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fea681da | 1 | .\" Copyright (C) 1994, 1995 by Daniel Quinlan (quinlan@yggdrasil.com) |
b4e9ee8f | 2 | .\" and Copyright (C) 2002-2008 Michael Kerrisk <mtk.manpages@gmail.com> |
fea681da MK |
3 | .\" with networking additions from Alan Cox (A.Cox@swansea.ac.uk) |
4 | .\" and scsi additions from Michael Neuffer (neuffer@mail.uni-mainz.de) | |
5 | .\" and sysctl additions from Andries Brouwer (aeb@cwi.nl) | |
6 | .\" and System V IPC (as well as various other) additions from | |
c11b1abf | 7 | .\" Michael Kerrisk <mtk.manpages@gmail.com> |
fea681da | 8 | .\" |
1dd72f9c | 9 | .\" %%%LICENSE_START(GPLv2+_DOC_FULL) |
fea681da MK |
10 | .\" This is free documentation; you can redistribute it and/or |
11 | .\" modify it under the terms of the GNU General Public License as | |
12 | .\" published by the Free Software Foundation; either version 2 of | |
13 | .\" the License, or (at your option) any later version. | |
14 | .\" | |
15 | .\" The GNU General Public License's references to "object code" | |
16 | .\" and "executables" are to be interpreted as the output of any | |
17 | .\" document formatting or typesetting system, including | |
18 | .\" intermediate and printed output. | |
19 | .\" | |
20 | .\" This manual is distributed in the hope that it will be useful, | |
21 | .\" but WITHOUT ANY WARRANTY; without even the implied warranty of | |
22 | .\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
23 | .\" GNU General Public License for more details. | |
24 | .\" | |
25 | .\" You should have received a copy of the GNU General Public | |
c715f741 MK |
26 | .\" License along with this manual; if not, see |
27 | .\" <http://www.gnu.org/licenses/>. | |
6a8d8745 | 28 | .\" %%%LICENSE_END |
fea681da MK |
29 | .\" |
30 | .\" Modified 1995-05-17 by faith@cs.unc.edu | |
31 | .\" Minor changes by aeb and Marty Leisner (leisner@sdsp.mc.xerox.com). | |
32 | .\" Modified 1996-04-13, 1996-07-22 by aeb@cwi.nl | |
33 | .\" Modified 2001-12-16 by rwhron@earthlink.net | |
34 | .\" Modified 2002-07-13 by jbelton@shaw.ca | |
35 | .\" Modified 2002-07-22, 2003-05-27, 2004-04-06, 2004-05-25 | |
c11b1abf | 36 | .\" by Michael Kerrisk <mtk.manpages@gmail.com> |
5d6d14a0 MK |
37 | .\" 2004-11-17, mtk -- updated notes on /proc/loadavg |
38 | .\" 2004-12-01, mtk, rtsig-max and rtsig-nr went away in 2.6.8 | |
568105c6 MK |
39 | .\" 2004-12-14, mtk, updated 'statm', and fixed error in order of list |
40 | .\" 2005-05-12, mtk, updated 'stat' | |
6d64ca9c | 41 | .\" 2005-07-13, mtk, added /proc/sys/fs/mqueue/* |
363f747c MK |
42 | .\" 2005-09-16, mtk, Added /proc/sys/fs/suid_dumpable |
43 | .\" 2005-09-19, mtk, added /proc/zoneinfo | |
b4e9ee8f | 44 | .\" 2005-03-01, mtk, moved /proc/sys/fs/mqueue/* material to mq_overview.7. |
69119dc7 MK |
45 | .\" 2008-06-05, mtk, Added /proc/[pid]/oom_score, /proc/[pid]/oom_adj, |
46 | .\" /proc/[pid]/limits, /proc/[pid]/mountinfo, /proc/[pid]/mountstats, | |
47 | .\" and /proc/[pid]/fdinfo/*. | |
48 | .\" 2008-06-19, mtk, Documented /proc/[pid]/status. | |
cc2d5c36 | 49 | .\" 2008-07-15, mtk, added /proc/config.gz |
363f747c | 50 | .\" |
43d42cc0 | 51 | .\" FIXME cross check against Documentation/filesystems/proc.txt |
c13182ef | 52 | .\" to see what information could be imported from that file |
c533af9d | 53 | .\" into this file. |
fea681da | 54 | .\" |
35deeb87 | 55 | .TH PROC 5 2016-12-12 "Linux" "Linux Programmer's Manual" |
fea681da | 56 | .SH NAME |
9ee4a2b6 | 57 | proc \- process information pseudo-filesystem |
fea681da MK |
58 | .SH DESCRIPTION |
59 | The | |
60 | .I proc | |
ac8727b6 | 61 | filesystem is a pseudo-filesystem which provides an interface to |
c13182ef MK |
62 | kernel data structures. |
63 | It is commonly mounted at | |
fea681da | 64 | .IR /proc . |
c13182ef | 65 | Most of it is read-only, but some files allow kernel variables to be |
fea681da | 66 | changed. |
fee59977 MK |
67 | .SS Mount options |
68 | The | |
69 | .I proc | |
70 | filesystem supports the following mount options: | |
71 | .TP | |
72 | .BR hidepid "=\fIn\fP (since Linux 3.3)" | |
73 | .\" commit 0499680a42141d86417a8fbaa8c8db806bea1201 | |
74 | This option controls who can access the information in | |
75 | .IR /proc/[pid] | |
76 | directories. | |
77 | The argument, | |
78 | .IR n , | |
79 | is one of the following values: | |
80 | .RS | |
81 | .TP 4 | |
82 | 0 | |
83 | Everybody may access all | |
84 | .IR /proc/[pid] | |
85 | directories. | |
86 | This is the traditional behavior, | |
87 | and the default if this mount option is not specified. | |
88 | .TP | |
89 | 1 | |
90 | Users may not access files and subdirectories inside any | |
91 | .IR /proc/[pid] | |
92 | directories but their own (the | |
93 | .IR /proc/[pid] | |
94 | directories themselves remain visible). | |
95 | Sensitive files such as | |
97949440 | 96 | .IR /proc/[pid]/cmdline |
fee59977 | 97 | and |
97949440 | 98 | .IR /proc/[pid]/status |
fee59977 MK |
99 | are now protected against other users. |
100 | This makes it impossible to learn whether any user is running a | |
101 | specific program | |
102 | (so long as the program doesn't otherwise reveal itself by its behavior). | |
103 | .\" As an additional bonus, since | |
97949440 | 104 | .\" .IR /proc/[pid]/cmdline |
fee59977 MK |
105 | .\" is unaccessible for other users, |
106 | .\" poorly written programs passing sensitive information via | |
107 | .\" program arguments are now protected against local eavesdroppers. | |
108 | .TP | |
109 | 2 | |
110 | As for mode 1, but in addition the | |
111 | .IR /proc/[pid] | |
112 | directories belonging to other users become invisible. | |
113 | This means that | |
114 | .IR /proc/[pid] | |
115 | entries can no longer be used to discover the PIDs on the system. | |
116 | This doesn't hide the fact that a process with a specific PID value exists | |
117 | (it can be learned by other means, for example, by "kill -0 $PID"), | |
118 | but it hides a process's UID and GID, | |
119 | which could otherwise be learned by employing | |
120 | .BR stat (2) | |
121 | on a | |
122 | .IR /proc/[pid] | |
123 | directory. | |
124 | This greatly complicates an attacker's task of gathering | |
125 | information about running processes (e.g., discovering whether | |
126 | some daemon is running with elevated privileges, | |
127 | whether another user is running some sensitive program, | |
128 | whether other users are running any program at all, and so on). | |
129 | .RE | |
130 | .TP | |
131 | .BR gid "=\fIgid\fP (since Linux 3.3)" | |
132 | .\" commit 0499680a42141d86417a8fbaa8c8db806bea1201 | |
133 | Specifies the ID of a group whose members are authorized to | |
134 | learn process information otherwise prohibited by | |
135 | .BR hidepid | |
95b1c1d1 | 136 | (i.e., users in this group behave as though |
fee59977 MK |
137 | .I /proc |
138 | was mounted with | |
95b1c1d1 | 139 | .IR hidepid=0 ). |
fee59977 MK |
140 | This group should be used instead of approaches such as putting |
141 | nonroot users into the | |
142 | .BR sudoers (5) | |
143 | file. | |
144 | .SS Files and directories | |
ac8727b6 | 145 | The following list describes many of the files and directories under the |
743638fd MK |
146 | .I /proc |
147 | hierarchy. | |
fea681da MK |
148 | .PD 1 |
149 | .TP | |
69119dc7 | 150 | .I /proc/[pid] |
fea681da MK |
151 | There is a numerical subdirectory for each running process; the |
152 | subdirectory is named by the process ID. | |
1e6a8e2f MK |
153 | |
154 | Each | |
155 | .I /proc/[pid] | |
156 | subdirectory contains the | |
157 | pseudo-files and directories described below. | |
3bdb8ec5 MK |
158 | These files are normally owned by the effective user and |
159 | effective group ID of the process. | |
160 | However, as a security measure, the ownership is made | |
161 | .IR root:root | |
162 | if the process's "dumpable" attribute is set to a value other than 1. | |
163 | This attribute may change for the following reasons: | |
164 | .RS | |
165 | .IP * 3 | |
166 | The attribute was explicitly set via the | |
167 | .BR prctl (2) | |
168 | .B PR_SET_DUMPABLE | |
169 | operation. | |
170 | .IP * | |
171 | The attribute was reset to the value in the file | |
172 | .IR /proc/sys/fs/suid_dumpable | |
173 | (described below), for the reasons described in | |
174 | .BR prctl (2). | |
175 | .RE | |
176 | .IP | |
177 | Resetting the "dumpable" attribute to 1 reverts the ownership of the | |
178 | .IR /proc/[pid]/* | |
179 | files to the process's real UID and real GID. | |
b7a42567 MK |
180 | .TP |
181 | .I /proc/[pid]/attr | |
182 | .\" https://lwn.net/Articles/28222/ | |
183 | .\" From: Stephen Smalley <sds@epoch.ncsc.mil> | |
184 | .\" To: LKML and others | |
185 | .\" Subject: [RFC][PATCH] Process Attribute API for Security Modules | |
186 | .\" Date: 08 Apr 2003 16:17:52 -0400 | |
187 | .\" | |
b3fb99e8 MK |
188 | .\" http://www.nsa.gov/research/_files/selinux/papers/module/x362.shtml |
189 | .\" | |
b7a42567 MK |
190 | The files in this directory provide an API for security modules. |
191 | The contents of this directory are files that can be read and written | |
192 | in order to set security-related attributes. | |
193 | This directory was added to support SELinux, | |
194 | but the intention was that the API be general enough to support | |
195 | other security modules. | |
196 | For the purpose of explanation, | |
197 | examples of how SELinux uses these files are provided below. | |
198 | ||
199 | This directory is present only if the kernel was configured with | |
200 | .BR CONFIG_SECURITY . | |
201 | .TP | |
202 | .IR /proc/[pid]/attr/current " (since Linux 2.6.0)" | |
203 | The contents of this file represent the current | |
204 | security attributes of the process. | |
205 | ||
fd44bdc7 TY |
206 | In SELinux, this file is used to get the security context of a process. |
207 | Prior to Linux 2.6.11, this file could not be used to set the security | |
208 | context (a write was always denied), since SELinux limited process security | |
209 | transitions to | |
b7a42567 MK |
210 | .BR execve (2) |
211 | (see the description of | |
212 | .IR /proc/[pid]/attr/exec , | |
213 | below). | |
fd44bdc7 TY |
214 | Since Linux 2.6.11, SELinux lifted this restriction and began supporting |
215 | "set" operations via writes to this node if authorized by policy, | |
216 | although use of this operation is only suitable for applications that are | |
217 | trusted to maintain any desired separation between the old and new security | |
b6620a25 MK |
218 | contexts. |
219 | Prior to Linux 2.6.28, SELinux did not allow threads within a | |
fd44bdc7 TY |
220 | multi-threaded process to set their security context via this node |
221 | as it would yield an inconsistency among the security contexts of the | |
b6620a25 MK |
222 | threads sharing the same memory space. |
223 | Since Linux 2.6.28, SELinux lifted | |
fd44bdc7 | 224 | this restriction and began supporting "set" operations for threads within |
b6620a25 | 225 | a multithreaded process if the new security context is bounded by the old |
fd44bdc7 TY |
226 | security context, where the bounded relation is defined in policy and |
227 | guarantees that the new security context has a subset of the permissions | |
228 | of the old security context. | |
b7a42567 MK |
229 | Other security modules may choose to support "set" operations via |
230 | writes to this node. | |
231 | .TP | |
232 | .IR /proc/[pid]/attr/exec " (since Linux 2.6.0)" | |
233 | This file represents the attributes to assign to the | |
234 | process upon a subsequent | |
235 | .BR execve (2). | |
236 | ||
237 | In SELinux, | |
238 | this is needed to support role/domain transitions, and | |
239 | .BR execve (2) | |
240 | is the preferred point to make such transitions because it offers better | |
241 | control over the initialization of the process in the new security label | |
242 | and the inheritance of state. | |
243 | In SELinux, this attribute is reset on | |
244 | .BR execve (2) | |
245 | so that the new program reverts to the default behavior for any | |
246 | .BR execve (2) | |
247 | calls that it may make. | |
248 | In SELinux, a process can set | |
249 | only its own | |
250 | .I /proc/[pid]/attr/exec | |
251 | attribute. | |
252 | .TP | |
253 | .IR /proc/[pid]/attr/fscreate " (since Linux 2.6.0)" | |
254 | This file represents the attributes to assign to files | |
255 | created by subsequent calls to | |
256 | .BR open (2), | |
257 | .BR mkdir (2), | |
258 | .BR symlink (2), | |
259 | and | |
260 | .BR mknod (2) | |
261 | ||
262 | SELinux employs this file to support creation of a file | |
263 | (using the aforementioned system calls) | |
264 | in a secure state, | |
265 | so that there is no risk of inappropriate access being obtained | |
266 | between the time of creation and the time that attributes are set. | |
267 | In SELinux, this attribute is reset on | |
268 | .BR execve (2), | |
269 | so that the new program reverts to the default behavior for | |
270 | any file creation calls it may make, but the attribute will persist | |
271 | across multiple file creation calls within a program unless it is | |
272 | explicitly reset. | |
273 | In SELinux, a process can set only its own | |
274 | .IR /proc/[pid]/attr/fscreate | |
275 | attribute. | |
276 | .TP | |
277 | .IR /proc/[pid]/attr/prev " (since Linux 2.6.0)" | |
278 | This file contains the security context of the process before the last | |
279 | .BR execve (2); | |
280 | that is, the previous value of | |
281 | .IR /proc/[pid]/attr/current . | |
666db07e MK |
282 | .TP |
283 | .IR /proc/[pid]/attr/keycreate " (since Linux 2.6.18)" | |
284 | .\" commit 4eb582cf1fbd7b9e5f466e3718a59c957e75254e | |
285 | .\" /Documentation/keys.txt | |
286 | If a process writes a security context into this file, | |
287 | all subsequently created keys | |
288 | .RB ( add_key (2)) | |
289 | will be labeled with this context. | |
290 | For further information, see the kernel source file | |
291 | .IR Documentation/keys.txt . | |
2702dc21 MK |
292 | .TP |
293 | .IR /proc/[pid]/attr/socketcreate " (since Linux 2.6.18)" | |
294 | .\" commit 42c3e03ef6b298813557cdb997bd6db619cd65a2 | |
295 | If a process writes a security context into this file, | |
296 | all subsequently created sockets will be labeled with this context. | |
39b35179 MK |
297 | .TP |
298 | .IR /proc/[pid]/autogroup " (since Linux 2.6.38)" | |
299 | .\" commit 5091faa449ee0b7d73bc296a93bca9540fc51d0a | |
300 | See | |
301 | .BR sched (7). | |
fea681da | 302 | .TP |
69119dc7 | 303 | .IR /proc/[pid]/auxv " (since 2.6.0-test7)" |
857f1942 | 304 | This contains the contents of the ELF interpreter information passed |
c13182ef | 305 | to the process at exec time. |
857f1942 | 306 | The format is one \fIunsigned long\fP ID |
c13182ef | 307 | plus one \fIunsigned long\fP value for each entry. |
857f1942 | 308 | The last entry contains two zeros. |
4c69c692 MK |
309 | See also |
310 | .BR getauxval (3). | |
82664739 MK |
311 | |
312 | Permission to access this file is governed by a ptrace access mode | |
313 | .B PTRACE_MODE_READ_FSCREDS | |
314 | check; see | |
315 | .BR ptrace (2). | |
b5d204d0 | 316 | .TP |
8d708d6b | 317 | .IR /proc/[pid]/cgroup " (since Linux 2.6.24)" |
5c2181ad MK |
318 | See |
319 | .BR cgroups (7). | |
76e0451c MK |
320 | .TP |
321 | .IR /proc/[pid]/clear_refs " (since Linux 2.6.22)" | |
322 | .\" commit b813e931b4c8235bb42e301096ea97dbdee3e8fe (2.6.22) | |
323 | .\" commit 398499d5f3613c47f2143b8c54a04efb5d7a6da9 (2.6.32) | |
324 | .\" commit 040fa02077de01c7e08fa75be6125e4ca5636011 (3.11) | |
b4e9ee8f | 325 | .\" |
b4e9ee8f | 326 | .\" "Clears page referenced bits shown in smaps output" |
76e0451c MK |
327 | .\" write-only, writable only by the owner of the process |
328 | ||
329 | This is a write-only file, writable only by owner of the process. | |
330 | ||
331 | The following values may be written to the file: | |
332 | .RS | |
333 | .TP | |
334 | 1 (since Linux 2.6.22) | |
335 | .\" Internally: CLEAR_REFS_ALL | |
336 | Reset the PG_Referenced and ACCESSED/YOUNG | |
337 | bits for all the pages associated with the process. | |
338 | (Before kernel 2.6.32, writing any nonzero value to this file | |
339 | had this effect.) | |
340 | .TP | |
341 | 2 (since Linux 2.6.32) | |
342 | .\" Internally: CLEAR_REFS_ANON | |
343 | Reset the PG_Referenced and ACCESSED/YOUNG | |
344 | bits for all anonymous pages associated with the process. | |
345 | .TP | |
346 | 3 (since Linux 2.6.32) | |
347 | .\" Internally: CLEAR_REFS_MAPPED | |
348 | Reset the PG_Referenced and ACCESSED/YOUNG | |
349 | bits for all file-mapped pages associated with the process. | |
350 | .RE | |
351 | .IP | |
352 | Clearing the PG_Referenced and ACCESSED/YOUNG bits provides a method | |
353 | to measure approximately how much memory a process is using. | |
322d49fb | 354 | One first inspects the values in the "Referenced" fields |
76e0451c MK |
355 | for the VMAs shown in |
356 | .IR /proc/[pid]/smaps | |
357 | to get an idea of the memory footprint of the | |
358 | process. | |
359 | One then clears the PG_Referenced and ACCESSED/YOUNG bits | |
360 | and, after some measured time interval, | |
322d49fb | 361 | once again inspects the values in the "Referenced" fields |
76e0451c MK |
362 | to get an idea of the change in memory footprint of the |
363 | process during the measured interval. | |
364 | If one is interested only in inspecting the selected mapping types, | |
365 | then the value 2 or 3 can be used instead of 1. | |
366 | ||
dfdf642e | 367 | Further values can be written to affect different properties: |
76e0451c MK |
368 | .RS |
369 | .TP | |
370 | 4 (since Linux 3.11) | |
371 | Clear the soft-dirty bit for all the pages associated with the process. | |
372 | .\" Internally: CLEAR_REFS_SOFT_DIRTY | |
373 | This is used (in conjunction with | |
374 | .IR /proc/[pid]/pagemap ) | |
375 | by the check-point restore system to discover which pages of a process | |
376 | have been dirtied since the file | |
377 | .IR /proc/[pid]/clear_refs | |
378 | was written to. | |
dfdf642e NK |
379 | .TP |
380 | 5 (since Linux 4.0) | |
381 | .\" Internally: CLEAR_REFS_MM_HIWATER_RSS | |
0989246e MK |
382 | Reset the peak resident set size ("high water mark") to the process's |
383 | current resident set size value. | |
76e0451c MK |
384 | .RE |
385 | .IP | |
386 | Writing any value to | |
387 | .IR /proc/[pid]/clear_refs | |
388 | other than those listed above has no effect. | |
389 | ||
390 | The | |
391 | .IR /proc/[pid]/clear_refs | |
392 | file is present only if the | |
393 | .B CONFIG_PROC_PAGE_MONITOR | |
394 | kernel configuration option is enabled. | |
857f1942 | 395 | .TP |
69119dc7 | 396 | .I /proc/[pid]/cmdline |
6975c16e | 397 | This read-only file holds the complete command line for the process, |
b447cd58 MK |
398 | unless the process is a zombie. |
399 | .\" In 2.3.26, this also used to be true if the process was swapped out. | |
400 | In the latter case, there is nothing in this file: | |
75b94dc3 | 401 | that is, a read on this file will return 0 characters. |
b447cd58 | 402 | The command-line arguments appear in this file as a set of |
6596d270 MK |
