numa_stats(),
    select_idle_capacity() and steal_cookie_task().
 
  - Update the RSEQ code & self-tests
 
  - Constify various scheduler methods
 
  - Remove unused methods
 
  - Refine __init tags
 
  - Documentation updates
 
  - ... Misc other cleanups, fixes
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:

 - Improve the scalability of the CFS bandwidth unthrottling logic with
   large number of CPUs.

 - Fix & rework various cpuidle routines, simplify interaction with the
   generic scheduler code. Add __cpuidle methods as noinstr to objtool's
   noinstr detection and fix boatloads of cpuidle bugs & quirks.

 - Add new ABI: introduce MEMBARRIER_CMD_GET_REGISTRATIONS, to query
   previously issued registrations.

 - Limit scheduler slice duration to the sysctl_sched_latency period, to
   improve scheduling granularity with a large number of SCHED_IDLE
   tasks.

 - Debuggability enhancement on sys_exit(): warn about disabled IRQs,
   but also enable them to prevent a cascade of followup problems and
   repeat warnings.

 - Fix the rescheduling logic in prio_changed_dl().

 - Micro-optimize cpufreq and sched-util methods.

 - Micro-optimize ttwu_runnable()

 - Micro-optimize the idle-scanning in update_numa_stats(),
   select_idle_capacity() and steal_cookie_task().

 - Update the RSEQ code & self-tests

 - Constify various scheduler methods

 - Remove unused methods

 - Refine __init tags

 - Documentation updates

 - Misc other cleanups, fixes

* tag 'sched-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (110 commits)
  sched/rt: pick_next_rt_entity(): check list_entry
  sched/deadline: Add more reschedule cases to prio_changed_dl()
  sched/fair: sanitize vruntime of entity being placed
  sched/fair: Remove capacity inversion detection
  sched/fair: unlink misfit task from cpu overutilized
  objtool: mem*() are not uaccess safe
  cpuidle: Fix poll_idle() noinstr annotation
  sched/clock: Make local_clock() noinstr
  sched/clock/x86: Mark sched_clock() noinstr
  x86/pvclock: Improve atomic update of last_value in pvclock_clocksource_read()
  x86/atomics: Always inline arch_atomic64*()
  cpuidle: tracing, preempt: Squash _rcuidle tracing
  cpuidle: tracing: Warn about !rcu_is_watching()
  cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG
  cpuidle: drivers: firmware: psci: Dont instrument suspend code
  KVM: selftests: Fix build of rseq test
  exit: Detect and fix irq disabled state in oops
  cpuidle, arm64: Fix the ARM64 cpuidle logic
  cpuidle: mvebu: Fix duplicate flags assignment
  sched/fair: Limit sched slice duration
  ...
2023-02-20 17:41:08 -08:00
Linus Torvalds
d644c670ef Remove get_kernel_pages()
Vmalloc page support is removed from shm_get_kernel_pages() and the
 get_kernel_pages() call is replaced by calls to get_page(). With no
 remaining callers of get_kernel_pages() the function is removed.
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Merge tag 'remove-get_kernel_pages-for-6.3' of https://git.linaro.org/people/jens.wiklander/linux-tee

Pull TEE update from Jens Wiklander:
 "Remove get_kernel_pages()

  Vmalloc page support is removed from shm_get_kernel_pages() and the
  get_kernel_pages() call is replaced by calls to get_page(). With no
  remaining callers of get_kernel_pages() the function is removed"

[ This looks like it's just some random 'tee' cleanup, but the bigger
  picture impetus for this is really to to to remove historical
  confusion with mixed use of kernel virtual addresses and 'struct page'
  pointers.

  Kernel virtual pointers in the vmalloc space is then particularly
  confusing - both for looking up a page pointer (when trying to then
  unify a "virtual address or page" interface) and _particularly_ when
  mixed with HIGHMEM support and the kmap*() family of remapping.

  This is particularly true with HIGHMEM getting much less test coverage
  with 32-bit architectures being increasingly legacy targets.

  So we actively wanted to remove get_kernel_pages() to make sure nobody
  else used it too, and thus the 'tee' part is "finally remove last
  user".

  See also commit 6647e76ab6 ("v4l2: don't fall back to follow_pfn()
  if pin_user_pages_fast() fails") for a totally different version of a
  conceptually similar "let's stop this confusion of different ways of
  referring to memory".   - Linus ]

* tag 'remove-get_kernel_pages-for-6.3' of https://git.linaro.org/people/jens.wiklander/linux-tee:
  mm: Remove get_kernel_pages()
  tee: Remove call to get_kernel_pages()
  tee: Remove vmalloc page support
  highmem: Enhance is_kmap_addr() to check kmap_local_page() mappings
2023-02-20 09:27:39 -08:00
Vishal Moola (Oracle)
3c1ea2c729 mm: add folio_get_nontail_page()
Patch series "Convert a couple migrate functions to use folios", v2.

This patchset introduces folio_movable_ops() and converts 3 functions in
mm/migrate.c to use folios.  It also introduces folio_get_nontail_page()
for folio conversions which may want to distinguish between head and tail
pages.


This patch (of 4):

folio_get_nontail_page() returns the folio associated with a head page. 
This is necessary for folio conversions where the behavior of that
function differs between head pages and tail pages.

Link: https://lkml.kernel.org/r/20230130214352.40538-1-vishal.moola@gmail.com
Link: https://lkml.kernel.org/r/20230130214352.40538-2-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-13 15:54:31 -08:00
Vishal Moola (Oracle)
fa4e3f5ffa mm: add folio_estimated_sharers()
Patch series "Convert various mempolicy.c functions to use folios", v4.

This patch series converts migrate_page_add() and queue_pages_required()
to migrate_folio_add() and queue_page_required().  It also converts the
callers of the functions to use folios as well, and introduces a helper
function to estimate the number of sharers of a folio.


This patch (of 6):

folio_estimated_sharers() takes in a folio and returns the precise number
of times the first subpage of the folio is mapped.

This function aims to provide an estimate for the number of sharers of a
folio.  This is necessary for folio conversions where we care about the
number of processes that share a folio, but don't necessarily want to
check every single page within that folio.

This is in contrast to folio_mapcount() which calculates the total number
of the times a folio and all its subpages are mapped.

Link: https://lkml.kernel.org/r/20230130201833.27042-1-vishal.moola@gmail.com
Link: https://lkml.kernel.org/r/20230130201833.27042-2-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-13 15:54:30 -08:00
Ira Weiny
816477edfb mm: Remove get_kernel_pages()
The only caller to get_kernel_pages() [shm_get_kernel_pages()] has been
updated to not need it.

Remove get_kernel_pages().

Cc: Mel Gorman <mgorman@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Fabio M. De Francesco" <fmdefrancesco@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Andrew Morton <akpm@linux-foudation.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2023-02-13 14:16:41 +01:00
Andrew Morton
f67d6b2664 Merge branch 'mm-hotfixes-stable' into mm-stable
To pick up depended-upon changes
2023-02-10 15:34:48 -08:00
Jason Gunthorpe
63b6051286 mm/gup: move gup_must_unshare() to mm/internal.h
This function is only used in gup.c and closely related.  It touches
FOLL_PIN so it must be moved before the next patch.

Link: https://lkml.kernel.org/r/12-v2-987e91b59705+36b-gup_tidy_jgg@nvidia.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:45 -08:00
Jason Gunthorpe
edad1bb1fb mm/gup: remove pin_user_pages_fast_only()
Commit ed29c26911 ("drm/i915: Fix userptr so we do not have to worry
about obj->mm.lock, v7.") removed the only caller, remove this dead code
too.

Link: https://lkml.kernel.org/r/10-v2-987e91b59705+36b-gup_tidy_jgg@nvidia.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:45 -08:00
Jason Gunthorpe
7ce154fe69 mm/gup: move try_grab_page() to mm/internal.h
This is part of the internal function of gup.c and is only non-static so
that the parts of gup.c in the huge_memory.c and hugetlb.c can call it.

Put it in internal.h beside the similarly purposed try_grab_folio()

Link: https://lkml.kernel.org/r/4-v2-987e91b59705+36b-gup_tidy_jgg@nvidia.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:44 -08:00
Suren Baghdasaryan
601c3c29db mm: introduce vm_flags_reset_once to replace WRITE_ONCE vm_flags updates
Provide vm_flags_reset_once() and replace the vm_flags updates which used
WRITE_ONCE() to prevent compiler optimizations.

Link: https://lkml.kernel.org/r/20230201000116.1333160-1-surenb@google.com
Fixes: 0cce31a0aa0e ("mm: replace vma->vm_flags direct modifications with modifier calls")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reported-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:41 -08:00
Suren Baghdasaryan
68f48381d7 mm: introduce __vm_flags_mod and use it in untrack_pfn
There are scenarios when vm_flags can be modified without exclusive
mmap_lock, such as:
- after VMA was isolated and mmap_lock was downgraded or dropped
- in exit_mmap when there are no other mm users and locking is unnecessary
Introduce __vm_flags_mod to avoid assertions when the caller takes
responsibility for the required locking.
Pass a hint to untrack_pfn to conditionally use __vm_flags_mod for
flags modification to avoid assertion.

Link: https://lkml.kernel.org/r/20230126193752.297968-7-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Oskolkov <posk@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Sebastian Reichel <sebastian.reichel@collabora.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:40 -08:00
Suren Baghdasaryan
1c71222e5f mm: replace vma->vm_flags direct modifications with modifier calls
Replace direct modifications to vma->vm_flags with calls to modifier
functions to be able to track flag changes and to keep vma locking
correctness.

[akpm@linux-foundation.org: fix drivers/misc/open-dice.c, per Hyeonggon Yoo]
Link: https://lkml.kernel.org/r/20230126193752.297968-5-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Oskolkov <posk@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:39 -08:00
Suren Baghdasaryan
e430a95a04 mm: replace VM_LOCKED_CLEAR_MASK with VM_LOCKED_MASK
To simplify the usage of VM_LOCKED_CLEAR_MASK in vm_flags_clear(), replace
it with VM_LOCKED_MASK bitmask and convert all users.

Link: https://lkml.kernel.org/r/20230126193752.297968-4-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Oskolkov <posk@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Sebastian Reichel <sebastian.reichel@collabora.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:39 -08:00
Suren Baghdasaryan
bc292ab00f mm: introduce vma->vm_flags wrapper functions
vm_flags are among VMA attributes which affect decisions like VMA merging
and splitting.  Therefore all vm_flags modifications are performed after
taking exclusive mmap_lock to prevent vm_flags updates racing with such
operations.  Introduce modifier functions for vm_flags to be used whenever
flags are updated.  This way we can better check and control correct
locking behavior during these updates.

Link: https://lkml.kernel.org/r/20230126193752.297968-3-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Oskolkov <posk@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Sebastian Reichel <sebastian.reichel@collabora.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:39 -08:00
Liam R. Howlett
cf51e86dfb mm/mmap: don't use __vma_adjust() in shift_arg_pages()
Introduce shrink_vma() which uses the vma_prepare() and vma_complete()
functions to reduce the vma coverage.

Convert shift_arg_pages() to use expand_vma() and the new shrink_vma()
function.  Remove support from __vma_adjust() to reduce a vma size since
shift_arg_pages() is the only user that shrinks a VMA in this way.

Link: https://lkml.kernel.org/r/20230120162650.984577-46-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:38 -08:00
Liam R. Howlett
7c9813e886 mm/mremap: convert vma_adjust() to vma_expand()
Stop using vma_adjust() in preparation for removing the function.  Export
vma_expand() to use instead.

Link: https://lkml.kernel.org/r/20230120162650.984577-45-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:37 -08:00
Liam R. Howlett
b2b3b88673 mm: don't use __vma_adjust() in __split_vma()
Use the abstracted locking and maple tree operations.  Since __split_vma()
is the only user of the __vma_adjust() function to use the insert
argument, drop that argument.  Remove the NULL passed through from
fs/exec's shift_arg_pages() and mremap() at the same time.

Link: https://lkml.kernel.org/r/20230120162650.984577-44-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:37 -08:00
Liam R. Howlett
b373037fa9 mm: add vma iterator to vma_adjust() arguments
Change the vma_adjust() function definition to accept the vma iterator and
pass it through to __vma_adjust().

Update fs/exec to use the new vma_adjust() function parameters.

Update mm/mremap to use the new vma_adjust() function parameters.

Revert the __split_vma() calls back from __vma_adjust() to vma_adjust()
and pass through the vma iterator.

Link: https://lkml.kernel.org/r/20230120162650.984577-37-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:36 -08:00
Liam R. Howlett
9e56044625 mm: pass through vma iterator to __vma_adjust()
Pass the vma iterator through to __vma_adjust() so the state can be
updated.

Link: https://lkml.kernel.org/r/20230120162650.984577-33-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:35 -08:00
Liam R. Howlett
fbcc3104b8 mmap: convert __vma_adjust() to use vma iterator
Use the vma iterator internally for __vma_adjust().  Avoid using the maple
tree interface directly for type safety.

Link: https://lkml.kernel.org/r/20230120162650.984577-32-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:35 -08:00
Liam R. Howlett
9760ebffbf mm: switch vma_merge(), split_vma(), and __split_vma to vma iterator
Drop the vmi_* functions and transition all users to use the vma iterator
directly.

Link: https://lkml.kernel.org/r/20230120162650.984577-30-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:35 -08:00
Liam R. Howlett
2286a6914c mm: change mprotect_fixup to vma iterator
Use the vma iterator so that the iterator can be invalidated or updated to
avoid each caller doing so.

Link: https://lkml.kernel.org/r/20230120162650.984577-18-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:33 -08:00
Liam R. Howlett
27b2670112 ipc/shm: introduce new do_vma_munmap() to munmap
The shm already has the vma iterator in position for a write. 
do_vmi_munmap() searches for the correct position and aligns the write, so
it is not the right function to use in this case.

The shm VMA tree modification is similar to the brk munmap situation, the
vma iterator is in position and the VMA is already known.  This patch
generalizes the brk munmap function do_brk_munmap() to be used for any
other callers with the vma iterator already in position to munmap a VMA.

Link: https://lkml.kernel.org/r/20230126212049.980501-1-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: Sven Schnelle <svens@linux.ibm.com>
  Link: https://lore.kernel.org/linux-mm/yt9dh6wec21a.fsf@linux.ibm.com/
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:33 -08:00
Liam R. Howlett
f2ebfe43ba mm: add temporary vma iterator versions of vma_merge(), split_vma(), and __split_vma()
These wrappers are short-lived in this patch set so that each user can be
converted on its own.  In the end, these functions are renamed in one
commit.

Link: https://lkml.kernel.org/r/20230120162650.984577-15-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:32 -08:00
Liam R. Howlett
183654ce26 mmap: change do_mas_munmap and do_mas_aligned_munmap() to use vma iterator
Start passing the vma iterator through the mm code.  This will allow for
reuse of the state and cleaner invalidation if necessary.

Link: https://lkml.kernel.org/r/20230120162650.984577-13-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:32 -08:00
Liam R. Howlett
b62b633e04 mm: expand vma iterator interface
Add wrappers for the maple tree to the vma iterator.  This will provide
type safety at compile time.

Link: https://lkml.kernel.org/r/20230120162650.984577-8-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:31 -08:00
Arnd Bergmann
3770e52fd4 mm: extend max struct page size for kmsan
After x86 enabled support for KMSAN, it has become possible to have larger
'struct page' than was expected when commit 5470dea49f ("mm: use
mm_zero_struct_page from SPARC on all 64b architectures") was merged:

include/linux/mm.h:156:10: warning: no case matching constant switch condition '96'
        switch (sizeof(struct page)) {

Extend the maximum accordingly.

Link: https://lkml.kernel.org/r/20230130130739.563628-1-arnd@kernel.org
Fixes: 5470dea49f ("mm: use mm_zero_struct_page from SPARC on all 64b architectures")
Fixes: 4ca8cc8d1b ("x86: kmsan: enable KMSAN builds for x86")
Fixes: f80be4571b ("kmsan: add KMSAN runtime core")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alex Sierra <alex.sierra@amd.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-03 17:52:24 -08:00
Jiaqi Yan
44b8f8bf24 mm: memory-failure: add memory failure stats to sysfs
Patch series "Introduce per NUMA node memory error statistics", v2.

Background
==========

In the RFC for Kernel Support of Memory Error Detection [1], one advantage
of software-based scanning over hardware patrol scrubber is the ability to
make statistics visible to system administrators.  The statistics include
2 categories:

* Memory error statistics, for example, how many memory error are
  encountered, how many of them are recovered by the kernel.  Note these
  memory errors are non-fatal to kernel: during the machine check
  exception (MCE) handling kernel already classified MCE's severity to be
  unnecessary to panic (but either action required or optional).

* Scanner statistics, for example how many times the scanner have fully
  scanned a NUMA node, how many errors are first detected by the scanner.

The memory error statistics are useful to userspace and actually not
specific to scanner detected memory errors, and are the focus of this
patchset.

Motivation
==========

Memory error stats are important to userspace but insufficient in kernel
today.  Datacenter administrators can better monitor a machine's memory
health with the visible stats.  For example, while memory errors are
inevitable on servers with 10+ TB memory, starting server maintenance when
there are only 1~2 recovered memory errors could be overreacting; in cloud
production environment maintenance usually means live migrate all the
workload running on the server and this usually causes nontrivial
disruption to the customer.  Providing insight into the scope of memory
errors on a system helps to determine the appropriate follow-up action. 
In addition, the kernel's existing memory error stats need to be
standardized so that userspace can reliably count on their usefulness.

Today kernel provides following memory error info to userspace, but they
are not sufficient or have disadvantages:
* HardwareCorrupted in /proc/meminfo: number of bytes poisoned in total,
  not per NUMA node stats though
* ras:memory_failure_event: only available after explicitly enabled
* /dev/mcelog provides many useful info about the MCEs, but doesn't
  capture how memory_failure recovered memory MCEs
* kernel logs: userspace needs to process log text

Exposing memory error stats is also a good start for the in-kernel memory
error detector.  Today the data source of memory error stats are either
direct memory error consumption, or hardware patrol scrubber detection
(either signaled as UCNA or SRAO).  Once in-kernel memory scanner is
implemented, it will be the main source as it is usually configured to
scan memory DIMMs constantly and faster than hardware patrol scrubber.

How Implemented
===============

As Naoya pointed out [2], exposing memory error statistics to userspace is
useful independent of software or hardware scanner.  Therefore we
implement the memory error statistics independent of the in-kernel memory
error detector.  It exposes the following per NUMA node memory error
counters:

  /sys/devices/system/node/node${X}/memory_failure/total
  /sys/devices/system/node/node${X}/memory_failure/recovered
  /sys/devices/system/node/node${X}/memory_failure/ignored
  /sys/devices/system/node/node${X}/memory_failure/failed
  /sys/devices/system/node/node${X}/memory_failure/delayed

These counters describe how many raw pages are poisoned and after the
attempted recoveries by the kernel, their resolutions: how many are
recovered, ignored, failed, or delayed respectively.  This approach can be
easier to extend for future use cases than /proc/meminfo, trace event, and
log.  The following math holds for the statistics:

* total = recovered + ignored + failed + delayed

These memory error stats are reset during machine boot.

The 1st commit introduces these sysfs entries.  The 2nd commit populates
memory error stats every time memory_failure attempts memory error
recovery.  The 3rd commit adds documentations for introduced stats.

[1] https://lore.kernel.org/linux-mm/7E670362-C29E-4626-B546-26530D54F937@gmail.com/T/#mc22959244f5388891c523882e61163c6e4d703af
[2] https://lore.kernel.org/linux-mm/7E670362-C29E-4626-B546-26530D54F937@gmail.com/T/#m52d8d7a333d8536bd7ce74253298858b1c0c0ac6


This patch (of 3):

Today kernel provides following memory error info to userspace, but each
has its own disadvantage

* HardwareCorrupted in /proc/meminfo: number of bytes poisoned in total,
  not per NUMA node stats though

* ras:memory_failure_event: only available after explicitly enabled

* /dev/mcelog provides many useful info about the MCEs, but
  doesn't capture how memory_failure recovered memory MCEs

* kernel logs: userspace needs to process log text

Exposes per NUMA node memory error stats as sysfs entries:

  /sys/devices/system/node/node${X}/memory_failure/total
  /sys/devices/system/node/node${X}/memory_failure/recovered
  /sys/devices/system/node/node${X}/memory_failure/ignored
  /sys/devices/system/node/node${X}/memory_failure/failed
  /sys/devices/system/node/node${X}/memory_failure/delayed

These counters describe how many raw pages are poisoned and after the
attempted recoveries by the kernel, their resolutions: how many are
recovered, ignored, failed, or delayed respectively.  The following math
holds for the statistics:

* total = recovered + ignored + failed + delayed

Link: https://lkml.kernel.org/r/20230120034622.2698268-1-jiaqiyan@google.com
Link: https://lkml.kernel.org/r/20230120034622.2698268-2-jiaqiyan@google.com
Signed-off-by: Jiaqi Yan <jiaqiyan@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:33:28 -08:00
Matthew Wilcox (Oracle)
bad6da6456 mm: convert set_compound_page_dtor() and set_compound_order() to folios
Replace uses of compound_dtor, compound_order and compound_nr by their
folio equivalents.

Link: https://lkml.kernel.org/r/20230111142915.1001531-19-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:32:58 -08:00
Matthew Wilcox (Oracle)
21a000fe97 mm: reimplement compound_nr()
Turn compound_nr() into a wrapper around folio_nr_pages().  Similarly to
compound_order(), casting the struct page directly to struct folio
preserves the existing behaviour, while calling page_folio() would change
the behaviour.  Move thp_nr_pages() down in the file so that compound_nr()
can be after folio_nr_pages().

[willy@infradead.org: fix assertion triggering]
  Link: https://lkml.kernel.org/r/Y8AFgZEEjnUIaCbf@casper.infradead.org
Link: https://lkml.kernel.org/r/20230111142915.1001531-18-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:32:58 -08:00
Matthew Wilcox (Oracle)
5eb5cea11d mm: reimplement compound_order()
Make compound_order() use struct folio.  It can't be turned into a wrapper
around folio_order() as a page can be turned into a tail page between a
check in compound_order() and the assertion in folio_test_large().

Link: https://lkml.kernel.org/r/20230111142915.1001531-17-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:32:58 -08:00
Matthew Wilcox (Oracle)
1aa4d03b60 mm: remove head_compound_mapcount() and _ptr functions
folio_mapcount_ptr(), compound_mapcount_ptr() and subpages_mapcount_ptr()
are all now unused.

Link: https://lkml.kernel.org/r/20230111142915.1001531-16-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:32:58 -08:00
Matthew Wilcox (Oracle)
c97eeb8f26 mm: convert page_mapcount() to use folio_entire_mapcount()
Remove a use of head_compound_mapcount().

Link: https://lkml.kernel.org/r/20230111142915.1001531-15-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:32:57 -08:00
Matthew Wilcox (Oracle)
b14224fbea mm: convert total_compound_mapcount() to folio_total_mapcount()
Instead of enforcing that the argument must be a head page by naming,
enforce it with the compiler by making it a folio.  Also rename the
counter in struct folio from _compound_mapcount to _entire_mapcount.

Link: https://lkml.kernel.org/r/20230111142915.1001531-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:32:55 -08:00
Matthew Wilcox (Oracle)
eec20426d4 mm: convert head_subpages_mapcount() into folio_nr_pages_mapped()
Calling this 'mapcount' is confusing since mapcount is usually the number
of times something is mapped; instead this is the number of mapped pages. 
It's also better to enforce that this is a folio rather than a head page.

Move folio_nr_pages_mapped() into mm/internal.h since this is not
something we want device drivers or filesystems poking at.  Get rid of
folio_subpages_mapcount_ptr() and use folio->_nr_pages_mapped directly.

Link: https://lkml.kernel.org/r/20230111142915.1001531-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:32:55 -08:00
Matthew Wilcox (Oracle)
94688e8eb4 mm: remove folio_pincount_ptr() and head_compound_pincount()
We can use folio->_pincount directly, since all users are guarded by tests
of compound/large.

