xref: /OK3568_Linux_fs/kernel/Documentation/admin-guide/sysctl/index.rst (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun===========================
2*4882a593SmuzhiyunDocumentation for /proc/sys
3*4882a593Smuzhiyun===========================
4*4882a593Smuzhiyun
5*4882a593SmuzhiyunCopyright (c) 1998, 1999,  Rik van Riel <riel@nl.linux.org>
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun------------------------------------------------------------------------------
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun'Why', I hear you ask, 'would anyone even _want_ documentation
10*4882a593Smuzhiyunfor them sysctl files? If anybody really needs it, it's all in
11*4882a593Smuzhiyunthe source...'
12*4882a593Smuzhiyun
13*4882a593SmuzhiyunWell, this documentation is written because some people either
14*4882a593Smuzhiyundon't know they need to tweak something, or because they don't
15*4882a593Smuzhiyunhave the time or knowledge to read the source code.
16*4882a593Smuzhiyun
17*4882a593SmuzhiyunFurthermore, the programmers who built sysctl have built it to
18*4882a593Smuzhiyunbe actually used, not just for the fun of programming it :-)
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun------------------------------------------------------------------------------
21*4882a593Smuzhiyun
22*4882a593SmuzhiyunLegal blurb:
23*4882a593Smuzhiyun
24*4882a593SmuzhiyunAs usual, there are two main things to consider:
25*4882a593Smuzhiyun
26*4882a593Smuzhiyun1. you get what you pay for
27*4882a593Smuzhiyun2. it's free
28*4882a593Smuzhiyun
29*4882a593SmuzhiyunThe consequences are that I won't guarantee the correctness of
30*4882a593Smuzhiyunthis document, and if you come to me complaining about how you
31*4882a593Smuzhiyunscrewed up your system because of wrong documentation, I won't
32*4882a593Smuzhiyunfeel sorry for you. I might even laugh at you...
33*4882a593Smuzhiyun
34*4882a593SmuzhiyunBut of course, if you _do_ manage to screw up your system using
35*4882a593Smuzhiyunonly the sysctl options used in this file, I'd like to hear of
36*4882a593Smuzhiyunit. Not only to have a great laugh, but also to make sure that
37*4882a593Smuzhiyunyou're the last RTFMing person to screw up.
38*4882a593Smuzhiyun
39*4882a593SmuzhiyunIn short, e-mail your suggestions, corrections and / or horror
40*4882a593Smuzhiyunstories to: <riel@nl.linux.org>
41*4882a593Smuzhiyun
42*4882a593SmuzhiyunRik van Riel.
43*4882a593Smuzhiyun
44*4882a593Smuzhiyun--------------------------------------------------------------
45*4882a593Smuzhiyun
46*4882a593SmuzhiyunIntroduction
47*4882a593Smuzhiyun============
48*4882a593Smuzhiyun
49*4882a593SmuzhiyunSysctl is a means of configuring certain aspects of the kernel
50*4882a593Smuzhiyunat run-time, and the /proc/sys/ directory is there so that you
51*4882a593Smuzhiyundon't even need special tools to do it!
52*4882a593SmuzhiyunIn fact, there are only four things needed to use these config
53*4882a593Smuzhiyunfacilities:
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun- a running Linux system
56*4882a593Smuzhiyun- root access
57*4882a593Smuzhiyun- common sense (this is especially hard to come by these days)
58*4882a593Smuzhiyun- knowledge of what all those values mean
59*4882a593Smuzhiyun
60*4882a593SmuzhiyunAs a quick 'ls /proc/sys' will show, the directory consists of
61*4882a593Smuzhiyunseveral (arch-dependent?) subdirs. Each subdir is mainly about
62*4882a593Smuzhiyunone part of the kernel, so you can do configuration on a piece
63*4882a593Smuzhiyunby piece basis, or just some 'thematic frobbing'.
64*4882a593Smuzhiyun
65*4882a593SmuzhiyunThis documentation is about:
66*4882a593Smuzhiyun
67*4882a593Smuzhiyun=============== ===============================================================
68*4882a593Smuzhiyunabi/		execution domains & personalities
69*4882a593Smuzhiyundebug/		<empty>
70*4882a593Smuzhiyundev/		device specific information (eg dev/cdrom/info)
71*4882a593Smuzhiyunfs/		specific filesystems
72*4882a593Smuzhiyun		filehandle, inode, dentry and quota tuning
73*4882a593Smuzhiyun		binfmt_misc <Documentation/admin-guide/binfmt-misc.rst>
74*4882a593Smuzhiyunkernel/		global kernel info / tuning
75*4882a593Smuzhiyun		miscellaneous stuff
76*4882a593Smuzhiyunnet/		networking stuff, for documentation look in:
77*4882a593Smuzhiyun		<Documentation/networking/>
78*4882a593Smuzhiyunproc/		<empty>
79*4882a593Smuzhiyunsunrpc/		SUN Remote Procedure Call (NFS)
80*4882a593Smuzhiyunvm/		memory management tuning
81*4882a593Smuzhiyun		buffer and cache management
82*4882a593Smuzhiyunuser/		Per user per user namespace limits
83*4882a593Smuzhiyun=============== ===============================================================
84*4882a593Smuzhiyun
85*4882a593SmuzhiyunThese are the subdirs I have on my system. There might be more
86*4882a593Smuzhiyunor other subdirs in another setup. If you see another dir, I'd
87*4882a593Smuzhiyunreally like to hear about it :-)
88*4882a593Smuzhiyun
89*4882a593Smuzhiyun.. toctree::
90*4882a593Smuzhiyun   :maxdepth: 1
91*4882a593Smuzhiyun
92*4882a593Smuzhiyun   abi
93*4882a593Smuzhiyun   fs
94*4882a593Smuzhiyun   kernel
95*4882a593Smuzhiyun   net
96*4882a593Smuzhiyun   sunrpc
97*4882a593Smuzhiyun   user
98*4882a593Smuzhiyun   vm
99