403 | strings separated by null bytes (\(aq\\0\(aq), |
404 | with a further null byte after the last string. | |
32d7ef00 MK |
405 | .TP |
406 | .IR /proc/[pid]/comm " (since Linux 2.6.33)" | |
407 | .\" commit 4614a696bd1c3a9af3a08f0e5874830a85b889d4 | |
408 | This file exposes the process's | |
409 | .I comm | |
410 | value\(emthat is, the command name associated with the process. | |
411 | Different threads in the same process may have different | |
412 | .I comm | |
413 | values, accessible via | |
414 | .IR /proc/[pid]/task/[tid]/comm . | |
415 | A thread may modify its | |
416 | .I comm | |
417 | value, or that of any of other thread in the same thread group (see | |
418 | the discussion of | |
419 | .B CLONE_THREAD | |
420 | in | |
421 | .BR clone (2)), | |
422 | by writing to the file | |
423 | .IR /proc/self/task/[tid]/comm . | |
424 | Strings longer than | |
425 | .B TASK_COMM_LEN | |
426 | (16) characters are silently truncated. | |
427 | ||
ef4f4031 | 428 | This file provides a superset of the |
32d7ef00 MK |
429 | .BR prctl (2) |
430 | .B PR_SET_NAME | |
431 | and | |
432 | .B PR_GET_NAME | |
433 | operations, and is employed by | |
434 | .BR pthread_setname_np (3) | |
435 | when used to rename threads other than the caller. | |
fea681da | 436 | .TP |
7e07d950 | 437 | .IR /proc/[pid]/coredump_filter " (since Linux 2.6.23)" |
b4e9ee8f MK |
438 | See |
439 | .BR core (5). | |
5c411b17 | 440 | .TP |
7e07d950 MK |
441 | .IR /proc/[pid]/cpuset " (since Linux 2.6.12)" |
442 | .\" and/proc/[pid]/task/[tid]/cpuset | |
5c411b17 MK |
443 | See |
444 | .BR cpuset (7). | |
b4e9ee8f | 445 | .TP |
69119dc7 | 446 | .I /proc/[pid]/cwd |
c13182ef | 447 | This is a symbolic link to the current working directory of the process. |
59a40ed7 MK |
448 | To find out the current working directory of process 20, |
449 | for instance, you can do this: | |
fea681da | 450 | |
59a40ed7 | 451 | .in +4n |
fea681da | 452 | .nf |
b43a3b30 | 453 | .RB "$" " cd /proc/20/cwd; /bin/pwd" |
fea681da | 454 | .fi |
59a40ed7 | 455 | .in |
fea681da | 456 | |
c13182ef MK |
457 | Note that the |
458 | .I pwd | |
e7b489f0 | 459 | command is often a shell built-in, and might |
c13182ef | 460 | not work properly. |
743638fd MK |
461 | In |
462 | .BR bash (1), | |
463 | you may use | |
464 | .IR "pwd\ \-P" . | |
afcaf646 MK |
465 | |
466 | .\" The following was still true as at kernel 2.6.13 | |
c13182ef MK |
467 | In a multithreaded process, the contents of this symbolic link |
468 | are not available if the main thread has already terminated | |
afcaf646 | 469 | (typically by calling |
59a40ed7 | 470 | .BR pthread_exit (3)). |
b902fe18 MK |
471 | |
472 | Permission to dereference or read | |
473 | .RB ( readlink (2)) | |
474 | this symbolic link is governed by a ptrace access mode | |
475 | .B PTRACE_MODE_READ_FSCREDS | |
476 | check; see | |
477 | .BR ptrace (2). | |
fea681da | 478 | .TP |
69119dc7 | 479 | .I /proc/[pid]/environ |
fea681da | 480 | This file contains the environment for the process. |
f81fb444 | 481 | The entries are separated by null bytes (\(aq\\0\(aq), |
b4e9ee8f | 482 | and there may be a null byte at the end. |
fea681da | 483 | Thus, to print out the environment of process 1, you would do: |
a08ea57c | 484 | .in +4n |
fea681da | 485 | .nf |
a08ea57c | 486 | |
13912780 | 487 | .RB "$" " strings /proc/1/environ" |
fea681da | 488 | .fi |
a08ea57c | 489 | .in |
82664739 MK |
490 | |
491 | Permission to access this file is governed by a ptrace access mode | |
492 | .B PTRACE_MODE_READ_FSCREDS | |
493 | check; see | |
494 | .BR ptrace (2). | |
fea681da | 495 | .TP |
69119dc7 | 496 | .I /proc/[pid]/exe |
fea681da | 497 | Under Linux 2.2 and later, this file is a symbolic link |
2d7195b8 | 498 | containing the actual pathname of the executed command. |
c13182ef MK |
499 | This symbolic link can be dereferenced normally; attempting to open |
500 | it will open the executable. | |
501 | You can even type | |
69119dc7 | 502 | .I /proc/[pid]/exe |
06dd061c | 503 | to run another copy of the same executable that is being run by |
69119dc7 | 504 | process [pid]. |
7e3c767a GJ |
505 | If the pathname has been unlinked, the symbolic link will contain the |
506 | string \(aq(deleted)\(aq appended to the original pathname. | |
afcaf646 | 507 | .\" The following was still true as at kernel 2.6.13 |
c13182ef MK |
508 | In a multithreaded process, the contents of this symbolic link |
509 | are not available if the main thread has already terminated | |
afcaf646 MK |
510 | (typically by calling |
511 | .BR pthread_exit (3)). | |
fea681da | 512 | |
b902fe18 MK |
513 | Permission to dereference or read |
514 | .RB ( readlink (2)) | |
515 | this symbolic link is governed by a ptrace access mode | |
516 | .B PTRACE_MODE_READ_FSCREDS | |
517 | check; see | |
518 | .BR ptrace (2). | |
519 | ||
eb9a0b2f | 520 | Under Linux 2.0 and earlier, |
69119dc7 | 521 | .I /proc/[pid]/exe |
c13182ef MK |
522 | is a pointer to the binary which was executed, |
523 | and appears as a symbolic link. | |
524 | A | |
fea681da MK |
525 | .BR readlink (2) |
526 | call on this file under Linux 2.0 returns a string in the format: | |
527 | ||
59a40ed7 | 528 | [device]:inode |
fea681da MK |
529 | |
530 | For example, [0301]:1502 would be inode 1502 on device major 03 (IDE, | |
531 | MFM, etc. drives) minor 01 (first partition on the first drive). | |
532 | ||
533 | .BR find (1) | |
59a40ed7 MK |
534 | with the |
535 | .I \-inum | |
536 | option can be used to locate the file. | |
fea681da | 537 | .TP |
d4529654 | 538 | .I /proc/[pid]/fd/ |
fea681da MK |
539 | This is a subdirectory containing one entry for each file which the |
540 | process has open, named by its file descriptor, and which is a | |
c13182ef | 541 | symbolic link to the actual file. |
f78ed33a | 542 | Thus, 0 is standard input, 1 standard output, 2 standard error, and so on. |
fea681da | 543 | |
f75715e0 MK |
544 | For file descriptors for pipes and sockets, |
545 | the entries will be symbolic links whose content is the | |
546 | file type with the inode. | |
d4529654 MF |
547 | A |
548 | .BR readlink (2) | |
549 | call on this file returns a string in the format: | |
f75715e0 | 550 | |
d4529654 | 551 | type:[inode] |
f75715e0 MK |
552 | |
553 | For example, | |
554 | .I socket:[2248868] | |
555 | will be a socket and its inode is 2248868. | |
556 | For sockets, that inode can be used to find more information | |
557 | in one of the files under | |
d4529654 MF |
558 | .IR /proc/net/ . |
559 | ||
2b7a2ac5 MK |
560 | For file descriptors that have no corresponding inode |
561 | (e.g., file descriptors produced by | |
562 | .BR epoll_create (2), | |
563 | .BR eventfd (2), | |
564 | .BR inotify_init (2), | |
565 | .BR signalfd (2), | |
566 | and | |
567 | .BR timerfd (2)), | |
568 | the entry will be a symbolic link with contents of the form | |
569 | ||
570 | anon_inode:<file-type> | |
571 | ||
572 | In some cases, the | |
573 | .I file-type | |
574 | is surrounded by square brackets. | |
575 | ||
576 | For example, an epoll file descriptor will have a symbolic link | |
577 | whose content is the string | |
578 | .IR "anon_inode:[eventpoll]" . | |
579 | ||
d4529654 | 580 | .\"The following was still true as at kernel 2.6.13 |
afcaf646 | 581 | In a multithreaded process, the contents of this directory |
c13182ef | 582 | are not available if the main thread has already terminated |
afcaf646 MK |
583 | (typically by calling |
584 | .BR pthread_exit (3)). | |
585 | ||
59a40ed7 MK |
586 | Programs that will take a filename as a command-line argument, |
587 | but will not take input from standard input if no argument is supplied, | |
588 | or that write to a file named as a command-line argument, | |
589 | but will not send their output to standard output | |
590 | if no argument is supplied, can nevertheless be made to use | |
591 | standard input or standard out using | |
69119dc7 | 592 | .IR /proc/[pid]/fd . |
59a40ed7 MK |
593 | For example, assuming that |
594 | .I \-i | |
595 | is the flag designating an input file and | |
596 | .I \-o | |
597 | is the flag designating an output file: | |
a08ea57c | 598 | .in +4n |
fea681da MK |
599 | .nf |
600 | ||
b43a3b30 | 601 | .RB "$" " foobar \-i /proc/self/fd/0 \-o /proc/self/fd/1 ..." |
fea681da | 602 | .fi |
a08ea57c MK |
603 | .in |
604 | ||
fea681da MK |
605 | and you have a working filter. |
606 | .\" The following is not true in my tests (MTK): | |
607 | .\" Note that this will not work for | |
608 | .\" programs that seek on their files, as the files in the fd directory | |
609 | .\" are not seekable. | |
610 | ||
59a40ed7 MK |
611 | .I /proc/self/fd/N |
612 | is approximately the same as | |
613 | .I /dev/fd/N | |
008f1ecc | 614 | in some UNIX and UNIX-like systems. |
c13182ef | 615 | Most Linux MAKEDEV scripts symbolically link |
59a40ed7 MK |
616 | .I /dev/fd |
617 | to | |
618 | .IR /proc/self/fd , | |
619 | in fact. | |
620 | ||
621 | Most systems provide symbolic links | |
622 | .IR /dev/stdin , | |
623 | .IR /dev/stdout , | |
624 | and | |
625 | .IR /dev/stderr , | |
626 | which respectively link to the files | |
627 | .IR 0 , | |
628 | .IR 1 , | |
629 | and | |
630 | .IR 2 | |
631 | in | |
632 | .IR /proc/self/fd . | |
633 | Thus the example command above could be written as: | |
634 | .in +4n | |
635 | .nf | |
636 | ||
b43a3b30 | 637 | .RB "$" " foobar \-i /dev/stdin \-o /dev/stdout ..." |
59a40ed7 MK |
638 | .fi |
639 | .in | |
138a191e MK |
640 | .IP |
641 | Permission to dereference or read | |
642 | .RB ( readlink (2)) | |
643 | the symbolic links in this directory is governed by a ptrace access mode | |
644 | .B PTRACE_MODE_READ_FSCREDS | |
645 | check; see | |
646 | .BR ptrace (2). | |
69ab425e MK |
647 | .\" FIXME Describe /proc/[pid]/loginuid |
648 | .\" Added in 2.6.11; updating requires CAP_AUDIT_CONTROL | |
649 | .\" CONFIG_AUDITSYSCALL | |
650 | .TP | |
7e07d950 | 651 | .IR /proc/[pid]/fdinfo/ " (since Linux 2.6.22)" |
69ab425e MK |
652 | This is a subdirectory containing one entry for each file which the |
653 | process has open, named by its file descriptor. | |
0275956d | 654 | The files in this directory are readable only by the owner of the process. |
69ab425e | 655 | The contents of each file can be read to obtain information |
0275956d MK |
656 | about the corresponding file descriptor. |
657 | The content depends on the type of file referred to by the | |
d9cb0d7d | 658 | corresponding file descriptor. |
0275956d MK |
659 | |
660 | For regular files and directories, we see something like: | |
69ab425e MK |
661 | .in +4n |
662 | .nf | |
663 | ||
664 | .RB "$" " cat /proc/12015/fdinfo/4" | |
665 | pos: 1000 | |
666 | flags: 01002002 | |
0275956d | 667 | mnt_id: 21 |
69ab425e MK |
668 | .fi |
669 | .in | |
670 | ||
9599cbb3 MK |
671 | The fields are as follows: |
672 | .RS | |
673 | .TP | |
69ab425e | 674 | .I pos |
9599cbb3 MK |
675 | This is a decimal number showing the file offset. |
676 | .TP | |
69ab425e | 677 | .I flags |
9599cbb3 | 678 | This is an octal number that displays the |
69ab425e MK |
679 | file access mode and file status flags (see |
680 | .BR open (2)). | |
d7e537ce MK |
681 | If the close-on-exec file descriptor flag is set, then |
682 | .I flags | |
683 | will also include the value | |
684 | .BR O_CLOEXEC . | |
685 | ||
686 | Before Linux 3.1, | |
687 | .\" commit 1117f72ea0217ba0cc19f05adbbd8b9a397f5ab7 | |
688 | this field incorrectly displayed the setting of | |
689 | .B O_CLOEXEC | |
690 | at the time the file was opened, | |
691 | rather than the current setting of the close-on-exec flag. | |
9599cbb3 MK |
692 | .TP |
693 | .I | |
0275956d | 694 | .I mnt_id |
9599cbb3 | 695 | This field, present since Linux 3.15, |
0275956d MK |
696 | .\" commit 49d063cb353265c3af701bab215ac438ca7df36d |
697 | is the ID of the mount point containing this file. | |
698 | See the description of | |
699 | .IR /proc/[pid]/mountinfo . | |
9599cbb3 MK |
700 | .RE |
701 | .IP | |
6e7622ee MK |
702 | For eventfd file descriptors (see |
703 | .BR eventfd (2)), | |
b6a7fd50 MK |
704 | we see (since Linux 3.8) |
705 | .\" commit cbac5542d48127b546a23d816380a7926eee1c25 | |
706 | the following fields: | |
6e7622ee MK |
707 | |
708 | .in +4n | |
709 | .nf | |
710 | pos: 0 | |
711 | flags: 02 | |
712 | mnt_id: 10 | |
713 | eventfd-count: 40 | |
714 | .fi | |
715 | .in | |
716 | ||
717 | .I eventfd-count | |
718 | is the current value of the eventfd counter, in hexadecimal. | |
719 | ||
58d375dd MK |
720 | For epoll file descriptors (see |
721 | .BR epoll (7)), | |
b6a7fd50 MK |
722 | we see (since Linux 3.8) |
723 | .\" commit 138d22b58696c506799f8de759804083ff9effae | |
724 | the following fields: | |
58d375dd MK |
725 | |
726 | .in +4n | |
727 | .nf | |
728 | pos: 0 | |
729 | flags: 02 | |
730 | mnt_id: 10 | |
731 | tfd: 9 events: 19 data: 74253d2500000009 | |
732 | tfd: 7 events: 19 data: 74253d2500000007 | |
733 | .fi | |
734 | .in | |
735 | ||
736 | Each of the lines beginning | |
737 | .I tfd | |
738 | describes one of the file descriptors being monitored via | |
739 | the epoll file descriptor (see | |
740 | .BR epoll_ctl (2) | |
741 | for some details). | |
742 | The | |
743 | .IR tfd | |
744 | field is the number of the file descriptor. | |
745 | The | |
746 | .I events | |
747 | field is a hexadecimal mask of the events being monitored for this file | |
748 | descriptor. | |
749 | The | |
750 | .I data | |
751 | field is the data value associated with this file descriptor. | |
752 | ||
f8a14cac MK |
753 | For signalfd file descriptors (see |
754 | .BR signalfd (2)), | |
b6a7fd50 MK |
755 | we see (since Linux 3.8) |
756 | .\" commit 138d22b58696c506799f8de759804083ff9effae | |
757 | the following fields: | |
f8a14cac MK |
758 | |
759 | .in +4n | |
760 | .nf | |
761 | pos: 0 | |
762 | flags: 02 | |
763 | mnt_id: 10 | |
764 | sigmask: 0000000000000006 | |
765 | .fi | |
766 | .in | |
767 | ||
768 | .I sigmask | |
769 | is the hexadecimal mask of signals that are accepted via this | |
770 | signalfd file descriptor. | |
771 | (In this example, bits 2 and 3 are set, corresponding to the signals | |
772 | .B SIGINT | |
773 | and | |
774 | .BR SIGQUIT ; | |
775 | see | |
776 | .BR signal (7).) | |
4e77145c MK |
777 | |
778 | For inotify file descriptors (see | |
779 | .BR inotify (7)), | |
780 | we see (since Linux 3.8) | |
781 | the following fields: | |
782 | ||
783 | .in +4n | |
784 | .nf | |
785 | pos: 0 | |
786 | flags: 00 | |
787 | mnt_id: 11 | |
788 | inotify wd:2 ino:7ef82a sdev:800001 mask:800afff ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:2af87e00220ffd73 | |
789 | inotify wd:1 ino:192627 sdev:800001 mask:800afff ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:27261900802dfd73 | |
790 | .fi | |
791 | .in | |
792 | ||
793 | Each of the lines beginning with "inotify" displays information about | |
794 | one file or directory that is being monitored. | |
795 | The fields in this line are as follows: | |
796 | .RS | |
797 | .TP | |
798 | .I wd | |
799 | A watch descriptor number (in decimal). | |
800 | .TP | |
801 | .I ino | |
802 | The inode number of the target file (in hexadecimal). | |
803 | .TP | |
804 | .I sdev | |
805 | The ID of the device where the target file resides (in hexadecimal). | |
806 | .TP | |
807 | .I mask | |
808 | The mask of events being monitored for the target file (in hexadecimal). | |
809 | .RE | |
810 | .IP | |
811 | If the kernel was built with exportfs support, the path to the target | |
812 | file is exposed as a file handle, via three hexadecimal fields: | |
813 | .IR fhandle-bytes , | |
814 | .IR fhandle-type , | |
815 | and | |
816 | .IR f_handle . | |
e2444bcb MK |
817 | |
818 | For fanotify file descriptors (see | |
819 | .BR fanotify (7)), | |
820 | we see (since Linux 3.8) | |
821 | the following fields: | |
822 | ||
823 | .in +4n | |
824 | .nf | |
825 | pos: 0 | |
826 | flags: 02 | |
827 | mnt_id: 11 | |
828 | fanotify flags:0 event-flags:88002 | |
829 | fanotify ino:19264f sdev:800001 mflags:0 mask:1 ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:4f261900a82dfd73 | |
830 | .fi | |
831 | .in | |
832 | ||
833 | The fourth line displays information defined when the fanotify group | |
834 | was created via | |
835 | .BR fanotify_init (2): | |
836 | .RS | |
837 | .TP | |
838 | .I flags | |
839 | The | |
840 | .I flags | |
841 | argument given to | |
842 | .BR fanotify_init (2) | |
843 | (expressed in hexadecimal). | |
844 | .TP | |
845 | .I event-flags | |
846 | The | |
847 | .I event_f_flags | |
848 | argument given to | |
849 | .BR fanotify_init (2) | |
850 | (expressed in hexadecimal). | |
851 | .RE | |
852 | .IP | |
853 | Each additional line shown in the file contains information | |
854 | about one of the marks in the fanotify group. | |
855 | Most of these fields are as for inotify, except: | |
856 | .RS | |
857 | .TP | |
858 | .I mflags | |
859 | The flags associated with the mark | |
860 | (expressed in hexadecimal). | |
861 | .TP | |
862 | .I mask | |
863 | The events mask for this mark | |
864 | (expressed in hexadecimal). | |
865 | .TP | |
866 | .I ignored_mask | |
867 | The mask of events that are ignored for this mark | |
868 | (expressed in hexadecimal). | |
869 | .RE | |
870 | .IP | |
871 | For details on these fields, see | |
872 | .BR fanotify_mark (2). | |
0ca2fc4d PS |
873 | .TP |
874 | .IR /proc/[pid]/io " (since kernel 2.6.20)" | |
68f11066 MK |
875 | .\" commit 7c3ab7381e79dfc7db14a67c6f4f3285664e1ec2 |
876 | This file contains I/O statistics for the process, for example: | |
0ca2fc4d PS |
877 | .in +4n |
878 | .nf | |
879 | ||
880 | .RB "#" " cat /proc/3828/io" | |
881 | rchar: 323934931 | |
882 | wchar: 323929600 | |
883 | syscr: 632687 | |
884 | syscw: 632675 | |
885 | read_bytes: 0 | |
886 | write_bytes: 323932160 | |
887 | cancelled_write_bytes: 0 | |
888 | .fi | |
889 | .in | |
890 | ||
891 | The fields are as follows: | |
892 | .RS | |
68f11066 MK |
893 | .TP |
894 | .IR rchar ": characters read" | |
0ca2fc4d PS |
895 | The number of bytes which this task has caused to be read from storage. |
896 | This is simply the sum of bytes which this process passed to | |
897 | .BR read (2) | |
68f11066 | 898 | and similar system calls. |
11256884 | 899 | It includes things such as terminal I/O and |
68f11066 MK |
900 | is unaffected by whether or not actual |
901 | physical disk I/O was required (the read might have been satisfied from | |
0ca2fc4d | 902 | pagecache). |
68f11066 MK |
903 | .TP |
904 | .IR wchar ": characters written" | |
0ca2fc4d PS |
905 | The number of bytes which this task has caused, or shall cause to be written |
906 | to disk. | |
907 | Similar caveats apply here as with | |
908 | .IR rchar . | |
68f11066 MK |
909 | .TP |
910 | .IR syscr ": read syscalls" | |
911 | Attempt to count the number of read I/O operations\(emthat is, | |
912 | system calls such as | |
0ca2fc4d PS |
913 | .BR read (2) |
914 | and | |
915 | .BR pread (2). | |
68f11066 MK |
916 | .TP |
917 | .IR syscw ": write syscalls" | |
918 | Attempt to count the number of write I/O operations\(emthat is, | |
919 | system calls such as | |
0ca2fc4d PS |
920 | .BR write (2) |
921 | and | |
922 | .BR pwrite (2). | |
68f11066 MK |