Link: https://lkml.kernel.org/r/20230111142915.1001531-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:32:54 -08:00
Ingo Molnar
57a30218fa Linux 6.2-rc6
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Merge tag 'v6.2-rc6' into sched/core, to pick up fixes

Pick up fixes before merging another batch of cpuidle updates.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2023-01-31 15:01:20 +01:00
Sidhartha Kumar
02d65d6fb1 mm: introduce folio_is_pfmemalloc
Add a folio equivalent for page_is_pfmemalloc. This removes two instances
of page_is_pfmemalloc(folio_page(folio, 0)) so the folio can be used
directly.

Link: https://lkml.kernel.org/r/20230106215251.599222-1-sidhartha.kumar@oracle.com
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:57 -08:00
David Hildenbrand
b6b7a8faf0 mm/nommu: don't use VM_MAYSHARE for MAP_PRIVATE mappings
Let's stop using VM_MAYSHARE for MAP_PRIVATE mappings and use
VM_MAYOVERLAY instead.  Rewrite determine_vm_flags() to make the whole
logic easier to digest, and to cleanly separate MAP_PRIVATE vs. 
MAP_SHARED.

No functional change intended.

Link: https://lkml.kernel.org/r/20230102160856.500584-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:57 -08:00
David Hildenbrand
fc4f4be9b5 mm/nommu: factor out check for NOMMU shared mappings into is_nommu_shared_mapping()
Patch series "mm/nommu: don't use VM_MAYSHARE for MAP_PRIVATE mappings".

Trying to reduce the confusion around VM_SHARED and VM_MAYSHARE first
requires !CONFIG_MMU to stop using VM_MAYSHARE for MAP_PRIVATE mappings. 
CONFIG_MMU only sets VM_MAYSHARE for MAP_SHARED mappings.

This paves the way for further VM_MAYSHARE and VM_SHARED cleanups: for
example, renaming VM_MAYSHARED to VM_MAP_SHARED to make it cleaner what is
actually means.

Let's first get the weird case out of the way and not use VM_MAYSHARE in
MAP_PRIVATE mappings, using a new VM_MAYOVERLAY flag instead.


This patch (of 3):

We want to stop using VM_MAYSHARE in private mappings to pave the way for
clarifying the semantics of VM_MAYSHARE vs.  VM_SHARED and reduce the
confusion.  While CONFIG_MMU uses VM_MAYSHARE to represent MAP_SHARED,
!CONFIG_MMU also sets VM_MAYSHARE for selected R/O private file mappings
that are an effective overlay of a file mapping.

Let's factor out all relevant VM_MAYSHARE checks in !CONFIG_MMU code into
is_nommu_shared_mapping() first.

Note that whenever VM_SHARED is set, VM_MAYSHARE must be set as well
(unless there is a serious BUG).  So there is not need to test for
VM_SHARED manually.

No functional change intended.

Link: https://lkml.kernel.org/r/20230102160856.500584-1-david@redhat.com
Link: https://lkml.kernel.org/r/20230102160856.500584-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:56 -08:00
Mike Kravetz
e9adcfecf5 mm: remove zap_page_range and create zap_vma_pages
zap_page_range was originally designed to unmap pages within an address
range that could span multiple vmas.  While working on [1], it was
discovered that all callers of zap_page_range pass a range entirely within
a single vma.  In addition, the mmu notification call within zap_page
range does not correctly handle ranges that span multiple vmas.  When
crossing a vma boundary, a new mmu_notifier_range_init/end call pair with
the new vma should be made.

Instead of fixing zap_page_range, do the following:
- Create a new routine zap_vma_pages() that will remove all pages within
  the passed vma.  Most users of zap_page_range pass the entire vma and
  can use this new routine.
- For callers of zap_page_range not passing the entire vma, instead call
  zap_page_range_single().
- Remove zap_page_range.

[1] https://lore.kernel.org/linux-mm/20221114235507.294320-2-mike.kravetz@oracle.com/
Link: https://lkml.kernel.org/r/20230104002732.232573-1-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Suggested-by: Peter Xu <peterx@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>	[s390]
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:55 -08:00
Peter Xu
a79390f5d6 mm/mprotect: use long for page accountings and retval
Switch to use type "long" for page accountings and retval across the whole
procedure of change_protection().

The change should have shrinked the possible maximum page number to be
half comparing to previous (ULONG_MAX / 2), but it shouldn't overflow on
any system either because the maximum possible pages touched by change
protection should be ULONG_MAX / PAGE_SIZE.

Two reasons to switch from "unsigned long" to "long":

  1. It suites better on count_vm_numa_events(), whose 2nd parameter takes
     a long type.

  2. It paves way for returning negative (error) values in the future.

Currently the only caller that consumes this retval is change_prot_numa(),
where the unsigned long was converted to an int.  Since at it, touching up
the numa code to also take a long, so it'll avoid any possible overflow
too during the int-size convertion.

Link: https://lkml.kernel.org/r/20230104225207.1066932-3-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: James Houghton <jthoughton@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:53 -08:00
David Hildenbrand
1ef488edd6 mm/mprotect: drop pgprot_t parameter from change_protection()
Being able to provide a custom protection opens the door for
inconsistencies and BUGs: for example, accidentally allowing for more
permissions than desired by other mechanisms (e.g., softdirty tracking). 
vma->vm_page_prot should be the single source of truth.

Only PROT_NUMA is special: there is no way we can erroneously allow
for more permissions when removing all permissions. Special-case using
the MM_CP_PROT_NUMA flag.

[david@redhat.com: PAGE_NONE might not be defined without CONFIG_NUMA_BALANCING]  
  Link: https://lkml.kernel.org/r/5084ff1c-ebb3-f918-6a60-bacabf550a88@redhat.com
Link: https://lkml.kernel.org/r/20221223155616.297723-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:50 -08:00
David Howells
b5054174ac mm: move FOLL_* defs to mm_types.h
Move FOLL_* definitions to linux/mm_types.h to make them more accessible
without having to drag in all of linux/mm.h and everything that drags in
too[1].

Link: https://lkml.kernel.org/r/2161258.1671657894@warthog.procyon.org.uk
Signed-off-by: David Howells <dhowells@redhat.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:48 -08:00
Vishal Moola (Oracle)
318e9342fb mm/memory: add vm_normal_folio()
Patch series "Convert deactivate_page() to folio_deactivate()", v4.

Deactivate_page() has already been converted to use folios.  This patch
series modifies the callers of deactivate_page() to use folios.  It also
introduces vm_normal_folio() to assist with folio conversions, and
converts deactivate_page() to folio_deactivate() which takes in a folio.


This patch (of 4):

Introduce a wrapper function called vm_normal_folio().  This function
calls vm_normal_page() and returns the folio of the page found, or null if
no page is found.

This function allows callers to get a folio from a pte, which will
eventually allow them to completely replace their struct page variables
with struct folio instead.

Link: https://lkml.kernel.org/r/20221221180848.20774-1-vishal.moola@gmail.com
Link: https://lkml.kernel.org/r/20221221180848.20774-2-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:47 -08:00
Sidhartha Kumar
04a42e72d7 mm: move folio_set_compound_order() to mm/internal.h
folio_set_compound_order() is moved to an mm-internal location so external
folio users cannot misuse this function.  Change the name of the function
to folio_set_order() and use WARN_ON_ONCE() rather than BUG_ON.  Also,
handle the case if a non-large folio is passed and add clarifying comments
to the function.

Link: https://lore.kernel.org/lkml/20221207223731.32784-1-sidhartha.kumar@oracle.com/T/
Link: https://lkml.kernel.org/r/20221215061757.223440-1-sidhartha.kumar@oracle.com
Fixes: 9fd330582b ("mm: add folio dtor and order setter functions")
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Suggested-by: Mike Kravetz <mike.kravetz@oracle.com>
Suggested-by: Muchun Song <songmuchun@bytedance.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Suggested-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:36 -08:00
SeongJae Park
0411d6ee50 include/linux/mm: fix release_pages_arg kernel doc comment
Commit 449c796768 ("mm: teach release_pages() to take an array of
encoded page pointers too") added the kernel doc comment for
release_pages() on top of 'union release_pages_arg', so making 'make
htmldocs' complains as below:

    ./include/linux/mm.h:1268: warning: cannot understand function prototype: 'typedef union '

The kernel doc comment for the function is already on top of the
function's definition in mm/swap.c, and the new comment is actually not
for the function but indeed release_pages_arg.  Fixing the comment to
reflect the intent would be one option.  But, kernel doc cannot parse
the union as below due to the attribute.

    ./include/linux/mm.h:1272: error: Cannot parse struct or union!

Modify the comment to reflect the intent but do not mark it as a kernel
doc comment.

Link: https://lkml.kernel.org/r/20230106203331.127532-1-sj@kernel.org
Fixes: 449c796768 ("mm: teach release_pages() to take an array of encoded page pointers too")
Signed-off-by: SeongJae Park <sj@kernel.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-11 16:14:21 -08:00
Mathieu Desnoyers
af7f588d8f sched: Introduce per-memory-map concurrency ID
This feature allows the scheduler to expose a per-memory map concurrency
ID to user-space. This concurrency ID is within the possible cpus range,
and is temporarily (and uniquely) assigned while threads are actively
running within a memory map. If a memory map has fewer threads than
cores, or is limited to run on few cores concurrently through sched
affinity or cgroup cpusets, the concurrency IDs will be values close
to 0, thus allowing efficient use of user-space memory for per-cpu
data structures.

This feature is meant to be exposed by a new rseq thread area field.

The primary purpose of this feature is to do the heavy-lifting needed
by memory allocators to allow them to use per-cpu data structures
efficiently in the following situations:

- Single-threaded applications,
- Multi-threaded applications on large systems (many cores) with limited
  cpu affinity mask,
- Multi-threaded applications on large systems (many cores) with
  restricted cgroup cpuset per container.

One of the key concern from scheduler maintainers is the overhead
associated with additional spin locks or atomic operations in the
scheduler fast-path. This is why the following optimization is
implemented.

On context switch between threads belonging to the same memory map,
transfer the mm_cid from prev to next without any atomic ops. This
takes care of use-cases involving frequent context switch between
threads belonging to the same memory map.

Additional optimizations can be done if the spin locks added when
context switching between threads belonging to different memory maps end
up being a performance bottleneck. Those are left out of this patch
though. A performance impact would have to be clearly demonstrated to
justify the added complexity.

The credit goes to Paul Turner (Google) for the original virtual cpu id
idea. This feature is implemented based on the discussions with Paul
Turner and Peter Oskolkov (Google), but I took the liberty to implement
scheduler fast-path optimizations and my own NUMA-awareness scheme. The
rumor has it that Google have been running a rseq vcpu_id extension
internally in production for a year. The tcmalloc source code indeed has
comments hinting at a vcpu_id prototype extension to the rseq system
call [1].

The following benchmarks do not show any significant overhead added to
the scheduler context switch by this feature:

* perf bench sched messaging (process)

Baseline:                    86.5±0.3 ms
With mm_cid:                 86.7±2.6 ms

* perf bench sched messaging (threaded)

Baseline:                    84.3±3.0 ms
With mm_cid:                 84.7±2.6 ms

* hackbench (process)

Baseline:                    82.9±2.7 ms
With mm_cid:                 82.9±2.9 ms

* hackbench (threaded)

Baseline:                    85.2±2.6 ms
With mm_cid:                 84.4±2.9 ms

[1] https://github.com/google/tcmalloc/blob/master/tcmalloc/internal/linux_syscall_support.h#L26

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-8-mathieu.desnoyers@efficios.com
2022-12-27 12:52:11 +01:00
Linus Torvalds
8fa590bf34 ARM64:
* Enable the per-vcpu dirty-ring tracking mechanism, together with an
   option to keep the good old dirty log around for pages that are
   dirtied by something other than a vcpu.
 
 * Switch to the relaxed parallel fault handling, using RCU to delay
   page table reclaim and giving better performance under load.
 
 * Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping option,
   which multi-process VMMs such as crosvm rely on (see merge commit 382b5b87a97d:
   "Fix a number of issues with MTE, such as races on the tags being
   initialised vs the PG_mte_tagged flag as well as the lack of support
   for VM_SHARED when KVM is involved.  Patches from Catalin Marinas and
   Peter Collingbourne").
 
 * Merge the pKVM shadow vcpu state tracking that allows the hypervisor
   to have its own view of a vcpu, keeping that state private.
 
 * Add support for the PMUv3p5 architecture revision, bringing support
   for 64bit counters on systems that support it, and fix the
   no-quite-compliant CHAIN-ed counter support for the machines that
   actually exist out there.
 
 * Fix a handful of minor issues around 52bit VA/PA support (64kB pages
   only) as a prefix of the oncoming support for 4kB and 16kB pages.
 
 * Pick a small set of documentation and spelling fixes, because no
   good merge window would be complete without those.
 
 s390:
 
 * Second batch of the lazy destroy patches
 
 * First batch of KVM changes for kernel virtual != physical address support
 
 * Removal of a unused function
 
 x86:
 
 * Allow compiling out SMM support
 
 * Cleanup and documentation of SMM state save area format
 
 * Preserve interrupt shadow in SMM state save area
 
 * Respond to generic signals during slow page faults
 
 * Fixes and optimizations for the non-executable huge page errata fix.
 
 * Reprogram all performance counters on PMU filter change
 
 * Cleanups to Hyper-V emulation and tests
 
 * Process Hyper-V TLB flushes from a nested guest (i.e. from a L2 guest
   running on top of a L1 Hyper-V hypervisor)
 
 * Advertise several new Intel features
 
 * x86 Xen-for-KVM:
 
 ** Allow the Xen runstate information to cross a page boundary
 
 ** Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured
 
 ** Add support for 32-bit guests in SCHEDOP_poll
 
 * Notable x86 fixes and cleanups:
 
 ** One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0).
 
 ** Reinstate IBPB on emulated VM-Exit that was incorrectly dropped a few
    years back when eliminating unnecessary barriers when switching between
    vmcs01 and vmcs02.
 
 ** Clean up vmread_error_trampoline() to make it more obvious that params
    must be passed on the stack, even for x86-64.
 
 ** Let userspace set all supported bits in MSR_IA32_FEAT_CTL irrespective
    of the current guest CPUID.
 
 ** Fudge around a race with TSC refinement that results in KVM incorrectly
    thinking a guest needs TSC scaling when running on a CPU with a
    constant TSC, but no hardware-enumerated TSC frequency.
 
 ** Advertise (on AMD) that the SMM_CTL MSR is not supported
 
 ** Remove unnecessary exports
 
 Generic:
 
 * Support for responding to signals during page faults; introduces
   new FOLL_INTERRUPTIBLE flag that was reviewed by mm folks
 
 Selftests:
 
 * Fix an inverted check in the access tracking perf test, and restore
   support for asserting that there aren't too many idle pages when
   running on bare metal.
 
 * Fix build errors that occur in certain setups (unsure exactly what is
   unique about the problematic setup) due to glibc overriding
   static_assert() to a variant that requires a custom message.
 
 * Introduce actual atomics for clear/set_bit() in selftests
 
 * Add support for pinning vCPUs in dirty_log_perf_test.
 
 * Rename the so called "perf_util" framework to "memstress".
 
 * Add a lightweight psuedo RNG for guest use, and use it to randomize
   the access pattern and write vs. read percentage in the memstress tests.
 
 * Add a common ucall implementation; code dedup and pre-work for running
   SEV (and beyond) guests in selftests.
 
 * Provide a common constructor and arch hook, which will eventually be
   used by x86 to automatically select the right hypercall (AMD vs. Intel).
 
 * A bunch of added/enabled/fixed selftests for ARM64, covering memslots,
   breakpoints, stage-2 faults and access tracking.
 
 * x86-specific selftest changes:
 
 ** Clean up x86's page table management.
 
 ** Clean up and enhance the "smaller maxphyaddr" test, and add a related
    test to cover generic emulation failure.
 
 ** Clean up the nEPT support checks.
 
 ** Add X86_PROPERTY_* framework to retrieve multi-bit CPUID values.
 
 ** Fix an ordering issue in the AMX test introduced by recent conversions
    to use kvm_cpu_has(), and harden the code to guard against similar bugs
    in the future.  Anything that tiggers caching of KVM's supported CPUID,
    kvm_cpu_has() in this case, effectively hides opt-in XSAVE features if
    the caching occurs before the test opts in via prctl().
 
 Documentation:
 
 * Remove deleted ioctls from documentation
 
 * Clean up the docs for the x86 MSR filter.
 
 * Various fixes
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM64:

   - Enable the per-vcpu dirty-ring tracking mechanism, together with an
     option to keep the good old dirty log around for pages that are
     dirtied by something other than a vcpu.

   - Switch to the relaxed parallel fault handling, using RCU to delay
     page table reclaim and giving better performance under load.

   - Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping
     option, which multi-process VMMs such as crosvm rely on (see merge
     commit 382b5b87a97d: "Fix a number of issues with MTE, such as
     races on the tags being initialised vs the PG_mte_tagged flag as
     well as the lack of support for VM_SHARED when KVM is involved.
     Patches from Catalin Marinas and Peter Collingbourne").

   - Merge the pKVM shadow vcpu state tracking that allows the
     hypervisor to have its own view of a vcpu, keeping that state
     private.

   - Add support for the PMUv3p5 architecture revision, bringing support
     for 64bit counters on systems that support it, and fix the
     no-quite-compliant CHAIN-ed counter support for the machines that
     actually exist out there.

   - Fix a handful of minor issues around 52bit VA/PA support (64kB
     pages only) as a prefix of the oncoming support for 4kB and 16kB
     pages.

   - Pick a small set of documentation and spelling fixes, because no
     good merge window would be complete without those.

  s390:

   - Second batch of the lazy destroy patches

   - First batch of KVM changes for kernel virtual != physical address
     support

   - Removal of a unused function

  x86:

   - Allow compiling out SMM support

   - Cleanup and documentation of SMM state save area format

   - Preserve interrupt shadow in SMM state save area

   - Respond to generic signals during slow page faults

   - Fixes and optimizations for the non-executable huge page errata
     fix.

   - Reprogram all performance counters on PMU filter change

   - Cleanups to Hyper-V emulation and tests

   - Process Hyper-V TLB flushes from a nested guest (i.e. from a L2
     guest running on top of a L1 Hyper-V hypervisor)

   - Advertise several new Intel features

   - x86 Xen-for-KVM:

      - Allow the Xen runstate information to cross a page boundary

      - Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured

      - Add support for 32-bit guests in SCHEDOP_poll

   - Notable x86 fixes and cleanups:

      - One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0).

      - Reinstate IBPB on emulated VM-Exit that was incorrectly dropped
        a few years back when eliminating unnecessary barriers when
        switching between vmcs01 and vmcs02.

      - Clean up vmread_error_trampoline() to make it more obvious that
        params must be passed on the stack, even for x86-64.

      - Let userspace set all supported bits in MSR_IA32_FEAT_CTL
        irrespective of the current guest CPUID.

      - Fudge around a race with TSC refinement that results in KVM
        incorrectly thinking a guest needs TSC scaling when running on a
        CPU with a constant TSC, but no hardware-enumerated TSC
        frequency.

      - Advertise (on AMD) that the SMM_CTL MSR is not supported

      - Remove unnecessary exports

  Generic:

   - Support for responding to signals during page faults; introduces
     new FOLL_INTERRUPTIBLE flag that was reviewed by mm folks

  Selftests:

   - Fix an inverted check in the access tracking perf test, and restore
     support for asserting that there aren't too many idle pages when
     running on bare metal.

   - Fix build errors that occur in certain setups (unsure exactly what
     is unique about the problematic setup) due to glibc overriding
     static_assert() to a variant that requires a custom message.

   - Introduce actual atomics for clear/set_bit() in selftests

   - Add support for pinning vCPUs in dirty_log_perf_test.

   - Rename the so called "perf_util" framework to "memstress".

   - Add a lightweight psuedo RNG for guest use, and use it to randomize
     the access pattern and write vs. read percentage in the memstress
     tests.

   - Add a common ucall implementation; code dedup and pre-work for
     running SEV (and beyond) guests in selftests.

   - Provide a common constructor and arch hook, which will eventually
     be used by x86 to automatically select the right hypercall (AMD vs.
     Intel).

   - A bunch of added/enabled/fixed selftests for ARM64, covering
     memslots, breakpoints, stage-2 faults and access tracking.

   - x86-specific selftest changes:

      - Clean up x86's page table management.

      - Clean up and enhance the "smaller maxphyaddr" test, and add a
        related test to cover generic emulation failure.

      - Clean up the nEPT support checks.

      - Add X86_PROPERTY_* framework to retrieve multi-bit CPUID values.

      - Fix an ordering issue in the AMX test introduced by recent
        conversions to use kvm_cpu_has(), and harden the code to guard
        against similar bugs in the future. Anything that tiggers
        caching of KVM's supported CPUID, kvm_cpu_has() in this case,
        effectively hides opt-in XSAVE features if the caching occurs
        before the test opts in via prctl().

  Documentation:

   - Remove deleted ioctls from documentation

   - Clean up the docs for the x86 MSR filter.

   - Various fixes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (361 commits)
  KVM: x86: Add proper ReST tables for userspace MSR exits/flags
  KVM: selftests: Allocate ucall pool from MEM_REGION_DATA
  KVM: arm64: selftests: Align VA space allocator with TTBR0
  KVM: arm64: Fix benign bug with incorrect use of VA_BITS
  KVM: arm64: PMU: Fix period computation for 64bit counters with 32bit overflow
  KVM: x86: Advertise that the SMM_CTL MSR is not supported
  KVM: x86: remove unnecessary exports
  KVM: selftests: Fix spelling mistake "probabalistic" -> "probabilistic"
  tools: KVM: selftests: Convert clear/set_bit() to actual atomics
  tools: Drop "atomic_" prefix from atomic test_and_set_bit()
  tools: Drop conflicting non-atomic test_and_{clear,set}_bit() helpers
  KVM: selftests: Use non-atomic clear/set bit helpers in KVM tests
  perf tools: Use dedicated non-atomic clear/set bit helpers
  tools: Take @bit as an "unsigned long" in {clear,set}_bit() helpers
  KVM: arm64: selftests: Enable single-step without a "full" ucall()
  KVM: x86: fix APICv/x2AVIC disabled when vm reboot by itself
  KVM: Remove stale comment about KVM_REQ_UNHALT
  KVM: Add missing arch for KVM_CREATE_DEVICE and KVM_{SET,GET}_DEVICE_ATTR
  KVM: Reference to kvm_userspace_memory_region in doc and comments
  KVM: Delete all references to removed KVM_SET_MEMORY_ALIAS ioctl
  ...
2022-12-15 11:12:21 -08:00
Linus Torvalds
e2ca6ba6ba MM patches for 6.2-rc1.
- More userfaultfs work from Peter Xu.
 
 - Several convert-to-folios series from Sidhartha Kumar and Huang Ying.
 
 - Some filemap cleanups from Vishal Moola.
 
 - David Hildenbrand added the ability to selftest anon memory COW handling.
 
 - Some cpuset simplifications from Liu Shixin.
 
 - Addition of vmalloc tracing support by Uladzislau Rezki.
 
 - Some pagecache folioifications and simplifications from Matthew Wilcox.
 
 - A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use it.
 
 - Miguel Ojeda contributed some cleanups for our use of the
   __no_sanitize_thread__ gcc keyword.  This series shold have been in the
   non-MM tree, my bad.
 
 - Naoya Horiguchi improved the interaction between memory poisoning and
   memory section removal for huge pages.
 
 - DAMON cleanups and tuneups from SeongJae Park
 
 - Tony Luck fixed the handling of COW faults against poisoned pages.
 
 - Peter Xu utilized the PTE marker code for handling swapin errors.
 
 - Hugh Dickins reworked compound page mapcount handling, simplifying it
   and making it more efficient.
 
 - Removal of the autonuma savedwrite infrastructure from Nadav Amit and
   David Hildenbrand.
 
 - zram support for multiple compression streams from Sergey Senozhatsky.
 
 - David Hildenbrand reworked the GUP code's R/O long-term pinning so
   that drivers no longer need to use the FOLL_FORCE workaround which
   didn't work very well anyway.
 
 - Mel Gorman altered the page allocator so that local IRQs can remnain
   enabled during per-cpu page allocations.
 
 - Vishal Moola removed the try_to_release_page() wrapper.
 
 - Stefan Roesch added some per-BDI sysfs tunables which are used to
   prevent network block devices from dirtying excessive amounts of
   pagecache.
 
 - David Hildenbrand did some cleanup and repair work on KSM COW
   breaking.
 
 - Nhat Pham and Johannes Weiner have implemented writeback in zswap's
   zsmalloc backend.
 
