linux-yocto/init
Tejun Heo 8195136669 sched_ext: Add cgroup support
Add sched_ext_ops operations to init/exit cgroups, and track task migrations
and config changes. A BPF scheduler may not implement or implement only
subset of cgroup features. The implemented features can be indicated using
%SCX_OPS_HAS_CGOUP_* flags. If cgroup configuration makes use of features
that are not implemented, a warning is triggered.

While a BPF scheduler is being enabled and disabled, relevant cgroup
operations are locked out using scx_cgroup_rwsem. This avoids situations
like task prep taking place while the task is being moved across cgroups,
making things easier for BPF schedulers.

v7: - cgroup interface file visibility toggling is dropped in favor just
      warning messages. Dynamically changing interface visiblity caused more
      confusion than helping.

v6: - Updated to reflect the removal of SCX_KF_SLEEPABLE.

    - Updated to use CONFIG_GROUP_SCHED_WEIGHT and fixes for
      !CONFIG_FAIR_GROUP_SCHED && CONFIG_EXT_GROUP_SCHED.

v5: - Flipped the locking order between scx_cgroup_rwsem and
      cpus_read_lock() to avoid locking order conflict w/ cpuset. Better
      documentation around locking.

    - sched_move_task() takes an early exit if the source and destination
      are identical. This triggered the warning in scx_cgroup_can_attach()
      as it left p->scx.cgrp_moving_from uncleared. Updated the cgroup
      migration path so that ops.cgroup_prep_move() is skipped for identity
      migrations so that its invocations always match ops.cgroup_move()
      one-to-one.

v4: - Example schedulers moved into their own patches.

    - Fix build failure when !CONFIG_CGROUP_SCHED, reported by Andrea Righi.

v3: - Make scx_example_pair switch all tasks by default.

    - Convert to BPF inline iterators.

    - scx_bpf_task_cgroup() is added to determine the current cgroup from
      CPU controller's POV. This allows BPF schedulers to accurately track
      CPU cgroup membership.

    - scx_example_flatcg added. This demonstrates flattened hierarchy
      implementation of CPU cgroup control and shows significant performance
      improvement when cgroups which are nested multiple levels are under
      competition.

v2: - Build fixes for different CONFIG combinations.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: David Vernet <dvernet@meta.com>
Acked-by: Josh Don <joshdon@google.com>
Acked-by: Hao Luo <haoluo@google.com>
Acked-by: Barret Rhoden <brho@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Andrea Righi <andrea.righi@canonical.com>
2024-09-04 10:24:59 -10:00
..
.gitignore
calibrate.c
do_mounts_initrd.c initrd: remove the now superfluous sentinel element from ctl_table array 2024-04-25 21:07:05 -07:00
do_mounts_rd.c
do_mounts.c init: replace deprecated strncpy with strscpy_pad 2024-04-30 10:34:29 -07:00
do_mounts.h init: flush async file closing 2024-02-08 18:41:03 +01:00
init_task.c sched_ext: Take out ->priq and ->flags from scx_dsq_node 2024-07-08 14:30:55 -10:00
initramfs.c Merge 6.9-rc5 into driver-core-next 2024-04-23 13:27:43 +02:00
Kconfig sched_ext: Add cgroup support 2024-09-04 10:24:59 -10:00
main.c Mainly singleton patches, documented in their respective changelogs. 2024-05-19 14:02:03 -07:00
Makefile kbuild: move init/build-version to scripts/ 2024-07-16 01:08:37 +09:00
noinitramfs.c
version-timestamp.c init/version-timestamp.c: remove unneeded #include <linux/version.h> 2023-01-09 07:34:38 +09:00
version.c init/version.c: Replace strlcpy with strscpy 2023-09-22 09:50:56 -07:00