923 | .TP |
924 | .IR read_bytes ": bytes read" | |
0ca2fc4d PS |
925 | Attempt to count the number of bytes which this process really did cause to |
926 | be fetched from the storage layer. | |
927 | This is accurate for block-backed filesystems. | |
68f11066 MK |
928 | .TP |
929 | .IR write_bytes ": bytes written" | |
0ca2fc4d PS |
930 | Attempt to count the number of bytes which this process caused to be sent to |
931 | the storage layer. | |
68f11066 | 932 | .TP |
0ca2fc4d | 933 | .IR cancelled_write_bytes : |
0ca2fc4d PS |
934 | The big inaccuracy here is truncate. |
935 | If a process writes 1MB to a file and then deletes the file, | |
936 | it will in fact perform no writeout. | |
937 | But it will have been accounted as having caused 1MB of write. | |
68f11066 | 938 | In other words: this field represents the number of bytes which this process |
0ca2fc4d | 939 | caused to not happen, by truncating pagecache. |
68f11066 | 940 | A task can cause "negative" I/O too. |
0ca2fc4d | 941 | If this task truncates some dirty pagecache, |
68f11066 MK |
942 | some I/O which another task has been accounted for |
943 | (in its | |
944 | .IR write_bytes ) | |
945 | will not be happening. | |
946 | .RE | |
0ca2fc4d PS |
947 | .IP |
948 | .IR Note : | |
68f11066 | 949 | In the current implementation, things are a bit racy on 32-bit systems: |
0ca2fc4d PS |
950 | if process A reads process B's |
951 | .I /proc/[pid]/io | |
68f11066 | 952 | while process B is updating one of these 64-bit counters, |
0ca2fc4d | 953 | process A could see an intermediate result. |
d8e2972a MK |
954 | |
955 | Permission to access this file is governed by a ptrace access mode | |
956 | .B PTRACE_MODE_READ_FSCREDS | |
957 | check; see | |
958 | .BR ptrace (2). | |
f6e17121 | 959 | .TP |
ccdc8958 | 960 | .IR /proc/[pid]/gid_map " (since Linux 3.5)" |
d06a6170 MK |
961 | See |
962 | .BR user_namespaces (7). | |
69ab425e | 963 | .TP |
7e07d950 | 964 | .IR /proc/[pid]/limits " (since Linux 2.6.24)" |
69ab425e MK |
965 | This file displays the soft limit, hard limit, and units of measurement |
966 | for each of the process's resource limits (see | |
967 | .BR getrlimit (2)). | |
968 | Up to and including Linux 2.6.35, | |
969 | this file is protected to allow reading only by the real UID of the process. | |
970 | Since Linux 2.6.36, | |
971 | .\" commit 3036e7b490bf7878c6dae952eec5fb87b1106589 | |
972 | this file is readable by all users on the system. | |
b4f89985 PE |
973 | .TP |
974 | .IR /proc/[pid]/map_files/ " (since kernel 3.3) | |
18cdd0ac MK |
975 | .\" commit 640708a2cff7f81e246243b0073c66e6ece7e53e |
976 | This subdirectory contains entries corresponding to memory-mapped | |
b4f89985 PE |
977 | files (see |
978 | .BR mmap (2)). | |
18cdd0ac MK |
979 | Entries are named by memory region start and end |
980 | address pair (expressed as hexadecimal numbers), | |
981 | and are symbolic links to the mapped files themselves. | |
982 | Here is an example, with the output wrapped and reformatted to fit on an 80-column display: | |
b4f89985 PE |
983 | .in +4n |
984 | .nf | |
985 | ||
f2aa4dcc | 986 | .RB "#" " ls -l /proc/self/map_files/" |
18cdd0ac MK |
987 | lr\-\-\-\-\-\-\-\-. 1 root root 64 Apr 16 21:31 |
988 | 3252e00000\-3252e20000 \-> /usr/lib64/ld-2.15.so | |
b4f89985 PE |
989 | \&... |
990 | .fi | |
991 | .in | |
992 | ||
993 | Although these entries are present for memory regions that were | |
d6a56978 | 994 | mapped with the |
b4f89985 | 995 | .BR MAP_FILE |
18cdd0ac | 996 | flag, the way anonymous shared memory (regions created with the |
b4f89985 PE |
997 | .B MAP_ANON | MAP_SHARED |
998 | flags) | |
999 | is implemented in Linux | |
18cdd0ac MK |
1000 | means that such regions also appear on this directory. |
1001 | Here is an example where the target file is the deleted | |
1002 | .I /dev/zero | |
1003 | one: | |
b4f89985 PE |
1004 | .in +4n |
1005 | .nf | |
1006 | ||
18cdd0ac MK |
1007 | lrw\-\-\-\-\-\-\-. 1 root root 64 Apr 16 21:33 |
1008 | 7fc075d2f000\-7fc075e6f000 \-> /dev/zero (deleted) | |
b4f89985 PE |
1009 | .fi |
1010 | .in | |
1011 | ||
1012 | This directory appears only if the | |
1013 | .B CONFIG_CHECKPOINT_RESTORE | |
1014 | kernel configuration option is enabled. | |
f2aa4dcc MK |
1015 | Privilege |
1016 | .RB ( CAP_SYS_ADMIN ) | |
1017 | .\" FIXME | |
1018 | .\" This may change. See the mail thread | |
43d42cc0 | 1019 | .\" "[RFC][PATCH v2] procfs: Always expose /proc/<pid>/map_files/ and make it readable" |
f2aa4dcc MK |
1020 | .\" from Jan 2015 |
1021 | is required to view the contents of this directory. | |
fea681da | 1022 | .TP |
69119dc7 | 1023 | .I /proc/[pid]/maps |
fea681da MK |
1024 | A file containing the currently mapped memory regions and their access |
1025 | permissions. | |
bbf9f397 MK |
1026 | See |
1027 | .BR mmap (2) | |
1028 | for some further information about memory mappings. | |
fea681da | 1029 | |
aee2f0bf MK |
1030 | Permission to access this file is governed by a ptrace access mode |
1031 | .B PTRACE_MODE_READ_FSCREDS | |
1032 | check; see | |
1033 | .BR ptrace (2). | |
1034 | ||
dd0c3b96 | 1035 | The format of the file is: |
fea681da | 1036 | |
21781757 | 1037 | .in -7n |
fea681da MK |
1038 | .nf |
1039 | .ft CW | |
fea681da | 1040 | .ft |
21781757 MK |
1041 | .I "address perms offset dev inode pathname" |
1042 | 00400000-00452000 r-xp 00000000 08:02 173521 /usr/bin/dbus-daemon | |
1043 | 00651000-00652000 r--p 00051000 08:02 173521 /usr/bin/dbus-daemon | |
1044 | 00652000-00655000 rw-p 00052000 08:02 173521 /usr/bin/dbus-daemon | |
1045 | 00e03000-00e24000 rw-p 00000000 00:00 0 [heap] | |
1046 | 00e24000-011f7000 rw-p 00000000 00:00 0 [heap] | |
182090db | 1047 | \&... |
21781757 MK |
1048 | 35b1800000-35b1820000 r-xp 00000000 08:02 135522 /usr/lib64/ld-2.15.so |
1049 | 35b1a1f000-35b1a20000 r--p 0001f000 08:02 135522 /usr/lib64/ld-2.15.so | |
1050 | 35b1a20000-35b1a21000 rw-p 00020000 08:02 135522 /usr/lib64/ld-2.15.so | |
7d2e6d74 | 1051 | 35b1a21000-35b1a22000 rw-p 00000000 00:00 0 |
21781757 MK |
1052 | 35b1c00000-35b1dac000 r-xp 00000000 08:02 135870 /usr/lib64/libc-2.15.so |
1053 | 35b1dac000-35b1fac000 ---p 001ac000 08:02 135870 /usr/lib64/libc-2.15.so | |
1054 | 35b1fac000-35b1fb0000 r--p 001ac000 08:02 135870 /usr/lib64/libc-2.15.so | |
1055 | 35b1fb0000-35b1fb2000 rw-p 001b0000 08:02 135870 /usr/lib64/libc-2.15.so | |
182090db | 1056 | \&... |
21781757 | 1057 | f2c6ff8c000-7f2c7078c000 rw-p 00000000 00:00 0 [stack:986] |
182090db | 1058 | \&... |
21781757 MK |
1059 | 7fffb2c0d000-7fffb2c2e000 rw-p 00000000 00:00 0 [stack] |
1060 | 7fffb2d48000-7fffb2d49000 r-xp 00000000 00:00 0 [vdso] | |
fea681da | 1061 | .fi |
21781757 | 1062 | .in |
fea681da | 1063 | |
7d2e6d74 | 1064 | The |
3eb8c588 MK |
1065 | .I address |
1066 | field is the address space in the process that the mapping occupies. | |
1067 | The | |
1068 | .I perms | |
1069 | field is a set of permissions: | |
fea681da MK |
1070 | |
1071 | .nf | |
1072 | .in +5 | |
1073 | r = read | |
1074 | w = write | |
1075 | x = execute | |
1076 | s = shared | |
1077 | p = private (copy on write) | |
1078 | .fi | |
1079 | .in | |
1080 | ||
3eb8c588 MK |
1081 | The |
1082 | .I offset | |
b844cf04 | 1083 | field is the offset into the file/whatever; |
3eb8c588 MK |
1084 | .I dev |
1085 | is the device | |
dd0c3b96 | 1086 | (major:minor); |
3eb8c588 MK |
1087 | .I inode |
1088 | is the inode on that device. | |
59a40ed7 | 1089 | 0 indicates that no inode is associated with the memory region, |
16e64bae | 1090 | as would be the case with BSS (uninitialized data). |
fea681da | 1091 | |
3eb8c588 MK |
1092 | The |
1093 | .I pathname | |
1094 | field will usually be the file that is backing the mapping. | |
491ea6f1 | 1095 | For ELF files, |
3eb8c588 MK |
1096 | you can easily coordinate with the |
1097 | .I offset | |
1098 | field by looking at the | |
491ea6f1 MK |
1099 | Offset field in the ELF program headers |
1100 | .RI ( "readelf\ \-l" ). | |
37d32c38 | 1101 | |
491ea6f1 | 1102 | There are additional helpful pseudo-paths: |
61b0b1f4 MK |
1103 | .RS 12 |
1104 | .TP | |
1105 | .IR [stack] | |
16e64bae | 1106 | The initial process's (also known as the main thread's) stack. |
61b0b1f4 | 1107 | .TP |
3eb8c588 | 1108 | .IR [stack:<tid>] " (since Linux 3.4)" |
a60894c5 | 1109 | .\" commit b76437579d1344b612cf1851ae610c636cec7db0 |
61b0b1f4 | 1110 | A thread's stack (where the |
3eb8c588 | 1111 | .IR <tid> |
61b0b1f4 | 1112 | is a thread ID). |
491ea6f1 | 1113 | It corresponds to the |
3eb8c588 | 1114 | .IR /proc/[pid]/task/[tid]/ |
37d32c38 | 1115 | path. |
61b0b1f4 | 1116 | .TP |
7d2e6d74 | 1117 | .IR [vdso] |
61b0b1f4 MK |
1118 | The virtual dynamically linked shared object. |
1119 | .TP | |
7d2e6d74 | 1120 | .IR [heap] |
61b0b1f4 MK |
1121 | The process's heap. |
1122 | .in | |
61b0b1f4 MK |
1123 | .RE |
1124 | .IP | |
3eb8c588 MK |
1125 | If the |
1126 | .I pathname | |
1127 | field is blank, | |
40382e5e MK |
1128 | this is an anonymous mapping as obtained via |
1129 | .BR mmap (2). | |
61b0b1f4 MK |
1130 | There is no easy way to coordinate this back to a process's source, |
1131 | short of running it through | |
491ea6f1 MK |
1132 | .BR gdb (1), |
1133 | .BR strace (1), | |
1134 | or similar. | |
37d32c38 | 1135 | |
eb9a0b2f | 1136 | Under Linux 2.0, there is no field giving pathname. |
fea681da | 1137 | .TP |
69119dc7 | 1138 | .I /proc/[pid]/mem |
fea681da MK |
1139 | This file can be used to access the pages of a process's memory through |
1140 | .BR open (2), | |
1141 | .BR read (2), | |
1142 | and | |
ccb2bb0d | 1143 | .BR lseek (2). |
aee2f0bf MK |
1144 | |
1145 | Permission to access this file is governed by a ptrace access mode | |
1146 | .B PTRACE_MODE_ATTACH_FSCREDS | |
1147 | check; see | |
1148 | .BR ptrace (2). | |
b4e9ee8f | 1149 | .TP |
69119dc7 | 1150 | .IR /proc/[pid]/mountinfo " (since Linux 2.6.26)" |
b4e9ee8f | 1151 | .\" This info adapted from Documentation/filesystems/proc.txt |
fb4bdaa1 | 1152 | .\" commit 2d4d4864ac08caff5c204a752bd004eed4f08760 |
ef5b47f6 MK |
1153 | This file contains information about mount points |
1154 | in the process's mount namespace (see | |
1155 | .BR mount_namespaces (7)). | |
fb4bdaa1 MK |
1156 | It supplies various information |
1157 | (e.g., propagation state, root of mount for bind mounts, | |
1158 | identifier for each mount and its parent) that is missing from the (older) | |
1159 | .IR /proc/[pid]/mounts | |
1160 | file, and fixes various other problems with that file | |
1161 | (e.g., nonextensibility, | |
1162 | failure to distinguish per-mount versus per-superblock options). | |
1163 | ||
1164 | The file contains lines of the form: | |
b4e9ee8f MK |
1165 | .nf |
1166 | .ft CW | |
b4e9ee8f | 1167 | |
0f619d1f | 1168 | 36 35 98:0 /mnt1 /mnt2 rw,noatime master:1 \- ext3 /dev/root rw,errors=continue |
b4e9ee8f | 1169 | (1)(2)(3) (4) (5) (6) (7) (8) (9) (10) (11) |
b4e9ee8f MK |
1170 | .ft |
1171 | .fi | |
1172 | .IP | |
1173 | The numbers in parentheses are labels for the descriptions below: | |
3bc960c2 | 1174 | .RS 7 |
b4e9ee8f MK |
1175 | .TP 5 |
1176 | (1) | |
0f619d1f | 1177 | mount ID: a unique ID for the mount (may be reused after |
b4e9ee8f MK |
1178 | .BR umount (2)). |
1179 | .TP | |
1180 | (2) | |
0f619d1f MK |
1181 | parent ID: the ID of the parent mount |
1182 | (or of self for the top of the mount tree). | |
b4e9ee8f MK |
1183 | .TP |
1184 | (3) | |
0f619d1f | 1185 | major:minor: the value of |
b4e9ee8f | 1186 | .I st_dev |
0f619d1f | 1187 | for files on this filesystem (see |
b4e9ee8f MK |
1188 | .BR stat (2)). |
1189 | .TP | |
1190 | (4) | |
0f619d1f | 1191 | root: the pathname of the directory in the filesystem |
8d857fcb | 1192 | which forms the root of this mount. |
b4e9ee8f MK |
1193 | .TP |
1194 | (5) | |
ebdc66e2 | 1195 | mount point: the pathname of the mount point relative |
0f619d1f | 1196 | to the process's root directory. |
b4e9ee8f MK |
1197 | .TP |
1198 | (6) | |
1199 | mount options: per-mount options. | |
1200 | .TP | |
1201 | (7) | |
0f619d1f | 1202 | optional fields: zero or more fields of the form "tag[:value]"; see below. |
b4e9ee8f MK |
1203 | .TP |
1204 | (8) | |
0f619d1f | 1205 | separator: the end of the optional fields is marked by a single hyphen. |
b4e9ee8f MK |
1206 | .TP |
1207 | (9) | |
0f619d1f | 1208 | filesystem type: the filesystem type in the form "type[.subtype]". |
b4e9ee8f MK |
1209 | .TP |
1210 | (10) | |
9ee4a2b6 | 1211 | mount source: filesystem-specific information or "none". |
b4e9ee8f MK |
1212 | .TP |
1213 | (11) | |
68d86eac | 1214 | super options: per-superblock options. |
b4e9ee8f MK |
1215 | .RE |
1216 | .IP | |
966b5839 MK |
1217 | Currently, the possible optional fields are |
1218 | .IR shared , | |
1219 | .IR master , | |
1220 | .IR propagate_from , | |
1221 | and | |
1222 | .IR unbindable . | |
1223 | See | |
1224 | .BR mount_namespaces (7) | |
1225 | for a description of these fields. | |
0f619d1f MK |
1226 | Parsers should ignore all unrecognized optional fields. |
1227 | .IP | |
b4e9ee8f MK |
1228 | For more information on mount propagation see: |
1229 | .I Documentation/filesystems/sharedsubtree.txt | |
66a9882e | 1230 | in the Linux kernel source tree. |
b4e9ee8f | 1231 | .TP |
cea61382 | 1232 | .IR /proc/[pid]/mounts " (since Linux 2.4.19)" |
226cb3a8 | 1233 | This file lists all the filesystems currently mounted in the |
ef5b47f6 MK |
1234 | process's mount namespace (see |
1235 | .BR mount_namespaces (7)). | |
cea61382 MK |
1236 | The format of this file is documented in |
1237 | .BR fstab (5). | |
226cb3a8 | 1238 | |
cea61382 MK |
1239 | Since kernel version 2.6.15, this file is pollable: |
1240 | after opening the file for reading, a change in this file | |
9ee4a2b6 | 1241 | (i.e., a filesystem mount or unmount) causes |
cea61382 | 1242 | .BR select (2) |
226cb3a8 | 1243 | to mark the file descriptor as having an exceptional condition, and |
cea61382 MK |
1244 | .BR poll (2) |
1245 | and | |
1246 | .BR epoll_wait (2) | |
226cb3a8 MK |
1247 | mark the file as having a priority event |
1248 | .RB ( POLLPRI ). | |
1249 | (Before Linux 2.6.30, | |
1250 | a change in this file was indicated by the file descriptor | |
1251 | being marked as readable for | |
1252 | .BR select (2), | |
1253 | and being marked as having an error condition for | |
1254 | .BR poll (2) | |
1255 | and | |
1256 | .BR epoll_wait (2).) | |
cea61382 | 1257 | .TP |
69119dc7 | 1258 | .IR /proc/[pid]/mountstats " (since Linux 2.6.17)" |
783a6233 | 1259 | This file exports information (statistics, configuration information) |
ef5b47f6 MK |
1260 | about the mount points in the process's mount namespace (see |
1261 | .BR mount_namespaces (7)). | |
b4e9ee8f MK |
1262 | Lines in this file have the form: |
1263 | .nf | |
1264 | ||
1265 | device /dev/sda7 mounted on /home with fstype ext3 [statistics] | |
1266 | ( 1 ) ( 2 ) (3 ) (4) | |
1267 | .fi | |
1268 | .IP | |
1269 | The fields in each line are: | |
3bc960c2 | 1270 | .RS 7 |
b4e9ee8f MK |
1271 | .TP 5 |
1272 | (1) | |
1273 | The name of the mounted device | |
1274 | (or "nodevice" if there is no corresponding device). | |
1275 | .TP | |
1276 | (2) | |
9ee4a2b6 | 1277 | The mount point within the filesystem tree. |
b4e9ee8f MK |
1278 | .TP |
1279 | (3) | |
9ee4a2b6 | 1280 | The filesystem type. |
b4e9ee8f MK |
1281 | .TP |
1282 | (4) | |
1283 | Optional statistics and configuration information. | |
9ee4a2b6 | 1284 | Currently (as at Linux 2.6.26), only NFS filesystems export |
b4e9ee8f MK |
1285 | information via this field. |
1286 | .RE | |
1287 | .IP | |
90878f7c | 1288 | This file is readable only by the owner of the process. |
b4e9ee8f | 1289 | .TP |
9fb88bc8 MK |
1290 | .IR |
1291 | /proc/[pid]/net " (since Linux 2.6.25)" | |
1292 | See the description of | |
1293 | .IR /proc/net . | |
1294 | .TP | |
b4a185e5 | 1295 | .IR /proc/[pid]/ns/ " (since Linux 3.0)" |
2c4201f0 | 1296 | .\" See commit 6b4e306aa3dc94a0545eb9279475b1ab6209a31f |
b4a185e5 EB |
1297 | This is a subdirectory containing one entry for each namespace that |
1298 | supports being manipulated by | |
80e63655 | 1299 | .BR setns (2). |
cf8bfe6d MK |
1300 | For more information, see |
1301 | .BR namespaces (7). | |
b4a185e5 | 1302 | .TP |
69119dc7 | 1303 | .IR /proc/[pid]/numa_maps " (since Linux 2.6.14)" |
610f75cc MK |
1304 | See |
1305 | .BR numa (7). | |
7388733a | 1306 | .TP |
69119dc7 | 1307 | .IR /proc/[pid]/oom_adj " (since Linux 2.6.11)" |
b4e9ee8f | 1308 | This file can be used to adjust the score used to select which process |
0425de01 | 1309 | should be killed in an out-of-memory (OOM) situation. |
b4e9ee8f MK |
1310 | The kernel uses this value for a bit-shift operation of the process's |
1311 | .IR oom_score | |
1312 | value: | |
5b8dbfd4 MK |
1313 | valid values are in the range \-16 to +15, |
1314 | plus the special value \-17, | |
b4e9ee8f MK |
1315 | which disables OOM-killing altogether for this process. |
1316 | A positive score increases the likelihood of this | |
1317 | process being killed by the OOM-killer; | |
1318 | a negative score decreases the likelihood. | |
de8e9cc1 | 1319 | .IP |
b4e9ee8f MK |
1320 | The default value for this file is 0; |
1321 | a new process inherits its parent's | |
1322 | .I oom_adj | |
1323 | setting. | |
1324 | A process must be privileged | |
1325 | .RB ( CAP_SYS_RESOURCE ) | |
1326 | to update this file. | |
f2c8b197 MK |
1327 | .IP |
1328 | Since Linux 2.6.36, use of this file is deprecated in favor of | |
1329 | .IR /proc/[pid]/oom_score_adj . | |
b4e9ee8f | 1330 | .TP |
69119dc7 | 1331 | .IR /proc/[pid]/oom_score " (since Linux 2.6.11)" |
b4e9ee8f MK |
1332 | .\" See mm/oom_kill.c::badness() in the 2.6.25 sources |
1333 | This file displays the current score that the kernel gives to | |
1334 | this process for the purpose of selecting a process | |
1335 | for the OOM-killer. | |
1336 | A higher score means that the process is more likely to be | |
1337 | selected by the OOM-killer. | |
1338 | The basis for this score is the amount of memory used by the process, | |
1339 | with increases (+) or decreases (\-) for factors including: | |
1340 | .\" See mm/oom_kill.c::badness() in the 2.6.25 sources | |
1341 | .RS | |
1342 | .IP * 2 | |
1343 | whether the process creates a lot of children using | |
1344 | .BR fork (2) | |
1345 | (+); | |
1346 | .IP * | |
1347 | whether the process has been running a long time, | |
1348 | or has used a lot of CPU time (\-); | |
1349 | .IP * | |
1350 | whether the process has a low nice value (i.e., > 0) (+); | |
1351 | .IP * | |
1352 | whether the process is privileged (\-); and | |
1353 | .\" More precisely, if it has CAP_SYS_ADMIN or CAP_SYS_RESOURCE | |
1354 | .IP * | |
1355 | whether the process is making direct hardware access (\-). | |
1356 | .\" More precisely, if it has CAP_SYS_RAWIO | |
1357 | .RE | |
1358 | .IP | |
1359 | The | |
1360 | .I oom_score | |
f2c8b197 MK |
1361 | also reflects the adjustment specified by the |
1362 | .I oom_score_adj | |
1363 | or | |
b4e9ee8f MK |
1364 | .I oom_adj |
1365 | setting for the process. | |
f2c8b197 MK |
1366 | .TP |
1367 | .IR /proc/[pid]/oom_score_adj " (since Linux 2.6.36)" | |
1368 | .\" Text taken from 3.7 Documentation/filesystems/proc.txt | |