 - Brian Foster has fixed a longstanding corner-case oddity in
   file[map]_write_and_wait_range().
 
 - sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang
   Chen.
 
 - Shiyang Ruan has done some work on fsdax, to make its reflink mode
   work better under xfstests.  Better, but still not perfect.
 
 - Christoph Hellwig has removed the .writepage() method from several
   filesystems.  They only need .writepages().
 
 - Yosry Ahmed wrote a series which fixes the memcg reclaim target
   beancounting.
 
 - David Hildenbrand has fixed some of our MM selftests for 32-bit
   machines.
 
 - Many singleton patches, as usual.
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Merge tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - More userfaultfs work from Peter Xu

 - Several convert-to-folios series from Sidhartha Kumar and Huang Ying

 - Some filemap cleanups from Vishal Moola

 - David Hildenbrand added the ability to selftest anon memory COW
   handling

 - Some cpuset simplifications from Liu Shixin

 - Addition of vmalloc tracing support by Uladzislau Rezki

 - Some pagecache folioifications and simplifications from Matthew
   Wilcox

 - A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use
   it

 - Miguel Ojeda contributed some cleanups for our use of the
   __no_sanitize_thread__ gcc keyword.

   This series should have been in the non-MM tree, my bad

 - Naoya Horiguchi improved the interaction between memory poisoning and
   memory section removal for huge pages

 - DAMON cleanups and tuneups from SeongJae Park

 - Tony Luck fixed the handling of COW faults against poisoned pages

 - Peter Xu utilized the PTE marker code for handling swapin errors

 - Hugh Dickins reworked compound page mapcount handling, simplifying it
   and making it more efficient

 - Removal of the autonuma savedwrite infrastructure from Nadav Amit and
   David Hildenbrand

 - zram support for multiple compression streams from Sergey Senozhatsky

 - David Hildenbrand reworked the GUP code's R/O long-term pinning so
   that drivers no longer need to use the FOLL_FORCE workaround which
   didn't work very well anyway

 - Mel Gorman altered the page allocator so that local IRQs can remnain
   enabled during per-cpu page allocations

 - Vishal Moola removed the try_to_release_page() wrapper

 - Stefan Roesch added some per-BDI sysfs tunables which are used to
   prevent network block devices from dirtying excessive amounts of
   pagecache

 - David Hildenbrand did some cleanup and repair work on KSM COW
   breaking

 - Nhat Pham and Johannes Weiner have implemented writeback in zswap's
   zsmalloc backend

 - Brian Foster has fixed a longstanding corner-case oddity in
   file[map]_write_and_wait_range()

 - sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang
   Chen

 - Shiyang Ruan has done some work on fsdax, to make its reflink mode
   work better under xfstests. Better, but still not perfect

 - Christoph Hellwig has removed the .writepage() method from several
   filesystems. They only need .writepages()

 - Yosry Ahmed wrote a series which fixes the memcg reclaim target
   beancounting

 - David Hildenbrand has fixed some of our MM selftests for 32-bit
   machines

 - Many singleton patches, as usual

* tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (313 commits)
  mm/hugetlb: set head flag before setting compound_order in __prep_compound_gigantic_folio
  mm: mmu_gather: allow more than one batch of delayed rmaps
  mm: fix typo in struct pglist_data code comment
  kmsan: fix memcpy tests
  mm: add cond_resched() in swapin_walk_pmd_entry()
  mm: do not show fs mm pc for VM_LOCKONFAULT pages
  selftests/vm: ksm_functional_tests: fixes for 32bit
  selftests/vm: cow: fix compile warning on 32bit
  selftests/vm: madv_populate: fix missing MADV_POPULATE_(READ|WRITE) definitions
  mm/gup_test: fix PIN_LONGTERM_TEST_READ with highmem
  mm,thp,rmap: fix races between updates of subpages_mapcount
  mm: memcg: fix swapcached stat accounting
  mm: add nodes= arg to memory.reclaim
  mm: disable top-tier fallback to reclaim on proactive reclaim
  selftests: cgroup: make sure reclaim target memcg is unprotected
  selftests: cgroup: refactor proactive reclaim code to reclaim_until()
  mm: memcg: fix stale protection of reclaim target memcg
  mm/mmap: properly unaccount memory on mas_preallocate() failure
  omfs: remove ->writepage
  jfs: remove ->writepage
  ...
2022-12-13 19:29:45 -08:00
Linus Torvalds
ce8a79d560 for-6.2/block-2022-12-08
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Merge tag 'for-6.2/block-2022-12-08' of git://git.kernel.dk/linux

Pull block updates from Jens Axboe:

 - NVMe pull requests via Christoph:
      - Support some passthrough commands without CAP_SYS_ADMIN (Kanchan
        Joshi)
      - Refactor PCIe probing and reset (Christoph Hellwig)
      - Various fabrics authentication fixes and improvements (Sagi
        Grimberg)
      - Avoid fallback to sequential scan due to transient issues (Uday
        Shankar)
      - Implement support for the DEAC bit in Write Zeroes (Christoph
        Hellwig)
      - Allow overriding the IEEE OUI and firmware revision in configfs
        for nvmet (Aleksandr Miloserdov)
      - Force reconnect when number of queue changes in nvmet (Daniel
        Wagner)
      - Minor fixes and improvements (Uros Bizjak, Joel Granados, Sagi
        Grimberg, Christoph Hellwig, Christophe JAILLET)
      - Fix and cleanup nvme-fc req allocation (Chaitanya Kulkarni)
      - Use the common tagset helpers in nvme-pci driver (Christoph
        Hellwig)
      - Cleanup the nvme-pci removal path (Christoph Hellwig)
      - Use kstrtobool() instead of strtobool (Christophe JAILLET)
      - Allow unprivileged passthrough of Identify Controller (Joel
        Granados)
      - Support io stats on the mpath device (Sagi Grimberg)
      - Minor nvmet cleanup (Sagi Grimberg)

 - MD pull requests via Song:
      - Code cleanups (Christoph)
      - Various fixes

 - Floppy pull request from Denis:
      - Fix a memory leak in the init error path (Yuan)

 - Series fixing some batch wakeup issues with sbitmap (Gabriel)

 - Removal of the pktcdvd driver that was deprecated more than 5 years
   ago, and subsequent removal of the devnode callback in struct
   block_device_operations as no users are now left (Greg)

 - Fix for partition read on an exclusively opened bdev (Jan)

 - Series of elevator API cleanups (Jinlong, Christoph)

 - Series of fixes and cleanups for blk-iocost (Kemeng)

 - Series of fixes and cleanups for blk-throttle (Kemeng)

 - Series adding concurrent support for sync queues in BFQ (Yu)

 - Series bringing drbd a bit closer to the out-of-tree maintained
   version (Christian, Joel, Lars, Philipp)

 - Misc drbd fixes (Wang)

 - blk-wbt fixes and tweaks for enable/disable (Yu)

 - Fixes for mq-deadline for zoned devices (Damien)

 - Add support for read-only and offline zones for null_blk
   (Shin'ichiro)

 - Series fixing the delayed holder tracking, as used by DM (Yu,
   Christoph)

 - Series enabling bio alloc caching for IRQ based IO (Pavel)

 - Series enabling userspace peer-to-peer DMA (Logan)

 - BFQ waker fixes (Khazhismel)

 - Series fixing elevator refcount issues (Christoph, Jinlong)

 - Series cleaning up references around queue destruction (Christoph)

 - Series doing quiesce by tagset, enabling cleanups in drivers
   (Christoph, Chao)

 - Series untangling the queue kobject and queue references (Christoph)

 - Misc fixes and cleanups (Bart, David, Dawei, Jinlong, Kemeng, Ye,
   Yang, Waiman, Shin'ichiro, Randy, Pankaj, Christoph)

* tag 'for-6.2/block-2022-12-08' of git://git.kernel.dk/linux: (247 commits)
  blktrace: Fix output non-blktrace event when blk_classic option enabled
  block: sed-opal: Don't include <linux/kernel.h>
  sed-opal: allow using IOC_OPAL_SAVE for locking too
  blk-cgroup: Fix typo in comment
  block: remove bio_set_op_attrs
  nvmet: don't open-code NVME_NS_ATTR_RO enumeration
  nvme-pci: use the tagset alloc/free helpers
  nvme: add the Apple shared tag workaround to nvme_alloc_io_tag_set
  nvme: only set reserved_tags in nvme_alloc_io_tag_set for fabrics controllers
  nvme: consolidate setting the tagset flags
  nvme: pass nr_maps explicitly to nvme_alloc_io_tag_set
  block: bio_copy_data_iter
  nvme-pci: split out a nvme_pci_ctrl_is_dead helper
  nvme-pci: return early on ctrl state mismatch in nvme_reset_work
  nvme-pci: rename nvme_disable_io_queues
  nvme-pci: cleanup nvme_suspend_queue
  nvme-pci: remove nvme_pci_disable
  nvme-pci: remove nvme_disable_admin_queue
  nvme: merge nvme_shutdown_ctrl into nvme_disable_ctrl
  nvme: use nvme_wait_ready in nvme_shutdown_ctrl
  ...
2022-12-13 10:43:59 -08:00
Sidhartha Kumar
9fd330582b mm: add folio dtor and order setter functions
Patch series "convert core hugetlb functions to folios", v5.

============== OVERVIEW ===========================
Now that many hugetlb helper functions that deal with hugetlb specific
flags[1] and hugetlb cgroups[2] are converted to folios, higher level
allocation, prep, and freeing functions within hugetlb can also be
converted to operate in folios.

Patch 1 of this series implements the wrapper functions around setting the
compound destructor and compound order for a folio.  Besides the user
added in patch 1, patch 2 and patch 9 also use these helper functions.

Patches 2-10 convert the higher level hugetlb functions to folios.

============== TESTING ===========================
LTP:
	Ran 10 back to back rounds of the LTP hugetlb test suite.

Gigantic Huge Pages:
	Test allocation and freeing via hugeadm commands:
		hugeadm --pool-pages-min 1GB:10
		hugeadm --pool-pages-min 1GB:0

Demote:
	Demote 1 1GB hugepages to 512 2MB hugepages
		echo 1 > /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages
		echo 1 > /sys/kernel/mm/hugepages/hugepages-1048576kB/demote
		cat /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
			# 512
		cat /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages
			# 0

[1] https://lore.kernel.org/lkml/20220922154207.1575343-1-sidhartha.kumar@oracle.com/
[2] https://lore.kernel.org/linux-mm/20221101223059.460937-1-sidhartha.kumar@oracle.com/


This patch (of 10):

Add folio equivalents for set_compound_order() and
set_compound_page_dtor().

Also remove extra new-lines introduced by mm/hugetlb: convert
move_hugetlb_state() to folios and mm/hugetlb_cgroup: convert
hugetlb_cgroup_uncharge_page() to folios.

[sidhartha.kumar@oracle.com: clarify folio_set_compound_order() zero support]
  Link: https://lkml.kernel.org/r/20221207223731.32784-1-sidhartha.kumar@oracle.com
Link: https://lkml.kernel.org/r/20221129225039.82257-1-sidhartha.kumar@oracle.com
Link: https://lkml.kernel.org/r/20221129225039.82257-2-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Suggested-by: Mike Kravetz <mike.kravetz@oracle.com>
Suggested-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Tarun Sahu <tsahu@linux.ibm.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Wei Chen <harperchen1110@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-12-11 18:12:13 -08:00
Feiyang Chen
2045a3b891 mm/sparse-vmemmap: generalise vmemmap_populate_hugepages()
Generalise vmemmap_populate_hugepages() so ARM64 & X86 & LoongArch can
share its implementation.

Link: https://lkml.kernel.org/r/20221027125253.3458989-4-chenhuacai@loongson.cn
Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Min Zhou <zhoumin@loongson.cn>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Philippe Mathieu-Daudé <philmd@linaro.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Xuefeng Li <lixuefeng@loongson.cn>
Cc: Xuerui Wang <kernel@xen0n.name>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-12-11 18:12:12 -08:00
Feiyang Chen
7b09f5af01 LoongArch: add sparse memory vmemmap support
Add sparse memory vmemmap support for LoongArch.  SPARSEMEM_VMEMMAP uses a
virtually mapped memmap to optimise pfn_to_page and page_to_pfn
operations.  This is the most efficient option when sufficient kernel
resources are available.

Link: https://lkml.kernel.org/r/20221027125253.3458989-3-chenhuacai@loongson.cn
Signed-off-by: Min Zhou <zhoumin@loongson.cn>
Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Philippe Mathieu-Daudé <philmd@linaro.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Will Deacon <will@kernel.org>
Cc: Xuefeng Li <lixuefeng@loongson.cn>
Cc: Xuerui Wang <kernel@xen0n.name>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-12-11 18:12:12 -08:00
David Hildenbrand
f7355e99d9 mm/gup: remove FOLL_MIGRATION
Fortunately, the last user (KSM) is gone, so let's just remove this rather
special code from generic GUP handling -- especially because KSM never
required the PMD handling as KSM only deals with individual base pages.

[akpm@linux-foundation.org: fix merge snafu]Link: https://lkml.kernel.org/r/20221021101141.84170-10-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-12-11 18:12:09 -08:00
Anshuman Khandual
7e25de77bc s390/mm: use pmd_pgtable_page() helper in __gmap_segment_gaddr()
In __gmap_segment_gaddr() pmd level page table page is being extracted
from the pmd pointer, similar to pmd_pgtable_page() implementation.  This
reduces some redundancy by directly using pmd_pgtable_page() instead,
though first making it available.

Link: https://lkml.kernel.org/r/20221125034502.1559986-1-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30 15:59:07 -08:00
Anshuman Khandual
373dfda2ba mm/thp: rename pmd_to_page() as pmd_pgtable_page()
Current pmd_to_page(), which derives the page table page containing the
pmd address has a very misleading name.  The problem being, it sounds
similar to pmd_page() which derives page embedded in a given pmd entry
either for next level page or a mapped huge page.  Rename it as
pmd_pgtable_page() instead.

Link: https://lkml.kernel.org/r/20221124131641.1523772-1-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30 15:59:07 -08:00
David Hildenbrand
84209e87c6 mm/gup: reliable R/O long-term pinning in COW mappings
We already support reliable R/O pinning of anonymous memory. However,
assume we end up pinning (R/O long-term) a pagecache page or the shared
zeropage inside a writable private ("COW") mapping. The next write access
will trigger a write-fault and replace the pinned page by an exclusive
anonymous page in the process page tables to break COW: the pinned page no
longer corresponds to the page mapped into the process' page table.

Now that FAULT_FLAG_UNSHARE can break COW on anything mapped into a
COW mapping, let's properly break COW first before R/O long-term
pinning something that's not an exclusive anon page inside a COW
mapping. FAULT_FLAG_UNSHARE will break COW and map an exclusive anon page
instead that can get pinned safely.

With this change, we can stop using FOLL_FORCE|FOLL_WRITE for reliable
R/O long-term pinning in COW mappings.

With this change, the new R/O long-term pinning tests for non-anonymous
memory succeed:
  # [RUN] R/O longterm GUP pin ... with shared zeropage
  ok 151 Longterm R/O pin is reliable
  # [RUN] R/O longterm GUP pin ... with memfd
  ok 152 Longterm R/O pin is reliable
  # [RUN] R/O longterm GUP pin ... with tmpfile
  ok 153 Longterm R/O pin is reliable
  # [RUN] R/O longterm GUP pin ... with huge zeropage
  ok 154 Longterm R/O pin is reliable
  # [RUN] R/O longterm GUP pin ... with memfd hugetlb (2048 kB)
  ok 155 Longterm R/O pin is reliable
  # [RUN] R/O longterm GUP pin ... with memfd hugetlb (1048576 kB)
  ok 156 Longterm R/O pin is reliable
  # [RUN] R/O longterm GUP-fast pin ... with shared zeropage
  ok 157 Longterm R/O pin is reliable
  # [RUN] R/O longterm GUP-fast pin ... with memfd
  ok 158 Longterm R/O pin is reliable
  # [RUN] R/O longterm GUP-fast pin ... with tmpfile
  ok 159 Longterm R/O pin is reliable
  # [RUN] R/O longterm GUP-fast pin ... with huge zeropage
  ok 160 Longterm R/O pin is reliable
  # [RUN] R/O longterm GUP-fast pin ... with memfd hugetlb (2048 kB)
  ok 161 Longterm R/O pin is reliable
  # [RUN] R/O longterm GUP-fast pin ... with memfd hugetlb (1048576 kB)
  ok 162 Longterm R/O pin is reliable

Note 1: We don't care about short-term R/O-pinning, because they have
snapshot semantics: they are not supposed to observe modifications that
happen after pinning.

As one example, assume we start direct I/O to read from a page and store
page content into a file: modifications to page content after starting
direct I/O are not guaranteed to end up in the file. So even if we'd pin
the shared zeropage, the end result would be as expected -- getting zeroes
stored to the file.

Note 2: For shared mappings we'll now always fallback to the slow path to
lookup the VMA when R/O long-term pining. While that's the necessary price
we have to pay right now, it's actually not that bad in practice: most
FOLL_LONGTERM users already specify FOLL_WRITE, for example, along with
FOLL_FORCE because they tried dealing with COW mappings correctly ...

Note 3: For users that use FOLL_LONGTERM right now without FOLL_WRITE,
such as VFIO, we'd now no longer pin the shared zeropage. Instead, we'd
populate exclusive anon pages that we can pin. There was a concern that
this could affect the memlock limit of existing setups.

For example, a VM running with VFIO could run into the memlock limit and
fail to run. However, we essentially had the same behavior already in
commit 17839856fd ("gup: document and work around "COW can break either
way" issue") which got merged into some enterprise distros, and there were
not any such complaints. So most probably, we're fine.

Link: https://lkml.kernel.org/r/20221116102659.70287-10-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30 15:58:58 -08:00
Pasha Tatashin
d09e8ca6cb mm: anonymous shared memory naming
Since commit 9a10064f56 ("mm: add a field to store names for private
anonymous memory"), name for private anonymous memory, but not shared
anonymous, can be set.  However, naming shared anonymous memory just as
useful for tracking purposes.

Extend the functionality to be able to set names for shared anon.

There are two ways to create anonymous shared memory, using memfd or
directly via mmap():
1. fd = memfd_create(...)
   mem = mmap(..., MAP_SHARED, fd, ...)
2. mem = mmap(..., MAP_SHARED | MAP_ANONYMOUS, -1, ...)

In both cases the anonymous shared memory is created the same way by
mapping an unlinked file on tmpfs.

The memfd way allows to give a name for anonymous shared memory, but
not useful when parts of shared memory require to have distinct names.

Example use case: The VMM maps VM memory as anonymous shared memory (not
private because VMM is sandboxed and drivers are running in their own
processes).  However, the VM tells back to the VMM how parts of the memory
are actually used by the guest, how each of the segments should be backed
(i.e.  4K pages, 2M pages), and some other information about the segments.
The naming allows us to monitor the effective memory footprint for each
of these segments from the host without looking inside the guest.

Sample output:
  /* Create shared anonymous segmenet */
  anon_shmem = mmap(NULL, SIZE, PROT_READ | PROT_WRITE,
                    MAP_SHARED | MAP_ANONYMOUS, -1, 0);
  /* Name the segment: "MY-NAME" */
  rv = prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME,
             anon_shmem, SIZE, "MY-NAME");

cat /proc/<pid>/maps (and smaps):
7fc8e2b4c000-7fc8f2b4c000 rw-s 00000000 00:01 1024 [anon_shmem:MY-NAME]

If the segment is not named, the output is:
7fc8e2b4c000-7fc8f2b4c000 rw-s 00000000 00:01 1024 /dev/zero (deleted)

Link: https://lkml.kernel.org/r/20221115020602.804224-1-pasha.tatashin@soleen.com
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Colin Cross <ccross@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Vincent Whitchurch <vincent.whitchurch@axis.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: xu xin <cgel.zte@gmail.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30 15:58:55 -08:00
Linus Torvalds
449c796768 mm: teach release_pages() to take an array of encoded page pointers too
release_pages() already could take either an array of page pointers, or an
array of folio pointers.  Expand it to also accept an array of encoded
page pointers, which is what both the existing mlock() use and the
upcoming mmu_gather use of encoded page pointers wants.

Note that release_pages() won't actually use, or react to, any extra
encoded bits.  Instead, this is very much a case of "I have walked the
array of encoded pages and done everything the extra bits tell me to do,
now release it all".

Also, while the "either page or folio pointers" dual use was handled with
a cast of the pointer in "release_folios()", this takes a slightly
different approach and uses the "transparent union" attribute to describe
the set of arguments to the function:

  https://gcc.gnu.org/onlinedocs/gcc/Common-Type-Attributes.html

which has been supported by gcc forever, but the kernel hasn't used
before.

That allows us to avoid using various wrappers with casts, and just use
the same function regardless of use.

Link: https://lkml.kernel.org/r/20221109203051.1835763-2-torvalds@linux-foundation.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30 15:58:50 -08:00
David Hildenbrand
6a56ccbcf6 mm/autonuma: use can_change_(pte|pmd)_writable() to replace savedwrite
commit b191f9b106 ("mm: numa: preserve PTE write permissions across a
NUMA hinting fault") added remembering write permissions using ordinary
pte_write() for PROT_NONE mapped pages to avoid write faults when
remapping the page !PROT_NONE on NUMA hinting faults.

That commit noted:

    The patch looks hacky but the alternatives looked worse. The tidest was
    to rewalk the page tables after a hinting fault but it was more complex
    than this approach and the performance was worse. It's not generally
    safe to just mark the page writable during the fault if it's a write
    fault as it may have been read-only for COW so that approach was
    discarded.

Later, commit 288bc54949 ("mm/autonuma: let architecture override how
the write bit should be stashed in a protnone pte.") introduced a family
of savedwrite PTE functions that didn't necessarily improve the whole
situation.

One confusing thing is that nowadays, if a page is pte_protnone()
and pte_savedwrite() then also pte_write() is true. Another source of
confusion is that there is only a single pte_mk_savedwrite() call in the
kernel. All other write-protection code seems to silently rely on
pte_wrprotect().

Ever since PageAnonExclusive was introduced and we started using it in
mprotect context via commit 64fe24a3e0 ("mm/mprotect: try avoiding write
faults for exclusive anonymous pages when changing protection"), we do
have machinery in place to avoid write faults when changing protection,
which is exactly what we want to do here.

Let's similarly do what ordinary mprotect() does nowadays when upgrading
write permissions and reuse can_change_pte_writable() and
can_change_pmd_writable() to detect if we can upgrade PTE permissions to be
writable.

For anonymous pages there should be absolutely no change: if an
anonymous page is not exclusive, it could not have been mapped writable --
because only exclusive anonymous pages can be mapped writable.

However, there *might* be a change for writable shared mappings that
require writenotify: if they are not dirty, we cannot map them writable.
While it might not matter in practice, we'd need a different way to
identify whether writenotify is actually required -- and ordinary mprotect
would benefit from that as well.

Note that we don't optimize for the actual migration case:
(1) When migration succeeds the new PTE will not be writable because the
    source PTE was not writable (protnone); in the future we
    might just optimize that case similarly by reusing
    can_change_pte_writable()/can_change_pmd_writable() when removing
    migration PTEs.
(2) When migration fails, we'd have to recalculate the "writable" flag
    because we temporarily dropped the PT lock; for now keep it simple and
    set "writable=false".

We'll remove all savedwrite leftovers next.

Link: https://lkml.kernel.org/r/20221108174652.198904-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30 15:58:49 -08:00
David Hildenbrand
eb309ec899 mm/mprotect: factor out check whether manual PTE write upgrades are required
Let's factor the check out into vma_wants_manual_pte_write_upgrade(), to be
reused in NUMA hinting fault context soon.

Link: https://lkml.kernel.org/r/20221108174652.198904-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30 15:58:49 -08:00
Hugh Dickins
4b51634cd1 mm,thp,rmap: subpages_mapcount COMPOUND_MAPPED if PMD-mapped
Can the lock_compound_mapcount() bit_spin_lock apparatus be removed now? 
Yes.  Not by atomic64_t or cmpxchg games, those get difficult on 32-bit;
but if we slightly abuse subpages_mapcount by additionally demanding that
one bit be set there when the compound page is PMD-mapped, then a cascade
of two atomic ops is able to maintain the stats without bit_spin_lock.

