linux-yocto/Documentation/sysctl
Linus Torvalds e16b396ce3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (47 commits)
  doc: CONFIG_UNEVICTABLE_LRU doesn't exist anymore
  Update cpuset info & webiste for cgroups
  dcdbas: force SMI to happen when expected
  arch/arm/Kconfig: remove one to many l's in the word.
  asm-generic/user.h: Fix spelling in comment
  drm: fix printk typo 'sracth'
  Remove one to many n's in a word
  Documentation/filesystems/romfs.txt: fixing link to genromfs
  drivers:scsi Change printk typo initate -> initiate
  serial, pch uart: Remove duplicate inclusion of linux/pci.h header
  fs/eventpoll.c: fix spelling
  mm: Fix out-of-date comments which refers non-existent functions
  drm: Fix printk typo 'failled'
  coh901318.c: Change initate to initiate.
  mbox-db5500.c Change initate to initiate.
  edac: correct i82975x error-info reported
  edac: correct i82975x mci initialisation
  edac: correct commented info
  fs: update comments to point correct document
  target: remove duplicate include of target/target_core_device.h from drivers/target/target_core_hba.c
  ...

Trivial conflict in fs/eventpoll.c (spelling vs addition)
2011-03-18 10:37:40 -07:00
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00-INDEX sysctl: remove obsolete comments 2011-01-13 08:03:18 -08:00
abi.txt Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
fs.txt Documentation: file handles are now freed 2011-03-16 10:47:03 -07:00
kernel.txt Documentation: default_message_level is a typo 2011-02-11 15:14:10 +01:00
net.txt net: Consistent skb timestamping 2010-05-15 23:57:10 -07:00
README Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sunrpc.txt Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
vm.txt doc: clarify the behaviour of dirty_ratio/dirty_bytes 2010-10-27 18:03:08 -07:00

Documentation for /proc/sys/ kernel version 2.2.10 (c) 1998, 1999, Rik van Riel riel@nl.linux.org

'Why', I hear you ask, 'would anyone even want documentation for them sysctl files? If anybody really needs it, it's all in the source...'

Well, this documentation is written because some people either don't know they need to tweak something, or because they don't have the time or knowledge to read the source code.

Furthermore, the programmers who built sysctl have built it to be actually used, not just for the fun of programming it :-)

==============================================================

Legal blurb:

As usual, there are two main things to consider:

  1. you get what you pay for
  2. it's free

The consequences are that I won't guarantee the correctness of this document, and if you come to me complaining about how you screwed up your system because of wrong documentation, I won't feel sorry for you. I might even laugh at you...

But of course, if you do manage to screw up your system using only the sysctl options used in this file, I'd like to hear of it. Not only to have a great laugh, but also to make sure that you're the last RTFMing person to screw up.

In short, e-mail your suggestions, corrections and / or horror stories to: riel@nl.linux.org

Rik van Riel.

==============================================================

Introduction:

Sysctl is a means of configuring certain aspects of the kernel at run-time, and the /proc/sys/ directory is there so that you don't even need special tools to do it! In fact, there are only four things needed to use these config facilities:

  • a running Linux system
  • root access
  • common sense (this is especially hard to come by these days)
  • knowledge of what all those values mean

As a quick 'ls /proc/sys' will show, the directory consists of several (arch-dependent?) subdirs. Each subdir is mainly about one part of the kernel, so you can do configuration on a piece by piece basis, or just some 'thematic frobbing'.

The subdirs are about: abi/ execution domains & personalities debug/ dev/ device specific information (eg dev/cdrom/info) fs/ specific filesystems filehandle, inode, dentry and quota tuning binfmt_misc <Documentation/binfmt_misc.txt> kernel/ global kernel info / tuning miscellaneous stuff net/ networking stuff, for documentation look in: <Documentation/networking/> proc/ sunrpc/ SUN Remote Procedure Call (NFS) vm/ memory management tuning buffer and cache management

These are the subdirs I have on my system. There might be more or other subdirs in another setup. If you see another dir, I'd really like to hear about it :-)