| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame] | 1 | =========================== |
| 2 | Documentation for /proc/sys |
| 3 | =========================== |
| 4 | |
| 5 | Copyright (c) 1998, 1999, Rik van Riel <riel@nl.linux.org> |
| 6 | |
| 7 | ------------------------------------------------------------------------------ |
| 8 | |
| 9 | 'Why', I hear you ask, 'would anyone even _want_ documentation |
| 10 | for them sysctl files? If anybody really needs it, it's all in |
| 11 | the source...' |
| 12 | |
| 13 | Well, this documentation is written because some people either |
| 14 | don't know they need to tweak something, or because they don't |
| 15 | have the time or knowledge to read the source code. |
| 16 | |
| 17 | Furthermore, the programmers who built sysctl have built it to |
| 18 | be actually used, not just for the fun of programming it :-) |
| 19 | |
| 20 | ------------------------------------------------------------------------------ |
| 21 | |
| 22 | Legal blurb: |
| 23 | |
| 24 | As usual, there are two main things to consider: |
| 25 | |
| 26 | 1. you get what you pay for |
| 27 | 2. it's free |
| 28 | |
| 29 | The consequences are that I won't guarantee the correctness of |
| 30 | this document, and if you come to me complaining about how you |
| 31 | screwed up your system because of wrong documentation, I won't |
| 32 | feel sorry for you. I might even laugh at you... |
| 33 | |
| 34 | But of course, if you _do_ manage to screw up your system using |
| 35 | only the sysctl options used in this file, I'd like to hear of |
| 36 | it. Not only to have a great laugh, but also to make sure that |
| 37 | you're the last RTFMing person to screw up. |
| 38 | |
| 39 | In short, e-mail your suggestions, corrections and / or horror |
| 40 | stories to: <riel@nl.linux.org> |
| 41 | |
| 42 | Rik van Riel. |
| 43 | |
| 44 | -------------------------------------------------------------- |
| 45 | |
| 46 | Introduction |
| 47 | ============ |
| 48 | |
| 49 | Sysctl is a means of configuring certain aspects of the kernel |
| 50 | at run-time, and the /proc/sys/ directory is there so that you |
| 51 | don't even need special tools to do it! |
| 52 | In fact, there are only four things needed to use these config |
| 53 | facilities: |
| 54 | |
| 55 | - a running Linux system |
| 56 | - root access |
| 57 | - common sense (this is especially hard to come by these days) |
| 58 | - knowledge of what all those values mean |
| 59 | |
| 60 | As a quick 'ls /proc/sys' will show, the directory consists of |
| 61 | several (arch-dependent?) subdirs. Each subdir is mainly about |
| 62 | one part of the kernel, so you can do configuration on a piece |
| 63 | by piece basis, or just some 'thematic frobbing'. |
| 64 | |
| 65 | This documentation is about: |
| 66 | |
| 67 | =============== =============================================================== |
| 68 | abi/ execution domains & personalities |
| 69 | debug/ <empty> |
| 70 | dev/ device specific information (eg dev/cdrom/info) |
| 71 | fs/ specific filesystems |
| 72 | filehandle, inode, dentry and quota tuning |
| 73 | binfmt_misc <Documentation/admin-guide/binfmt-misc.rst> |
| 74 | kernel/ global kernel info / tuning |
| 75 | miscellaneous stuff |
| 76 | net/ networking stuff, for documentation look in: |
| 77 | <Documentation/networking/> |
| 78 | proc/ <empty> |
| 79 | sunrpc/ SUN Remote Procedure Call (NFS) |
| 80 | vm/ memory management tuning |
| 81 | buffer and cache management |
| 82 | user/ Per user per user namespace limits |
| 83 | =============== =============================================================== |
| 84 | |
| 85 | These are the subdirs I have on my system. There might be more |
| 86 | or other subdirs in another setup. If you see another dir, I'd |
| 87 | really like to hear about it :-) |
| 88 | |
| 89 | .. toctree:: |
| 90 | :maxdepth: 1 |
| 91 | |
| 92 | abi |
| 93 | fs |
| 94 | kernel |
| 95 | net |
| 96 | sunrpc |
| 97 | user |
| 98 | vm |