This is harder to reason about than when bit_spin_locked, but I believe
safe; and no drift in stats detected when testing.  When there are racing
removes and adds, of course the sequence of operations is less well-
defined; but each operation on subpages_mapcount is atomically good.  What
might be disastrous, is if subpages_mapcount could ever fleetingly appear
negative: but the pte lock (or pmd lock) these rmap functions are called
under, ensures that a last remove cannot race ahead of a first add.

Continue to make an exception for hugetlb (PageHuge) pages, though that
exception can be easily removed by a further commit if necessary: leave
subpages_mapcount 0, don't bother with COMPOUND_MAPPED in its case, just
carry on checking compound_mapcount too in folio_mapped(), page_mapped().

Evidence is that this way goes slightly faster than the previous
implementation in all cases (pmds after ptes now taking around 103ms); and
relieves us of worrying about contention on the bit_spin_lock.

Link: https://lkml.kernel.org/r/3978f3ca-5473-55a7-4e14-efea5968d892@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dan Carpenter <error27@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30 15:58:48 -08:00
Hugh Dickins
be5ef2d9b0 mm,thp,rmap: subpages_mapcount of PTE-mapped subpages
Patch series "mm,thp,rmap: rework the use of subpages_mapcount", v2.


This patch (of 3):

Following suggestion from Linus, instead of counting every PTE map of a
compound page in subpages_mapcount, just count how many of its subpages
are PTE-mapped: this yields the exact number needed for NR_ANON_MAPPED and
NR_FILE_MAPPED stats, without any need for a locked scan of subpages; and
requires updating the count less often.

This does then revert total_mapcount() and folio_mapcount() to needing a
scan of subpages; but they are inherently racy, and need no locking, so
Linus is right that the scans are much better done there.  Plus (unlike in
6.1 and previous) subpages_mapcount lets us avoid the scan in the common
case of no PTE maps.  And page_mapped() and folio_mapped() remain scanless
and just as efficient with the new meaning of subpages_mapcount: those are
the functions which I most wanted to remove the scan from.

The updated page_dup_compound_rmap() is no longer suitable for use by anon
THP's __split_huge_pmd_locked(); but page_add_anon_rmap() can be used for
that, so long as its VM_BUG_ON_PAGE(!PageLocked) is deleted.

Evidence is that this way goes slightly faster than the previous
implementation for most cases; but significantly faster in the (now
scanless) pmds after ptes case, which started out at 870ms and was brought
down to 495ms by the previous series, now takes around 105ms.

Link: https://lkml.kernel.org/r/a5849eca-22f1-3517-bf29-95d982242742@google.com
Link: https://lkml.kernel.org/r/eec17e16-4e1-7c59-f1bc-5bca90dac919@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dan Carpenter <error27@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30 15:58:47 -08:00
Hugh Dickins
cb67f4282b mm,thp,rmap: simplify compound page mapcount handling
Compound page (folio) mapcount calculations have been different for anon
and file (or shmem) THPs, and involved the obscure PageDoubleMap flag. 
And each huge mapping and unmapping of a file (or shmem) THP involved
atomically incrementing and decrementing the mapcount of every subpage of
that huge page, dirtying many struct page cachelines.

Add subpages_mapcount field to the struct folio and first tail page, so
that the total of subpage mapcounts is available in one place near the
head: then page_mapcount() and total_mapcount() and page_mapped(), and
their folio equivalents, are so quick that anon and file and hugetlb don't
need to be optimized differently.  Delete the unloved PageDoubleMap.

page_add and page_remove rmap functions must now maintain the
subpages_mapcount as well as the subpage _mapcount, when dealing with pte
mappings of huge pages; and correct maintenance of NR_ANON_MAPPED and
NR_FILE_MAPPED statistics still needs reading through the subpages, using
nr_subpages_unmapped() - but only when first or last pmd mapping finds
subpages_mapcount raised (double-map case, not the common case).

But are those counts (used to decide when to split an anon THP, and in
vmscan's pagecache_reclaimable heuristic) correctly maintained?  Not
quite: since page_remove_rmap() (and also split_huge_pmd()) is often
called without page lock, there can be races when a subpage pte mapcount
0<->1 while compound pmd mapcount 0<->1 is scanning - races which the
previous implementation had prevented.  The statistics might become
inaccurate, and even drift down until they underflow through 0.  That is
not good enough, but is better dealt with in a followup patch.

Update a few comments on first and second tail page overlaid fields. 
hugepage_add_new_anon_rmap() has to "increment" compound_mapcount, but
subpages_mapcount and compound_pincount are already correctly at 0, so
delete its reinitialization of compound_pincount.

A simple 100 X munmap(mmap(2GB, MAP_SHARED|MAP_POPULATE, tmpfs), 2GB) took
18 seconds on small pages, and used to take 1 second on huge pages, but
now takes 119 milliseconds on huge pages.  Mapping by pmds a second time
used to take 860ms and now takes 92ms; mapping by pmds after mapping by
ptes (when the scan is needed) used to take 870ms and now takes 495ms. 
But there might be some benchmarks which would show a slowdown, because
tail struct pages now fall out of cache until final freeing checks them.

Link: https://lkml.kernel.org/r/47ad693-717-79c8-e1ba-46c3a6602e48@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30 15:58:46 -08:00
Tony Luck
d302c2398b mm, hwpoison: when copy-on-write hits poison, take page offline
Cannot call memory_failure() directly from the fault handler because
mmap_lock (and others) are held.

It is important, but not urgent, to mark the source page as h/w poisoned
and unmap it from other tasks.

Use memory_failure_queue() to request a call to memory_failure() for the
page with the error.

Also provide a stub version for CONFIG_MEMORY_FAILURE=n

Link: https://lkml.kernel.org/r/20221021200120.175753-3-tony.luck@intel.com
Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Shuai Xue <xueshuai@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30 15:58:40 -08:00
Shakeel Butt
f1a7941243 mm: convert mm's rss stats into percpu_counter
Currently mm_struct maintains rss_stats which are updated on page fault
and the unmapping codepaths.  For page fault codepath the updates are
cached per thread with the batch of TASK_RSS_EVENTS_THRESH which is 64. 
The reason for caching is performance for multithreaded applications
otherwise the rss_stats updates may become hotspot for such applications.

However this optimization comes with the cost of error margin in the rss
stats.  The rss_stats for applications with large number of threads can be
very skewed.  At worst the error margin is (nr_threads * 64) and we have a
lot of applications with 100s of threads, so the error margin can be very
high.  Internally we had to reduce TASK_RSS_EVENTS_THRESH to 32.

Recently we started seeing the unbounded errors for rss_stats for specific
applications which use TCP rx0cp.  It seems like vm_insert_pages()
codepath does not sync rss_stats at all.

This patch converts the rss_stats into percpu_counter to convert the error
margin from (nr_threads * 64) to approximately (nr_cpus ^ 2).  However
this conversion enable us to get the accurate stats for situations where
accuracy is more important than the cpu cost.

This patch does not make such tradeoffs - we can just use
percpu_counter_add_local() for the updates and percpu_counter_sum() (or
percpu_counter_sync() + percpu_counter_read) for the readers.  At the
moment the readers are either procfs interface, oom_killer and memory
reclaim which I think are not performance critical and should be ok with
slow read.  However I think we can make that change in a separate patch.

Link: https://lkml.kernel.org/r/20221024052841.3291983-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30 15:58:40 -08:00
Andrew Morton
a38358c934 Merge branch 'mm-hotfixes-stable' into mm-stable 2022-11-30 14:58:42 -08:00
Mike Kravetz
04ada095dc hugetlb: don't delete vma_lock in hugetlb MADV_DONTNEED processing
madvise(MADV_DONTNEED) ends up calling zap_page_range() to clear page
tables associated with the address range.  For hugetlb vmas,
zap_page_range will call __unmap_hugepage_range_final.  However,
__unmap_hugepage_range_final assumes the passed vma is about to be removed
and deletes the vma_lock to prevent pmd sharing as the vma is on the way
out.  In the case of madvise(MADV_DONTNEED) the vma remains, but the
missing vma_lock prevents pmd sharing and could potentially lead to issues
with truncation/fault races.

This issue was originally reported here [1] as a BUG triggered in
page_try_dup_anon_rmap.  Prior to the introduction of the hugetlb
vma_lock, __unmap_hugepage_range_final cleared the VM_MAYSHARE flag to
prevent pmd sharing.  Subsequent faults on this vma were confused as
VM_MAYSHARE indicates a sharable vma, but was not set so page_mapping was
not set in new pages added to the page table.  This resulted in pages that
appeared anonymous in a VM_SHARED vma and triggered the BUG.

Address issue by adding a new zap flag ZAP_FLAG_UNMAP to indicate an unmap
call from unmap_vmas().  This is used to indicate the 'final' unmapping of
a hugetlb vma.  When called via MADV_DONTNEED, this flag is not set and
the vm_lock is not deleted.

[1] https://lore.kernel.org/lkml/CAO4mrfdLMXsao9RF4fUE8-Wfde8xmjsKrTNMNC9wjUb6JudD0g@mail.gmail.com/

Link: https://lkml.kernel.org/r/20221114235507.294320-3-mike.kravetz@oracle.com
Fixes: 90e7e7f5ef ("mm: enable MADV_DONTNEED for hugetlb mappings")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Wei Chen <harperchen1110@gmail.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30 14:49:40 -08:00
Mike Kravetz
21b85b0952 madvise: use zap_page_range_single for madvise dontneed
This series addresses the issue first reported in [1], and fully described
in patch 2.  Patches 1 and 2 address the user visible issue and are tagged
for stable backports.

While exploring solutions to this issue, related problems with mmu
notification calls were discovered.  This is addressed in the patch
"hugetlb: remove duplicate mmu notifications:".  Since there are no user
visible effects, this third is not tagged for stable backports.

Previous discussions suggested further cleanup by removing the
routine zap_page_range.  This is possible because zap_page_range_single
is now exported, and all callers of zap_page_range pass ranges entirely
within a single vma.  This work will be done in a later patch so as not
to distract from this bug fix.

[1] https://lore.kernel.org/lkml/CAO4mrfdLMXsao9RF4fUE8-Wfde8xmjsKrTNMNC9wjUb6JudD0g@mail.gmail.com/


This patch (of 2):

Expose the routine zap_page_range_single to zap a range within a single
vma.  The madvise routine madvise_dontneed_single_vma can use this routine
as it explicitly operates on a single vma.  Also, update the mmu
notification range in zap_page_range_single to take hugetlb pmd sharing
into account.  This is required as MADV_DONTNEED supports hugetlb vmas.

Link: https://lkml.kernel.org/r/20221114235507.294320-1-mike.kravetz@oracle.com
Link: https://lkml.kernel.org/r/20221114235507.294320-2-mike.kravetz@oracle.com
Fixes: 90e7e7f5ef ("mm: enable MADV_DONTNEED for hugetlb mappings")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Wei Chen <harperchen1110@gmail.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30 14:49:40 -08:00
Logan Gunthorpe
4003f107fa mm: introduce FOLL_PCI_P2PDMA to gate getting PCI P2PDMA pages
GUP Callers that expect PCI P2PDMA pages can now set FOLL_PCI_P2PDMA to
allow obtaining P2PDMA pages. If GUP is called without the flag and a
P2PDMA page is found, it will return an error in try_grab_page() or
try_grab_folio().

The check is safe to do before taking the reference to the page in both
cases seeing the page should be protected by either the appropriate
ptl or mmap_lock; or the gup fast guarantees preventing TLB flushes.

try_grab_folio() has one call site that WARNs on failure and cannot
actually deal with the failure of this function (it seems it will
get into an infinite loop). Expand the comment there to document a
couple more conditions on why it will not fail.

FOLL_PCI_P2PDMA cannot be set if FOLL_LONGTERM is set. This is to copy
fsdax until pgmap refcounts are fixed (see the link below for more
information).

Link: https://lkml.kernel.org/r/Yy4Ot5MoOhsgYLTQ@ziepe.ca
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20221021174116.7200-3-logang@deltatee.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-09 11:29:20 -07:00
Logan Gunthorpe
0f0892356f mm: allow multiple error returns in try_grab_page()
In order to add checks for P2PDMA memory into try_grab_page(), expand
the error return from a bool to an int/error code. Update all the
callsites handle change in usage.

Also remove the WARN_ON_ONCE() call at the callsites seeing there
already is a WARN_ON_ONCE() inside the function if it fails.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221021174116.7200-2-logang@deltatee.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-09 11:29:20 -07:00
Peter Xu
93c5c61d9e mm/gup: Add FOLL_INTERRUPTIBLE
We have had FAULT_FLAG_INTERRUPTIBLE but it was never applied to GUPs.  One
issue with it is that not all GUP paths are able to handle signal delivers
besides SIGKILL.

That's not ideal for the GUP users who are actually able to handle these
cases, like KVM.

KVM uses GUP extensively on faulting guest pages, during which we've got
existing infrastructures to retry a page fault at a later time.  Allowing
the GUP to be interrupted by generic signals can make KVM related threads
to be more responsive.  For examples:

  (1) SIGUSR1: which QEMU/KVM uses to deliver an inter-process IPI,
      e.g. when the admin issues a vm_stop QMP command, SIGUSR1 can be
      generated to kick the vcpus out of kernel context immediately,

  (2) SIGINT: which can be used with interactive hypervisor users to stop a
      virtual machine with Ctrl-C without any delays/hangs,

  (3) SIGTRAP: which grants GDB capability even during page faults that are
      stuck for a long time.

Normally hypervisor will be able to receive these signals properly, but not
if we're stuck in a GUP for a long time for whatever reason.  It happens
easily with a stucked postcopy migration when e.g. a network temp failure
happens, then some vcpu threads can hang death waiting for the pages.  With
the new FOLL_INTERRUPTIBLE, we can allow GUP users like KVM to selectively
enable the ability to trap these signals.

Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20221011195809.557016-2-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09 12:31:26 -05:00
Kairui Song
ea0ffd0c08 swap: add a limit for readahead page-cluster value
Currenty there is no upper limit for /proc/sys/vm/page-cluster, and it's a
bit shift value, so it could result in overflow of the 32-bit integer. 
Add a reasonable upper limit for it, read-in at most 2**31 pages, which is
a large enough value for readahead.

Link: https://lkml.kernel.org/r/20221023162533.81561-1-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 17:37:22 -08:00
Naoya Horiguchi
5033091de8 mm/hwpoison: introduce per-memory_block hwpoison counter
Currently PageHWPoison flag does not behave well when experiencing memory
hotremove/hotplug.  Any data field in struct page is unreliable when the
associated memory is offlined, and the current mechanism can't tell
whether a memory block is onlined because a new memory devices is
installed or because previous failed offline operations are undone. 
Especially if there's a hwpoisoned memory, it's unclear what the best
option is.

So introduce a new mechanism to make struct memory_block remember that a
memory block has hwpoisoned memory inside it.  And make any online event
fail if the onlining memory block contains hwpoison.  struct memory_block
is freed and reallocated over ACPI-based hotremove/hotplug, but not over
sysfs-based hotremove/hotplug.  So the new counter can distinguish these
cases.

Link: https://lkml.kernel.org/r/20221024062012.1520887-5-naoya.horiguchi@linux.dev
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 17:37:22 -08:00
Naoya Horiguchi
a46c9304b4 mm/hwpoison: pass pfn to num_poisoned_pages_*()
No functional change.

Link: https://lkml.kernel.org/r/20221024062012.1520887-4-naoya.horiguchi@linux.dev
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 17:37:22 -08:00
Naoya Horiguchi
d027122d83 mm/hwpoison: move definitions of num_poisoned_pages_* to memory-failure.c
These interfaces will be used by drivers/base/memory.c by later patch, so
as a preparatory work move them to more common header file visible to the
file.

Link: https://lkml.kernel.org/r/20221024062012.1520887-3-naoya.horiguchi@linux.dev
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 17:37:22 -08:00
Naoya Horiguchi
e591ef7d96 mm,hwpoison,hugetlb,memory_hotplug: hotremove memory section with hwpoisoned hugepage
Patch series "mm, hwpoison: improve handling workload related to hugetlb
and memory_hotplug", v7.

This patchset tries to solve the issue among memory_hotplug, hugetlb and hwpoison.
In this patchset, memory hotplug handles hwpoison pages like below:

  - hwpoison pages should not prevent memory hotremove,
  - memory block with hwpoison pages should not be onlined.


This patch (of 4):

HWPoisoned page is not supposed to be accessed once marked, but currently
such accesses can happen during memory hotremove because
do_migrate_range() can be called before dissolve_free_huge_pages() is
called.

Clear HPageMigratable for hwpoisoned hugepages to prevent them from being
migrated.  This should be done in hugetlb_lock to avoid race against
isolate_hugetlb().

get_hwpoison_huge_page() needs to have a flag to show it's called from
unpoison to take refcount of hwpoisoned hugepages, so add it.

[naoya.horiguchi@linux.dev: remove TestClearHPageMigratable and reduce to test and clear separately]
  Link: https://lkml.kernel.org/r/20221025053559.GA2104800@ik1-406-35019.vs.sakura.ne.jp
Link: https://lkml.kernel.org/r/20221024062012.1520887-1-naoya.horiguchi@linux.dev
Link: https://lkml.kernel.org/r/20221024062012.1520887-2-naoya.horiguchi@linux.dev
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reported-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 17:37:21 -08:00
Rolf Eike Beer
3e0ee84342 mm: fix typo in struct vm_operations_struct comments
There is no eprotect(), so I assume this is about mprotect().

Link: https://lkml.kernel.org/r/2385684.8vm7BOzihM@mobilepool36.emlix.com
Signed-off-by: Rolf Eike Beer <eb@emlix.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 17:37:13 -08:00
Miaohe Lin
5749fcc5f0 mm/page_alloc: add __init annotations to init_mem_debugging_and_hardening()
It's only called by mm_init(). Add __init annotations to it.

Link: https://lkml.kernel.org/r/20220916072257.9639-6-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:28 -07:00
Matthew Wilcox (Oracle)
c3a15bff46 mm: reimplement folio_order() and folio_nr_pages()
Instead of calling compound_order() and compound_nr_pages(), use the folio
directly.  Saves 1905 bytes from mm/filemap.o due to folio_test_large()
now being a cheaper check than PageHead().

Link: https://lkml.kernel.org/r/20220902194653.1739778-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:44 -07:00
Michal Hocko
974f4367dd mm: reduce noise in show_mem for lowmem allocations
While discussing early DMA pool pre-allocation failure with Christoph [1]
I have realized that the allocation failure warning is rather noisy for
constrained allocations like GFP_DMA{32}.  Those zones are usually not
populated on all nodes very often as their memory ranges are constrained.

This is an attempt to reduce the ballast that doesn't provide any relevant
information for those allocation failures investigation.  Please note that
I have only compile tested it (in my default config setup) and I am
throwing it mostly to see what people think about it.

[1] http://lkml.kernel.org/r/20220817060647.1032426-1-hch@lst.de

[mhocko@suse.com: update]
  Link: https://lkml.kernel.org/r/Yw29bmJTIkKogTiW@dhcp22.suse.cz
[mhocko@suse.com: fix build]
[akpm@linux-foundation.org: fix it for mapletree]
[akpm@linux-foundation.org: update it for Michal's update]
[mhocko@suse.com: fix arch/powerpc/xmon/xmon.c]
  Link: https://lkml.kernel.org/r/Ywh3C4dKB9B93jIy@dhcp22.suse.cz
[akpm@linux-foundation.org: fix arch/sparc/kernel/setup_32.c]
Link: https://lkml.kernel.org/r/YwScVmVofIZkopkF@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:29 -07:00
David Hildenbrand
474098edac mm/gup: replace FOLL_NUMA by gup_can_follow_protnone()
Patch series "mm: minor cleanups around NUMA hinting".

Working on some GUP cleanups (e.g., getting rid of some FOLL_ flags) and
preparing for other GUP changes (getting rid of FOLL_FORCE|FOLL_WRITE for
for taking a R/O longterm pin), this is something I can easily send out
independently.

Get rid of FOLL_NUMA, allow FOLL_FORCE access to PROT_NONE mapped pages in
GUP-fast, and fixup some documentation around NUMA hinting.


This patch (of 3):

No need for a special flag that is not even properly documented to be
internal-only.

Let's just factor this check out and get rid of this flag.  The separate
function has the nice benefit that we can centralize comments.

Link: https://lkml.kernel.org/r/20220825164659.89824-2-david@redhat.com
Link: https://lkml.kernel.org/r/20220825164659.89824-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:28 -07:00
Liam R. Howlett
763ecb0350 mm: remove the vma linked list
Replace any vm_next use with vma_find().

Update free_pgtables(), unmap_vmas(), and zap_page_range() to use the
maple tree.

Use the new free_pgtables() and unmap_vmas() in do_mas_align_munmap().  At
the same time, alter the loop to be more compact.

Now that free_pgtables() and unmap_vmas() take a maple tree as an
argument, rearrange do_mas_align_munmap() to use the new tree to hold the
vmas to remove.

Remove __vma_link_list() and __vma_unlink_list() as they are exclusively
used to update the linked list.

Drop linked list update from __insert_vm_struct().

Rework validation of tree as it was depending on the linked list.

[yang.lee@linux.alibaba.com: fix one kernel-doc comment]
  Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=1949
  Link: https://lkml.kernel.org/r/20220824021918.94116-1-yang.lee@linux.alibaba.comLink: https://lkml.kernel.org/r/20220906194824.2110408-69-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:26 -07:00
Liam R. Howlett
11f9a21ab6 mm/mmap: reorganize munmap to use maple states
Remove __do_munmap() in favour of do_munmap(), do_mas_munmap(), and
do_mas_align_munmap().

do_munmap() is a wrapper to create a maple state for any callers that have
not been converted to the maple tree.

do_mas_munmap() takes a maple state to mumap a range.  This is just a
small function which checks for error conditions and aligns the end of the
range.

do_mas_align_munmap() uses the aligned range to mumap a range.
do_mas_align_munmap() starts with the first VMA in the range, then finds
the last VMA in the range.  Both start and end are split if necessary.
Then the VMAs are removed from the linked list and the mm mlock count is
updated at the same time.  Followed by a single tree operation of
overwriting the area in with a NULL.  Finally, the detached list is
unmapped and freed.

By reorganizing the munmap calls as outlined, it is now possible to avoid
extra work of aligning pre-aligned callers which are known to be safe,
avoid extra VMA lookups or tree walks for modifications.

detach_vmas_to_be_unmapped() is no longer used, so drop this code.

vm_brk_flags() can just call the do_mas_munmap() as it checks for
intersecting VMAs directly.

Link: https://lkml.kernel.org/r/20220906194824.2110408-29-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:18 -07:00
Liam R. Howlett
d7c6229557 mm: convert vma_lookup() to use mtree_load()
Unlike the rbtree, the Maple Tree will return a NULL if there's nothing at
a particular address.

Since the previous commit dropped the vmacache, it is now possible to
consult the tree directly.

Link: https://lkml.kernel.org/r/20220906194824.2110408-27-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:18 -07:00
Liam R. Howlett
abdba2dda0 mm: use maple tree operations for find_vma_intersection()
Move find_vma_intersection() to mmap.c and change implementation to maple
tree.

When searching for a vma within a range, it is easier to use the maple
tree interface.

Exported find_vma_intersection() for kvm module.

Link: https://lkml.kernel.org/r/20220906194824.2110408-24-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:17 -07:00
Liam R. Howlett
dc8635b25e mm: optimize find_exact_vma() to use vma_lookup()
Use vma_lookup() to walk the tree to the start value requested.  If the
vma at the start does not match, then the answer is NULL and there is no
need to look at the next vma the way that find_vma() would.

Link: https://lkml.kernel.org/r/20220906194824.2110408-21-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:17 -07:00
Liam R. Howlett
524e00b36e mm: remove rb tree.
Remove the RB tree and start using the maple tree for vm_area_struct
tracking.

Drop validate_mm() calls in expand_upwards() and expand_downwards() as the
lock is not held.

Link: https://lkml.kernel.org/r/20220906194824.2110408-18-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:16 -07:00
Liam R. Howlett
c9dbe82cb9 kernel/fork: use maple tree for dup_mmap() during forking
The maple tree was already tracking VMAs in this function by an earlier
commit, but the rbtree iterator was being used to iterate the list.
Change the iterator to use a maple tree native iterator and switch to the
maple tree advanced API to avoid multiple walks of the tree during insert
operations.  Unexport the now-unused vma_store() function.

