4eeab4f558
Add an admin_reserve_kbytes knob to allow admins to change the hardcoded memory reserve to something other than 3%, which may be multiple gigabytes on large memory systems. Only about 8MB is necessary to enable recovery in the default mode, and only a few hundred MB are required even when overcommit is disabled. This affects OVERCOMMIT_GUESS and OVERCOMMIT_NEVER. admin_reserve_kbytes is initialized to min(3% free pages, 8MB) I arrived at 8MB by summing the RSS of sshd or login, bash, and top. Please see first patch in this series for full background, motivation, testing, and full changelog. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: make init_admin_reserve() static] Signed-off-by: Andrew Shewmaker <agshew@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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| 00-INDEX | ||
| abi.txt | ||
| fs.txt | ||
| kernel.txt | ||
| net.txt | ||
| README | ||
| sunrpc.txt | ||
| vm.txt | ||
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 :-)
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Legal blurb:
As usual, there are two main things to consider:
- you get what you pay for
- 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.
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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 :-)