1369 | This file can be used to adjust the badness heuristic used to select which | |
1370 | process gets killed in out-of-memory conditions. | |
1371 | ||
1372 | The badness heuristic assigns a value to each candidate task ranging from 0 | |
1373 | (never kill) to 1000 (always kill) to determine which process is targeted. | |
1374 | The units are roughly a proportion along that range of | |
1375 | allowed memory the process may allocate from, | |
1376 | based on an estimation of its current memory and swap use. | |
1377 | For example, if a task is using all allowed memory, | |
1378 | its badness score will be 1000. | |
1379 | If it is using half of its allowed memory, its score will be 500. | |
1380 | ||
1381 | There is an additional factor included in the badness score: root | |
1382 | processes are given 3% extra memory over other tasks. | |
1383 | ||
1384 | The amount of "allowed" memory depends on the context | |
0633f951 | 1385 | in which the OOM-killer was called. |
f2c8b197 MK |
1386 | If it is due to the memory assigned to the allocating task's cpuset |
1387 | being exhausted, | |
1388 | the allowed memory represents the set of mems assigned to that | |
1389 | cpuset (see | |
1390 | .BR cpuset (7)). | |
1391 | If it is due to a mempolicy's node(s) being exhausted, | |
1392 | the allowed memory represents the set of mempolicy nodes. | |
1393 | If it is due to a memory limit (or swap limit) being reached, | |
1394 | the allowed memory is that configured limit. | |
1395 | Finally, if it is due to the entire system being out of memory, the | |
1396 | allowed memory represents all allocatable resources. | |
1397 | ||
1398 | The value of | |
0633f951 | 1399 | .I oom_score_adj |
f2c8b197 MK |
1400 | is added to the badness score before it |
1401 | is used to determine which task to kill. | |
1402 | Acceptable values range from \-1000 | |
1403 | (OOM_SCORE_ADJ_MIN) to +1000 (OOM_SCORE_ADJ_MAX). | |
0633f951 | 1404 | This allows user space to control the preference for OOM-killing, |
f2c8b197 | 1405 | ranging from always preferring a certain |
f082ada4 | 1406 | task or completely disabling it from OOM killing. |
f2c8b197 | 1407 | The lowest possible value, \-1000, is |
0633f951 | 1408 | equivalent to disabling OOM-killing entirely for that task, |
f2c8b197 MK |
1409 | since it will always report a badness score of 0. |
1410 | ||
1411 | Consequently, it is very simple for user space to define | |
1412 | the amount of memory to consider for each task. | |
1413 | Setting a | |
1414 | .I oom_score_adj | |
1415 | value of +500, for example, | |
1416 | is roughly equivalent to allowing the remainder of tasks sharing the | |
1417 | same system, cpuset, mempolicy, or memory controller resources | |
1418 | to use at least 50% more memory. | |
1419 | A value of \-500, on the other hand, would be roughly | |
1420 | equivalent to discounting 50% of the task's | |
1421 | allowed memory from being considered as scoring against the task. | |
1422 | ||
0633f951 | 1423 | For backward compatibility with previous kernels, |
f2c8b197 MK |
1424 | .I /proc/[pid]/oom_adj |
1425 | can still be used to tune the badness score. | |
1426 | Its value is | |
9f1b9726 | 1427 | scaled linearly with |
f2c8b197 MK |
1428 | .IR oom_score_adj . |
1429 | ||
1430 | Writing to | |
1431 | .IR /proc/[pid]/oom_score_adj | |
1432 | or | |
1433 | .IR /proc/[pid]/oom_adj | |
1434 | will change the other with its scaled value. | |
b0aa1e51 MK |
1435 | .TP |
1436 | .IR /proc/[pid]/pagemap " (since Linux 2.6.25)" | |
1437 | This file shows the mapping of each of the process's virtual pages | |
1438 | into physical page frames or swap area. | |
1439 | It contains one 64-bit value for each virtual page, | |
1440 | with the bits set as follows: | |
1441 | .RS 12 | |
1442 | .TP | |
1443 | 63 | |
1444 | If set, the page is present in RAM. | |
1445 | .TP | |
1446 | 62 | |
1447 | If set, the page is in swap space | |
1448 | .TP | |
1449 | 61 (since Linux 3.5) | |
1450 | The page is a file-mapped page or a shared anonymous page. | |
1451 | .TP | |
1452 | 60-56 (since Linux 3.11) | |
1453 | Zero | |
1454 | .\" Not quite true; see commit 541c237c0923f567c9c4cabb8a81635baadc713f | |
1455 | .TP | |
1456 | 55 (Since Linux 3.11) | |
1457 | PTE is soft-dirty | |
1458 | (see the kernel source file | |
1459 | .IR Documentation/vm/soft-dirty.txt ). | |
1460 | .TP | |
1461 | 54-0 | |
1462 | If the page is present in RAM (bit 63), then these bits | |
1463 | provide the page frame number, which can be used to index | |
1464 | .IR /proc/kpageflags | |
1465 | and | |
1466 | .IR /proc/kpagecount . | |
1467 | If the page is present in swap (bit 62), | |
1468 | then bits 4-0 give the swap type, and bits 54-5 encode the swap offset. | |
1469 | .RE | |
1470 | .IP | |
1471 | Before Linux 3.11, bits 60-55 were | |
1472 | used to encode the base-2 log of the page size. | |
1473 | .IP | |
1474 | To employ | |
1475 | .IR /proc/[pid]/pagemap | |
1476 | efficiently, use | |
1477 | .IR /proc/[pid]/maps | |
1478 | to determine which areas of memory are actually mapped and seek | |
1479 | to skip over unmapped regions. | |
1480 | .IP | |
1481 | The | |
1482 | .IR /proc/[pid]/pagemap | |
1483 | file is present only if the | |
1484 | .B CONFIG_PROC_PAGE_MONITOR | |
1485 | kernel configuration option is enabled. | |
aee2f0bf MK |
1486 | |
1487 | Permission to access this file is governed by a ptrace access mode | |
1488 | .B PTRACE_MODE_READ_FSCREDS | |
1489 | check; see | |
1490 | .BR ptrace (2). | |
7c2905d1 MK |
1491 | .TP |
1492 | .IR /proc/[pid]/personality " (since Linux 2.6.28)" | |
1493 | .\" commit 478307230810d7e2a753ed220db9066dfdf88718 | |
1494 | This read-only file exposes the process's execution domain, as set by | |
1495 | .BR personality (2). | |
1496 | The value is displayed in hexadecimal notation. | |
4834ae91 MK |
1497 | |
1498 | Permission to access this file is governed by a ptrace access mode | |
1499 | .B PTRACE_MODE_ATTACH_FSCREDS | |
1500 | check; see | |
1501 | .BR ptrace (2). | |
fea681da | 1502 | .TP |
69119dc7 | 1503 | .I /proc/[pid]/root |
008f1ecc | 1504 | UNIX and Linux support the idea of a per-process root of the |
9ee4a2b6 | 1505 | filesystem, set by the |
fea681da | 1506 | .BR chroot (2) |
c13182ef MK |
1507 | system call. |
1508 | This file is a symbolic link that points to the process's | |
14d70713 MK |
1509 | root directory, and behaves in the same way as |
1510 | .IR exe , | |
1511 | and | |
1512 | .IR fd/* . | |
afcaf646 | 1513 | |
948f0ff4 | 1514 | Note however that this file is not merely a symbolic link. |
2b312241 MF |
1515 | It provides the same view of the filesystem (including namespaces and the |
1516 | set of per-process mounts) as the process itself. | |
a77efd58 MK |
1517 | An example illustrates this point. |
1518 | In one terminal, we start a shell in new user and mount namespaces, | |
1519 | and in that shell we create some new mount points: | |
1520 | ||
1521 | .nf | |
1522 | .in +4n | |
1523 | $ \fBPS1='sh1# ' unshare \-Urnm\fP | |
1524 | sh1# \fBmount \-t tmpfs tmpfs /etc\fP # Mount empty tmpfs at /etc | |
1525 | sh1# \fBmount \-\-bind /usr /dev\fP # Mount /usr at /dev | |
89f92905 | 1526 | sh1# \fBecho $$\fP |
a77efd58 MK |
1527 | 27123 |
1528 | .in | |
1529 | .fi | |
1530 | ||
1531 | In a second terminal window, in the initial mount namespace, | |
1532 | we look at the contents of the corresponding mounts in | |
1533 | the initial and new namespaces: | |
89f92905 | 1534 | |
a77efd58 MK |
1535 | .nf |
1536 | .in +4n | |
89f92905 | 1537 | $ \fBPS1='sh2# ' sudo sh\fP |
a77efd58 MK |
1538 | sh2# \fBls /etc | wc \-l\fP # In initial NS |
1539 | 309 | |
1540 | sh2# \fBls /proc/27123/root/etc | wc \-l\fP # /etc in other NS | |
1541 | 0 # The empty tmpfs dir | |
1542 | sh2# \fBls /dev | wc \-l\fP # In initial NS | |
1543 | 205 | |
1544 | sh2# \fBls /proc/27123/root/dev | wc \-l\fP # /dev in other NS | |
1545 | 11 # Actually bind | |
1546 | # mounted to /usr | |
1547 | sh2# \fBls /usr | wc \-l\fP # /usr in initial NS | |
1548 | 11 | |
1549 | .in | |
1550 | .fi | |
2b312241 | 1551 | |
afcaf646 | 1552 | .\" The following was still true as at kernel 2.6.13 |
3ed7270e MK |
1553 | In a multithreaded process, the contents of the |
1554 | .I /proc/[pid]/root | |
1555 | symbolic link are not available if the main thread has already terminated | |
afcaf646 MK |
1556 | (typically by calling |
1557 | .BR pthread_exit (3)). | |
b902fe18 MK |
1558 | |
1559 | Permission to dereference or read | |
1560 | .RB ( readlink (2)) | |
1561 | this symbolic link is governed by a ptrace access mode | |
1562 | .B PTRACE_MODE_READ_FSCREDS | |
1563 | check; see | |
1564 | .BR ptrace (2). | |
f34f0182 | 1565 | .\" FIXME Describe /proc/[pid]/projid_map |
43d42cc0 MK |
1566 | .\" Added in 3.7 |
1567 | .\" commit f76d207a66c3a53defea67e7d36c3eb1b7d6d61d | |
69119dc7 | 1568 | .\" FIXME Describe /proc/[pid]/seccomp |
6aefb6df | 1569 | .\" Added in 2.6.12 |
15869389 MK |
1570 | .TP |
1571 | .IR /proc/[pid]/seccomp " (Linux 2.6.12 to 2.6.22)" | |
1572 | This file can be used to read and change the process's | |
1573 | secure computing (seccomp) mode setting. | |
1574 | It contains the value 0 if the process is not in seccomp mode, | |
1575 | and 1 if the process is in strict seccomp mode (see | |
1576 | .BR seccomp (2)). | |
1577 | Writing 1 to this file places the process irreversibly in strict seccomp mode. | |
1578 | (Further attempts to write to the file fail with the | |
1579 | .B EPERM | |
1580 | error.) | |
1581 | ||
1582 | In Linux 2.6.23, | |
1583 | this file went away, to be replaced by the | |
1584 | .BR prctl (2) | |
1585 | .BR PR_GET_SECCOMP | |
1586 | and | |
1587 | .BR PR_SET_SECCOMP | |
1588 | operations (and later by | |
1589 | .BR seccomp (2) | |
1590 | and the | |
1591 | .I Seccomp | |
1592 | field in | |
1593 | .IR /proc/[pid]/status ). | |
69119dc7 | 1594 | .\" FIXME Describe /proc/[pid]/sessionid |
b3fb99e8 | 1595 | .\" commit 1e0bd7550ea9cf474b1ad4c6ff5729a507f75fdc |
b4e9ee8f | 1596 | .\" CONFIG_AUDITSYSCALL |
43d42cc0 | 1597 | .\" Added in 2.6.25; read-only; only readable by real UID |
bea08fec | 1598 | .\" |
69119dc7 | 1599 | .\" FIXME Describe /proc/[pid]/sched |
b4e9ee8f MK |
1600 | .\" Added in 2.6.23 |
1601 | .\" CONFIG_SCHED_DEBUG, and additional fields if CONFIG_SCHEDSTATS | |
1602 | .\" Displays various scheduling parameters | |
1603 | .\" This file can be written, to reset stats | |
ef4f4031 | 1604 | .\" The set of fields exposed by this file have changed |
b3fb99e8 MK |
1605 | .\" significantly over time. |
1606 | .\" commit 43ae34cb4cd650d1eb4460a8253a8e747ba052ac | |
1607 | .\" | |
69119dc7 MK |
1608 | .\" FIXME Describe /proc/[pid]/schedstats and |
1609 | .\" /proc/[pid]/task/[tid]/schedstats | |
b4e9ee8f MK |
1610 | .\" Added in 2.6.9 |
1611 | .\" CONFIG_SCHEDSTATS | |
fea681da | 1612 | .TP |
51dea63a MK |
1613 | .IR /proc/[pid]/seccomp " (from Linux 2.6.12 to 2.6.22)" |
1614 | Read/set the seccomp mode for the process. | |
1615 | If this file contains the value zero, seccomp mode is not enabled. | |
1616 | Writing the value 1 to this file (irreversibly) places the process in | |
1617 | seccomp mode: the only permitted system calls are | |
1618 | .BR read (2), | |
1619 | .BR write (2), | |
1620 | .BR _exit (2), | |
1621 | and | |
1622 | .BR sigreturn (2). | |
1623 | This file went away in Linux 2.6.23, | |
1624 | .\" commit 1d9d02feeee89e9132034d504c9a45eeaf618a3d | |
1625 | when it was replaced by a | |
1626 | .BR prctl (2)-based | |
1627 | mechanism. | |
1628 | .TP | |
5c92b1b7 | 1629 | .IR /proc/[pid]/setgroups " (since Linux 3.19)" |
ab28dba9 MK |
1630 | See |
1631 | .BR user_namespaces (7). | |
d520465b | 1632 | .TP |
69119dc7 | 1633 | .IR /proc/[pid]/smaps " (since Linux 2.6.14)" |
b07b19c4 | 1634 | This file shows memory consumption for each of the process's mappings. |
859503c3 MK |
1635 | (The |
1636 | .BR pmap (1) | |
1637 | command displays similar information, | |
1638 | in a form that may be easier for parsing.) | |
1f0add28 | 1639 | For each mapping there is a series of lines such as the following: |
a08ea57c | 1640 | .in +4n |
b07b19c4 MK |
1641 | .nf |
1642 | ||
1f0add28 | 1643 | 00400000-0048a000 r-xp 00000000 fd:03 960637 /bin/bash |
95fe794d PG |
1644 | Size: 552 kB |
1645 | Rss: 460 kB | |
1646 | Pss: 100 kB | |
1647 | Shared_Clean: 452 kB | |
1648 | Shared_Dirty: 0 kB | |
1649 | Private_Clean: 8 kB | |
1650 | Private_Dirty: 0 kB | |
1651 | Referenced: 460 kB | |
1652 | Anonymous: 0 kB | |
1653 | AnonHugePages: 0 kB | |
4ad958e1 MK |
1654 | ShmemHugePages: 0 kB |
1655 | ShmemPmdMapped: 0 kB | |
95fe794d PG |
1656 | Swap: 0 kB |
1657 | KernelPageSize: 4 kB | |
1658 | MMUPageSize: 4 kB | |
6861f8f0 MK |
1659 | KernelPageSize: 4 kB |
1660 | MMUPageSize: 4 kB | |
95fe794d | 1661 | Locked: 0 kB |
2f057281 | 1662 | ProtectionKey: 0 |
eb848708 | 1663 | VmFlags: rd ex mr mw me dw |
b07b19c4 MK |
1664 | |
1665 | .fi | |
a08ea57c | 1666 | .in |
b07b19c4 MK |
1667 | The first of these lines shows the same information as is displayed |
1668 | for the mapping in | |
69119dc7 | 1669 | .IR /proc/[pid]/maps . |
c3d59262 | 1670 | The following lines show the size of the mapping, |
95fe794d | 1671 | the amount of the mapping that is currently resident in RAM ("Rss"), |
a5a3e91b | 1672 | the process's proportional share of this mapping ("Pss"), |
1f0add28 | 1673 | the number of clean and dirty shared pages in the mapping, |
c7ce200d | 1674 | and the number of clean and dirty private pages in the mapping. |
95fe794d | 1675 | "Referenced" indicates the amount of memory currently marked as |
1f0add28 MK |
1676 | referenced or accessed. |
1677 | "Anonymous" shows the amount of memory | |
1678 | that does not belong to any file. | |
1679 | "Swap" shows how much | |
95fe794d PG |
1680 | would-be-anonymous memory is also used, but out on swap. |
1681 | ||
6861f8f0 MK |
1682 | The "KernelPageSize" line (available since Linux 2.6.29) |
1683 | is the page size used by the kernel to back the virtual memory area. | |
1f0add28 MK |
1684 | This matches the size used by the MMU in the majority of cases. |
1685 | However, one counter-example occurs on PPC64 kernels | |
6861f8f0 | 1686 | whereby a kernel using 64kB as a base page size may still use 4kB |
1f0add28 | 1687 | pages for the MMU on older processors. |
6861f8f0 MK |
1688 | To distinguish the two attributes, the "MMUPageSize" line |
1689 | (also available since Linux 2.6.29) | |
1690 | reports the page size used by the MMU. | |
95fe794d PG |
1691 | |
1692 | The "Locked" indicates whether the mapping is locked in memory | |
1693 | or not. | |
1694 | ||
9b780b06 MK |
1695 | The "ProtectionKey" line (available since Linux 4.9, on x86 only) |
1696 | contains the memory protection key (see | |
1697 | .BR pkeys (7)) | |
1698 | associated with the virtual memory area. | |
1699 | This entry is present only if the kernel was built with the | |
1700 | .B CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS | |
1701 | configuration option. | |
1702 | ||
eb848708 MK |
1703 | The "VmFlags" line (available since Linux 3.8) |
1704 | represents the kernel flags associated with the virtual memory area, | |
1705 | encoded using the following two-letter codes: | |
1f0add28 | 1706 | |
95fe794d | 1707 | rd - readable |
1f0add28 | 1708 | wr - writable |
95fe794d PG |
1709 | ex - executable |
1710 | sh - shared | |
1711 | mr - may read | |
1712 | mw - may write | |
1713 | me - may execute | |
1714 | ms - may share | |
723e333c | 1715 | gd - stack segment grows down |
95fe794d PG |
1716 | pf - pure PFN range |
1717 | dw - disabled write to the mapped file | |
1718 | lo - pages are locked in memory | |
1719 | io - memory mapped I/O area | |
1720 | sr - sequential read advise provided | |
1721 | rr - random read advise provided | |
1722 | dc - do not copy area on fork | |
1723 | de - do not expand area on remapping | |
1724 | ac - area is accountable | |
1725 | nr - swap space is not reserved for the area | |
1726 | ht - area uses huge tlb pages | |
1727 | nl - non-linear mapping | |
1728 | ar - architecture specific flag | |
1729 | dd - do not include area into core dump | |
1730 | sd - soft-dirty flag | |
1731 | mm - mixed map area | |
1732 | hg - huge page advise flag | |
1733 | nh - no-huge page advise flag | |
b5408a0f | 1734 | mg - mergeable advise flag |
b07b19c4 | 1735 | |
be729d66 DH |
1736 | "ProtectionKey" field contains the memory protection key (see |
1737 | .BR pkeys (5)) | |
1738 | associated with the virtual memory area. | |
f12f1b9b | 1739 | Present only if the kernel was built with the |
be729d66 DH |
1740 | .B CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS |
1741 | configuration option. (since Linux 4.6) | |
1742 | ||
e618d945 MK |
1743 | The |
1744 | .IR /proc/[pid]/smaps | |
1745 | file is present only if the | |
1746 | .B CONFIG_PROC_PAGE_MONITOR | |
1747 | kernel configuration option is enabled. | |
b07b19c4 | 1748 | .TP |
67aac6fb MK |
1749 | .IR /proc/[pid]/stack " (since Linux 2.6.29)" |
1750 | .\" 2ec220e27f5040aec1e88901c1b6ea3d135787ad | |
1751 | This file provides a symbolic trace of the function calls in this | |
1752 | process's kernel stack. | |
1753 | This file is provided only if the kernel was built with the | |
1754 | .B CONFIG_STACKTRACE | |
1755 | configuration option. | |
4834ae91 MK |
1756 | |
1757 | Permission to access this file is governed by a ptrace access mode | |
1758 | .B PTRACE_MODE_ATTACH_FSCREDS | |
1759 | check; see | |
1760 | .BR ptrace (2). | |
67aac6fb | 1761 | .TP |
69119dc7 | 1762 | .I /proc/[pid]/stat |
c13182ef MK |
1763 | Status information about the process. |
1764 | This is used by | |
1765 | .BR ps (1). | |
082bf5b8 MK |
1766 | It is defined in the kernel source file |
1767 | .IR fs/proc/array.c "." | |
fea681da MK |
1768 | |
1769 | The fields, in order, with their proper | |
1770 | .BR scanf (3) | |
b02b4b74 MK |
1771 | format specifiers, are listed below. |
1772 | Whether or not certain of these fields display valid information is governed by | |
1773 | a ptrace access mode | |
1774 | .BR PTRACE_MODE_READ_FSCREDS "\ |\ " PTRACE_MODE_NOAUDIT | |
1775 | check (refer to | |
1776 | .BR ptrace (2)). | |
1777 | If the check denies access, then the field value is displayed as 0. | |
1778 | The affected fields are indicated with the marking [PT]. | |
1779 | ||
fea681da | 1780 | .RS |
62e4a418 MK |
1781 | .TP 10 |
1782 | (1) \fIpid\fP \ %d | |
1783 | .br | |
1784 | The process ID. | |
fea681da | 1785 | .TP |
62e4a418 MK |
1786 | (2) \fIcomm\fP \ %s |
1787 | The filename of the executable, in parentheses. | |
c13182ef | 1788 | This is visible whether or not the executable is swapped out. |
fea681da | 1789 | .TP |
62e4a418 | 1790 | (3) \fIstate\fP \ %c |
31293f37 MK |
1791 | One of the following characters, indicating process state: |
1792 | .RS | |
1793 | .IP R 3 | |
1794 | Running | |
1795 | .IP S | |
1796 | Sleeping in an interruptible wait | |
1797 | .IP D | |
1798 | Waiting in uninterruptible | |
1799 | disk sleep | |
1800 | .IP Z | |
1801 | Zombie | |
1802 | .IP T | |
1803 | Stopped (on a signal) or (before Linux 2.6.33) trace stopped | |
1804 | .IP t | |
1805 | .\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29 | |