For performance reasons we bulk allocate the maple tree nodes.  The node
calculations are done internally to the tree and use the VMA count and
assume the worst-case node requirements.  The VM_DONT_COPY flag does not
allow for the most efficient copy method of the tree and so a bulk loading
algorithm is used.

Link: https://lkml.kernel.org/r/20220906194824.2110408-15-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:16 -07:00
Matthew Wilcox (Oracle)
f39af05949 mm: add VMA iterator
This thin layer of abstraction over the maple tree state is for iterating
over VMAs.  You can go forwards, go backwards or ask where the iterator
is.  Rename the existing vma_next() to __vma_next() -- it will be removed
by the end of this series.

Link: https://lkml.kernel.org/r/20220906194824.2110408-10-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:15 -07:00
Liam R. Howlett
d4af56c5c7 mm: start tracking VMAs with maple tree
Start tracking the VMAs with the new maple tree structure in parallel with
the rb_tree.  Add debug and trace events for maple tree operations and
duplicate the rb_tree that is created on forks into the maple tree.

The maple tree is added to the mm_struct including the mm_init struct,
added support in required mm/mmap functions, added tracking in kernel/fork
for process forking, and used to find the unmapped_area and checked
against what the rbtree finds.

This also moves the mmap_lock() in exit_mmap() since the oom reaper call
does walk the VMAs.  Otherwise lockdep will be unhappy if oom happens.

When splitting a vma fails due to allocations of the maple tree nodes,
the error path in __split_vma() calls new->vm_ops->close(new).  The page
accounting for hugetlb is actually in the close() operation,  so it
accounts for the removal of 1/2 of the VMA which was not adjusted.  This
results in a negative exit value.  To avoid the negative charge, set
vm_start = vm_end and vm_pgoff = 0.

There is also a potential accounting issue in special mappings from
insert_vm_struct() failing to allocate, so reverse the charge there in
the failure scenario.

Link: https://lkml.kernel.org/r/20220906194824.2110408-9-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:14 -07:00
Yu Zhao
018ee47f14 mm: multi-gen LRU: exploit locality in rmap
Searching the rmap for PTEs mapping each page on an LRU list (to test and
clear the accessed bit) can be expensive because pages from different VMAs
(PA space) are not cache friendly to the rmap (VA space).  For workloads
mostly using mapped pages, searching the rmap can incur the highest CPU
cost in the reclaim path.

This patch exploits spatial locality to reduce the trips into the rmap. 
When shrink_page_list() walks the rmap and finds a young PTE, a new
function lru_gen_look_around() scans at most BITS_PER_LONG-1 adjacent
PTEs.  On finding another young PTE, it clears the accessed bit and
updates the gen counter of the page mapped by this PTE to
(max_seq%MAX_NR_GENS)+1.

Server benchmark results:
  Single workload:
    fio (buffered I/O): no change

  Single workload:
    memcached (anon): +[3, 5]%
                Ops/sec      KB/sec
      patch1-6: 1106168.46   43025.04
      patch1-7: 1147696.57   44640.29

  Configurations:
    no change

Client benchmark results:
  kswapd profiles:
    patch1-6
      39.03%  lzo1x_1_do_compress (real work)
      18.47%  page_vma_mapped_walk (overhead)
       6.74%  _raw_spin_unlock_irq
       3.97%  do_raw_spin_lock
       2.49%  ptep_clear_flush
       2.48%  anon_vma_interval_tree_iter_first
       1.92%  folio_referenced_one
       1.88%  __zram_bvec_write
       1.48%  memmove
       1.31%  vma_interval_tree_iter_next

    patch1-7
      48.16%  lzo1x_1_do_compress (real work)
       8.20%  page_vma_mapped_walk (overhead)
       7.06%  _raw_spin_unlock_irq
       2.92%  ptep_clear_flush
       2.53%  __zram_bvec_write
       2.11%  do_raw_spin_lock
       2.02%  memmove
       1.93%  lru_gen_look_around
       1.56%  free_unref_page_list
       1.40%  memset

  Configurations:
    no change

Link: https://lkml.kernel.org/r/20220918080010.2920238-8-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Acked-by: Barry Song <baohua@kernel.org>
Acked-by: Brian Geffon <bgeffon@google.com>
Acked-by: Jan Alexander Steffens (heftig) <heftig@archlinux.org>
Acked-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Acked-by: Steven Barrett <steven@liquorix.net>
Acked-by: Suleiman Souhlal <suleiman@google.com>
Tested-by: Daniel Byrne <djbyrne@mtu.edu>
Tested-by: Donald Carr <d@chaos-reins.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Konstantin Kharlamov <Hi-Angel@yandex.ru>
Tested-by: Shuang Zhai <szhai2@cs.rochester.edu>
Tested-by: Sofia Trinh <sofia.trinh@edi.works>
Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Larabel <Michael@MichaelLarabel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:09 -07:00
David Hildenbrand
088b8aa537 mm: fix PageAnonExclusive clearing racing with concurrent RCU GUP-fast
commit 6c287605fd ("mm: remember exclusively mapped anonymous pages with
PG_anon_exclusive") made sure that when PageAnonExclusive() has to be
cleared during temporary unmapping of a page, that the PTE is
cleared/invalidated and that the TLB is flushed.

What we want to achieve in all cases is that we cannot end up with a pin on
an anonymous page that may be shared, because such pins would be
unreliable and could result in memory corruptions when the mapped page
and the pin go out of sync due to a write fault.

That TLB flush handling was inspired by an outdated comment in
mm/ksm.c:write_protect_page(), which similarly required the TLB flush in
the past to synchronize with GUP-fast. However, ever since general RCU GUP
fast was introduced in commit 2667f50e8b ("mm: introduce a general RCU
get_user_pages_fast()"), a TLB flush is no longer sufficient to handle
concurrent GUP-fast in all cases -- it only handles traditional IPI-based
GUP-fast correctly.

Peter Xu (thankfully) questioned whether that TLB flush is really
required. On architectures that send an IPI broadcast on TLB flush,
it works as expected. To synchronize with RCU GUP-fast properly, we're
conceptually fine, however, we have to enforce a certain memory order and
are missing memory barriers.

Let's document that, avoid the TLB flush where possible and use proper
explicit memory barriers where required. We shouldn't really care about the
additional memory barriers here, as we're not on extremely hot paths --
and we're getting rid of some TLB flushes.

We use a smp_mb() pair for handling concurrent pinning and a
smp_rmb()/smp_wmb() pair for handling the corner case of only temporary
PTE changes but permanent PageAnonExclusive changes.

One extreme example, whereby GUP-fast takes a R/O pin and KSM wants to
convert an exclusive anonymous page to a KSM page, and that page is already
mapped write-protected (-> no PTE change) would be:

	Thread 0 (KSM)			Thread 1 (GUP-fast)

					(B1) Read the PTE
					# (B2) skipped without FOLL_WRITE
	(A1) Clear PTE
	smp_mb()
	(A2) Check pinned
					(B3) Pin the mapped page
					smp_mb()
	(A3) Clear PageAnonExclusive
	smp_wmb()
	(A4) Restore PTE
					(B4) Check if the PTE changed
					smp_rmb()
					(B5) Check PageAnonExclusive

Thread 1 will properly detect that PageAnonExclusive was cleared and
back off.

Note that we don't need a memory barrier between checking if the page is
pinned and clearing PageAnonExclusive, because stores are not
speculated.

The possible issues due to reordering are of theoretical nature so far
and attempts to reproduce the race failed.

Especially the "no PTE change" case isn't the common case, because we'd
need an exclusive anonymous page that's mapped R/O and the PTE is clean
in KSM code -- and using KSM with page pinning isn't extremely common.
Further, the clear+TLB flush we used for now implies a memory barrier.
So the problematic missing part should be the missing memory barrier
after pinning but before checking if the PTE changed.

Link: https://lkml.kernel.org/r/20220901083559.67446-1-david@redhat.com
Fixes: 6c287605fd ("mm: remember exclusively mapped anonymous pages with PG_anon_exclusive")
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Christoph von Recklinghausen <crecklin@redhat.com>
Cc: Don Dutile <ddutile@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:11 -07:00
Kefeng Wang
fb70c4878d mm: kill find_min_pfn_with_active_regions()
find_min_pfn_with_active_regions() is only called from free_area_init(). 
Open-code the PHYS_PFN(memblock_start_of_DRAM()) into free_area_init(),
and kill find_min_pfn_with_active_regions().

Link: https://lkml.kernel.org/r/20220815111017.39341-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:25:56 -07:00
Huang Ying
33024536ba memory tiering: hot page selection with hint page fault latency
Patch series "memory tiering: hot page selection", v4.

To optimize page placement in a memory tiering system with NUMA balancing,
the hot pages in the slow memory nodes need to be identified. 
Essentially, the original NUMA balancing implementation selects the mostly
recently accessed (MRU) pages to promote.  But this isn't a perfect
algorithm to identify the hot pages.  Because the pages with quite low
access frequency may be accessed eventually given the NUMA balancing page
table scanning period could be quite long (e.g.  60 seconds).  So in this
patchset, we implement a new hot page identification algorithm based on
the latency between NUMA balancing page table scanning and hint page
fault.  Which is a kind of mostly frequently accessed (MFU) algorithm.

In NUMA balancing memory tiering mode, if there are hot pages in slow
memory node and cold pages in fast memory node, we need to promote/demote
hot/cold pages between the fast and cold memory nodes.

A choice is to promote/demote as fast as possible.  But the CPU cycles and
memory bandwidth consumed by the high promoting/demoting throughput will
hurt the latency of some workload because of accessing inflating and slow
memory bandwidth contention.

A way to resolve this issue is to restrict the max promoting/demoting
throughput.  It will take longer to finish the promoting/demoting.  But
the workload latency will be better.  This is implemented in this patchset
as the page promotion rate limit mechanism.

The promotion hot threshold is workload and system configuration
dependent.  So in this patchset, a method to adjust the hot threshold
automatically is implemented.  The basic idea is to control the number of
the candidate promotion pages to match the promotion rate limit.

We used the pmbench memory accessing benchmark tested the patchset on a
2-socket server system with DRAM and PMEM installed.  The test results are
as follows,

		pmbench score		promote rate
		 (accesses/s)			MB/s
		-------------		------------
base		  146887704.1		       725.6
hot selection     165695601.2		       544.0
rate limit	  162814569.8		       165.2
auto adjustment	  170495294.0                  136.9

From the results above,

With hot page selection patch [1/3], the pmbench score increases about
12.8%, and promote rate (overhead) decreases about 25.0%, compared with
base kernel.

With rate limit patch [2/3], pmbench score decreases about 1.7%, and
promote rate decreases about 69.6%, compared with hot page selection
patch.

With threshold auto adjustment patch [3/3], pmbench score increases about
4.7%, and promote rate decrease about 17.1%, compared with rate limit
patch.

Baolin helped to test the patchset with MySQL on a machine which contains
1 DRAM node (30G) and 1 PMEM node (126G).

sysbench /usr/share/sysbench/oltp_read_write.lua \
......
--tables=200 \
--table-size=1000000 \
--report-interval=10 \
--threads=16 \
--time=120

The tps can be improved about 5%.


This patch (of 3):

To optimize page placement in a memory tiering system with NUMA balancing,
the hot pages in the slow memory node need to be identified.  Essentially,
the original NUMA balancing implementation selects the mostly recently
accessed (MRU) pages to promote.  But this isn't a perfect algorithm to
identify the hot pages.  Because the pages with quite low access frequency
may be accessed eventually given the NUMA balancing page table scanning
period could be quite long (e.g.  60 seconds).  The most frequently
accessed (MFU) algorithm is better.

So, in this patch we implemented a better hot page selection algorithm. 
Which is based on NUMA balancing page table scanning and hint page fault
as follows,

- When the page tables of the processes are scanned to change PTE/PMD
  to be PROT_NONE, the current time is recorded in struct page as scan
  time.

- When the page is accessed, hint page fault will occur.  The scan
  time is gotten from the struct page.  And The hint page fault
  latency is defined as

    hint page fault time - scan time

The shorter the hint page fault latency of a page is, the higher the
probability of their access frequency to be higher.  So the hint page
fault latency is a better estimation of the page hot/cold.

It's hard to find some extra space in struct page to hold the scan time. 
Fortunately, we can reuse some bits used by the original NUMA balancing.

NUMA balancing uses some bits in struct page to store the page accessing
CPU and PID (referring to page_cpupid_xchg_last()).  Which is used by the
multi-stage node selection algorithm to avoid to migrate pages shared
accessed by the NUMA nodes back and forth.  But for pages in the slow
memory node, even if they are shared accessed by multiple NUMA nodes, as
long as the pages are hot, they need to be promoted to the fast memory
node.  So the accessing CPU and PID information are unnecessary for the
slow memory pages.  We can reuse these bits in struct page to record the
scan time.  For the fast memory pages, these bits are used as before.

For the hot threshold, the default value is 1 second, which works well in
our performance test.  All pages with hint page fault latency < hot
threshold will be considered hot.

It's hard for users to determine the hot threshold.  So we don't provide a
kernel ABI to set it, just provide a debugfs interface for advanced users
to experiment.  We will continue to work on a hot threshold automatic
adjustment mechanism.

The downside of the above method is that the response time to the workload
hot spot changing may be much longer.  For example,

- A previous cold memory area becomes hot

- The hint page fault will be triggered.  But the hint page fault
  latency isn't shorter than the hot threshold.  So the pages will
  not be promoted.

- When the memory area is scanned again, maybe after a scan period,
  the hint page fault latency measured will be shorter than the hot
  threshold and the pages will be promoted.

To mitigate this, if there are enough free space in the fast memory node,
the hot threshold will not be used, all pages will be promoted upon the
hint page fault for fast response.

Thanks Zhong Jiang reported and tested the fix for a bug when disabling
memory tiering mode dynamically.

Link: https://lkml.kernel.org/r/20220713083954.34196-1-ying.huang@intel.com
Link: https://lkml.kernel.org/r/20220713083954.34196-2-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Wei Xu <weixugc@google.com>
Cc: osalvador <osalvador@suse.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Zhong Jiang <zhongjiang-ali@linux.alibaba.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:25:54 -07:00
Alex Williamson
fcab34b433 mm: re-allow pinning of zero pfns (again)
The below referenced commit makes the same error as 1c56343258 ("mm: fix
is_pinnable_page against a cma page"), re-interpreting the logic to
exclude pinning of the zero page, which breaks device assignment with
vfio.

To avoid further subtle mistakes, split the logic into discrete tests.

[akpm@linux-foundation.org: simplify comment, per John]
Link: https://lkml.kernel.org/r/166015037385.760108.16881097713975517242.stgit@omen
Link: https://lore.kernel.org/all/165490039431.944052.12458624139225785964.stgit@omen
Fixes: f25cbb7a95 ("mm: add zone device coherent type memory support")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Suggested-by: Felix Kuehling <felix.kuehling@amd.com>
Tested-by: Slawomir Laba <slawomirx.laba@intel.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Alex Sierra <alex.sierra@amd.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-28 14:02:44 -07:00
David Hildenbrand
5535be3099 mm/gup: fix FOLL_FORCE COW security issue and remove FOLL_COW
Ever since the Dirty COW (CVE-2016-5195) security issue happened, we know
that FOLL_FORCE can be possibly dangerous, especially if there are races
that can be exploited by user space.

Right now, it would be sufficient to have some code that sets a PTE of a
R/O-mapped shared page dirty, in order for it to erroneously become
writable by FOLL_FORCE.  The implications of setting a write-protected PTE
dirty might not be immediately obvious to everyone.

And in fact ever since commit 9ae0f87d00 ("mm/shmem: unconditionally set
pte dirty in mfill_atomic_install_pte"), we can use UFFDIO_CONTINUE to map
a shmem page R/O while marking the pte dirty.  This can be used by
unprivileged user space to modify tmpfs/shmem file content even if the
user does not have write permissions to the file, and to bypass memfd
write sealing -- Dirty COW restricted to tmpfs/shmem (CVE-2022-2590).

To fix such security issues for good, the insight is that we really only
need that fancy retry logic (FOLL_COW) for COW mappings that are not
writable (!VM_WRITE).  And in a COW mapping, we really only broke COW if
we have an exclusive anonymous page mapped.  If we have something else
mapped, or the mapped anonymous page might be shared (!PageAnonExclusive),
we have to trigger a write fault to break COW.  If we don't find an
exclusive anonymous page when we retry, we have to trigger COW breaking
once again because something intervened.

Let's move away from this mandatory-retry + dirty handling and rely on our
PageAnonExclusive() flag for making a similar decision, to use the same
COW logic as in other kernel parts here as well.  In case we stumble over
a PTE in a COW mapping that does not map an exclusive anonymous page, COW
was not properly broken and we have to trigger a fake write-fault to break
COW.

Just like we do in can_change_pte_writable() added via commit 64fe24a3e0
("mm/mprotect: try avoiding write faults for exclusive anonymous pages
when changing protection") and commit 76aefad628 ("mm/mprotect: fix
soft-dirty check in can_change_pte_writable()"), take care of softdirty
and uffd-wp manually.

For example, a write() via /proc/self/mem to a uffd-wp-protected range has
to fail instead of silently granting write access and bypassing the
userspace fault handler.  Note that FOLL_FORCE is not only used for debug
access, but also triggered by applications without debug intentions, for
example, when pinning pages via RDMA.

This fixes CVE-2022-2590. Note that only x86_64 and aarch64 are
affected, because only those support CONFIG_HAVE_ARCH_USERFAULTFD_MINOR.

Fortunately, FOLL_COW is no longer required to handle FOLL_FORCE. So
let's just get rid of it.

Thanks to Nadav Amit for pointing out that the pte_dirty() check in
FOLL_FORCE code is problematic and might be exploitable.

Note 1: We don't check for the PTE being dirty because it doesn't matter
	for making a "was COWed" decision anymore, and whoever modifies the
	page has to set the page dirty either way.

Note 2: Kernels before extended uffd-wp support and before
	PageAnonExclusive (< 5.19) can simply revert the problematic
	commit instead and be safe regarding UFFDIO_CONTINUE. A backport to
	v5.19 requires minor adjustments due to lack of
	vma_soft_dirty_enabled().

Link: https://lkml.kernel.org/r/20220809205640.70916-1-david@redhat.com
Fixes: 9ae0f87d00 ("mm/shmem: unconditionally set pte dirty in mfill_atomic_install_pte")
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: <stable@vger.kernel.org>	[5.16]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-20 15:17:44 -07:00
Naoya Horiguchi
6f4614886b mm, hwpoison: enable memory error handling on 1GB hugepage
Now error handling code is prepared, so remove the blocking code and
enable memory error handling on 1GB hugepage.

Link: https://lkml.kernel.org/r/20220714042420.1847125-9-naoya.horiguchi@linux.dev
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08 18:06:44 -07:00
Naoya Horiguchi
38f6d29397 mm, hwpoison: set PG_hwpoison for busy hugetlb pages
If memory_failure() fails to grab page refcount on a hugetlb page because
it's busy, it returns without setting PG_hwpoison on it.  This not only
loses a chance of error containment, but breaks the rule that
action_result() should be called only when memory_failure() do any of
handling work (even if that's just setting PG_hwpoison).  This
inconsistency could harm code maintainability.

So set PG_hwpoison and call hugetlb_set_page_hwpoison() for such a case.

Link: https://lkml.kernel.org/r/20220714042420.1847125-6-naoya.horiguchi@linux.dev
Fixes: 405ce05123 ("mm/hwpoison: fix race between hugetlb free/demotion and memory_failure_hugetlb()")
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08 18:06:44 -07:00
Muchun Song
998a299788 mm: hugetlb_vmemmap: move vmemmap code related to HugeTLB to hugetlb_vmemmap.c
When I first introduced vmemmap manipulation functions related to HugeTLB,
I thought those functions may be reused by other modules (e.g.  using
similar approach to optimize vmemmap pages, unfortunately, the DAX used
the same approach but does not use those functions).  After two years, we
didn't see any other users.  So move those functions to hugetlb_vmemmap.c.
Code movement without any functional change.

Link: https://lkml.kernel.org/r/20220628092235.91270-5-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Will Deacon <will@kernel.org>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08 18:06:42 -07:00
Linus Torvalds
6614a3c316 - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
Lin, Yang Shi, Anshuman Khandual and Mike Rapoport
 
 - Some kmemleak fixes from Patrick Wang and Waiman Long
 
 - DAMON updates from SeongJae Park
 
 - memcg debug/visibility work from Roman Gushchin
 
 - vmalloc speedup from Uladzislau Rezki
 
 - more folio conversion work from Matthew Wilcox
 
 - enhancements for coherent device memory mapping from Alex Sierra
 
 - addition of shared pages tracking and CoW support for fsdax, from
   Shiyang Ruan
 
 - hugetlb optimizations from Mike Kravetz
 
 - Mel Gorman has contributed some pagealloc changes to improve latency
   and realtime behaviour.
 
 - mprotect soft-dirty checking has been improved by Peter Xu
 
 - Many other singleton patches all over the place
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Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Most of the MM queue. A few things are still pending.

  Liam's maple tree rework didn't make it. This has resulted in a few
  other minor patch series being held over for next time.

  Multi-gen LRU still isn't merged as we were waiting for mapletree to
  stabilize. The current plan is to merge MGLRU into -mm soon and to
  later reintroduce mapletree, with a view to hopefully getting both
  into 6.1-rc1.

  Summary:

   - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
     Lin, Yang Shi, Anshuman Khandual and Mike Rapoport

   - Some kmemleak fixes from Patrick Wang and Waiman Long

   - DAMON updates from SeongJae Park

   - memcg debug/visibility work from Roman Gushchin

   - vmalloc speedup from Uladzislau Rezki

   - more folio conversion work from Matthew Wilcox

   - enhancements for coherent device memory mapping from Alex Sierra

   - addition of shared pages tracking and CoW support for fsdax, from
     Shiyang Ruan

   - hugetlb optimizations from Mike Kravetz

   - Mel Gorman has contributed some pagealloc changes to improve
     latency and realtime behaviour.

   - mprotect soft-dirty checking has been improved by Peter Xu

   - Many other singleton patches all over the place"

 [ XFS merge from hell as per Darrick Wong in

   https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ]

* tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits)
  tools/testing/selftests/vm/hmm-tests.c: fix build
  mm: Kconfig: fix typo
  mm: memory-failure: convert to pr_fmt()
  mm: use is_zone_movable_page() helper
  hugetlbfs: fix inaccurate comment in hugetlbfs_statfs()
  hugetlbfs: cleanup some comments in inode.c
  hugetlbfs: remove unneeded header file
  hugetlbfs: remove unneeded hugetlbfs_ops forward declaration
  hugetlbfs: use helper macro SZ_1{K,M}
  mm: cleanup is_highmem()
  mm/hmm: add a test for cross device private faults
  selftests: add soft-dirty into run_vmtests.sh
  selftests: soft-dirty: add test for mprotect
  mm/mprotect: fix soft-dirty check in can_change_pte_writable()
  mm: memcontrol: fix potential oom_lock recursion deadlock
  mm/gup.c: fix formatting in check_and_migrate_movable_page()
  xfs: fail dax mount if reflink is enabled on a partition
  mm/memcontrol.c: remove the redundant updating of stats_flush_threshold
  userfaultfd: don't fail on unrecognized features
  hugetlb_cgroup: fix wrong hugetlb cgroup numa stat
  ...
2022-08-05 16:32:45 -07:00
Linus Torvalds
79b7e67bb9 This pull request contains the following changes for UML:
- KASAN support for x86_64
 - noreboot command line option, just like qemu's -no-reboot
 - Various fixes and cleanups
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Merge tag 'for-linus-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

Pull UML updates from Richard Weinberger:

 - KASAN support for x86_64

 - noreboot command line option, just like qemu's -no-reboot

 - Various fixes and cleanups

* tag 'for-linus-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: include sys/types.h for size_t
  um: Replace to_phys() and to_virt() with less generic function names
  um: Add missing apply_returns()
  um: add "noreboot" command line option for PANIC_TIMEOUT=-1 setups
  um: include linux/stddef.h for __always_inline
  UML: add support for KASAN under x86_64
  mm: Add PAGE_ALIGN_DOWN macro
  um: random: Don't initialise hwrng struct with zero
  um: remove unused mm_copy_segments
  um: remove unused variable
  um: Remove straying parenthesis
  um: x86: print RIP with symbol
  arch: um: Fix build for statically linked UML w/ constructors
  x86/um: Kconfig: Fix indentation
  um/drivers: Kconfig: Fix indentation
  um: Kconfig: Fix indentation
2022-08-05 14:03:11 -07:00
Muchun Song
f4f451a16d mm: fix missing wake-up event for FSDAX pages
FSDAX page refcounts are 1-based, rather than 0-based: if refcount is
1, then the page is freed.  The FSDAX pages can be pinned through GUP,
then they will be unpinned via unpin_user_page() using a folio variant
to put the page, however, folio variants did not consider this special
case, the result will be to miss a wakeup event (like the user of
__fuse_dax_break_layouts()).  This results in a task being permanently
stuck in TASK_INTERRUPTIBLE state.

Since FSDAX pages are only possibly obtained by GUP users, so fix GUP
instead of folio_put() to lower overhead.

Link: https://lkml.kernel.org/r/20220705123532.283-1-songmuchun@bytedance.com
Fixes: d8ddc099c6 ("mm/gup: Add gup_put_folio()")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-18 15:07:51 -07:00
Anshuman Khandual
3d923c5f1e mm/mmap: drop ARCH_HAS_VM_GET_PAGE_PROT
Now all the platforms enable ARCH_HAS_GET_PAGE_PROT.  They define and
export own vm_get_page_prot() whether custom or standard
DECLARE_VM_GET_PAGE_PROT.  Hence there is no need for default generic
fallback for vm_get_page_prot().  Just drop this fallback and also
ARCH_HAS_GET_PAGE_PROT mechanism.

Link: https://lkml.kernel.org/r/20220711070600.2378316-27-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:41 -07:00
Anshuman Khandual
09095f7413 mm/mmap: build protect protection_map[] with ARCH_HAS_VM_GET_PAGE_PROT
Now that protection_map[] has been moved inside those platforms that
enable ARCH_HAS_VM_GET_PAGE_PROT.  Hence generic protection_map[] array
now can be protected with CONFIG_ARCH_HAS_VM_GET_PAGE_PROT intead of
__P000.

Link: https://lkml.kernel.org/r/20220711070600.2378316-8-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:38 -07:00
Anshuman Khandual
840532711d mm/mmap: build protect protection_map[] with __P000
Patch series "mm/mmap: Drop __SXXX/__PXXX macros from across platforms",
v7.

__SXXX/__PXXX macros are unnecessary abstraction layer in creating the
generic protection_map[] array which is used for vm_get_page_prot().  This
abstraction layer can be avoided, if the platforms just define the array
protection_map[] for all possible vm_flags access permission combinations
and also export vm_get_page_prot() implementation.

This series drops __SXXX/__PXXX macros from across platforms in the tree. 
First it build protects generic protection_map[] array with '#ifdef
__P000' and moves it inside platforms which enable
ARCH_HAS_VM_GET_PAGE_PROT.  Later this build protects same array with
'#ifdef ARCH_HAS_VM_GET_PAGE_PROT' and moves inside remaining platforms
while enabling ARCH_HAS_VM_GET_PAGE_PROT.  This adds a new macro
DECLARE_VM_GET_PAGE_PROT defining the current generic vm_get_page_prot(),
in order for it to be reused on platforms that do not require custom
implementation.  Finally, ARCH_HAS_VM_GET_PAGE_PROT can just be dropped,
as all platforms now define and export vm_get_page_prot(), via looking up
a private and static protection_map[] array.  protection_map[] data type
has been changed as 'static const' on all platforms that do not change it
during boot.


This patch (of 26):

Build protect generic protection_map[] array with __P000, so that it can
be moved inside all the platforms one after the other.  Otherwise there
will be build failures during this process. 
CONFIG_ARCH_HAS_VM_GET_PAGE_PROT cannot be used for this purpose as only
certain platforms enable this config now.

Link: https://lkml.kernel.org/r/20220711070600.2378316-1-anshuman.khandual@arm.com
Link: https://lkml.kernel.org/r/20220711070600.2378316-2-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:37 -07:00
Shiyang Ruan
c36e202495 mm: introduce mf_dax_kill_procs() for fsdax case
This new function is a variant of mf_generic_kill_procs that accepts a
file, offset pair instead of a struct to support multiple files sharing a
DAX mapping.  It is intended to be called by the file systems as part of
the memory_failure handler after the file system performed a reverse
mapping from the storage address to the file and file offset.

Link: https://lkml.kernel.org/r/20220603053738.1218681-6-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.wiliams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:30 -07:00
Alex Sierra
f25cbb7a95 mm: add zone device coherent type memory support
Device memory that is cache coherent from device and CPU point of view. 
This is used on platforms that have an advanced system bus (like CAPI or
CXL).  Any page of a process can be migrated to such memory.  However, no
one should be allowed to pin such memory so that it can always be evicted.

[hch@lst.de: rebased ontop of the refcount changes, remove is_dev_private_or_coherent_page]
Link: https://lkml.kernel.org/r/20220715150521.18165-4-alex.sierra@amd.com
Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:27 -07:00
Alex Sierra
5bb88dc571 mm: move page zone helpers from mm.h to mmzone.h
It makes more sense to have these helpers in zone specific header
file, rather than the generic mm.h

Link: https://lkml.kernel.org/r/20220715150521.18165-3-alex.sierra@amd.com
Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:27 -07:00
Alex Sierra
6077c943be mm: rename is_pinnable_page() to is_longterm_pinnable_page()
Patch series "Add MEMORY_DEVICE_COHERENT for coherent device memory
mapping", v9.

This patch series introduces MEMORY_DEVICE_COHERENT, a type of memory
owned by a device that can be mapped into CPU page tables like
MEMORY_DEVICE_GENERIC and can also be migrated like MEMORY_DEVICE_PRIVATE.

This patch series is mostly self-contained except for a few places where
it needs to update other subsystems to handle the new memory type.

System stability and performance are not affected according to our ongoing
testing, including xfstests.

How it works: The system BIOS advertises the GPU device memory (aka VRAM)
as SPM (special purpose memory) in the UEFI system address map.

The amdgpu driver registers the memory with devmap as
MEMORY_DEVICE_COHERENT using devm_memremap_pages.  The initial user for
this hardware page migration capability is the Frontier supercomputer
project.  This functionality is not AMD-specific.  We expect other GPU
vendors to find this functionality useful, and possibly other hardware
types in the future.

Our test nodes in the lab are similar to the Frontier configuration, with
.5 TB of system memory plus 256 GB of device memory split across 4 GPUs,
all in a single coherent address space.  Page migration is expected to
improve application efficiency significantly.  We will report empirical
results as they become available.

Coherent device type pages at gup are now migrated back to system memory
if they are being pinned long-term (FOLL_LONGTERM).  The reason is, that
long-term pinning would interfere with the device memory manager owning
the device-coherent pages (e.g.  evictions in TTM).  These series
incorporate Alistair Popple patches to do this migration from
pin_user_pages() calls.  hmm_gup_test has been added to hmm-test to test
different get user pages calls.

This series includes handling of device-managed anonymous pages returned
by vm_normal_pages.  Although they behave like normal pages for purposes
of mapping in CPU page tables and for COW, they do not support LRU lists,
NUMA migration or THP.

We also introduced a FOLL_LRU flag that adds the same behaviour to
follow_page and related APIs, to allow callers to specify that they expect
to put pages on an LRU list.


This patch (of 14):

is_pinnable_page() and folio_is_pinnable() are renamed to
is_longterm_pinnable_page() and folio_is_longterm_pinnable() respectively.
These functions are used in the FOLL_LONGTERM flag context.

Link: https://lkml.kernel.org/r/20220715150521.18165-1-alex.sierra@amd.com
Link: https://lkml.kernel.org/r/20220715150521.18165-2-alex.sierra@amd.com
Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:27 -07:00
David Gow
335e52c28c mm: Add PAGE_ALIGN_DOWN macro
This is just the same as PAGE_ALIGN(), but rounds the address down, not
up.

Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David Gow <davidgow@google.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
2022-07-17 23:35:02 +02:00
Matthew Wilcox (Oracle)
5375336c8c mm: convert destroy_compound_page() to destroy_large_folio()
All callers now have a folio, so push the folio->page conversion
down to this function.

[akpm@linux-foundation.org: uninline destroy_large_folio() to fix build issue]
Link: https://lkml.kernel.org/r/20220617175020.717127-20-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03 18:08:48 -07:00
Matthew Wilcox (Oracle)
8d29c7036f mm/swap: convert __put_page() to __folio_put()
Saves 11 bytes of text by removing a check of PageTail.

Link: https://lkml.kernel.org/r/20220617175020.717127-16-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03 18:08:47 -07:00
Matthew Wilcox (Oracle)
e3c4cebf3f mm: add folios_put()
Patch series "Convert the swap code to be more folio-based".

There's still more to do with the swap code, but this reaps a lot of the
folio benefit.  More than 4kB of kernel text saved (with the UEK7 kernel
config).  I don't know how much that's going to translate into CPU
savings, but some of those compound_head() calls are on every page free,
so it should be noticable.  It might even be noticable just from an
I-cache consumption perspective.


This patch (of 22):

This is just a wrapper around release_pages() for now.  Place the
prototype in mm.h along with folio_put() and folio_put_refs().

Link: https://lkml.kernel.org/r/20220617175020.717127-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20220617175020.717127-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03 18:08:45 -07:00
David Hildenbrand
64fe24a3e0 mm/mprotect: try avoiding write faults for exclusive anonymous pages when changing protection
Similar to our MM_CP_DIRTY_ACCT handling for shared, writable mappings, we
can try mapping anonymous pages in a private writable mapping writable if
they are exclusive, the PTE is already dirty, and no special handling
applies.  Mapping the anonymous page writable is essentially the same
thing the write fault handler would do in this case.

Special handling is required for uffd-wp and softdirty tracking, so take
care of that properly.  Also, leave PROT_NONE handling alone for now; in
the future, we could similarly extend the logic in do_numa_page() or use
pte_mk_savedwrite() here.

While this improves mprotect(PROT_READ)+mprotect(PROT_READ|PROT_WRITE)
performance, it should also be a valuable optimization for uffd-wp, when
un-protecting.

This has been previously suggested by Peter Collingbourne in [1], relevant
in the context of the Scudo memory allocator, before we had
PageAnonExclusive.

This commit doesn't add the same handling for PMDs (i.e., anonymous THP,
anonymous hugetlb); benchmark results from Andrea indicate that there are
minor performance gains, so it's might still be valuable to streamline
that logic for all anonymous pages in the future.

As we now also set MM_CP_DIRTY_ACCT for private mappings, let's rename it
to MM_CP_TRY_CHANGE_WRITABLE, to make it clearer what's actually
happening.

Micro-benchmark courtesy of Andrea:

===
 #define _GNU_SOURCE
 #include <sys/mman.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 #include <unistd.h>

 #define SIZE (1024*1024*1024)

int main(int argc, char *argv[])
{
	char *p;
	if (posix_memalign((void **)&p, sysconf(_SC_PAGESIZE)*512, SIZE))
		perror("posix_memalign"), exit(1);
	if (madvise(p, SIZE, argc > 1 ? MADV_HUGEPAGE : MADV_NOHUGEPAGE))
		perror("madvise");
	explicit_bzero(p, SIZE);
	for (int loops = 0; loops < 40; loops++) {
		if (mprotect(p, SIZE, PROT_READ))
			perror("mprotect"), exit(1);
		if (mprotect(p, SIZE, PROT_READ|PROT_WRITE))
			perror("mprotect"), exit(1);
		explicit_bzero(p, SIZE);
	}
}
===

Results on my Ryzen 9 3900X:

Stock 10 runs (lower is better):   AVG 6.398s, STDEV 0.043
Patched 10 runs (lower is better): AVG 3.780s, STDEV 0.026

===

[1] https://lkml.kernel.org/r/20210429214801.2583336-1-pcc@google.com

Link: https://lkml.kernel.org/r/20220614093629.76309-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Suggested-by: Peter Collingbourne <pcc@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03 18:08:44 -07:00
zhenwei pi
67f22ba775 mm/memory-failure: disable unpoison once hw error happens
Currently unpoison_memory(unsigned long pfn) is designed for soft
poison(hwpoison-inject) only.  Since 17fae1294a, the KPTE gets cleared
on a x86 platform once hardware memory corrupts.

Unpoisoning a hardware corrupted page puts page back buddy only, the
kernel has a chance to access the page with *NOT PRESENT* KPTE.  This
leads BUG during accessing on the corrupted KPTE.

Suggested by David&Naoya, disable unpoison mechanism when a real HW error
happens to avoid BUG like this:

 Unpoison: Software-unpoisoned page 0x61234
 BUG: unable to handle page fault for address: ffff888061234000
 #PF: supervisor write access in kernel mode
 #PF: error_code(0x0002) - not-present page
 PGD 2c01067 P4D 2c01067 PUD 107267063 PMD 10382b063 PTE 800fffff9edcb062
 Oops: 0002 [#1] PREEMPT SMP NOPTI
 CPU: 4 PID: 26551 Comm: stress Kdump: loaded Tainted: G   M       OE     5.18.0.bm.1-amd64 #7
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...
 RIP: 0010:clear_page_erms+0x7/0x10
 Code: ...
 RSP: 0000:ffffc90001107bc8 EFLAGS: 00010246
 RAX: 0000000000000000 RBX: 0000000000000901 RCX: 0000000000001000
 RDX: ffffea0001848d00 RSI: ffffea0001848d40 RDI: ffff888061234000
 RBP: ffffea0001848d00 R08: 0000000000000901 R09: 0000000000001276
 R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000001
 R13: 0000000000000000 R14: 0000000000140dca R15: 0000000000000001
 FS:  00007fd8b2333740(0000) GS:ffff88813fd00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: ffff888061234000 CR3: 00000001023d2005 CR4: 0000000000770ee0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 PKRU: 55555554
 Call Trace:
  <TASK>
  prep_new_page+0x151/0x170
  get_page_from_freelist+0xca0/0xe20
  ? sysvec_apic_timer_interrupt+0xab/0xc0
  ? asm_sysvec_apic_timer_interrupt+0x1b/0x20
  __alloc_pages+0x17e/0x340
  __folio_alloc+0x17/0x40
  vma_alloc_folio+0x84/0x280
  __handle_mm_fault+0x8d4/0xeb0
  handle_mm_fault+0xd5/0x2a0
  do_user_addr_fault+0x1d0/0x680
  ? kvm_read_and_reset_apf_flags+0x3b/0x50
  exc_page_fault+0x78/0x170
  asm_exc_page_fault+0x27/0x30

Link: https://lkml.kernel.org/r/20220615093209.259374-2-pizhenwei@bytedance.com
Fixes: 847ce401df ("HWPOISON: Add unpoisoning support")
Fixes: 17fae1294a ("x86/{mce,mm}: Unmap the entire page if the whole page is affected and poisoned")
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>	[5.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-06-16 19:11:32 -07:00
Alex Williamson
034e5afad9 mm: re-allow pinning of zero pfns
The commit referenced below subtly and inadvertently changed the logic to
disallow pinning of zero pfns.  This breaks device assignment with vfio
and potentially various other users of gup.  Exclude the zero page test
from the negation.

Link: https://lkml.kernel.org/r/165490039431.944052.12458624139225785964.stgit@omen
Fixes: 1c56343258 ("mm: fix is_pinnable_page against a cma page")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Reported-by: Yishai Hadas <yishaih@nvidia.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: John Dias <joaodias@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Zhangfei Gao <zhangfei.gao@linaro.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-06-16 19:11:32 -07:00
Linus Torvalds
8291eaafed Two followon fixes for the post-5.19 series "Use pageblock_order for cma
and alloc_contig_range alignment", from Zi Yan.
 
 A series of z3fold cleanups and fixes from Miaohe Lin.
 
 Some memcg selftests work from Michal Koutný <mkoutny@suse.com>
 
 Some swap fixes and cleanups from Miaohe Lin.
 
 Several individual minor fixups.
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Merge tag 'mm-stable-2022-05-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull more MM updates from Andrew Morton:

 - Two follow-on fixes for the post-5.19 series "Use pageblock_order for
   cma and alloc_contig_range alignment", from Zi Yan.

 - A series of z3fold cleanups and fixes from Miaohe Lin.

 - Some memcg selftests work from Michal Koutný <mkoutny@suse.com>

 - Some swap fixes and cleanups from Miaohe Lin

 - Several individual minor fixups

* tag 'mm-stable-2022-05-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (25 commits)
  mm/shmem.c: suppress shift warning
  mm: Kconfig: reorganize misplaced mm options
  mm: kasan: fix input of vmalloc_to_page()
  mm: fix is_pinnable_page against a cma page
  mm: filter out swapin error entry in shmem mapping
  mm/shmem: fix infinite loop when swap in shmem error at swapoff time
  mm/madvise: free hwpoison and swapin error entry in madvise_free_pte_range
  mm/swapfile: fix lost swap bits in unuse_pte()
  mm/swapfile: unuse_pte can map random data if swap read fails
  selftests: memcg: factor out common parts of memory.{low,min} tests
  selftests: memcg: remove protection from top level memcg
  selftests: memcg: adjust expected reclaim values of protected cgroups
  selftests: memcg: expect no low events in unprotected sibling
  selftests: memcg: fix compilation
  mm/z3fold: fix z3fold_page_migrate races with z3fold_map
  mm/z3fold: fix z3fold_reclaim_page races with z3fold_free
  mm/z3fold: always clear PAGE_CLAIMED under z3fold page lock
  mm/z3fold: put z3fold page back into unbuddied list when reclaim or migration fails
  revert "mm/z3fold.c: allow __GFP_HIGHMEM in z3fold_alloc"
  mm/z3fold: throw warning on failure of trylock_page in z3fold_alloc
  ...
2022-05-27 11:40:49 -07:00
Minchan Kim
1c56343258 mm: fix is_pinnable_page against a cma page
Pages in the CMA area could have MIGRATE_ISOLATE as well as MIGRATE_CMA so
the current is_pinnable_page() could miss CMA pages which have
MIGRATE_ISOLATE.  It ends up pinning CMA pages as longterm for the
pin_user_pages() API so CMA allocations keep failing until the pin is
released.

     CPU 0                                   CPU 1 - Task B

cma_alloc
alloc_contig_range
                                        pin_user_pages_fast(FOLL_LONGTERM)
change pageblock as MIGRATE_ISOLATE
                                        internal_get_user_pages_fast
                                        lockless_pages_from_mm
                                        gup_pte_range
                                        try_grab_folio
                                        is_pinnable_page
                                          return true;
                                        So, pinned the page successfully.
page migration failure with pinned page
                                        ..
                                        .. After 30 sec
                                        unpin_user_page(page)

CMA allocation succeeded after 30 sec.

The CMA allocation path protects the migration type change race using
zone->lock but what GUP path need to know is just whether the page is on
CMA area or not rather than exact migration type.  Thus, we don't need
zone->lock but just checks migration type in either of (MIGRATE_ISOLATE
and MIGRATE_CMA).

Adding the MIGRATE_ISOLATE check in is_pinnable_page could cause rejecting
of pinning pages on MIGRATE_ISOLATE pageblocks even though it's neither
CMA nor movable zone if the page is temporarily unmovable.  However, such
a migration failure by unexpected temporal refcount holding is general
issue, not only come from MIGRATE_ISOLATE and the MIGRATE_ISOLATE is also
transient state like other temporal elevated refcount problem.

Link: https://lkml.kernel.org/r/20220524171525.976723-1-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-27 09:33:46 -07:00
Linus Torvalds
98931dd95f Yang Shi has improved the behaviour of khugepaged collapsing of readonly
file-backed transparent hugepages.
 
 Johannes Weiner has arranged for zswap memory use to be tracked and
 managed on a per-cgroup basis.
 
 Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for runtime
 enablement of the recent huge page vmemmap optimization feature.
 
 Baolin Wang contributes a series to fix some issues around hugetlb
 pagetable invalidation.
 
 Zhenwei Pi has fixed some interactions between hwpoisoned pages and
 virtualization.
 
 Tong Tiangen has enabled the use of the presently x86-only
 page_table_check debugging feature on arm64 and riscv.
 
 David Vernet has done some fixup work on the memcg selftests.
 
 Peter Xu has taught userfaultfd to handle write protection faults against
 shmem- and hugetlbfs-backed files.
 
 More DAMON development from SeongJae Park - adding online tuning of the
 feature and support for monitoring of fixed virtual address ranges.  Also
 easier discovery of which monitoring operations are available.
 
 Nadav Amit has done some optimization of TLB flushing during mprotect().
 
 Neil Brown continues to labor away at improving our swap-over-NFS support.
 
 David Hildenbrand has some fixes to anon page COWing versus
 get_user_pages().
 
 Peng Liu fixed some errors in the core hugetlb code.
 
 Joao Martins has reduced the amount of memory consumed by device-dax's
 compound devmaps.
 
 Some cleanups of the arch-specific pagemap code from Anshuman Khandual.
 
 Muchun Song has found and fixed some errors in the TLB flushing of
 transparent hugepages.
 
 Roman Gushchin has done more work on the memcg selftests.
 
 And, of course, many smaller fixes and cleanups.  Notably, the customary
 million cleanup serieses from Miaohe Lin.
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Merge tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Almost all of MM here. A few things are still getting finished off,
  reviewed, etc.

   - Yang Shi has improved the behaviour of khugepaged collapsing of
     readonly file-backed transparent hugepages.

   - Johannes Weiner has arranged for zswap memory use to be tracked and
     managed on a per-cgroup basis.

   - Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for
     runtime enablement of the recent huge page vmemmap optimization
     feature.

   - Baolin Wang contributes a series to fix some issues around hugetlb
     pagetable invalidation.

   - Zhenwei Pi has fixed some interactions between hwpoisoned pages and
     virtualization.

   - Tong Tiangen has enabled the use of the presently x86-only
     page_table_check debugging feature on arm64 and riscv.

   - David Vernet has done some fixup work on the memcg selftests.

   - Peter Xu has taught userfaultfd to handle write protection faults
     against shmem- and hugetlbfs-backed files.

   - More DAMON development from SeongJae Park - adding online tuning of
     the feature and support for monitoring of fixed virtual address
     ranges. Also easier discovery of which monitoring operations are
     available.

   - Nadav Amit has done some optimization of TLB flushing during
     mprotect().

   - Neil Brown continues to labor away at improving our swap-over-NFS
     support.

   - David Hildenbrand has some fixes to anon page COWing versus
     get_user_pages().

   - Peng Liu fixed some errors in the core hugetlb code.

   - Joao Martins has reduced the amount of memory consumed by
     device-dax's compound devmaps.

   - Some cleanups of the arch-specific pagemap code from Anshuman
     Khandual.

   - Muchun Song has found and fixed some errors in the TLB flushing of
     transparent hugepages.

   - Roman Gushchin has done more work on the memcg selftests.

  ... and, of course, many smaller fixes and cleanups. Notably, the
  customary million cleanup serieses from Miaohe Lin"

* tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (381 commits)
  mm: kfence: use PAGE_ALIGNED helper
  selftests: vm: add the "settings" file with timeout variable
  selftests: vm: add "test_hmm.sh" to TEST_FILES
  selftests: vm: check numa_available() before operating "merge_across_nodes" in ksm_tests
  selftests: vm: add migration to the .gitignore
  selftests/vm/pkeys: fix typo in comment
  ksm: fix typo in comment
  selftests: vm: add process_mrelease tests
  Revert "mm/vmscan: never demote for memcg reclaim"
  mm/kfence: print disabling or re-enabling message
  include/trace/events/percpu.h: cleanup for "percpu: improve percpu_alloc_percpu event trace"
  include/trace/events/mmflags.h: cleanup for "tracing: incorrect gfp_t conversion"
  mm: fix a potential infinite loop in start_isolate_page_range()
  MAINTAINERS: add Muchun as co-maintainer for HugeTLB
  zram: fix Kconfig dependency warning
  mm/shmem: fix shmem folio swapoff hang
  cgroup: fix an error handling path in alloc_pagecache_max_30M()
  mm: damon: use HPAGE_PMD_SIZE
  tracing: incorrect isolate_mote_t cast in mm_vmscan_lru_isolate
  nodemask.h: fix compilation error with GCC12
  ...
2022-05-26 12:32:41 -07:00
Jason A. Donenfeld
5ad7dd882e random: move randomize_page() into mm where it belongs
randomize_page is an mm function. It is documented like one. It contains
the history of one. It has the naming convention of one. It looks
just like another very similar function in mm, randomize_stack_top().
And it has always been maintained and updated by mm people. There is no
need for it to be in random.c. In the "which shape does not look like
the other ones" test, pointing to randomize_page() is correct.