1806 | Tracing stop (Linux 2.6.33 onward) | |
1807 | .IP W | |
1808 | Paging (only before Linux 2.6.0) | |
1809 | .IP X | |
ef4f4031 | 1810 | Dead (from Linux 2.6.0 onward) |
31293f37 MK |
1811 | .IP x |
1812 | .\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29 | |
1813 | Dead (Linux 2.6.33 to | |
1814 | .\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457 | |
1815 | 3.13 only) | |
1816 | .IP K | |
1817 | .\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29 | |
1818 | Wakekill (Linux 2.6.33 to | |
1819 | .\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457 | |
1820 | 3.13 only) | |
1821 | .IP W | |
1822 | .\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29 | |
1823 | Waking (Linux 2.6.33 to | |
1824 | .\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457 | |
1825 | 3.13 only) | |
1826 | .IP P | |
1827 | .\" commit f2530dc71cf0822f90bb63ea4600caaef33a66bb | |
1828 | Parked (Linux 3.9 to | |
1829 | .\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457 | |
1830 | 3.13 only) | |
1831 | .RE | |
fea681da | 1832 | .TP |
62e4a418 | 1833 | (4) \fIppid\fP \ %d |
e0fdc57c | 1834 | The PID of the parent of this process. |
fea681da | 1835 | .TP |
62e4a418 MK |
1836 | (5) \fIpgrp\fP \ %d |
1837 | The process group ID of the process. | |
fea681da | 1838 | .TP |
62e4a418 MK |
1839 | (6) \fIsession\fP \ %d |
1840 | The session ID of the process. | |
fea681da | 1841 | .TP |
62e4a418 MK |
1842 | (7) \fItty_nr\fP \ %d |
1843 | The controlling terminal of the process. | |
59a40ed7 MK |
1844 | (The minor device number is contained in the combination of bits |
1845 | 31 to 20 and 7 to 0; | |
b97deb97 | 1846 | the major device number is in bits 15 to 8.) |
fea681da | 1847 | .TP |
62e4a418 | 1848 | (8) \fItpgid\fP \ %d |
fea681da | 1849 | .\" This field and following, up to and including wchan added 0.99.1 |
62e4a418 | 1850 | The ID of the foreground process group of the controlling |
59a40ed7 | 1851 | terminal of the process. |
fea681da | 1852 | .TP |
62e4a418 MK |
1853 | (9) \fIflags\fP \ %u |
1854 | The kernel flags word of the process. | |
c13182ef | 1855 | For bit meanings, |
66a9882e | 1856 | see the PF_* defines in the Linux kernel source file |
00702acc | 1857 | .IR include/linux/sched.h . |
fea681da | 1858 | Details depend on the kernel version. |
62e4a418 MK |
1859 | |
1860 | The format for this field was %lu before Linux 2.6. | |
fea681da | 1861 | .TP |
ee566744 | 1862 | (10) \fIminflt\fP \ %lu |
62e4a418 | 1863 | The number of minor faults the process has made which have not |
fea681da MK |
1864 | required loading a memory page from disk. |
1865 | .TP | |
62e4a418 MK |
1866 | (11) \fIcminflt\fP \ %lu |
1867 | The number of minor faults that the process's | |
fea681da MK |
1868 | waited-for children have made. |
1869 | .TP | |
62e4a418 MK |
1870 | (12) \fImajflt\fP \ %lu |
1871 | The number of major faults the process has made which have | |
fea681da MK |
1872 | required loading a memory page from disk. |
1873 | .TP | |
62e4a418 MK |
1874 | (13) \fIcmajflt\fP \ %lu |
1875 | The number of major faults that the process's | |
fea681da MK |
1876 | waited-for children have made. |
1877 | .TP | |
62e4a418 MK |
1878 | (14) \fIutime\fP \ %lu |
1879 | Amount of time that this process has been scheduled in user mode, | |
7a017e24 | 1880 | measured in clock ticks (divide by |
67914165 | 1881 | .IR sysconf(_SC_CLK_TCK) ). |
a1c9dc59 MK |
1882 | This includes guest time, \fIguest_time\fP |
1883 | (time spent running a virtual CPU, see below), | |
1884 | so that applications that are not aware of the guest time field | |
1885 | do not lose that time from their calculations. | |
fea681da | 1886 | .TP |
62e4a418 MK |
1887 | (15) \fIstime\fP \ %lu |
1888 | Amount of time that this process has been scheduled in kernel mode, | |
7a017e24 | 1889 | measured in clock ticks (divide by |
67914165 | 1890 | .IR sysconf(_SC_CLK_TCK) ). |
fea681da | 1891 | .TP |
62e4a418 MK |
1892 | (16) \fIcutime\fP \ %ld |
1893 | Amount of time that this process's | |
7a017e24 MK |
1894 | waited-for children have been scheduled in user mode, |
1895 | measured in clock ticks (divide by | |
67914165 | 1896 | .IR sysconf(_SC_CLK_TCK) ). |
c13182ef | 1897 | (See also |
fea681da | 1898 | .BR times (2).) |
a1c9dc59 MK |
1899 | This includes guest time, \fIcguest_time\fP |
1900 | (time spent running a virtual CPU, see below). | |
fea681da | 1901 | .TP |
62e4a418 MK |
1902 | (17) \fIcstime\fP \ %ld |
1903 | Amount of time that this process's | |
7a017e24 MK |
1904 | waited-for children have been scheduled in kernel mode, |
1905 | measured in clock ticks (divide by | |
67914165 | 1906 | .IR sysconf(_SC_CLK_TCK) ). |
fea681da | 1907 | .TP |
62e4a418 MK |
1908 | (18) \fIpriority\fP \ %ld |
1909 | (Explanation for Linux 2.6) | |
59a40ed7 MK |
1910 | For processes running a real-time scheduling policy |
1911 | .RI ( policy | |
1912 | below; see | |
1913 | .BR sched_setscheduler (2)), | |
1914 | this is the negated scheduling priority, minus one; | |
1915 | that is, a number in the range \-2 to \-100, | |
1916 | corresponding to real-time priorities 1 to 99. | |
1917 | For processes running under a non-real-time scheduling policy, | |
1918 | this is the raw nice value | |
1919 | .RB ( setpriority (2)) | |
1920 | as represented in the kernel. | |
1921 | The kernel stores nice values as numbers | |
1922 | in the range 0 (high) to 39 (low), | |
1923 | corresponding to the user-visible nice range of \-20 to 19. | |
1924 | ||
1925 | Before Linux 2.6, this was a scaled value based on | |
1926 | the scheduler weighting given to this process. | |
1927 | .\" And back in kernel 1.2 days things were different again. | |
fea681da | 1928 | .TP |
62e4a418 MK |
1929 | (19) \fInice\fP \ %ld |
1930 | The nice value (see | |
59a40ed7 MK |
1931 | .BR setpriority (2)), |
1932 | a value in the range 19 (low priority) to \-20 (high priority). | |
1933 | .\" Back in kernel 1.2 days things were different. | |
fea681da MK |
1934 | .\" .TP |
1935 | .\" \fIcounter\fP %ld | |
1936 | .\" The current maximum size in jiffies of the process's next timeslice, | |
1937 | .\" or what is currently left of its current timeslice, if it is the | |
1938 | .\" currently running process. | |
1939 | .\" .TP | |
1940 | .\" \fItimeout\fP %u | |
1941 | .\" The time in jiffies of the process's next timeout. | |
0e94f77b | 1942 | .\" timeout was removed sometime around 2.1/2.2 |
aa610245 | 1943 | .TP |
62e4a418 MK |
1944 | (20) \fInum_threads\fP \ %ld |
1945 | Number of threads in this process (since Linux 2.6). | |
bb83d1b9 | 1946 | Before kernel 2.6, this field was hard coded to 0 as a placeholder |
0e94f77b | 1947 | for an earlier removed field. |
fea681da | 1948 | .TP |
62e4a418 MK |
1949 | (21) \fIitrealvalue\fP \ %ld |
1950 | The time in jiffies before the next | |
8bd58774 MK |
1951 | .B SIGALRM |
1952 | is sent to the process due to an interval timer. | |
0e94f77b MK |
1953 | Since kernel 2.6.17, this field is no longer maintained, |
1954 | and is hard coded as 0. | |
fea681da | 1955 | .TP |
62e4a418 MK |
1956 | (22) \fIstarttime\fP \ %llu |
1957 | The time the process started after system boot. | |
055024ed MK |
1958 | In kernels before Linux 2.6, this value was expressed in jiffies. |
1959 | Since Linux 2.6, the value is expressed in clock ticks (divide by | |
1960 | .IR sysconf(_SC_CLK_TCK) ). | |
62e4a418 MK |
1961 | |
1962 | The format for this field was %lu before Linux 2.6. | |
fea681da | 1963 | .TP |
62e4a418 MK |
1964 | (23) \fIvsize\fP \ %lu |
1965 | Virtual memory size in bytes. | |
fea681da | 1966 | .TP |
62e4a418 MK |
1967 | (24) \fIrss\fP \ %ld |
1968 | Resident Set Size: number of pages the process has in real memory. | |
c13182ef | 1969 | This is just the pages which |
5fab2e7c | 1970 | count toward text, data, or stack space. |
c13182ef | 1971 | This does not include pages |
fea681da MK |
1972 | which have not been demand-loaded in, or which are swapped out. |
1973 | .TP | |
62e4a418 MK |
1974 | (25) \fIrsslim\fP \ %lu |
1975 | Current soft limit in bytes on the rss of the process; | |
59a40ed7 MK |
1976 | see the description of |
1977 | .B RLIMIT_RSS | |
1978 | in | |
2b5407af | 1979 | .BR getrlimit (2). |
fea681da | 1980 | .TP |
b02b4b74 | 1981 | (26) \fIstartcode\fP \ %lu \ [PT] |
62e4a418 | 1982 | The address above which program text can run. |
fea681da | 1983 | .TP |
b02b4b74 | 1984 | (27) \fIendcode\fP \ %lu \ [PT] |
62e4a418 | 1985 | The address below which program text can run. |
fea681da | 1986 | .TP |
b02b4b74 | 1987 | (28) \fIstartstack\fP \ %lu \ [PT] |
62e4a418 | 1988 | The address of the start (i.e., bottom) of the stack. |
fea681da | 1989 | .TP |
b02b4b74 | 1990 | (29) \fIkstkesp\fP \ %lu \ [PT] |
62e4a418 | 1991 | The current value of ESP (stack pointer), as found in the |
fea681da MK |
1992 | kernel stack page for the process. |
1993 | .TP | |
b02b4b74 | 1994 | (30) \fIkstkeip\fP \ %lu \ [PT] |
62e4a418 | 1995 | The current EIP (instruction pointer). |
fea681da | 1996 | .TP |
62e4a418 MK |
1997 | (31) \fIsignal\fP \ %lu |
1998 | The bitmap of pending signals, displayed as a decimal number. | |
59a40ed7 | 1999 | Obsolete, because it does not provide information on real-time signals; use |
69119dc7 | 2000 | .I /proc/[pid]/status |
59a40ed7 | 2001 | instead. |
fea681da | 2002 | .TP |
62e4a418 MK |
2003 | (32) \fIblocked\fP \ %lu |
2004 | The bitmap of blocked signals, displayed as a decimal number. | |
59a40ed7 | 2005 | Obsolete, because it does not provide information on real-time signals; use |
69119dc7 | 2006 | .I /proc/[pid]/status |
59a40ed7 | 2007 | instead. |
fea681da | 2008 | .TP |
62e4a418 MK |
2009 | (33) \fIsigignore\fP \ %lu |
2010 | The bitmap of ignored signals, displayed as a decimal number. | |
59a40ed7 | 2011 | Obsolete, because it does not provide information on real-time signals; use |
69119dc7 | 2012 | .I /proc/[pid]/status |
59a40ed7 | 2013 | instead. |
fea681da | 2014 | .TP |
62e4a418 MK |
2015 | (34) \fIsigcatch\fP \ %lu |
2016 | The bitmap of caught signals, displayed as a decimal number. | |
59a40ed7 | 2017 | Obsolete, because it does not provide information on real-time signals; use |
69119dc7 | 2018 | .I /proc/[pid]/status |
59a40ed7 | 2019 | instead. |
fea681da | 2020 | .TP |
b02b4b74 | 2021 | (35) \fIwchan\fP \ %lu \ [PT] |
62e4a418 | 2022 | This is the "channel" in which the process is waiting. |
2054f761 MK |
2023 | It is the address of a location in the kernel where the process is sleeping. |
2024 | The corresponding symbolic name can be found in | |
2025 | .IR /proc/[pid]/wchan . | |
fea681da | 2026 | .TP |
62e4a418 | 2027 | (36) \fInswap\fP \ %lu |
0633f951 | 2028 | .\" nswap was added in 2.0 |
4d9b6984 | 2029 | Number of pages swapped (not maintained). |
fea681da | 2030 | .TP |
62e4a418 | 2031 | (37) \fIcnswap\fP \ %lu |
0633f951 | 2032 | .\" cnswap was added in 2.0 |
4d9b6984 | 2033 | Cumulative \fInswap\fP for child processes (not maintained). |
fea681da | 2034 | .TP |
62e4a418 MK |
2035 | (38) \fIexit_signal\fP \ %d \ (since Linux 2.1.22) |
2036 | Signal to be sent to parent when we die. | |
fea681da | 2037 | .TP |
62e4a418 MK |
2038 | (39) \fIprocessor\fP \ %d \ (since Linux 2.2.8) |
2039 | CPU number last executed on. | |
568105c6 | 2040 | .TP |
62e4a418 MK |
2041 | (40) \fIrt_priority\fP \ %u \ (since Linux 2.5.19) |
2042 | Real-time scheduling priority, a number in the range 1 to 99 for | |
59a40ed7 MK |
2043 | processes scheduled under a real-time policy, |
2044 | or 0, for non-real-time processes (see | |
568105c6 MK |
2045 | .BR sched_setscheduler (2)). |
2046 | .TP | |
62e4a418 MK |
2047 | (41) \fIpolicy\fP \ %u \ (since Linux 2.5.19) |
2048 | Scheduling policy (see | |
568105c6 | 2049 | .BR sched_setscheduler (2)). |
cd60dedd | 2050 | Decode using the SCHED_* constants in |
59a40ed7 | 2051 | .IR linux/sched.h . |
62e4a418 MK |
2052 | |
2053 | The format for this field was %lu before Linux 2.6.22. | |
167450d6 | 2054 | .TP |
62e4a418 MK |
2055 | (42) \fIdelayacct_blkio_ticks\fP \ %llu \ (since Linux 2.6.18) |
2056 | Aggregated block I/O delays, measured in clock ticks (centiseconds). | |
14c06953 | 2057 | .TP |
62e4a418 MK |
2058 | (43) \fIguest_time\fP \ %lu \ (since Linux 2.6.24) |
2059 | Guest time of the process (time spent running a virtual CPU | |
7a017e24 | 2060 | for a guest operating system), measured in clock ticks (divide by |
67914165 | 2061 | .IR sysconf(_SC_CLK_TCK) ). |
14c06953 | 2062 | .TP |
62e4a418 MK |
2063 | (44) \fIcguest_time\fP \ %ld \ (since Linux 2.6.24) |
2064 | Guest time of the process's children, measured in clock ticks (divide by | |
67914165 | 2065 | .IR sysconf(_SC_CLK_TCK) ). |
fea681da | 2066 | .TP |
b02b4b74 | 2067 | (45) \fIstart_data\fP \ %lu \ (since Linux 3.3) \ [PT] |
0be30a54 | 2068 | .\" commit b3f7f573a20081910e34e99cbc91831f4f02f1ff |
62e4a418 | 2069 | Address above which program initialized and |
426bc8d7 | 2070 | uninitialized (BSS) data are placed. |
12449ae3 | 2071 | .TP |
b02b4b74 | 2072 | (46) \fIend_data\fP \ %lu \ (since Linux 3.3) \ [PT] |
0be30a54 | 2073 | .\" commit b3f7f573a20081910e34e99cbc91831f4f02f1ff |
62e4a418 | 2074 | Address below which program initialized and |
426bc8d7 | 2075 | uninitialized (BSS) data are placed. |
12449ae3 | 2076 | .TP |
b02b4b74 | 2077 | (47) \fIstart_brk\fP \ %lu \ (since Linux 3.3) \ [PT] |
0be30a54 | 2078 | .\" commit b3f7f573a20081910e34e99cbc91831f4f02f1ff |
62e4a418 | 2079 | Address above which program heap can be expanded with |
426bc8d7 | 2080 | .BR brk (2). |
12449ae3 | 2081 | .TP |
b02b4b74 | 2082 | (48) \fIarg_start\fP \ %lu \ (since Linux 3.5) \ [PT] |
0be30a54 | 2083 | .\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3 |
62e4a418 | 2084 | Address above which program command-line arguments |
426bc8d7 MK |
2085 | .RI ( argv ) |
2086 | are placed. | |
12449ae3 | 2087 | .TP |
b02b4b74 | 2088 | (49) \fIarg_end\fP \ %lu \ (since Linux 3.5) \ [PT] |
0be30a54 | 2089 | .\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3 |
62e4a418 | 2090 | Address below program command-line arguments |
426bc8d7 MK |
2091 | .RI ( argv ) |
2092 | are placed. | |
12449ae3 | 2093 | .TP |
b02b4b74 | 2094 | (50) \fIenv_start\fP \ %lu \ (since Linux 3.5) \ [PT] |
0be30a54 | 2095 | .\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3 |
62e4a418 | 2096 | Address above which program environment is placed. |
12449ae3 | 2097 | .TP |
b02b4b74 | 2098 | (51) \fIenv_end\fP \ %lu \ (since Linux 3.5) \ [PT] |
0be30a54 | 2099 | .\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3 |
62e4a418 | 2100 | Address below which program environment is placed. |
12449ae3 | 2101 | .TP |
b02b4b74 | 2102 | (52) \fIexit_code\fP \ %d \ (since Linux 3.5) \ [PT] |
0be30a54 | 2103 | .\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3 |
62e4a418 | 2104 | The thread's exit status in the form reported by |
426bc8d7 | 2105 | .BR waitpid (2). |
12449ae3 | 2106 | .RE |
2107 | .TP | |
69119dc7 | 2108 | .I /proc/[pid]/statm |
59a40ed7 | 2109 | Provides information about memory usage, measured in pages. |
c13182ef | 2110 | The columns are: |
a08ea57c MK |
2111 | .in +4n |
2112 | .nf | |
2113 | ||
cb42fb56 | 2114 | size (1) total program size |
69119dc7 | 2115 | (same as VmSize in \fI/proc/[pid]/status\fP) |
cb42fb56 | 2116 | resident (2) resident set size |
69119dc7 | 2117 | (same as VmRSS in \fI/proc/[pid]/status\fP) |
4e6fa352 MK |
2118 | shared (3) number of resident shared pages (i.e., backed by a file) |
2119 | (same as RssFile+RssShmem in \fI/proc/[pid]/status\fP) | |
cb42fb56 | 2120 | text (4) text (code) |
59a40ed7 | 2121 | .\" (not including libs; broken, includes data segment) |
d133b9b3 | 2122 | lib (5) library (unused since Linux 2.6; always 0) |
cb42fb56 | 2123 | data (6) data + stack |
59a40ed7 | 2124 | .\" (including libs; broken, includes library text) |
d133b9b3 | 2125 | dt (7) dirty pages (unused since Linux 2.6; always 0) |
a08ea57c MK |
2126 | .fi |
2127 | .in | |
fea681da | 2128 | .TP |
69119dc7 | 2129 | .I /proc/[pid]/status |
fea681da | 2130 | Provides much of the information in |
69119dc7 | 2131 | .I /proc/[pid]/stat |
fea681da | 2132 | and |
69119dc7 | 2133 | .I /proc/[pid]/statm |
fea681da | 2134 | in a format that's easier for humans to parse. |
16b5f7ba MK |
2135 | Here's an example: |
2136 | .in +4n | |
2137 | .nf | |
2138 | ||
b43a3b30 | 2139 | .RB "$" " cat /proc/$$/status" |
16b5f7ba | 2140 | Name: bash |
a79343e9 | 2141 | Umask: 0022 |
16b5f7ba | 2142 | State: S (sleeping) |
aac0b30f | 2143 | Tgid: 17248 |
2d2dfb69 | 2144 | Ngid: 0 |
aac0b30f MK |
2145 | Pid: 17248 |
2146 | PPid: 17200 | |
16b5f7ba MK |
2147 | TracerPid: 0 |
2148 | Uid: 1000 1000 1000 1000 | |
2149 | Gid: 100 100 100 100 | |
2150 | FDSize: 256 | |
2151 | Groups: 16 33 100 | |
aac0b30f MK |
2152 | NStgid: 17248 |
2153 | NSpid: 17248 | |
2154 | NSpgid: 17248 | |
2155 | NSsid: 17200 | |
06b7cee0 MK |
2156 | VmPeak: 131168 kB |
2157 | VmSize: 131168 kB | |
2158 | VmLck: 0 kB | |
2159 | VmPin: 0 kB | |
2160 | VmHWM: 13484 kB | |
2161 | VmRSS: 13484 kB | |
e546617e MK |
2162 | RssAnon: 10264 kB |
2163 | RssFile: 3220 kB | |
2164 | RssShmem: 0 kB | |
06b7cee0 MK |
2165 | VmData: 10332 kB |
2166 | VmStk: 136 kB | |
2167 | VmExe: 992 kB | |
2168 | VmLib: 2104 kB | |
2169 | VmPTE: 76 kB | |
2170 | VmPMD: 12 kB | |
2171 | VmSwap: 0 kB | |
4084d612 | 2172 | HugetlbPages: 0 kB # 4.4 |
16b5f7ba MK |
2173 | Threads: 1 |
2174 | SigQ: 0/3067 | |
2175 | SigPnd: 0000000000000000 | |
2176 | ShdPnd: 0000000000000000 | |
2177 | SigBlk: 0000000000010000 | |
2178 | SigIgn: 0000000000384004 | |
2179 | SigCgt: 000000004b813efb | |
2180 | CapInh: 0000000000000000 | |
2181 | CapPrm: 0000000000000000 | |
2182 | CapEff: 0000000000000000 | |
2183 | CapBnd: ffffffffffffffff | |
6112ea97 | 2184 | CapAmb: 0000000000000000 |
6c0ed873 | 2185 | NoNewPrivs: 0 |
039b6546 | 2186 | Seccomp: 0 |
16b5f7ba MK |
2187 | Cpus_allowed: 00000001 |
2188 | Cpus_allowed_list: 0 | |
2189 | Mems_allowed: 1 | |
2190 | Mems_allowed_list: 0 | |
2191 | voluntary_ctxt_switches: 150 | |
2192 | nonvoluntary_ctxt_switches: 545 | |
2193 | .fi | |
2194 | .in | |
2195 | .IP | |
2196 | The fields are as follows: | |
2197 | .RS | |
2198 | .IP * 2 | |
2199 | .IR Name : | |
2200 | Command run by this process. | |
2201 | .IP * | |
a79343e9 | 2202 | .IR Umask : |
53473996 MK |
2203 | Process umask, expressed in octal with a leading zero; see |
2204 | .BR umask (2). | |
a79343e9 MK |
2205 | (Since Linux 4.7.) |
2206 | .IP * | |
16b5f7ba | 2207 | .IR State : |
4175f999 MK |
2208 | Current state of the process. |
2209 | One of | |
16b5f7ba MK |
2210 | "R (running)", |
2211 | "S (sleeping)", | |
2212 | "D (disk sleep)", | |
2213 | "T (stopped)", | |
2214 | "T (tracing stop)", | |
2215 | "Z (zombie)", | |
2216 | or | |
2217 | "X (dead)". | |
2218 | .IP * | |
2219 | .IR Tgid : | |
2220 | Thread group ID (i.e., Process ID). | |
2221 | .IP * | |
2d2dfb69 MK |
2222 | .IR Ngid : |
2223 | NUMA group ID (0 if none; since Linux 3.13). | |
2224 | .IP * | |
16b5f7ba MK |
2225 | .IR Pid : |
2226 | Thread ID (see | |
2227 | .BR gettid (2)). | |
2228 | .IP * | |
a1bc91d5 MK |
2229 | .IR PPid : |
2230 | PID of parent process. | |
2231 | .IP * | |
16b5f7ba MK |
2232 | .IR TracerPid : |