So move randomize_page() into mm/util.c, right next to the similar
randomize_stack_top() function.

This commit contains no actual code changes.

Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-05-19 16:54:15 +02:00
Peter Xu
05e90bd05e mm/hugetlb: only drop uffd-wp special pte if required
As with shmem uffd-wp special ptes, only drop the uffd-wp special swap pte
if unmapping an entire vma or synchronized such that faults can not race
with the unmap operation.  This requires passing zap_flags all the way to
the lowest level hugetlb unmap routine: __unmap_hugepage_range.

In general, unmap calls originated in hugetlbfs code will pass the
ZAP_FLAG_DROP_MARKER flag as synchronization is in place to prevent
faults.  The exception is hole punch which will first unmap without any
synchronization.  Later when hole punch actually removes the page from the
file, it will check to see if there was a subsequent fault and if so take
the hugetlb fault mutex while unmapping again.  This second unmap will
pass in ZAP_FLAG_DROP_MARKER.

The justification of "whether to apply ZAP_FLAG_DROP_MARKER flag when
unmap a hugetlb range" is (IMHO): we should never reach a state when a
page fault could errornously fault in a page-cache page that was
wr-protected to be writable, even in an extremely short period.  That
could happen if e.g.  we pass ZAP_FLAG_DROP_MARKER when
hugetlbfs_punch_hole() calls hugetlb_vmdelete_list(), because if a page
faults after that call and before remove_inode_hugepages() is executed,
the page cache can be mapped writable again in the small racy window, that
can cause unexpected data overwritten.

[peterx@redhat.com: fix sparse warning]
  Link: https://lkml.kernel.org/r/Ylcdw8I1L5iAoWhb@xz-m1.local
[akpm@linux-foundation.org: move zap_flags_t from mm.h to mm_types.h to fix build issues]
Link: https://lkml.kernel.org/r/20220405014915.14873-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13 07:20:11 -07:00
Peter Xu
999dad824c mm/shmem: persist uffd-wp bit across zapping for file-backed
File-backed memory is prone to being unmapped at any time.  It means all
information in the pte will be dropped, including the uffd-wp flag.

To persist the uffd-wp flag, we'll use the pte markers.  This patch
teaches the zap code to understand uffd-wp and know when to keep or drop
the uffd-wp bit.

Add a new flag ZAP_FLAG_DROP_MARKER and set it in zap_details when we
don't want to persist such an information, for example, when destroying
the whole vma, or punching a hole in a shmem file.  For the rest cases we
should never drop the uffd-wp bit, or the wr-protect information will get
lost.

The new ZAP_FLAG_DROP_MARKER needs to be put into mm.h rather than
memory.c because it'll be further referenced in hugetlb files later.

Link: https://lkml.kernel.org/r/20220405014847.14295-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13 07:20:10 -07:00
Nadav Amit
4a18419f71 mm/mprotect: use mmu_gather
Patch series "mm/mprotect: avoid unnecessary TLB flushes", v6.

This patchset is intended to remove unnecessary TLB flushes during
mprotect() syscalls.  Once this patch-set make it through, similar and
further optimizations for MADV_COLD and userfaultfd would be possible.

Basically, there are 3 optimizations in this patch-set:

1. Use TLB batching infrastructure to batch flushes across VMAs and do
   better/fewer flushes.  This would also be handy for later userfaultfd
   enhancements.

2. Avoid unnecessary TLB flushes.  This optimization is the one that
   provides most of the performance benefits.  Unlike previous versions,
   we now only avoid flushes that would not result in spurious
   page-faults.

3. Avoiding TLB flushes on change_huge_pmd() that are only needed to
   prevent the A/D bits from changing.

Andrew asked for some benchmark numbers.  I do not have an easy
determinate macrobenchmark in which it is easy to show benefit.  I
therefore ran a microbenchmark: a loop that does the following on
anonymous memory, just as a sanity check to see that time is saved by
avoiding TLB flushes.  The loop goes:

	mprotect(p, PAGE_SIZE, PROT_READ)
	mprotect(p, PAGE_SIZE, PROT_READ|PROT_WRITE)
	*p = 0; // make the page writable

The test was run in KVM guest with 1 or 2 threads (the second thread was
busy-looping).  I measured the time (cycles) of each operation:

		1 thread		2 threads
		mmots	+patch		mmots	+patch
PROT_READ	3494	2725 (-22%)	8630	7788 (-10%)
PROT_READ|WRITE	3952	2724 (-31%)	9075	2865 (-68%)

[ mmots = v5.17-rc6-mmots-2022-03-06-20-38 ]

The exact numbers are really meaningless, but the benefit is clear.  There
are 2 interesting results though.  

(1) PROT_READ is cheaper, while one can expect it not to be affected. 
This is presumably due to TLB miss that is saved

(2) Without memory access (*p = 0), the speedup of the patch is even
greater.  In that scenario mprotect(PROT_READ) also avoids the TLB flush. 
As a result both operations on the patched kernel take roughly ~1500
cycles (with either 1 or 2 threads), whereas on mmotm their cost is as
high as presented in the table.


This patch (of 3):

change_pXX_range() currently does not use mmu_gather, but instead
implements its own deferred TLB flushes scheme.  This both complicates the
code, as developers need to be aware of different invalidation schemes,
and prevents opportunities to avoid TLB flushes or perform them in finer
granularity.

The use of mmu_gather for modified PTEs has benefits in various scenarios
even if pages are not released.  For instance, if only a single page needs
to be flushed out of a range of many pages, only that page would be
flushed.  If a THP page is flushed, on x86 a single TLB invlpg instruction
can be used instead of 512 instructions (or a full TLB flush, which would
Linux would actually use by default).  mprotect() over multiple VMAs
requires a single flush.

Use mmu_gather in change_pXX_range().  As the pages are not released, only
record the flushed range using tlb_flush_pXX_range().

Handle THP similarly and get rid of flush_cache_range() which becomes
redundant since tlb_start_vma() calls it when needed.

Link: https://lkml.kernel.org/r/20220401180821.1986781-1-namit@vmware.com
Link: https://lkml.kernel.org/r/20220401180821.1986781-2-namit@vmware.com
Signed-off-by: Nadav Amit <namit@vmware.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Nick Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13 07:20:05 -07:00
David Hildenbrand
a7f2266041 mm/gup: trigger FAULT_FLAG_UNSHARE when R/O-pinning a possibly shared anonymous page
Whenever GUP currently ends up taking a R/O pin on an anonymous page that
might be shared -- mapped R/O and !PageAnonExclusive() -- any write fault
on the page table entry will end up replacing the mapped anonymous page
due to COW, resulting in the GUP pin no longer being consistent with the
page actually mapped into the page table.

The possible ways to deal with this situation are:
 (1) Ignore and pin -- what we do right now.
 (2) Fail to pin -- which would be rather surprising to callers and
     could break user space.
 (3) Trigger unsharing and pin the now exclusive page -- reliable R/O
     pins.

Let's implement 3) because it provides the clearest semantics and allows
for checking in unpin_user_pages() and friends for possible BUGs: when
trying to unpin a page that's no longer exclusive, clearly something went
very wrong and might result in memory corruptions that might be hard to
debug.  So we better have a nice way to spot such issues.

This change implies that whenever user space *wrote* to a private mapping
(IOW, we have an anonymous page mapped), that GUP pins will always remain
consistent: reliable R/O GUP pins of anonymous pages.

As a side note, this commit fixes the COW security issue for hugetlb with
FOLL_PIN as documented in:
  https://lore.kernel.org/r/3ae33b08-d9ef-f846-56fb-645e3b9b4c66@redhat.com
The vmsplice reproducer still applies, because vmsplice uses FOLL_GET
instead of FOLL_PIN.

Note that follow_huge_pmd() doesn't apply because we cannot end up in
there with FOLL_PIN.

This commit is heavily based on prototype patches by Andrea.

Link: https://lkml.kernel.org/r/20220428083441.37290-17-david@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Co-developed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Don Dutile <ddutile@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Liang Zhang <zhangliang5@huawei.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Oded Gabbay <oded.gabbay@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pedro Demarchi Gomes <pedrodemargomes@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-09 18:20:45 -07:00
David Hildenbrand
fb3d824d1a mm/rmap: split page_dup_rmap() into page_dup_file_rmap() and page_try_dup_anon_rmap()
...  and move the special check for pinned pages into
page_try_dup_anon_rmap() to prepare for tracking exclusive anonymous pages
via a new pageflag, clearing it only after making sure that there are no
GUP pins on the anonymous page.

We really only care about pins on anonymous pages, because they are prone
to getting replaced in the COW handler once mapped R/O.  For !anon pages
in cow-mappings (!VM_SHARED && VM_MAYWRITE) we shouldn't really care about
that, at least not that I could come up with an example.

Let's drop the is_cow_mapping() check from page_needs_cow_for_dma(), as we
know we're dealing with anonymous pages.  Also, drop the handling of
pinned pages from copy_huge_pud() and add a comment if ever supporting
anonymous pages on the PUD level.

This is a preparation for tracking exclusivity of anonymous pages in the
rmap code, and disallowing marking a page shared (-> failing to duplicate)
if there are GUP pins on a page.

Link: https://lkml.kernel.org/r/20220428083441.37290-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Don Dutile <ddutile@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Liang Zhang <zhangliang5@huawei.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Oded Gabbay <oded.gabbay@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pedro Demarchi Gomes <pedrodemargomes@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-09 18:20:43 -07:00
David Hildenbrand
623a1ddfeb mm/hugetlb: take src_mm->write_protect_seq in copy_hugetlb_page_range()
Let's do it just like copy_page_range(), taking the seqlock and making
sure the mmap_lock is held in write mode.

This allows for add a VM_BUG_ON to page_needs_cow_for_dma() and properly
synchronizes concurrent fork() with GUP-fast of hugetlb pages, which will
be relevant for further changes.

Link: https://lkml.kernel.org/r/20220428083441.37290-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Don Dutile <ddutile@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Liang Zhang <zhangliang5@huawei.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Oded Gabbay <oded.gabbay@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pedro Demarchi Gomes <pedrodemargomes@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-09 18:20:42 -07:00
Joao Martins
4917f55b4e mm/sparse-vmemmap: improve memory savings for compound devmaps
A compound devmap is a dev_pagemap with @vmemmap_shift > 0 and it means
that pages are mapped at a given huge page alignment and utilize uses
compound pages as opposed to order-0 pages.

Take advantage of the fact that most tail pages look the same (except the
first two) to minimize struct page overhead.  Allocate a separate page for
the vmemmap area which contains the head page and separate for the next 64
pages.  The rest of the subsections then reuse this tail vmemmap page to
initialize the rest of the tail pages.

Sections are arch-dependent (e.g.  on x86 it's 64M, 128M or 512M) and when
initializing compound devmap with big enough @vmemmap_shift (e.g.  1G PUD)
it may cross multiple sections.  The vmemmap code needs to consult @pgmap
so that multiple sections that all map the same tail data can refer back
to the first copy of that data for a given gigantic page.

On compound devmaps with 2M align, this mechanism lets 6 pages be saved
out of the 8 necessary PFNs necessary to set the subsection's 512 struct
pages being mapped.  On a 1G compound devmap it saves 4094 pages.

Altmap isn't supported yet, given various restrictions in altmap pfn
allocator, thus fallback to the already in use vmemmap_populate().  It is
worth noting that altmap for devmap mappings was there to relieve the
pressure of inordinate amounts of memmap space to map terabytes of pmem. 
With compound pages the motivation for altmaps for pmem gets reduced.

Link: https://lkml.kernel.org/r/20220420155310.9712-5-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-04-28 23:16:16 -07:00
Joao Martins
e3246d8f52 mm/sparse-vmemmap: add a pgmap argument to section activation
Patch series "sparse-vmemmap: memory savings for compound devmaps (device-dax)", v9.

This series minimizes 'struct page' overhead by pursuing a similar
approach as Muchun Song series "Free some vmemmap pages of hugetlb page"
(now merged since v5.14), but applied to devmap with @vmemmap_shift
(device-dax).  

The vmemmap dedpulication original idea (already used in HugeTLB) is to
reuse/deduplicate tail page vmemmap areas, particular the area which only
describes tail pages.  So a vmemmap page describes 64 struct pages, and
the first page for a given ZONE_DEVICE vmemmap would contain the head page
and 63 tail pages.  The second vmemmap page would contain only tail pages,
and that's what gets reused across the rest of the subsection/section. 
The bigger the page size, the bigger the savings (2M hpage -> save 6
vmemmap pages; 1G hpage -> save 4094 vmemmap pages).  

This is done for PMEM /specifically only/ on device-dax configured
namespaces, not fsdax.  In other words, a devmap with a @vmemmap_shift.

In terms of savings, per 1Tb of memory, the struct page cost would go down
with compound devmap:

* with 2M pages we lose 4G instead of 16G (0.39% instead of 1.5% of
  total memory)

* with 1G pages we lose 40MB instead of 16G (0.0014% instead of 1.5% of
  total memory)

The series is mostly summed up by patch 4, and to summarize what the
series does:

Patches 1 - 3: Minor cleanups in preparation for patch 4.  Move the very
nice docs of hugetlb_vmemmap.c into a Documentation/vm/ entry.

Patch 4: Patch 4 is the one that takes care of the struct page savings
(also referred to here as tail-page/vmemmap deduplication).  Much like
Muchun series, we reuse the second PTE tail page vmemmap areas across a
given @vmemmap_shift On important difference though, is that contrary to
the hugetlbfs series, there's no vmemmap for the area because we are
late-populating it as opposed to remapping a system-ram range.  IOW no
freeing of pages of already initialized vmemmap like the case for
hugetlbfs, which greatly simplifies the logic (besides not being
arch-specific).  altmap case unchanged and still goes via the
vmemmap_populate().  Also adjust the newly added docs to the device-dax
case.

[Note that device-dax is still a little behind HugeTLB in terms of
savings.  I have an additional simple patch that reuses the head vmemmap
page too, as a follow-up.  That will double the savings and namespaces
initialization.]

Patch 5: Initialize fewer struct pages depending on the page size with
DRAM backed struct pages -- because fewer pages are unique and most tail
pages (with bigger vmemmap_shift).

    NVDIMM namespace bootstrap improves from ~268-358 ms to
    ~80-110/<1ms on 128G NVDIMMs with 2M and 1G respectivally.  And struct
    page needed capacity will be 3.8x / 1071x smaller for 2M and 1G
    respectivelly.  Tested on x86 with 1.5Tb of pmem (including pinning,
    and RDMA registration/deregistration scalability with 2M MRs)


This patch (of 5):

In support of using compound pages for devmap mappings, plumb the pgmap
down to the vmemmap_populate implementation.  Note that while altmap is
retrievable from pgmap the memory hotplug code passes altmap without
pgmap[*], so both need to be independently plumbed.

So in addition to @altmap, pass @pgmap to sparse section populate
functions namely:

	sparse_add_section
	  section_activate
	    populate_section_memmap
   	      __populate_section_memmap

Passing @pgmap allows __populate_section_memmap() to both fetch the
vmemmap_shift in which memmap metadata is created for and also to let
sparse-vmemmap fetch pgmap ranges to co-relate to a given section and pick
whether to just reuse tail pages from past onlined sections.

While at it, fix the kdoc for @altmap for sparse_add_section().

[*] https://lore.kernel.org/linux-mm/20210319092635.6214-1-osalvador@suse.de/

Link: https://lkml.kernel.org/r/20220420155310.9712-1-joao.m.martins@oracle.com
Link: https://lkml.kernel.org/r/20220420155310.9712-2-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-04-28 23:16:15 -07:00
Muchun Song
47010c040d mm: hugetlb_vmemmap: cleanup CONFIG_HUGETLB_PAGE_FREE_VMEMMAP*
The word of "free" is not expressive enough to express the feature of
optimizing vmemmap pages associated with each HugeTLB, rename this keywork
to "optimize".  In this patch , cheanup configs to make code more
expressive.

Link: https://lkml.kernel.org/r/20220404074652.68024-4-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-04-28 23:16:15 -07:00
Muchun Song
0e5e64c0b0 mm: simplify follow_invalidate_pte()
The only user (DAX) of range and pmdpp parameters of
follow_invalidate_pte() is gone, it is safe to remove them and make it
static to simlify the code.  This is revertant of the following commits:

  0979639595 ("mm: add follow_pte_pmd()")
  a4d1a88525 ("dax: update to new mmu_notifier semantic")

There is only one caller of the follow_invalidate_pte().  So just fold it
into follow_pte() and remove it.

Link: https://lkml.kernel.org/r/20220403053957.10770-7-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Ross Zwisler <zwisler@kernel.org>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Cc: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-04-28 23:16:10 -07:00
Naoya Horiguchi
2ba2b008a8 Revert "mm/memory-failure.c: fix race with changing page compound again"
Reverts commit 888af2701d ("mm/memory-failure.c: fix race with changing
page compound again") because now we fetch the page refcount under
hugetlb_lock in try_memory_failure_hugetlb() so that the race check is no
longer necessary.

Link: https://lkml.kernel.org/r/20220408135323.1559401-4-naoya.horiguchi@linux.dev
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Suggested-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-04-28 23:16:02 -07:00
Naoya Horiguchi
405ce05123 mm/hwpoison: fix race between hugetlb free/demotion and memory_failure_hugetlb()
There is a race condition between memory_failure_hugetlb() and hugetlb
free/demotion, which causes setting PageHWPoison flag on the wrong page.
The one simple result is that wrong processes can be killed, but another
(more serious) one is that the actual error is left unhandled, so no one
prevents later access to it, and that might lead to more serious results
like consuming corrupted data.

Think about the below race window:

  CPU 1                                   CPU 2
  memory_failure_hugetlb
  struct page *head = compound_head(p);
                                          hugetlb page might be freed to
                                          buddy, or even changed to another
                                          compound page.

  get_hwpoison_page -- page is not what we want now...

The current code first does prechecks roughly and then reconfirms after
taking refcount, but it's found that it makes code overly complicated,
so move the prechecks in a single hugetlb_lock range.

A newly introduced function, try_memory_failure_hugetlb(), always takes
hugetlb_lock (even for non-hugetlb pages).  That can be improved, but
memory_failure() is rare in principle, so should not be a big problem.

Link: https://lkml.kernel.org/r/20220408135323.1559401-2-naoya.horiguchi@linux.dev
Fixes: 761ad8d7c7 ("mm: hwpoison: introduce memory_failure_hugetlb()")
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reported-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-04-21 20:01:09 -07:00
David Hildenbrand
55c62fa7c5 mm/huge_memory: remove stale page_trans_huge_mapcount()
All users are gone, let's remove it.

Link: https://lkml.kernel.org/r/20220131162940.210846-9-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Don Dutile <ddutile@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Liang Zhang <zhangliang5@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-24 19:06:51 -07:00
Linus Torvalds
6b1f86f8e9 Filesystem folio changes for 5.18
Primarily this series converts some of the address_space operations
 to take a folio instead of a page.
 
 ->is_partially_uptodate() takes a folio instead of a page and changes the
 type of the 'from' and 'count' arguments to make it obvious they're bytes.
 ->invalidatepage() becomes ->invalidate_folio() and has a similar type change.
 ->launder_page() becomes ->launder_folio()
 ->set_page_dirty() becomes ->dirty_folio() and adds the address_space as
 an argument.
 
 There are a couple of other misc changes up front that weren't worth
 separating into their own pull request.
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Merge tag 'folio-5.18b' of git://git.infradead.org/users/willy/pagecache

Pull filesystem folio updates from Matthew Wilcox:
 "Primarily this series converts some of the address_space operations to
  take a folio instead of a page.

  Notably:

   - a_ops->is_partially_uptodate() takes a folio instead of a page and
     changes the type of the 'from' and 'count' arguments to make it
     obvious they're bytes.

   - a_ops->invalidatepage() becomes ->invalidate_folio() and has a
     similar type change.

   - a_ops->launder_page() becomes ->launder_folio()

   - a_ops->set_page_dirty() becomes ->dirty_folio() and adds the
     address_space as an argument.

  There are a couple of other misc changes up front that weren't worth
  separating into their own pull request"

* tag 'folio-5.18b' of git://git.infradead.org/users/willy/pagecache: (53 commits)
  fs: Remove aops ->set_page_dirty
  fb_defio: Use noop_dirty_folio()
  fs: Convert __set_page_dirty_no_writeback to noop_dirty_folio
  fs: Convert __set_page_dirty_buffers to block_dirty_folio
  nilfs: Convert nilfs_set_page_dirty() to nilfs_dirty_folio()
  mm: Convert swap_set_page_dirty() to swap_dirty_folio()
  ubifs: Convert ubifs_set_page_dirty to ubifs_dirty_folio
  f2fs: Convert f2fs_set_node_page_dirty to f2fs_dirty_node_folio
  f2fs: Convert f2fs_set_data_page_dirty to f2fs_dirty_data_folio
  f2fs: Convert f2fs_set_meta_page_dirty to f2fs_dirty_meta_folio
  afs: Convert afs_dir_set_page_dirty() to afs_dir_dirty_folio()
  btrfs: Convert extent_range_redirty_for_io() to use folios
  fs: Convert trivial uses of __set_page_dirty_nobuffers to filemap_dirty_folio
  btrfs: Convert from set_page_dirty to dirty_folio
  fscache: Convert fscache_set_page_dirty() to fscache_dirty_folio()
  fs: Add aops->dirty_folio
  fs: Remove aops->launder_page
  orangefs: Convert launder_page to launder_folio
  nfs: Convert from launder_page to launder_folio
  fuse: Convert from launder_page to launder_folio
  ...
2022-03-22 18:26:56 -07:00
Linus Torvalds
9030fb0bb9 Folio changes for 5.18
- Rewrite how munlock works to massively reduce the contention
    on i_mmap_rwsem (Hugh Dickins):
    https://lore.kernel.org/linux-mm/8e4356d-9622-a7f0-b2c-f116b5f2efea@google.com/
  - Sort out the page refcount mess for ZONE_DEVICE pages (Christoph Hellwig):
    https://lore.kernel.org/linux-mm/20220210072828.2930359-1-hch@lst.de/
  - Convert GUP to use folios and make pincount available for order-1
    pages. (Matthew Wilcox)
  - Convert a few more truncation functions to use folios (Matthew Wilcox)
  - Convert page_vma_mapped_walk to use PFNs instead of pages (Matthew Wilcox)
  - Convert rmap_walk to use folios (Matthew Wilcox)
  - Convert most of shrink_page_list() to use a folio (Matthew Wilcox)
  - Add support for creating large folios in readahead (Matthew Wilcox)
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Merge tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecache

Pull folio updates from Matthew Wilcox:

 - Rewrite how munlock works to massively reduce the contention on
   i_mmap_rwsem (Hugh Dickins):

     https://lore.kernel.org/linux-mm/8e4356d-9622-a7f0-b2c-f116b5f2efea@google.com/

 - Sort out the page refcount mess for ZONE_DEVICE pages (Christoph
   Hellwig):

     https://lore.kernel.org/linux-mm/20220210072828.2930359-1-hch@lst.de/

 - Convert GUP to use folios and make pincount available for order-1
   pages. (Matthew Wilcox)

 - Convert a few more truncation functions to use folios (Matthew
   Wilcox)

 - Convert page_vma_mapped_walk to use PFNs instead of pages (Matthew
   Wilcox)

 - Convert rmap_walk to use folios (Matthew Wilcox)

 - Convert most of shrink_page_list() to use a folio (Matthew Wilcox)

 - Add support for creating large folios in readahead (Matthew Wilcox)

* tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecache: (114 commits)
  mm/damon: minor cleanup for damon_pa_young
  selftests/vm/transhuge-stress: Support file-backed PMD folios
  mm/filemap: Support VM_HUGEPAGE for file mappings
  mm/readahead: Switch to page_cache_ra_order
  mm/readahead: Align file mappings for non-DAX
  mm/readahead: Add large folio readahead
  mm: Support arbitrary THP sizes
  mm: Make large folios depend on THP
  mm: Fix READ_ONLY_THP warning
  mm/filemap: Allow large folios to be added to the page cache
  mm: Turn can_split_huge_page() into can_split_folio()
  mm/vmscan: Convert pageout() to take a folio
  mm/vmscan: Turn page_check_references() into folio_check_references()
  mm/vmscan: Account large folios correctly
  mm/vmscan: Optimise shrink_page_list for non-PMD-sized folios
  mm/vmscan: Free non-shmem folios without splitting them
  mm/rmap: Constify the rmap_walk_control argument
  mm/rmap: Convert rmap_walk() to take a folio
  mm: Turn page_anon_vma() into folio_anon_vma()
  mm/rmap: Turn page_lock_anon_vma_read() into folio_lock_anon_vma_read()
  ...
2022-03-22 17:03:12 -07:00
Nadav Amit
824ddc601a userfaultfd: provide unmasked address on page-fault
Userfaultfd is supposed to provide the full address (i.e., unmasked) of
the faulting access back to userspace.  However, that is not the case for
quite some time.

Even running "userfaultfd_demo" from the userfaultfd man page provides the
wrong output (and contradicts the man page).  Notice that
"UFFD_EVENT_PAGEFAULT event" shows the masked address (7fc5e30b3000) and
not the first read address (0x7fc5e30b300f).

	Address returned by mmap() = 0x7fc5e30b3000

	fault_handler_thread():
	    poll() returns: nready = 1; POLLIN = 1; POLLERR = 0
	    UFFD_EVENT_PAGEFAULT event: flags = 0; address = 7fc5e30b3000
		(uffdio_copy.copy returned 4096)
	Read address 0x7fc5e30b300f in main(): A
	Read address 0x7fc5e30b340f in main(): A
	Read address 0x7fc5e30b380f in main(): A
	Read address 0x7fc5e30b3c0f in main(): A

The exact address is useful for various reasons and specifically for
prefetching decisions.  If it is known that the memory is populated by
certain objects whose size is not page-aligned, then based on the faulting
address, the uffd-monitor can decide whether to prefetch and prefault the
adjacent page.

This bug has been for quite some time in the kernel: since commit
1a29d85eb0 ("mm: use vmf->address instead of of vmf->virtual_address")
vmf->virtual_address"), which dates back to 2016.  A concern has been
raised that existing userspace application might rely on the old/wrong
behavior in which the address is masked.  Therefore, it was suggested to
provide the masked address unless the user explicitly asks for the exact
address.

Add a new userfaultfd feature UFFD_FEATURE_EXACT_ADDRESS to direct
userfaultfd to provide the exact address.  Add a new "real_address" field
to vmf to hold the unmasked address.  Provide the address to userspace
accordingly.

Initialize real_address in various code-paths to be consistent with
address, even when it is not used, to be on the safe side.

[namit@vmware.com: initialize real_address on all code paths, per Jan]
  Link: https://lkml.kernel.org/r/20220226022655.350562-1-namit@vmware.com
[akpm@linux-foundation.org: fix typo in comment, per Jan]

Link: https://lkml.kernel.org/r/20220218041003.3508-1-namit@vmware.com
Signed-off-by: Nadav Amit <namit@vmware.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 15:57:08 -07:00
Muchun Song
e540841734 mm: sparsemem: move vmemmap related to HugeTLB to CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
The vmemmap_remap_free/alloc are relevant to HugeTLB, so move those
functiongs to the scope of CONFIG_HUGETLB_PAGE_FREE_VMEMMAP.

Link: https://lkml.kernel.org/r/20211101031651.75851-6-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Barry Song <song.bao.hua@hisilicon.com>
Cc: Bodeddula Balasubramaniam <bodeddub@amazon.com>
Cc: Chen Huang <chenhuang5@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Fam Zheng <fam.zheng@bytedance.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 15:57:08 -07:00
Miaohe Lin
888af2701d mm/memory-failure.c: fix race with changing page compound again
Patch series "A few fixup patches for memory failure", v2.

This series contains a few patches to fix the race with changing page
compound page, make non-LRU movable pages unhandlable and so on.  More
details can be found in the respective changelogs.

There is a race window where we got the compound_head, the hugetlb page
could be freed to buddy, or even changed to another compound page just
before we try to get hwpoison page.  Think about the below race window:

  CPU 1					  CPU 2
  memory_failure_hugetlb
  struct page *head = compound_head(p);
					  hugetlb page might be freed to
					  buddy, or even changed to another
					  compound page.

  get_hwpoison_page -- page is not what we want now...

If this race happens, just bail out.  Also MF_MSG_DIFFERENT_PAGE_SIZE is
introduced to record this event.

[akpm@linux-foundation.org: s@/**@/*@, per Naoya Horiguchi]

Link: https://lkml.kernel.org/r/20220312074613.4798-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20220312074613.4798-2-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 15:57:07 -07:00
Oscar Salvador
1ca75fa7f1 arch/x86/mm/numa: Do not initialize nodes twice
On x86, prior to ("mm: handle uninitialized numa nodes gracecully"), NUMA
nodes could be allocated at three different places.

 - numa_register_memblks
 - init_cpu_to_node
 - init_gi_nodes

All these calls happen at setup_arch, and have the following order:

setup_arch
  ...
  x86_numa_init
   numa_init
    numa_register_memblks
  ...
  init_cpu_to_node
   init_memory_less_node
    alloc_node_data
    free_area_init_memoryless_node
  init_gi_nodes
   init_memory_less_node
    alloc_node_data
    free_area_init_memoryless_node

numa_register_memblks() is only interested in those nodes which have
memory, so it skips over any memoryless node it founds.  Later on, when
we have read ACPI's SRAT table, we call init_cpu_to_node() and
init_gi_nodes(), which initialize any memoryless node we might have that
have either CPU or Initiator affinity, meaning we allocate pg_data_t
struct for them and we mark them as ONLINE.

So far so good, but the thing is that after ("mm: handle uninitialized
numa nodes gracefully"), we allocate all possible NUMA nodes in
free_area_init(), meaning we have a picture like the following:

setup_arch
  x86_numa_init
   numa_init
    numa_register_memblks  <-- allocate non-memoryless node
  x86_init.paging.pagetable_init
   ...
    free_area_init
     free_area_init_memoryless <-- allocate memoryless node
  init_cpu_to_node
   alloc_node_data             <-- allocate memoryless node with CPU
   free_area_init_memoryless_node
  init_gi_nodes
   alloc_node_data             <-- allocate memoryless node with Initiator
   free_area_init_memoryless_node

free_area_init() already allocates all possible NUMA nodes, but
init_cpu_to_node() and init_gi_nodes() are clueless about that, so they
go ahead and allocate a new pg_data_t struct without checking anything,
meaning we end up allocating twice.

It should be mad clear that this only happens in the case where
memoryless NUMA node happens to have a CPU/Initiator affinity.

So get rid of init_memory_less_node() and just set the node online.

Note that setting the node online is needed, otherwise we choke down the
chain when bringup_nonboot_cpus() ends up calling
__try_online_node()->register_one_node()->...  and we blow up in
bus_add_device().  As can be seen here:

  BUG: kernel NULL pointer dereference, address: 0000000000000060
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 0 P4D 0
  Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.0-rc4-1-default+ #45
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/4
  RIP: 0010:bus_add_device+0x5a/0x140
  Code: 8b 74 24 20 48 89 df e8 84 96 ff ff 85 c0 89 c5 75 38 48 8b 53 50 48 85 d2 0f 84 bb 00 004
  RSP: 0000:ffffc9000022bd10 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff888100987400 RCX: ffff8881003e4e19
  RDX: ffff8881009a5e00 RSI: ffff888100987400 RDI: ffff888100987400
  RBP: 0000000000000000 R08: ffff8881003e4e18 R09: ffff8881003e4c98
  R10: 0000000000000000 R11: ffff888100402bc0 R12: ffffffff822ceba0
  R13: 0000000000000000 R14: ffff888100987400 R15: 0000000000000000
  FS:  0000000000000000(0000) GS:ffff88853fc00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000060 CR3: 000000000200a001 CR4: 00000000001706b0
  Call Trace:
   device_add+0x4c0/0x910
   __register_one_node+0x97/0x2d0
   __try_online_node+0x85/0xc0
   try_online_node+0x25/0x40
   cpu_up+0x4f/0x100
   bringup_nonboot_cpus+0x4f/0x60
   smp_init+0x26/0x79
   kernel_init_freeable+0x130/0x2f1
   kernel_init+0x17/0x150
   ret_from_fork+0x22/0x30

The reason is simple, by the time bringup_nonboot_cpus() gets called, we
did not register the node_subsys bus yet, so we crash when
bus_add_device() tries to dereference bus()->p.

The following shows the order of the calls:

kernel_init_freeable
 smp_init
  bringup_nonboot_cpus
   ...
     bus_add_device()      <- we did not register node_subsys yet
 do_basic_setup
  do_initcalls
   postcore_initcall(register_node_type);
    register_node_type
     subsys_system_register
      subsys_register
       bus_register         <- register node_subsys bus

Why setting the node online saves us then? Well, simply because
__try_online_node() backs off when the node is online, meaning we do not
end up calling register_one_node() in the first place.

This is subtle, broken and deserves a deep analysis and thought about
how to put this into shape, but for now let us have this easy fix for
the leaking memory issue.

[osalvador@suse.de: add comments]
  Link: https://lkml.kernel.org/r/20220221142649.3457-1-osalvador@suse.de

Link: https://lkml.kernel.org/r/20220218224302.5282-2-osalvador@suse.de
Fixes: da4490c958ad ("mm: handle uninitialized numa nodes gracefully")
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Rafael Aquini <raquini@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Alexey Makhalov <amakhalov@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 15:57:06 -07:00
John Hubbard
73fd16d808 mm/gup: remove unused get_user_pages_locked()
Now that the last caller of get_user_pages_locked() is gone, remove it.

Link: https://lkml.kernel.org/r/20220204020010.68930-6-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 15:57:01 -07:00
John Hubbard
ad6c441266 mm/gup: remove unused pin_user_pages_locked()
This routine was used for a short while, but then the calling code was
refactored and the only caller was removed.

Link: https://lkml.kernel.org/r/20220204020010.68930-4-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 15:57:01 -07:00
Matthew Wilcox (Oracle)
18788cfa23 mm: Support arbitrary THP sizes
For code which has not yet been converted from THP to folios, use the
compound size of the page instead of assuming PTE or PMD size.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-03-21 13:01:36 -04:00
Matthew Wilcox (Oracle)
e05b34539d mm: Turn page_anon_vma() into folio_anon_vma()
Move the prototype from mm.h to mm/internal.h and convert all callers
to pass a folio.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-03-21 13:01:35 -04:00
Matthew Wilcox (Oracle)
4ba1119cd5 mm: Add folio_mapcount()
This implements the same algorithm as total_mapcount(), which is
transformed into a wrapper function.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-03-21 12:59:02 -04:00
Matthew Wilcox (Oracle)
74e8ee4708 mm: Turn head_compound_mapcount() into folio_entire_mapcount()
Adjust documentation to be more clear.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-03-21 12:59:02 -04:00
Matthew Wilcox (Oracle)
d6c75dc22c mm/truncate: Split invalidate_inode_page() into mapping_evict_folio()
Some of the callers already have the address_space and can avoid calling
folio_mapping() and checking if the folio was already truncated.  Also
add kernel-doc and fix the return type (in case we ever support folios
larger than 4TB).

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
2022-03-21 12:59:02 -04:00
Matthew Wilcox (Oracle)
06d20bdb98 mm: Add lru_to_folio()
Since page->lru occupies the same bytes as compound_head, any page
on the LRU list must be a folio.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-03-21 12:59:01 -04:00
Matthew Wilcox (Oracle)
536939ff51 mm: Add three folio wrappers
folio_is_zone_device() is equivalent to is_zone_device_page(),
folio_is_device_private() is equivalent to is_device_private_page(),
and folio_is_pinnable() is equivalent to is_pinnable_page().

All of these tests return the same result for every page in the folio,
so we can just pass the head page of the folio to the page variant of
the function.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-03-21 12:57:38 -04:00
Matthew Wilcox (Oracle)
659508f9c9 mm/gup: Turn compound_range_next() into gup_folio_range_next()
Convert the only caller to work on folios instead of pages.
This removes the last caller of put_compound_head(), so delete it.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-03-21 12:56:36 -04:00
Matthew Wilcox (Oracle)
822951d846 mm/hugetlb: Use try_grab_folio() instead of try_grab_compound_head()
follow_hugetlb_page() only cares about success or failure, so it doesn't
need to know the type of the returned pointer, only whether it's NULL
or not.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-03-21 12:56:35 -04:00
Matthew Wilcox (Oracle)
40fcc7fc2c mm: Remove page_cache_add_speculative() and page_cache_get_speculative()
These wrappers have no more callers, so delete them.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-03-21 12:56:35 -04:00
Matthew Wilcox (Oracle)
0b90ddae13 mm: Turn page_maybe_dma_pinned() into folio_maybe_dma_pinned()
Replace three calls to compound_head() with one.  This removes the last
user of compound_pincount(), so remove that helper too.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-03-21 12:56:35 -04:00
Matthew Wilcox (Oracle)
3d11b225ae mm: Add folio_pincount_ptr()
This is the folio equivalent of compound_pincount_ptr().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-03-21 12:56:35 -04:00
Matthew Wilcox (Oracle)
5232c63f46 mm: Make compound_pincount always available
Move compound_pincount from the third page to the second page, which
means it's available for all compound pages.  That lets us delete
hpage_pincount_available().

On 32-bit systems, there isn't enough space for both compound_pincount
and compound_nr in the second page (it would collide with page->private,
which is in use for pages in the swap cache), so revert the optimisation
of storing both compound_order and compound_nr on 32-bit systems.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-03-21 12:56:35 -04:00
Matthew Wilcox (Oracle)
4c65422901 mm/gup: Remove an assumption of a contiguous memmap
This assumption needs the inverse of nth_page(), which is temporarily
named page_nth() until it's renamed later in this series.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-03-21 12:56:35 -04:00
Matthew Wilcox (Oracle)
5ad6b2bdaa fs: Turn do_invalidatepage() into folio_invalidate()
Take a folio instead of a page, fix the types of the offset & length,
and export it to filesystems.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs
Tested-by: David Howells <dhowells@redhat.com> # afs
2022-03-15 08:23:25 -04:00
Suren Baghdasaryan
5c26f6ac94 mm: refactor vm_area_struct::anon_vma_name usage code
Avoid mixing strings and their anon_vma_name referenced pointers by
using struct anon_vma_name whenever possible.  This simplifies the code
and allows easier sharing of anon_vma_name structures when they
represent the same name.

[surenb@google.com: fix comment]

Link: https://lkml.kernel.org/r/20220223153613.835563-1-surenb@google.com
Link: https://lkml.kernel.org/r/20220224231834.1481408-1-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Colin Cross <ccross@google.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Alexey Gladkov <legion@kernel.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Chris Hyser <chris.hyser@oracle.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Xiaofeng Cao <caoxiaofeng@yulong.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-05 11:08:32 -08:00
Christoph Hellwig
27674ef6c7 mm: remove the extra ZONE_DEVICE struct page refcount
ZONE_DEVICE struct pages have an extra reference count that complicates
the code for put_page() and several places in the kernel that need to
check the reference count to see that a page is not being used (gup,
compaction, migration, etc.). Clean up the code so the reference count
doesn't need to be treated specially for ZONE_DEVICE pages.

Note that this excludes the special idle page wakeup for fsdax pages,
which still happens at refcount 1.  This is a separate issue and will
be sorted out later.  Given that only fsdax pages require the
notifiacation when the refcount hits 1 now, the PAGEMAP_OPS Kconfig
symbol can go away and be replaced with a FS_DAX check for this hook
in the put_page fastpath.

Based on an earlier patch from Ralph Campbell <rcampbell@nvidia.com>.

Link: https://lkml.kernel.org/r/20220210072828.2930359-8-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Tested-by: "Sierra Guiza, Alejandro (Alex)" <alex.sierra@amd.com>

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Chaitanya Kulkarni <kch@nvidia.com>
Cc: Christian Knig <christian.koenig@amd.com>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-03-03 12:47:33 -05:00
Christoph Hellwig
dc90f0846d mm: don't include <linux/memremap.h> in <linux/mm.h>
Move the check for the actual pgmap types that need the free at refcount
one behavior into the out of line helper, and thus avoid the need to
pull memremap.h into mm.h.

Link: https://lkml.kernel.org/r/20220210072828.2930359-7-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Tested-by: "Sierra Guiza, Alejandro (Alex)" <alex.sierra@amd.com>

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Chaitanya Kulkarni <kch@nvidia.com>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-03-03 12:47:33 -05:00
Christoph Hellwig
895749455f mm: simplify freeing of devmap managed pages
Make put_devmap_managed_page return if it took charge of the page
or not and remove the separate page_is_devmap_managed helper.

Link: https://lkml.kernel.org/r/20220210072828.2930359-6-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: "Sierra Guiza, Alejandro (Alex)" <alex.sierra@amd.com>

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Christian Knig <christian.koenig@amd.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-03-03 12:47:33 -05:00
Christoph Hellwig
75e55d8a10 mm: move free_devmap_managed_page to memremap.c
free_devmap_managed_page has nothing to do with the code in swap.c,
move it to live with the rest of the code for devmap handling.

Link: https://lkml.kernel.org/r/20220210072828.2930359-5-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: "Sierra Guiza, Alejandro (Alex)" <alex.sierra@amd.com>

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Christian Knig <christian.koenig@amd.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-03-03 12:47:33 -05:00
Christoph Hellwig
5c3f1f9cc4 mm: remove the __KERNEL__ guard from <linux/mm.h>
__KERNEL__ ifdefs don't make sense outside of include/uapi/.

Link: https://lkml.kernel.org/r/20220210072828.2930359-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: "Sierra Guiza, Alejandro (Alex)" <alex.sierra@amd.com>

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Christian Knig <christian.koenig@amd.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-03-03 12:47:33 -05:00
Hugh Dickins
b67bf49ce7 mm/munlock: delete FOLL_MLOCK and FOLL_POPULATE
If counting page mlocks, we must not double-count: follow_page_pte() can
tell if a page has already been Mlocked or not, but cannot tell if a pte
has already been counted or not: that will have to be done when the pte
is mapped in (which lru_cache_add_inactive_or_unevictable() already tracks
for new anon pages, but there's no such tracking yet for others).

Delete all the FOLL_MLOCK code - faulting in the missing pages will do
all that is necessary, without special mlock_vma_page() calls from here.

But then FOLL_POPULATE turns out to serve no purpose - it was there so
that its absence would tell faultin_page() not to faultin page when
setting up VM_LOCKONFAULT areas; but if there's no special work needed
here for mlock, then there's no work at all here for VM_LOCKONFAULT.

Have I got that right?  I've not looked into the history, but see that
FOLL_POPULATE goes back before VM_LOCKONFAULT: did it serve a different
purpose before?  Ah, yes, it was used to skip the old stack guard page.

And is it intentional that COW is not broken on existing pages when
setting up a VM_LOCKONFAULT area?  I can see that being argued either
way, and have no reason to disagree with current behaviour.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-02-17 11:56:36 -05:00
Peter Collingbourne
27fe73394a mm, kasan: use compare-exchange operation to set KASAN page tag
It has been reported that the tag setting operation on newly-allocated
pages can cause the page flags to be corrupted when performed
concurrently with other flag updates as a result of the use of
non-atomic operations.

Fix the problem by using a compare-exchange loop to update the tag.

Link: https://lkml.kernel.org/r/20220120020148.1632253-1-pcc@google.com
Link: https://linux-review.googlesource.com/id/I456b24a2b9067d93968d43b4bb3351c0cec63101
Fixes: 2813b9c029 ("kasan, mm, arm64: tag non slab memory allocated via pagealloc")
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-30 09:56:58 +02:00
Linus Torvalds
b68b10b626 Three small folio patches.
One bug fix, one patch pulled forward from the patches destined for 5.18
 and then a patch to make use of that functionality.
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Merge tag 'folio-5.17a' of git://git.infradead.org/users/willy/pagecache

Pull more folio updates from Matthew Wilcox:
 "Three small folio patches.

  One bug fix, one patch pulled forward from the patches destined for
  5.18 and then a patch to make use of that functionality"

* tag 'folio-5.17a' of git://git.infradead.org/users/willy/pagecache:
  filemap: Use folio_put_refs() in filemap_free_folio()
  mm: Add folio_put_refs()
  pagevec: Initialise folio_batch->percpu_pvec_drained
2022-01-22 10:43:07 +02:00
Matthew Wilcox (Oracle)
3fe7fa5843 mm: Add folio_put_refs()
This is like folio_put(), but puts N references at once instead of
just one.  It's like put_page_refs(), but does one atomic operation
instead of two, and is available to more than just gup.c.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-16 19:52:13 -05:00
Linus Torvalds
f56caedaf9 Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
 "146 patches.

  Subsystems affected by this patch series: kthread, ia64, scripts,
  ntfs, squashfs, ocfs2, vfs, and mm (slab-generic, slab, kmemleak,
  dax, kasan, debug, pagecache, gup, shmem, frontswap, memremap,
  memcg, selftests, pagemap, dma, vmalloc, memory-failure, hugetlb,
  userfaultfd, vmscan, mempolicy, oom-kill, hugetlbfs, migration, thp,
  ksm, page-poison, percpu, rmap, zswap, zram, cleanups, hmm, and
  damon)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (146 commits)
  mm/damon: hide kernel pointer from tracepoint event
  mm/damon/vaddr: hide kernel pointer from damon_va_three_regions() failure log
  mm/damon/vaddr: use pr_debug() for damon_va_three_regions() failure logging
  mm/damon/dbgfs: remove an unnecessary variable
  mm/damon: move the implementation of damon_insert_region to damon.h
  mm/damon: add access checking for hugetlb pages
  Docs/admin-guide/mm/damon/usage: update for schemes statistics
  mm/damon/dbgfs: support all DAMOS stats
  Docs/admin-guide/mm/damon/reclaim: document statistics parameters
  mm/damon/reclaim: provide reclamation statistics
  mm/damon/schemes: account how many times quota limit has exceeded
  mm/damon/schemes: account scheme actions that successfully applied
  mm/damon: remove a mistakenly added comment for a future feature
  Docs/admin-guide/mm/damon/usage: update for kdamond_pid and (mk|rm)_contexts
  Docs/admin-guide/mm/damon/usage: mention tracepoint at the beginning
  Docs/admin-guide/mm/damon/usage: remove redundant information
  Docs/admin-guide/mm/damon/usage: update for scheme quotas and watermarks
  mm/damon: convert macro functions to static inline functions
  mm/damon: modify damon_rand() macro to static inline function
  mm/damon: move damon_rand() definition into damon.h
  ...
2022-01-15 20:37:06 +02:00
Naoya Horiguchi
bf181c5825 mm/hwpoison: fix unpoison_memory()
After recent soft-offline rework, error pages can be taken off from
buddy allocator, but the existing unpoison_memory() does not properly
undo the operation.  Moreover, due to the recent change on
__get_hwpoison_page(), get_page_unless_zero() is hardly called for
hwpoisoned pages.  So __get_hwpoison_page() highly likely returns -EBUSY
(meaning to fail to grab page refcount) and unpoison just clears
PG_hwpoison without releasing a refcount.  That does not lead to a
critical issue like kernel panic, but unpoisoned pages never get back to
buddy (leaked permanently), which is not good.

To (partially) fix this, we need to identify "taken off" pages from
other types of hwpoisoned pages.  We can't use refcount or page flags
for this purpose, so a pseudo flag is defined by hacking ->private
field.  Someone might think that put_page() is enough to cancel
taken-off pages, but the normal free path contains some operations not
suitable for the current purpose, and can fire VM_BUG_ON().

Note that unpoison_memory() is now supposed to be cancel hwpoison events
injected only by madvise() or
/sys/devices/system/memory/{hard,soft}_offline_page, not by MCE
injection, so please don't try to use unpoison when testing with MCE
injection.

[lkp@intel.com: report build failure for ARCH=i386]

Link: https://lkml.kernel.org/r/20211115084006.3728254-4-naoya.horiguchi@linux.dev
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Ding Hui <dinghui@sangfor.com.cn>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15 16:30:31 +02:00