2233 | PID of process tracing this process (0 if not being traced). | |
2234 | .IP * | |
2235 | .IR Uid ", " Gid : | |
9ee4a2b6 | 2236 | Real, effective, saved set, and filesystem UIDs (GIDs). |
16b5f7ba MK |
2237 | .IP * |
2238 | .IR FDSize : | |
2239 | Number of file descriptor slots currently allocated. | |
2240 | .IP * | |
2241 | .IR Groups : | |
2242 | Supplementary group list. | |
2243 | .IP * | |
ecc9535d | 2244 | .I NStgid : |
aac0b30f MK |
2245 | Thread group ID (i.e., PID) in each of the PID namespaces of which |
2246 | .I [pid] | |
2247 | is a member. | |
2248 | The leftmost entry shows the value with respect to the PID namespace | |
2249 | of the reading process, | |
2250 | followed by the value in successively nested inner namespaces. | |
2251 | .\" commit e4bc33245124db69b74a6d853ac76c2976f472d5 | |
2252 | (Since Linux 4.1.) | |
2253 | .IP * | |
ecc9535d | 2254 | .IR NSpid: |
aac0b30f MK |
2255 | Thread ID in each of the PID namespaces of which |
2256 | .I [pid] | |
2257 | is a member. | |
2258 | The fields are ordered as for | |
2259 | .IR NStgid . | |
2260 | (Since Linux 4.1.) | |
2261 | .IP * | |
ecc9535d | 2262 | .IR NSpgid : |
aac0b30f MK |
2263 | Process group ID in each of the PID namespaces of which |
2264 | .I [pid] | |
2265 | is a member. | |
2266 | The fields are ordered as for | |
2267 | .IR NStgid . | |
2268 | (Since Linux 4.1.) | |
2269 | .IP * | |
ecc9535d | 2270 | .IR NSsid : |
aac0b30f MK |
2271 | descendant namespace session ID hierarchy |
2272 | Session ID in each of the PID namespaces of which | |
2273 | .I [pid] | |
2274 | is a member. | |
2275 | The fields are ordered as for | |
2276 | .IR NStgid . | |
2277 | (Since Linux 4.1.) | |
2278 | .IP * | |
16b5f7ba MK |
2279 | .IR VmPeak : |
2280 | Peak virtual memory size. | |
2281 | .IP * | |
2282 | .IR VmSize : | |
2283 | Virtual memory size. | |
2284 | .IP * | |
2285 | .IR VmLck : | |
fde39195 MK |
2286 | Locked memory size (see |
2287 | .BR mlock (3)). | |
16b5f7ba | 2288 | .IP * |
15789039 TY |
2289 | .IR VmPin : |
2290 | Pinned memory size | |
2291 | .\" commit bc3e53f682d93df677dbd5006a404722b3adfe18 | |
2292 | (since Linux 3.2). | |
2293 | These are pages that can't be moved because something needs to | |
2294 | directly access physical memory. | |
2295 | .IP * | |
16b5f7ba MK |
2296 | .IR VmHWM : |
2297 | Peak resident set size ("high water mark"). | |
2298 | .IP * | |
2299 | .IR VmRSS : | |
2300 | Resident set size. | |
e546617e MK |
2301 | Note that the value here is the sum of |
2302 | .IR RssAnon , | |
2303 | .IR RssFile , | |
2304 | and | |
2305 | .IR RssShmem . | |
2306 | .IP * | |
2307 | .IR RssAnon : | |
2308 | Size of resident anonymous memory. | |
2309 | .\" commit bf9683d6990589390b5178dafe8fd06808869293 | |
2310 | (since Linux 4.5). | |
2311 | .IP * | |
2312 | .IR RssFile : | |
2313 | Size of resident file mappings. | |
2314 | .\" commit bf9683d6990589390b5178dafe8fd06808869293 | |
2315 | (since Linux 4.5). | |
2316 | .IP * | |
2317 | .IR RssShmem : | |
78230722 | 2318 | Size of resident shared memory (includes System V shared memory, |
4e07c70f MK |
2319 | mappings from |
2320 | .BR tmpfs (5), | |
2321 | and shared anonymous mappings). | |
e546617e MK |
2322 | .\" commit bf9683d6990589390b5178dafe8fd06808869293 |
2323 | (since Linux 4.5). | |
16b5f7ba MK |
2324 | .IP * |
2325 | .IR VmData ", " VmStk ", " VmExe : | |
2326 | Size of data, stack, and text segments. | |
2327 | .IP * | |
2328 | .IR VmLib : | |
2329 | Shared library code size. | |
2330 | .IP * | |
2331 | .IR VmPTE : | |
2332 | Page table entries size (since Linux 2.6.10). | |
2333 | .IP * | |
e28af9cd MK |
2334 | .IR VmPMD : |
2335 | .\" commit dc6c9a35b66b520cf67e05d8ca60ebecad3b0479 | |
73b9cbe1 | 2336 | Size of second-level page tables (since Linux 4.0). |
e28af9cd | 2337 | .IP * |
ac4b0eb3 | 2338 | .IR VmSwap : |
1ddc1665 | 2339 | .\" commit b084d4353ff99d824d3bc5a5c2c22c70b1fba722 |
fce21149 MK |
2340 | Swapped-out virtual memory size by anonymous private pages; |
2341 | shmem swap usage is not included (since Linux 2.6.34). | |
49f6dda7 | 2342 | .IP * |
4084d612 MK |
2343 | .IR HugetlbPages : |
2344 | Size of hugetlb memory portions. | |
2345 | .\" commit 5d317b2b6536592a9b51fe65faed43d65ca9158e | |
2346 | (since Linux 4.4). | |
2347 | .IP * | |
16b5f7ba MK |
2348 | .IR Threads : |
2349 | Number of threads in process containing this thread. | |
2350 | .IP * | |
6ee625eb MK |
2351 | .IR SigQ : |
2352 | This field contains two slash-separated numbers that relate to | |
2353 | queued signals for the real user ID of this process. | |
2354 | The first of these is the number of currently queued | |
2355 | signals for this real user ID, and the second is the | |
2356 | resource limit on the number of queued signals for this process | |
2357 | (see the description of | |
2358 | .BR RLIMIT_SIGPENDING | |
2359 | in | |
2360 | .BR getrlimit (2)). | |
2361 | .IP * | |
16b5f7ba MK |
2362 | .IR SigPnd ", " ShdPnd : |
2363 | Number of signals pending for thread and for process as a whole (see | |
2364 | .BR pthreads (7) | |
2365 | and | |
2366 | .BR signal (7)). | |
2367 | .IP * | |
2368 | .IR SigBlk ", " SigIgn ", " SigCgt : | |
2369 | Masks indicating signals being blocked, ignored, and caught (see | |
2370 | .BR signal (7)). | |
2371 | .IP * | |
2372 | .IR CapInh ", " CapPrm ", " CapEff : | |
2373 | Masks of capabilities enabled in inheritable, permitted, and effective sets | |
2374 | (see | |
2375 | .BR capabilities (7)). | |
2376 | .IP * | |
2377 | .IR CapBnd : | |
2378 | Capability Bounding set | |
7e07d950 | 2379 | (since Linux 2.6.26, see |
16b5f7ba MK |
2380 | .BR capabilities (7)). |
2381 | .IP * | |
6112ea97 MK |
2382 | .IR CapAmb : |
2383 | Ambient capability set | |
2384 | (since Linux 4.3, see | |
2385 | .BR capabilities (7)). | |
2386 | .IP * | |
6c0ed873 MK |
2387 | .IR NoNewPrivs : |
2388 | .\" commit af884cd4a5ae62fcf5e321fecf0ec1014730353d | |
2389 | Value of the | |
2390 | .I no_new_privs | |
2391 | bit | |
2392 | (since Linux 4.10, see | |
2393 | .BR prctl (2)). | |
2394 | .IP * | |
039b6546 MK |
2395 | .IR Seccomp : |
2396 | .\" commit 2f4b3bf6b2318cfaa177ec5a802f4d8d6afbd816 | |
2397 | Seccomp mode of the process | |
2398 | (since Linux 3.8, see | |
2399 | .BR seccomp (2)). | |
2400 | 0 means | |
2401 | .BR SECCOMP_MODE_DISABLED ; | |
2402 | 1 means | |
2403 | .BR SECCOMP_MODE_STRICT ; | |
2404 | 2 means | |
2405 | .BR SECCOMP_MODE_FILTER . | |
2406 | This field is provided only if the kernel was built with the | |
2407 | .BR CONFIG_SECCOMP | |
2408 | kernel configuration option enabled. | |
2409 | .IP * | |
16b5f7ba MK |
2410 | .IR Cpus_allowed : |
2411 | Mask of CPUs on which this process may run | |
2412 | (since Linux 2.6.24, see | |
2413 | .BR cpuset (7)). | |
2414 | .IP * | |
2415 | .IR Cpus_allowed_list : | |
2416 | Same as previous, but in "list format" | |
2417 | (since Linux 2.6.26, see | |
2418 | .BR cpuset (7)). | |
2419 | .IP * | |
2420 | .IR Mems_allowed : | |
2421 | Mask of memory nodes allowed to this process | |
2422 | (since Linux 2.6.24, see | |
2423 | .BR cpuset (7)). | |
2424 | .IP * | |
2425 | .IR Mems_allowed_list : | |
2426 | Same as previous, but in "list format" | |
2427 | (since Linux 2.6.26, see | |
2428 | .BR cpuset (7)). | |
2429 | .IP * | |
7c82878a | 2430 | .IR voluntary_ctxt_switches ", " nonvoluntary_ctxt_switches : |
16b5f7ba MK |
2431 | Number of voluntary and involuntary context switches (since Linux 2.6.23). |
2432 | .RE | |
afb7b014 MK |
2433 | .TP |
2434 | .IR /proc/[pid]/syscall " (since Linux 2.6.27)" | |
2435 | .\" commit ebcb67341fee34061430f3367f2e507e52ee051b | |
2436 | This file exposes the system call number and argument registers for the | |
2437 | system call currently being executed by the process, | |
2438 | followed by the values of the stack pointer and program counter registers. | |
2439 | The values of all six argument registers are exposed, | |
2440 | although most system calls use fewer registers. | |
2441 | ||
2442 | If the process is blocked, but not in a system call, | |
1fb61947 | 2443 | then the file displays \-1 in place of the system call number, |
afb7b014 | 2444 | followed by just the values of the stack pointer and program counter. |
64fcb6e1 | 2445 | If process is not blocked, then the file contains just the string "running". |
afb7b014 MK |
2446 | |
2447 | This file is present only if the kernel was configured with | |
2448 | .BR CONFIG_HAVE_ARCH_TRACEHOOK . | |
4834ae91 MK |
2449 | |
2450 | Permission to access this file is governed by a ptrace access mode | |
2451 | .B PTRACE_MODE_ATTACH_FSCREDS | |
2452 | check; see | |
2453 | .BR ptrace (2). | |
fea681da | 2454 | .TP |
69119dc7 | 2455 | .IR /proc/[pid]/task " (since Linux 2.6.0-test6)" |
afcaf646 MK |
2456 | This is a directory that contains one subdirectory |
2457 | for each thread in the process. | |
69119dc7 MK |
2458 | The name of each subdirectory is the numerical thread ID |
2459 | .RI ( [tid] ) | |
2460 | of the thread (see | |
afcaf646 MK |
2461 | .BR gettid (2)). |
2462 | Within each of these subdirectories, there is a set of | |
2463 | files with the same names and contents as under the | |
69119dc7 | 2464 | .I /proc/[pid] |
afcaf646 MK |
2465 | directories. |
2466 | For attributes that are shared by all threads, the contents for | |
2467 | each of the files under the | |
69119dc7 | 2468 | .I task/[tid] |
afcaf646 | 2469 | subdirectories will be the same as in the corresponding |
c13182ef | 2470 | file in the parent |
69119dc7 | 2471 | .I /proc/[pid] |
afcaf646 | 2472 | directory |
c13182ef | 2473 | (e.g., in a multithreaded process, all of the |
69119dc7 | 2474 | .I task/[tid]/cwd |
c13182ef | 2475 | files will have the same value as the |
69119dc7 | 2476 | .I /proc/[pid]/cwd |
c13182ef | 2477 | file in the parent directory, since all of the threads in a process |
afcaf646 MK |
2478 | share a working directory). |
2479 | For attributes that are distinct for each thread, | |
c13182ef | 2480 | the corresponding files under |
69119dc7 | 2481 | .I task/[tid] |
afcaf646 | 2482 | may have different values (e.g., various fields in each of the |
69119dc7 | 2483 | .I task/[tid]/status |
4a40c703 JH |
2484 | files may be different for each thread), |
2485 | .\" in particular: "children" :/ | |
2486 | or they might not exist in | |
2487 | .I /proc/[pid] | |
2488 | at all. | |
afcaf646 MK |
2489 | .\" The following was still true as at kernel 2.6.13 |
2490 | In a multithreaded process, the contents of the | |
69119dc7 | 2491 | .I /proc/[pid]/task |
c13182ef | 2492 | directory are not available if the main thread has already terminated |
afcaf646 MK |
2493 | (typically by calling |
2494 | .BR pthread_exit (3)). | |
4a40c703 JH |
2495 | |
2496 | .TP | |
2497 | .IR /proc/[pid]/task/[tid]/children " (since Linux 3.5)" | |
2498 | .\" commit 818411616baf46ceba0cff6f05af3a9b294734f7 | |
2499 | A space-separated list of child tasks of this task. | |
2500 | Each child task is represented by its TID. | |
2501 | ||
2502 | .\" see comments in get_children_pid() in fs/proc/array.c | |
45dd5092 MK |
2503 | This option is intended for use by the checkpoint-restore (CRIU) system, |
2504 | and reliably provides a list of children only if all of the child processes | |
2505 | are stopped or frozen. | |
2506 | It does not work properly if children of the target task exit while | |
4a40c703 | 2507 | the file is being read! |
45dd5092 | 2508 | Exiting children may cause non-exiting children to be omitted from the list. |
4a40c703 | 2509 | This makes this interface even more unreliable than classic PID-based |
45dd5092 MK |
2510 | approaches if the inspected task and its children aren't frozen, |
2511 | and most code should probably not use this interface. | |
7ded2db4 MK |
2512 | |
2513 | Until Linux 4.2, the presence of this file was governed by the | |
2514 | .B CONFIG_CHECKPOINT_RESTORE | |
2515 | kernel configuration option. | |
2516 | Since Linux 4.2, | |
2517 | .\" commit 2e13ba54a2682eea24918b87ad3edf70c2cf085b | |
ae34c521 | 2518 | it is governed by the |
7ded2db4 MK |
2519 | .B CONFIG_PROC_CHILDREN |
2520 | option. | |
afcaf646 | 2521 | .TP |
1509ca0e MK |
2522 | .IR /proc/[pid]/timers " (since Linux 3.10)" |
2523 | .\" commit 5ed67f05f66c41e39880a6d61358438a25f9fee5 | |
2524 | .\" commit 48f6a7a511ef8823fdff39afee0320092d43a8a0 | |
2525 | A list of the POSIX timers for this process. | |
93691c1e | 2526 | Each timer is listed with a line that starts with the string "ID:". |
1509ca0e MK |
2527 | For example: |
2528 | ||
2529 | .in +4n | |
2530 | .nf | |
2531 | ID: 1 | |
2532 | signal: 60/00007fff86e452a8 | |
2533 | notify: signal/pid.2634 | |
2534 | ClockID: 0 | |
2535 | ID: 0 | |
2536 | signal: 60/00007fff86e452a8 | |
2537 | notify: signal/pid.2634 | |
2538 | ClockID: 1 | |
2539 | .fi | |
2540 | .in | |
2541 | ||
2542 | The lines shown for each timer have the following meanings: | |
2543 | .RS | |
2544 | .TP | |
2545 | .I ID | |
2546 | The ID for this timer. | |
2547 | This is not the same as the timer ID returned by | |
2548 | .BR timer_create (2); | |
2549 | rather, it is the same kernel-internal ID that is available via the | |
2550 | .I si_timerid | |
2551 | field of the | |
2552 | .IR siginfo_t | |
2553 | structure (see | |
2554 | .BR sigaction (2)). | |
2555 | .TP | |
2556 | .I signal | |
2557 | This is the signal number that this timer uses to deliver notifications | |
2558 | followed by a slash, and then the | |
7f1ea8fb | 2559 | .I sigev_value |
1509ca0e MK |
2560 | value supplied to the signal handler. |
2561 | Valid only for timers that notify via a signal. | |
2562 | .TP | |
2563 | .I notify | |
2564 | The part before the slash specifies the mechanism | |
2565 | that this timer uses to deliver notifications, | |
2566 | and is one of "thread", "signal", or "none". | |
2567 | Immediately following the slash is either the string "tid" for timers | |
2568 | with | |
2569 | .B SIGEV_THREAD_ID | |
2570 | notification, or "pid" for timers that notify by other mechanisms. | |
dbe6f88b MK |
2571 | Following the "." is the PID of the process |
2572 | (or the kernel thread ID of the thread) that will be delivered | |
1509ca0e MK |
2573 | a signal if the timer delivers notifications via a signal. |
2574 | .TP | |
2575 | .I ClockID | |
2576 | This field identifies the clock that the timer uses for measuring time. | |
2577 | For most clocks, this is a number that matches one of the user-space | |
2578 | .BR CLOCK_* | |
9d54c087 | 2579 | constants exposed via |
1509ca0e MK |
2580 | .IR <time.h> . |
2581 | .B CLOCK_PROCESS_CPUTIME_ID | |
2582 | timers display with a value of -6 | |
2583 | in this field. | |
2584 | .B CLOCK_THREAD_CPUTIME_ID | |
2585 | timers display with a value of -2 | |
2586 | in this field. | |
2587 | .RE | |
5734da6d MK |
2588 | .IP |
2589 | This file is available only when the kernel was configured with | |
2590 | .BR CONFIG_CHECKPOINT_RESTORE . | |
1509ca0e | 2591 | .TP |
11f60142 MK |
2592 | .IR /proc/[pid]/timerslack_ns " (since Linux 4.6)" |
2593 | .\" commit da8b44d5a9f8bf26da637b7336508ca534d6b319 | |
2594 | .\" commit 5de23d435e88996b1efe0e2cebe242074ce67c9e | |
2595 | This file exposes the process's "current" timer slack value, | |
2596 | expressed in nanoseconds. | |
2597 | The file is writable, | |
2598 | allowing the process's timer slack value to be changed. | |
2599 | Writing 0 to this file resets the "current" timer slack to the | |
2600 | "default" timer slack value. | |
2601 | For further details, see the discussion of | |
2602 | .BR PR_SET_TIMERSLACK | |
2603 | in | |
2604 | .BR prctl (2). | |
a62e0e01 MK |
2605 | |
2606 | Permission to access this file is governed by a ptrace access mode | |
2607 | .B PTRACE_MODE_ATTACH_FSCREDS | |
2608 | check; see | |
2609 | .BR ptrace (2). | |
11f60142 | 2610 | .TP |
b1aad373 MK |
2611 | .IR /proc/[pid]/uid_map ", " /proc/[pid]/gid_map " (since Linux 3.5)" |
2612 | See | |
2613 | .BR user_namespaces (7). | |
2614 | .TP | |
2615 | .IR /proc/[pid]/wchan " (since Linux 2.6.0)" | |
2616 | The symbolic name corresponding to the location | |
2617 | in the kernel where the process is sleeping. | |
82664739 MK |
2618 | |
2619 | Permission to access this file is governed by a ptrace access mode | |
2620 | .B PTRACE_MODE_READ_FSCREDS | |
2621 | check; see | |
2622 | .BR ptrace (2). | |
b1aad373 MK |
2623 | .TP |
2624 | .I /proc/apm | |
2625 | Advanced power management version and battery information when | |
2626 | .B CONFIG_APM | |
2627 | is defined at kernel compilation time. | |
2628 | .TP | |
2629 | .I /proc/buddyinfo | |
2630 | This file contains information which is used for diagnosing memory | |
2631 | fragmentation issues. | |
2632 | Each line starts with the identification of the node and the name | |
2633 | of the zone which together identify a memory region | |
2634 | This is then | |
2635 | followed by the count of available chunks of a certain order in | |
2636 | which these zones are split. | |
2637 | The size in bytes of a certain order is given by the formula: | |
2638 | ||
2639 | (2^order)\ *\ PAGE_SIZE | |
2640 | ||
2641 | The binary buddy allocator algorithm inside the kernel will split | |
2642 | one chunk into two chunks of a smaller order (thus with half the | |
2643 | size) or combine two contiguous chunks into one larger chunk of | |
2644 | a higher order (thus with double the size) to satisfy allocation | |
2645 | requests and to counter memory fragmentation. | |
2646 | The order matches the column number, when starting to count at zero. | |
2647 | ||
2648 | For example on a x86_64 system: | |
2649 | ||
2650 | .in -12n | |
2651 | .nf | |
2652 | Node 0, zone DMA 1 1 1 0 2 1 1 0 1 1 3 | |
2653 | Node 0, zone DMA32 65 47 4 81 52 28 13 10 5 1 404 | |
2654 | Node 0, zone Normal 216 55 189 101 84 38 37 27 5 3 587 | |
2655 | .fi | |
2656 | .in | |
2657 | ||
2658 | In this example, there is one node containing three zones and there | |
2659 | are 11 different chunk sizes. | |
2660 | If the page size is 4 kilobytes, then the first zone called | |
2661 | .I DMA | |
2662 | (on x86 the first 16 megabyte of memory) has 1 chunk of 4 kilobytes | |
2663 | (order 0) available and has 3 chunks of 4 megabytes (order 10) available. | |
2664 | ||
2665 | If the memory is heavily fragmented, the counters for higher | |
2666 | order chunks will be zero and allocation of large contiguous areas | |
2667 | will fail. | |
2668 | ||
2669 | Further information about the zones can be found in | |
2670 | .IR /proc/zoneinfo . | |
2671 | .TP | |
2672 | .I /proc/bus | |
2673 | Contains subdirectories for installed busses. | |
2674 | .TP | |
2675 | .I /proc/bus/pccard | |
2676 | Subdirectory for PCMCIA devices when | |
2677 | .B CONFIG_PCMCIA | |
2678 | is set at kernel compilation time. | |
2679 | .TP | |
fea681da MK |
2680 | .I /proc/bus/pccard/drivers |
2681 | .TP | |
2682 | .I /proc/bus/pci | |
c13182ef | 2683 | Contains various bus subdirectories and pseudo-files containing |
59a40ed7 | 2684 | information about PCI busses, installed devices, and device |
c13182ef MK |
2685 | drivers. |
2686 | Some of these files are not ASCII. | |
fea681da MK |
2687 | .TP |
2688 | .I /proc/bus/pci/devices | |
59a40ed7 | 2689 | Information about PCI devices. |
c13182ef | 2690 | They may be accessed through |
fea681da MK |
2691 | .BR lspci (8) |
2692 | and | |
2693 | .BR setpci (8). | |
2694 | .TP | |
12b23dfe MK |
2695 | .IR /proc/cgroups " (since Linux 2.6.24)" |
2696 | See | |
2697 | .BR cgroups (7). | |
2698 | .TP | |
fea681da | 2699 | .I /proc/cmdline |
c13182ef MK |
2700 | Arguments passed to the Linux kernel at boot time. |
2701 | Often done via a boot manager such as | |
59a40ed7 MK |
2702 | .BR lilo (8) |
2703 | or | |
2704 | .BR grub (8). | |
f6e524c4 MK |
2705 | .TP |
2706 | .IR /proc/config.gz " (since Linux 2.6)" | |
2707 | This file exposes the configuration options that were used | |
c3d9780d | 2708 | to build the currently running kernel, |
f6e524c4 MK |
2709 | in the same format as they would be shown in the |
2710 | .I .config | |
2711 | file that resulted when configuring the kernel (using | |
2712 | .IR "make xconfig" , | |
2713 | .IR "make config" , | |
2714 | or similar). | |
2715 | The file contents are compressed; view or search them using | |
f78ed33a MK |
2716 | .BR zcat (1) |
2717 | and | |
2718 | .BR zgrep (1). | |
f6e524c4 | 2719 | As long as no changes have been made to the following file, |
250e01ec MK |
2720 | the contents of |
2721 | .I /proc/config.gz | |
2722 | are the same as those provided by : | |
f6e524c4 MK |
2723 | .in +4n |
2724 | .nf | |
2725 | ||
c3074d70 | 2726 | cat /lib/modules/$(uname \-r)/build/.config |
f6e524c4 MK |
2727 | .fi |
2728 | .in | |
250e01ec MK |
2729 | .IP |
2730 | .I /proc/config.gz | |
90878f7c | 2731 | is provided only if the kernel is configured with |
250e01ec | 2732 | .BR CONFIG_IKCONFIG_PROC . |
fea681da | 2733 | .TP |
577c0e20 MK |
2734 | .I /proc/crypto |
2735 | A list of the ciphers provided by the kernel crypto API. | |
2736 | For details, see the kernel | |
2737 | .I "Linux Kernel Crypto API" | |
2738 | documentation available under the kernel source directory | |
2739 | .IR Documentation/DocBook . | |
2740 | (That documentation can be built using a command such as | |
2741 | .IR "make htmldocs" | |
2742 | in the root directory of the kernel source tree.) | |
2743 | .TP | |
fea681da MK |
2744 | .I /proc/cpuinfo |
2745 | This is a collection of CPU and system architecture dependent items, | |
2746 | for each supported architecture a different list. | |
2747 | Two common entries are \fIprocessor\fP which gives CPU number and | |
c13182ef MK |
2748 | \fIbogomips\fP; a system constant that is calculated |
2749 | during kernel initialization. | |
2750 | SMP machines have information for | |
fea681da | 2751 | each CPU. |
a091f002 MK |
2752 | The |
2753 | .BR lscpu (1) | |
2754 | command gathers its information from this file. | |
fea681da MK |
2755 | .TP |
2756 | .I /proc/devices | |
c13182ef MK |
2757 | Text listing of major numbers and device groups. |
2758 | This can be used by MAKEDEV scripts for consistency with the kernel. | |
fea681da MK |
2759 | .TP |
2760 | .IR /proc/diskstats " (since Linux 2.5.69)" | |
2761 | This file contains disk I/O statistics for each disk device. | |
66a9882e | 2762 | See the Linux kernel source file |
fea681da MK |
2763 | .I Documentation/iostats.txt |
2764 | for further information. | |
2765 | .TP | |
2766 | .I /proc/dma | |
c13182ef | 2767 | This is a list of the registered \fIISA\fP DMA (direct memory access) |
fea681da MK |
2768 | channels in use. |
2769 | .TP | |
2770 | .I /proc/driver | |
2771 | Empty subdirectory. | |
2772 | .TP | |
2773 | .I /proc/execdomains | |
2774 | List of the execution domains (ABI personalities). | |
2775 | .TP | |
2776 | .I /proc/fb | |
097585ed MK |
2777 | Frame buffer information when |
2778 | .B CONFIG_FB | |
2779 | is defined during kernel compilation. | |
fea681da MK |
2780 | .TP |
2781 | .I /proc/filesystems | |
9ee4a2b6 MK |
2782 | A text listing of the filesystems which are supported by the kernel, |
2783 | namely filesystems which were compiled into the kernel or whose kernel | |
6387216b MK |
2784 | modules are currently loaded. |
2785 | (See also | |
fb477da2 | 2786 | .BR filesystems (5).) |
9ee4a2b6 | 2787 | If a filesystem is marked with "nodev", |
809d0164 | 2788 | this means that it does not require a block device to be mounted |
9ee4a2b6 | 2789 | (e.g., virtual filesystem, network filesystem). |
809d0164 MK |
2790 | |
2791 | Incidentally, this file may be used by | |
2792 | .BR mount (8) | |
9ee4a2b6 MK |
2793 | when no filesystem is specified and it didn't manage to determine the |
2794 | filesystem type. | |
2795 | Then filesystems contained in this file are tried | |
809d0164 | 2796 | (excepted those that are marked with "nodev"). |
fea681da MK |
2797 | .TP |
2798 | .I /proc/fs | |
df352acc | 2799 | .\" FIXME Much more needs to be said about /proc/fs |
91085d85 | 2800 | .\" |
df352acc MK |
2801 | Contains subdirectories that in turn contain files |
2802 | with information about (certain) mounted filesystems. | |
fea681da MK |
2803 | .TP |
2804 | .I /proc/ide | |
2805 | This directory | |
59a40ed7 MK |
2806 | exists on systems with the IDE bus. |
2807 | There are directories for each IDE channel and attached device. | |
c13182ef | 2808 | Files include: |
fea681da | 2809 | |
a08ea57c | 2810 | .in +4n |
fea681da MK |
2811 | .nf |
2812 | cache buffer size in KB | |
2813 | capacity number of sectors | |
2814 | driver driver version | |
2815 | geometry physical and logical geometry | |
9fdfa163 | 2816 | identify in hexadecimal |
fea681da MK |
2817 | media media type |
2818 | model manufacturer's model number | |
2819 | settings drive settings | |
9fdfa163 MK |
2820 | smart_thresholds in hexadecimal |
2821 | smart_values in hexadecimal | |
fea681da | 2822 | .fi |
a08ea57c | 2823 | .in |
fea681da | 2824 | |
c13182ef | 2825 | The |
fea681da MK |
2826 | .BR hdparm (8) |
2827 | utility provides access to this information in a friendly format. | |
2828 | .TP | |
2829 | .I /proc/interrupts | |
23ec6ff0 MK |
2830 | This is used to record the number of interrupts per CPU per IO device. |
2831 | Since Linux 2.6.24, | |
2832 | for the i386 and x86_64 architectures, at least, this also includes | |
2833 | interrupts internal to the system (that is, not associated with a device | |
2834 | as such), such as NMI (nonmaskable interrupt), LOC (local timer interrupt), | |
2835 | and for SMP systems, TLB (TLB flush interrupt), RES (rescheduling | |
2836 | interrupt), CAL (remote function call interrupt), and possibly others. | |
2837 | Very easy to read formatting, done in ASCII. | |
fea681da MK |
2838 | .TP |
2839 | .I /proc/iomem | |
2840 | I/O memory map in Linux 2.4. | |
2841 | .TP | |
2842 | .I /proc/ioports | |
c13182ef | 2843 | This is a list of currently registered Input-Output port regions that |
fea681da MK |
2844 | are in use. |
2845 | .TP | |
2846 | .IR /proc/kallsyms " (since Linux 2.5.71)" | |
2847 | This holds the kernel exported symbol definitions used by the | |
2848 | .BR modules (X) | |
2849 | tools to dynamically link and bind loadable modules. | |
2850 | In Linux 2.5.47 and earlier, a similar file with slightly different syntax | |
2851 | was named | |
2852 | .IR ksyms . | |
2853 | .TP | |
2854 | .I /proc/kcore | |
2855 | This file represents the physical memory of the system and is stored | |
c13182ef MK |
2856 | in the ELF core file format. |
2857 | With this pseudo-file, and an unstripped | |
9a67332e MK |
2858 | kernel |
2859 | .RI ( /usr/src/linux/vmlinux ) | |
2860 | binary, GDB can be used to | |
fea681da MK |
2861 | examine the current state of any kernel data structures. |
2862 | ||
2863 | The total length of the file is the size of physical memory (RAM) plus | |
2864 | 4KB. | |
2865 | .TP | |
2866 | .I /proc/kmsg | |
2867 | This file can be used instead of the | |
2868 | .BR syslog (2) | |
c13182ef MK |
2869 | system call to read kernel messages. |
2870 | A process must have superuser | |
fea681da | 2871 | privileges to read this file, and only one process should read this |
c13182ef MK |
2872 | file. |
2873 | This file should not be read if a syslog process is running | |
fea681da MK |
2874 | which uses the |
2875 | .BR syslog (2) | |
2876 | system call facility to log kernel messages. | |
2877 | ||
2878 | Information in this file is retrieved with the | |
c4517613 | 2879 | .BR dmesg (1) |
fea681da MK |
2880 | program. |
2881 | .TP | |
ff56ac8b MK |
2882 | .IR /proc/kpagecount " (since Linux 2.6.25)" |
2883 | This file contains a 64-bit count of the number of | |
2884 | times each physical page frame is mapped, | |
2885 | indexed by page frame number (see the discussion of | |
2886 | .IR /proc/[pid]/pagemap ). | |
2887 | .IP | |
2888 | The | |
2889 | .IR /proc/kpagecount | |
2890 | file is present only if the | |
2891 | .B CONFIG_PROC_PAGE_MONITOR | |
59d566a9 MK |
2892 | kernel configuration option is enabled. |
2893 | .TP | |
2894 | .IR /proc/kpageflags " (since Linux 2.6.25)" | |
ef4f4031 | 2895 | This file contains 64-bit masks corresponding to each physical page frame; |
59d566a9 MK |
2896 | it is indexed by page frame number (see the discussion of |
2897 | .IR /proc/[pid]/pagemap ). | |
2898 | The bits are as follows: | |
2899 | ||
2900 | 0 - KPF_LOCKED | |
2901 | 1 - KPF_ERROR | |
2902 | 2 - KPF_REFERENCED | |
2903 | 3 - KPF_UPTODATE | |
2904 | 4 - KPF_DIRTY | |
2905 | 5 - KPF_LRU | |
2906 | 6 - KPF_ACTIVE | |
2907 | 7 - KPF_SLAB | |
2908 | 8 - KPF_WRITEBACK | |
2909 | 9 - KPF_RECLAIM | |
2910 | 10 - KPF_BUDDY | |
2911 | 11 - KPF_MMAP (since Linux 2.6.31) | |
2912 | 12 - KPF_ANON (since Linux 2.6.31) | |
2913 | 13 - KPF_SWAPCACHE (since Linux 2.6.31) | |
2914 | 14 - KPF_SWAPBACKED (since Linux 2.6.31) | |
2915 | 15 - KPF_COMPOUND_HEAD (since Linux 2.6.31) | |
2916 | 16 - KPF_COMPOUND_TAIL (since Linux 2.6.31) | |
2917 | 16 - KPF_HUGE (since Linux 2.6.31) | |
2918 | 18 - KPF_UNEVICTABLE (since Linux 2.6.31) | |
2919 | 19 - KPF_HWPOISON (since Linux 2.6.31) | |
2920 | 20 - KPF_NOPAGE (since Linux 2.6.31) | |
2921 | 21 - KPF_KSM (since Linux 2.6.32) | |
2922 | 22 - KPF_THP (since Linux 3.4) | |
2923 | ||
2924 | For further details on the meanings of these bits, | |
2925 | see the kernel source file | |
2926 | .IR Documentation/vm/pagemap.txt . | |
2927 | Before kernel 2.6.29, | |
2928 | .\" commit ad3bdefe877afb47480418fdb05ecd42842de65e | |
2929 | .\" commit e07a4b9217d1e97d2f3a62b6b070efdc61212110 | |
2930 | .BR KPF_WRITEBACK , | |
2931 | .BR KPF_RECLAIM , | |
2932 | .BR KPF_BUDDY , | |
2933 | and | |
2934 | .BR KPF_LOCKED | |
2935 | did not report correctly. | |
2936 | .IP | |
2937 | The | |
2938 | .IR /proc/kpageflags | |
2939 | file is present only if the | |
2940 | .B CONFIG_PROC_PAGE_MONITOR | |
ff56ac8b MK |
2941 | kernel configuration option is enabled. |
2942 | .TP | |
fea681da MK |
2943 | .IR /proc/ksyms " (Linux 1.1.23-2.5.47)" |
2944 | See | |
2945 | .IR /proc/kallsyms . | |
2946 | .TP | |
2947 | .I /proc/loadavg | |
6b05dc38 MK |
2948 | The first three fields in this file are load average figures |
2949 | giving the number of jobs in the run queue (state R) | |
fea681da MK |
2950 | or waiting for disk I/O (state D) averaged over 1, 5, and 15 minutes. |
2951 | They are the same as the load average numbers given by | |
2952 | .BR uptime (1) | |
2953 | and other programs. | |
6b05dc38 | 2954 | The fourth field consists of two numbers separated by a slash (/). |
78fc91ec EDB |
2955 | The first of these is the number of currently runnable kernel |
2956 | scheduling entities (processes, threads). | |
6b05dc38 MK |
2957 | The value after the slash is the number of kernel scheduling entities |
2958 | that currently exist on the system. | |
2959 | The fifth field is the PID of the process that was most | |
2960 | recently created on the system. | |
fea681da MK |
2961 | .TP |
2962 | .I /proc/locks | |
2963 | This file shows current file locks | |
2964 | .RB ( flock "(2) and " fcntl (2)) | |
2965 | and leases | |
2966 | .RB ( fcntl (2)). | |
9f1002a1 MK |
2967 | The |
2968 | .BR lslocks (8) | |
2969 | command provides a bit more information about each lock. | |
fea681da | 2970 | .TP |
89dd5f8a | 2971 | .IR /proc/malloc " (only up to and including Linux 2.2)" |
59a40ed7 | 2972 | .\" It looks like this only ever did something back in 1.0 days |
90878f7c | 2973 | This file is present only if |
89dd5f8a | 2974 | .B CONFIG_DEBUG_MALLOC |
097585ed | 2975 | was defined during compilation. |
fea681da MK |
2976 | .TP |
2977 | .I /proc/meminfo | |
77b802ec MK |
2978 | This file reports statistics about memory usage on the system. |
2979 | It is used by | |
fea681da MK |
2980 | .BR free (1) |
2981 | to report the amount of free and used memory (both physical and swap) | |
2982 | on the system as well as the shared memory and buffers used by the | |
2983 | kernel. | |
3ba3d5b1 MK |
2984 | Each line of the file consists of a parameter name, followed by a colon, |
2985 | the value of the parameter, and an option unit of measurement (e.g., "kB"). | |
2986 | The list below describes the parameter names and | |
2987 | the format specifier required to read the field value. | |
2988 | Except as noted below, | |
2989 | all of the fields have been present since at least Linux 2.6.0. | |
86cf87d7 | 2990 | Some fields are displayed only if the kernel was configured |
3ba3d5b1 MK |
2991 | with various options; those dependencies are noted in the list. |
2992 | .RS | |
2993 | .TP | |
2994 | .IR MemTotal " %lu" | |
449dd4e2 | 2995 | Total usable RAM (i.e., physical RAM minus a few reserved |
99e91586 | 2996 | bits and the kernel binary code). |
3ba3d5b1 MK |
2997 | .TP |
2998 | .IR MemFree " %lu" | |
7bccb7d4 DP |
2999 | The sum of |
3000 | .IR LowFree + HighFree . | |
3ba3d5b1 | 3001 | .TP |
8b4b1f68 MK |
3002 | .IR MemAvailable " %lu (since Linux 3.14)" |
3003 | An estimate of how much memory is available for starting new | |
3004 | applications, without swapping. | |
3005 | .TP | |
3ba3d5b1 | 3006 | .IR Buffers " %lu" |
99e91586 | 3007 | Relatively temporary storage for raw disk blocks that |
3ba3d5b1 MK |
3008 | shouldn't get tremendously large (20MB or so). |
3009 | .TP | |
3010 | .IR Cached " %lu" | |
3011 | In-memory cache for files read from the disk (the page cache). | |
3012 | Doesn't include | |
3013 | .IR SwapCached . | |
3014 | .TP | |
3015 | .IR SwapCached " %lu" | |
3016 | Memory that once was swapped out, is swapped back in but | |
3017 | still also is in the swap file. | |
fa1d2749 | 3018 | (If memory pressure is high, these pages |
3ba3d5b1 | 3019 | don't need to be swapped out again because they are already |
99e91586 | 3020 | in the swap file. |
3ba3d5b1 MK |
3021 | This saves I/O.) |
3022 | .TP | |
3023 | .IR Active " %lu" | |
3024 | Memory that has been used more recently and usually not | |
3025 | reclaimed unless absolutely necessary. | |
3026 | .TP | |
3027 | .IR Inactive " %lu" | |
3028 | Memory which has been less recently used. | |
3029 | It is more eligible to be reclaimed for other purposes. | |
3030 | .TP | |
3031 | .IR Active(anon) " %lu (since Linux 2.6.28)" | |
3032 | [To be documented.] | |
3033 | .TP | |
3034 | .IR Inactive(anon) " %lu (since Linux 2.6.28)" | |
3035 | [To be documented.] | |
3036 | .TP | |
3037 | .IR Active(file) " %lu (since Linux 2.6.28)" | |
3038 | [To be documented.] | |
3039 | .TP | |
3040 | .IR Inactive(file) " %lu (since Linux 2.6.28)" | |
3041 | [To be documented.] | |
3042 | .TP | |
3043 | .IR Unevictable " %lu (since Linux 2.6.28)" | |
3044 | (From Linux 2.6.28 to 2.6.30, | |
3045 | \fBCONFIG_UNEVICTABLE_LRU\fP was required.) | |
3046 | [To be documented.] | |
3047 | .TP | |
46fbfc07 | 3048 | .IR Mlocked " %lu (since Linux 2.6.28)" |
3ba3d5b1 MK |
3049 | (From Linux 2.6.28 to 2.6.30, |
3050 | \fBCONFIG_UNEVICTABLE_LRU\fP was required.) | |
3051 | [To be documented.] | |
3052 | .TP | |
3053 | .IR HighTotal " %lu" | |
3054 | (Starting with Linux 2.6.19, \fBCONFIG_HIGHMEM\fP is required.) | |
3055 | Total amount of highmem. | |
99e91586 | 3056 | Highmem is all memory above ~860MB of physical memory. |
3ba3d5b1 MK |
3057 | Highmem areas are for use by user-space programs, |
3058 | or for the page cache. | |
3059 | The kernel must use tricks to access | |
3060 | this memory, making it slower to access than lowmem. | |
3061 | .TP | |
3062 | .IR HighFree " %lu | |
3063 | (Starting with Linux 2.6.19, \fBCONFIG_HIGHMEM\fP is required.) | |
3064 | Amount of free highmem. | |
3065 | .TP | |
3066 | .IR LowTotal " %lu | |
3067 | (Starting with Linux 2.6.19, \fBCONFIG_HIGHMEM\fP is required.) | |
3068 | Total amount of lowmem. | |
3069 | Lowmem is memory which can be used for everything that | |
3070 | highmem can be used for, but it is also available for the | |
3071 | kernel's use for its own data structures. | |
3072 | Among many other things, | |
99e91586 | 3073 | it is where everything from |
7bccb7d4 DP |
3074 | .I Slab |
3075 | is allocated. | |
3ba3d5b1 MK |
3076 | Bad things happen when you're out of lowmem. |
3077 | .TP | |
3078 | .IR LowFree " %lu | |
3079 | (Starting with Linux 2.6.19, \fBCONFIG_HIGHMEM\fP is required.) | |
3080 | Amount of free lowmem. | |
3081 | .TP | |
3082 | .IR MmapCopy " %lu (since Linux 2.6.29)" | |
99e91586 DP |
3083 | .RB ( CONFIG_MMU |
3084 | is required.) | |
3ba3d5b1 MK |
3085 | [To be documented.] |
3086 | .TP | |
3087 | .IR SwapTotal " %lu" | |
3088 | Total amount of swap space available. | |
3089 | .TP | |
3090 | .IR SwapFree " %lu" | |
c16d4f25 | 3091 | Amount of swap space that is currently unused. |
3ba3d5b1 MK |
3092 | .TP |
3093 | .IR Dirty " %lu" | |
3094 | Memory which is waiting to get written back to the disk. | |
3095 | .TP | |
3096 | .IR Writeback " %lu" | |
3097 | Memory which is actively being written back to the disk. | |
3098 | .TP | |
3099 | .IR AnonPages " %lu (since Linux 2.6.18)" | |
3100 | Non-file backed pages mapped into user-space page tables. | |
3101 | .TP | |
3102 | .IR Mapped " %lu" | |
fda70f5b MK |
3103 | Files which have been mapped into memory (with |
3104 | .BR mmap (2)), | |
3105 | such as libraries. | |
3ba3d5b1 MK |
3106 | .TP |
3107 | .IR Shmem " %lu (since Linux 2.6.32)" | |
eb775c04 MK |
3108 | Amount of memory consumed in |
3109 | .BR tmpfs (5) | |
3110 | filesystems. | |
3ba3d5b1 MK |
3111 | .TP |
3112 | .IR Slab " %lu" | |
3113 | In-kernel data structures cache. | |
3114 | .TP | |
3115 | .IR SReclaimable " %lu (since Linux 2.6.19)" | |
7bccb7d4 DP |
3116 | Part of |
3117 | .IR Slab , | |
3118 | that might be reclaimed, such as caches. | |
3ba3d5b1 MK |
3119 | .TP |
3120 | .IR SUnreclaim " %lu (since Linux 2.6.19)" | |
7bccb7d4 DP |
3121 | Part of |
3122 | .IR Slab , | |
3123 | that cannot be reclaimed on memory pressure. | |
3ba3d5b1 MK |
3124 | .TP |
3125 | .IR KernelStack " %lu (since Linux 2.6.32)" | |
3126 | Amount of memory allocated to kernel stacks. | |
3127 | .TP | |
3128 | .IR PageTables " %lu (since Linux 2.6.18)" | |
3129 | Amount of memory dedicated to the lowest level of page tables. | |
3130 | .TP | |
3131 | .IR Quicklists " %lu (since Linux 2.6.27)" | |
3132 | (\fBCONFIG_QUICKLIST\fP is required.) | |
3133 | [To be documented.] | |
3134 | .TP | |
3135 | .IR NFS_Unstable " %lu (since Linux 2.6.18)" | |
3136 | NFS pages sent to the server, but not yet committed to stable storage. | |
3137 | .TP | |
3138 | .IR Bounce " %lu (since Linux 2.6.18)" | |
3139 | Memory used for block device "bounce buffers". | |
3140 | .TP | |
3141 | .IR WritebackTmp " %lu (since Linux 2.6.26)" | |
3142 | Memory used by FUSE for temporary writeback buffers. | |
3143 | .TP | |
3144 | .IR CommitLimit " %lu (since Linux 2.6.10)" | |
cd7b6c40 MK |
3145 | This is the total amount of memory currently available to |
3146 | be allocated on the system, expressed in kilobytes. | |
90878f7c MK |
3147 | This limit is adhered to |
3148 | only if strict overcommit accounting is enabled (mode 2 in | |
cd7b6c40 MK |
3149 | .IR /proc/sys/vm/overcommit_memory ). |
3150 | The limit is calculated according to the formula described under | |
3151 | .IR /proc/sys/vm/overcommit_memory . | |
3152 | For further details, see the kernel source file | |
3ba3d5b1 MK |
3153 | .IR Documentation/vm/overcommit-accounting . |
3154 | .TP | |
3155 | .IR Committed_AS " %lu" | |
3156 | The amount of memory presently allocated on the system. | |
3157 | The committed memory is a sum of all of the memory which | |
3158 | has been allocated by processes, even if it has not been | |
3159 | "used" by them as of yet. | |
3160 | A process which allocates 1GB of memory (using | |
3161 | .BR malloc (3) | |
33a0ccb2 | 3162 | or similar), but touches only 300MB of that memory will show up |
90878f7c | 3163 | as using only 300MB of memory even if it has the address space |
3ba3d5b1 | 3164 | allocated for the entire 1GB. |
cd7b6c40 | 3165 | |
3ba3d5b1 MK |
3166 | This 1GB is memory which has been "committed" to by the VM |
3167 | and can be used at any time by the allocating application. | |
cd7b6c40 | 3168 | With strict overcommit enabled on the system (mode 2 in |
d9e0f03d | 3169 | .IR /proc/sys/vm/overcommit_memory ), |
3ba3d5b1 MK |
3170 | allocations which would exceed the |
3171 | .I CommitLimit | |
cd7b6c40 | 3172 | will not be permitted. |
3ba3d5b1 MK |
3173 | This is useful if one needs to guarantee that processes will not |
3174 | fail due to lack of memory once that memory has been successfully allocated. | |
3175 | .TP | |
3176 | .IR VmallocTotal " %lu" | |
3177 | Total size of vmalloc memory area. | |
3178 | .TP | |
3179 | .IR VmallocUsed " %lu" | |
3180 | Amount of vmalloc area which is used. | |
3181 | .TP | |
3182 | .IR VmallocChunk " %lu" | |
3183 | Largest contiguous block of vmalloc area which is free. | |
3184 | .TP | |
3185 | .IR HardwareCorrupted " %lu (since Linux 2.6.32)" | |
3186 | (\fBCONFIG_MEMORY_FAILURE\fP is required.) | |
3187 | [To be documented.] | |
3188 | .TP | |
3189 | .IR AnonHugePages " %lu (since Linux 2.6.38)" | |
3190 | (\fBCONFIG_TRANSPARENT_HUGEPAGE\fP is required.) | |
7fac88a9 | 3191 | Non-file backed huge pages mapped into user-space page tables. |
3ba3d5b1 | 3192 | .TP |
4ad958e1 MK |
3193 | .IR ShmemHugePages " %lu (since Linux 4.8)" |
3194 | (\fBCONFIG_TRANSPARENT_HUGEPAGE\fP is required.) | |
4e07c70f MK |
3195 | Memory used by shared memory (shmem) and |
3196 | .BR tmpfs (5) | |
3197 | allocated with huge pages | |
4ad958e1 MK |
3198 | .TP |
3199 | .IR ShmemPmdMapped " %lu (since Linux 4.8)" | |
3200 | (\fBCONFIG_TRANSPARENT_HUGEPAGE\fP is required.) | |
956e74b4 | 3201 | Shared memory mapped into user space with huge pages. |
4ad958e1 | 3202 | .TP |
43179f55 MK |
3203 | .IR CmaTotal " %lu (since Linux 3.1)" |
3204 | Total CMA (Contiguous Memory Allocator) pages. | |
3205 | (\fBCONFIG_CMA\fP is required.) | |
3206 | .TP | |
3207 | .IR CmaFree " %lu (since Linux 3.1)" | |
3208 | Free CMA (Contiguous Memory Allocator) pages. | |
3209 | (\fBCONFIG_CMA\fP is required.) | |
3210 | .TP | |
3ba3d5b1 MK |
3211 | .IR HugePages_Total " %lu" |
3212 | (\fBCONFIG_HUGETLB_PAGE\fP is required.) | |
3213 | The size of the pool of huge pages. | |
3214 | .TP | |
3215 | .IR HugePages_Free " %lu" | |
3216 | (\fBCONFIG_HUGETLB_PAGE\fP is required.) | |
3217 | The number of huge pages in the pool that are not yet allocated. | |
3218 | .TP | |
3219 | .IR HugePages_Rsvd " %lu (since Linux 2.6.17)" | |
3220 | (\fBCONFIG_HUGETLB_PAGE\fP is required.) | |
3221 | This is the number of huge pages for | |
3222 | which a commitment to allocate from the pool has been made, | |
3223 | but no allocation has yet been made. | |
3224 | These reserved huge pages | |
3225 | guarantee that an application will be able to allocate a | |
3226 | huge page from the pool of huge pages at fault time. | |
3227 | .TP | |
aa8a6b4f | 3228 | .IR HugePages_Surp " %lu (since Linux 2.6.24)" |
3ba3d5b1 MK |
3229 | (\fBCONFIG_HUGETLB_PAGE\fP is required.) |
3230 | This is the number of huge pages in | |
3231 | the pool above the value in | |
3232 | .IR /proc/sys/vm/nr_hugepages . | |
3233 | The maximum number of surplus huge pages is controlled by | |
3234 | .IR /proc/sys/vm/nr_overcommit_hugepages . | |
3235 | .TP | |
3236 | .IR Hugepagesize " %lu" | |
3237 | (\fBCONFIG_HUGETLB_PAGE\fP is required.) | |
3238 | The size of huge pages. | |
d5268de1 MK |
3239 | .TP |
3240 | .IR DirectMap4k " %lu (since Linux 2.6.27)" | |
3241 | Number of bytes of RAM linearly mapped by kernel in 4kB pages. | |
3242 | (x86.) | |
3243 | .TP | |
3244 | .IR DirectMap4M " %lu (since Linux 2.6.27)" | |
3245 | Number of bytes of RAM linearly mapped by kernel in 4MB pages. | |
3246 | (x86 with | |
3247 | .BR CONFIG_X86_64 | |
3248 | or | |
3249 | .BR CONFIG_X86_PAE | |
3250 | enabled.) | |
3251 | .TP | |
3252 | .IR DirectMap2M " %lu (since Linux 2.6.27)" | |
3253 | Number of bytes of RAM linearly mapped by kernel in 2MB pages. | |
3254 | (x86 with neither | |
3255 | .BR CONFIG_X86_64 | |
3256 | nor | |
3257 | .BR CONFIG_X86_PAE | |
3258 | enabled.) | |
3259 | .TP | |
3260 | .IR DirectMap1G " %lu (since Linux 2.6.27)" | |
3261 | (x86 with | |
3262 | .BR CONFIG_X86_64 | |
3263 | and | |
3264 | .B CONFIG_X86_DIRECT_GBPAGES | |
3265 | enabled.) | |
3ba3d5b1 | 3266 | .RE |
fea681da | 3267 | .TP |
aa341984 MK |
3268 | .I /proc/modules |
3269 | A text list of the modules that have been loaded by the system. | |
3270 | See also | |
3271 | .BR lsmod (8). | |
3272 | .TP | |
fea681da | 3273 | .I /proc/mounts |
c1eea65a | 3274 | Before kernel 2.4.19, this file was a list |
9ee4a2b6 | 3275 | of all the filesystems currently mounted on the system. |
ef5b47f6 MK |
3276 | With the introduction of per-process mount namespaces in Linux 2.4.19 (see |
3277 | .BR mount_namespaces (7)), | |
3278 | this file became a link to | |
c1eea65a | 3279 | .IR /proc/self/mounts , |
732e54dd | 3280 | which lists the mount points of the process's own mount namespace. |
fea681da | 3281 | The format of this file is documented in |
31e9a9ec | 3282 | .BR fstab (5). |
fea681da | 3283 | .TP |
fea681da | 3284 | .I /proc/mtrr |
c13182ef | 3285 | Memory Type Range Registers. |
66a9882e | 3286 | See the Linux kernel source file |
cfe70b66 | 3287 | .I Documentation/mtrr.txt |
fea681da MK |
3288 | for details. |
3289 | .TP | |
3290 | .I /proc/net | |
ccb4bcdc MK |
3291 | This directory contains various files and subdirectories containing |
3292 | information about the networking layer. | |
3293 | The files contain ASCII structures and are, | |
59a40ed7 MK |
3294 | therefore, readable with |
3295 | .BR cat (1). | |
c13182ef | 3296 | However, the standard |
fea681da MK |
3297 | .BR netstat (8) |
3298 | suite provides much cleaner access to these files. | |
9fb88bc8 MK |
3299 | |
3300 | With the advent of network namespaces, | |
3301 | various information relating to the network stack is virtualized (see | |
3302 | .BR namespaces (7)). | |
3303 | Thus, since Linux 2.6.25, | |
3304 | .\" commit e9720acd728a46cb40daa52c99a979f7c4ff195c | |
3305 | .IR /proc/net | |
3306 | is a symbolic link to the directory | |
3307 | .IR /proc/self/net , | |
3308 | which contains the same files and directories as listed below. | |
3309 | However, these files and directories now expose information | |
3310 | for the network namespace of which the process is a member. | |
fea681da MK |
3311 | .TP |
3312 | .I /proc/net/arp | |
3313 | This holds an ASCII readable dump of the kernel ARP table used for | |
c13182ef | 3314 | address resolutions. |
01d0a447 | 3315 | It will show both dynamically learned and preprogrammed ARP entries. |
c13182ef | 3316 | The format is: |
fea681da MK |
3317 | |
3318 | .nf | |
3319 | .ft CW | |
3320 | .in 8n | |
3321 | IP address HW type Flags HW address Mask Device | |
3322 | 192.168.0.50 0x1 0x2 00:50:BF:25:68:F3 * eth0 | |
3323 | 192.168.0.250 0x1 0xc 00:00:00:00:00:00 * eth0 | |
3324 | .ft | |
3325 | .fi | |
3326 | .in | |
3327 | ||
6c04f928 | 3328 | Here "IP address" is the IPv4 address of the machine and the "HW type" |
c13182ef MK |
3329 | is the hardware type of the address from RFC\ 826. |
3330 | The flags are the internal | |
9a67332e MK |
3331 | flags of the ARP structure (as defined in |
3332 | .IR /usr/include/linux/if_arp.h ) | |
3333 | and | |
6c04f928 | 3334 | the "HW address" is the data link layer mapping for that IP address if |
fea681da MK |
3335 | it is known. |
3336 | .TP | |
3337 | .I /proc/net/dev | |
c13182ef MK |
3338 | The dev pseudo-file contains network device status information. |
3339 | This gives | |
3340 | the number of received and sent packets, the number of errors and | |
fea681da | 3341 | collisions |
c13182ef MK |
3342 | and other basic statistics. |
3343 | These are used by the | |
fea681da | 3344 | .BR ifconfig (8) |
c13182ef MK |
3345 | program to report device status. |
3346 | The format is: | |
fea681da MK |
3347 | |
3348 | .nf | |
3349 | .ft CW | |
3350 | .in 1n | |
3351 | Inter-| Receive | Transmit | |
3352 | face |bytes packets errs drop fifo frame compressed multicast|bytes packets errs drop fifo colls carrier compressed | |
3353 | lo: 2776770 11307 0 0 0 0 0 0 2776770 11307 0 0 0 0 0 0 | |
3354 | eth0: 1215645 2751 0 0 0 0 0 0 1782404 4324 0 0 0 427 0 0 | |
3355 | ppp0: 1622270 5552 1 0 0 0 0 0 354130 5669 0 0 0 0 0 0 | |
3356 | tap0: 7714 81 0 0 0 0 0 0 7714 81 0 0 0 0 0 0 | |
3357 | .in | |
3358 | .ft | |
3359 | .fi | |
3360 | .\" .TP | |
3361 | .\" .I /proc/net/ipx | |
3362 | .\" No information. | |
3363 | .\" .TP | |
3364 | .\" .I /proc/net/ipx_route | |
3365 | .\" No information. | |
3366 | .TP | |
3367 | .I /proc/net/dev_mcast | |
3368 | Defined in | |
3369 | .IR /usr/src/linux/net/core/dev_mcast.c : | |
3370 | .nf | |
3371 | .in +5 | |
9fdfa163 | 3372 | indx interface_name dmi_u dmi_g dmi_address |
fea681da MK |
3373 | 2 eth0 1 0 01005e000001 |
3374 | 3 eth1 1 0 01005e000001 | |
3375 | 4 eth2 1 0 01005e000001 | |
3376 | .in | |
3377 | .fi | |
3378 | .TP | |
3379 | .I /proc/net/igmp | |
c13182ef MK |
3380 | Internet Group Management Protocol. |
3381 | Defined in | |
fea681da MK |
3382 | .IR /usr/src/linux/net/core/igmp.c . |
3383 | .TP | |
3384 | .I /proc/net/rarp | |
3385 | This file uses the same format as the | |
3386 | .I arp | |
3387 | file and contains the current reverse mapping database used to provide | |
3388 | .BR rarp (8) | |
c13182ef MK |
3389 | reverse address lookup services. |
3390 | If RARP is not configured into the | |
fea681da MK |
3391 | kernel, |
3392 | this file will not be present. | |
3393 | .TP | |
3394 | .I /proc/net/raw | |
c13182ef MK |
3395 | Holds a dump of the RAW socket table. |
3396 | Much of the information is not of | |
fea681da | 3397 | use |
c13182ef | 3398 | apart from debugging. |
6c04f928 | 3399 | The "sl" value is the kernel hash slot for the |
fea681da | 3400 | socket, |
6c04f928 MK |
3401 | the "local_address" is the local address and protocol number pair. |
3402 | \&"St" is | |
c13182ef MK |
3403 | the internal status of the socket. |
3404 | The "tx_queue" and "rx_queue" are the | |
fea681da | 3405 | outgoing and incoming data queue in terms of kernel memory usage. |
94e9d9fe | 3406 | The "tr", "tm\->when", and "rexmits" fields are not used by RAW. |
fdc196f5 MK |
3407 | The "uid" |
3408 | field holds the effective UID of the creator of the socket. | |
fea681da MK |
3409 | .\" .TP |
3410 | .\" .I /proc/net/route | |
3411 | .\" No information, but looks similar to | |
3412 | .\" .BR route (8). | |
3413 | .TP | |
3414 | .I /proc/net/snmp | |
c13182ef | 3415 | This file holds the ASCII data needed for the IP, ICMP, TCP, and UDP |
fea681da | 3416 | management |
763f0e47 | 3417 | information bases for an SNMP agent. |
fea681da MK |
3418 | .TP |
3419 | .I /proc/net/tcp | |
c13182ef MK |
3420 | Holds a dump of the TCP socket table. |
3421 | Much of the information is not | |
3422 | of use apart from debugging. | |
3423 | The "sl" value is the kernel hash slot | |
6beb1671 MK |
3424 | for the socket, the "local_address" is the local address and port number pair. |
3425 | The "rem_address" is the remote address and port number pair | |
6c04f928 MK |
3426 | (if connected). |
3427 | \&"St" is the internal status of the socket. | |
3428 | The "tx_queue" and "rx_queue" are the | |
fea681da | 3429 | outgoing and incoming data queue in terms of kernel memory usage. |
94e9d9fe | 3430 | The "tr", "tm\->when", and "rexmits" fields hold internal information of |
f33774c4 | 3431 | the kernel socket state and are useful only for debugging. |
fdc196f5 MK |
3432 | The "uid" |
3433 | field holds the effective UID of the creator of the socket. | |
fea681da MK |
3434 | .TP |
3435 | .I /proc/net/udp | |
c13182ef MK |
3436 | Holds a dump of the UDP socket table. |
3437 | Much of the information is not of | |
3438 | use apart from debugging. | |
3439 | The "sl" value is the kernel hash slot for the | |
6beb1671 MK |
3440 | socket, the "local_address" is the local address and port number pair. |
3441 | The "rem_address" is the remote address and port number pair | |
f2d607ee MK |
3442 | (if connected). |
3443 | "St" is the internal status of the socket. | |
fea681da | 3444 | The "tx_queue" and "rx_queue" are the outgoing and incoming data queue |
c13182ef | 3445 | in terms of kernel memory usage. |
94e9d9fe | 3446 | The "tr", "tm\->when", and "rexmits" fields |
c13182ef | 3447 | are not used by UDP. |
fdc196f5 MK |
3448 | The "uid" |
3449 | field holds the effective UID of the creator of the socket. | |
fea681da MK |
3450 | The format is: |
3451 | ||
3452 | .nf | |
3453 | .ft CW | |
3454 | .in 1n | |
94e9d9fe | 3455 | sl local_address rem_address st tx_queue rx_queue tr rexmits tm\->when uid |
fea681da MK |
3456 | 1: 01642C89:0201 0C642C89:03FF 01 00000000:00000001 01:000071BA 00000000 0 |
3457 | 1: 00000000:0801 00000000:0000 0A 00000000:00000000 00:00000000 6F000100 0 | |
3458 | 1: 00000000:0201 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 | |
3459 | .in | |
3460 | .ft | |
3461 | .fi | |
3462 | .TP | |
3463 | .I /proc/net/unix | |
008f1ecc | 3464 | Lists the UNIX domain sockets present within the system and their |
c13182ef MK |
3465 | status. |
3466 | The format is: | |
fea681da MK |
3467 | .nf |
3468 | .sp .5 | |
3469 | .ft CW | |
3470 | Num RefCount Protocol Flags Type St Path | |
3471 | 0: 00000002 00000000 00000000 0001 03 | |
3472 | 1: 00000001 00000000 00010000 0001 01 /dev/printer | |
3473 | .ft | |
3474 | .sp .5 | |
3475 | .fi | |
3476 | ||
756f55f6 MK |
3477 | The fields are as follows: |
3478 | .RS | |
3479 | .TP 10 | |
3480 | .IR Num : | |
3481 | the kernel table slot number. | |
3482 | .TP | |
3483 | .IR RefCount : | |
3484 | the number of users of the socket. | |
3485 | .TP | |
3486 | .IR Protocol : | |
3487 | currently always 0. | |
3488 | .TP | |
3489 | .IR Flags : | |
3490 | the internal kernel flags holding the status of the socket. | |
3491 | .TP | |
3492 | .IR Type : | |
a405066e MK |
3493 | the socket type. |
3494 | For | |
3495 | .BR SOCK_STREAM | |
3496 | sockets, this is 0001; for | |
3497 | .BR SOCK_DGRAM | |
3498 | sockets, it is 0002; and for | |
3499 | .BR SOCK_SEQPACKET | |
3500 | sockets, it is 0005. | |
756f55f6 MK |
3501 | .TP |
3502 | .IR St : | |
3503 | the internal state of the socket. | |
3504 | .TP | |
3505 | .IR Path : | |
3506 | the bound path (if any) of the socket. | |
8f8a46fb MK |
3507 | Sockets in the abstract namespace are included in the list, |
3508 | and are shown with a | |
3509 | .I Path | |
3510 | that commences with the character '@'. | |
756f55f6 | 3511 | .RE |
fea681da | 3512 | .TP |
ed8de0e4 | 3513 | .I /proc/net/netfilter/nfnetlink_queue |
6f858d5c | 3514 | This file contains information about netfilter user-space queueing, if used. |
f2d607ee MK |
3515 | Each line represents a queue. |
3516 | Queues that have not been subscribed to | |
6f858d5c | 3517 | by user space are not shown. |
ed8de0e4 FW |
3518 | .nf |
3519 | ||
3520 | 1 4207 0 2 65535 0 0 0 1 | |
3521 | (1) (2) (3)(4) (5) (6) (7) (8) | |
3522 | .fi | |
3523 | .IP | |
3524 | The fields in each line are: | |
3525 | .RS 7 | |
3526 | .TP 5 | |
3527 | (1) | |
f2d607ee MK |
3528 | The ID of the queue. |
3529 | This matches what is specified in the | |
ed8de0e4 FW |
3530 | .B \-\-queue\-num |
3531 | or | |
3532 | .B \-\-queue\-balance | |
3533 | options to the | |
3534 | .BR iptables (8) | |
f2d607ee MK |
3535 | NFQUEUE target. |
3536 | See | |
ed8de0e4 FW |
3537 | .BR iptables-extensions (8) |
3538 | for more information. | |
3539 | .TP | |
3540 | (2) | |
7672e08e | 3541 | The netlink port ID subscribed to the queue. |
ed8de0e4 FW |
3542 | .TP |
3543 | (3) | |
3544 | The number of packets currently queued and waiting to be processed by | |
3545 | the application. | |
3546 | .TP | |
3547 | (4) | |
f2d607ee MK |
3548 | The copy mode of the queue. |
3549 | It is either 1 (metadata only) or 2 | |
6f858d5c | 3550 | (also copy payload data to user space). |
ed8de0e4 FW |
3551 | .TP |
3552 | (5) | |
1dea597b | 3553 | Copy range; that is, how many bytes of packet payload should be copied to |
6f858d5c | 3554 | user space at most. |
ed8de0e4 FW |
3555 | .TP |
3556 | (6) | |
f2d607ee MK |
3557 | queue dropped. |
3558 | Number of packets that had to be dropped by the kernel because | |
6f858d5c | 3559 | too many packets are already waiting for user space to send back the mandatory |
ed8de0e4 FW |
3560 | accept/drop verdicts. |
3561 | .TP | |
3562 | (7) | |
f2d607ee MK |
3563 | queue user dropped. |
3564 | Number of packets that were dropped within the netlink | |
3565 | subsystem. | |
3566 | Such drops usually happen when the corresponding socket buffer is | |
6f858d5c | 3567 | full; that is, user space is not able to read messages fast enough. |
ed8de0e4 FW |
3568 | .TP |
3569 | (8) | |
f2d607ee MK |
3570 | sequence number. |
3571 | Every queued packet is associated with a (32-bit) | |
ed8de0e4 FW |
3572 | monotonically-increasing sequence number. |
3573 | This shows the ID of the most recent packet queued. | |
3574 | .RE | |
3575 | .IP | |
f33774c4 | 3576 | The last number exists only for compatibility reasons and is always 1. |
ed8de0e4 | 3577 | .TP |
fea681da | 3578 | .I /proc/partitions |
f042d149 MK |
3579 | Contains the major and minor numbers of each partition as well as the number |
3580 | of 1024-byte blocks and the partition name. | |
fea681da MK |
3581 | .TP |
3582 | .I /proc/pci | |
3583 | This is a listing of all PCI devices found during kernel initialization | |
3584 | and their configuration. | |
2990d781 | 3585 | |
59a40ed7 MK |
3586 | This file has been deprecated in favor of a new |
3587 | .I /proc | |
2990d781 MK |
3588 | interface for PCI |
3589 | .RI ( /proc/bus/pci ). | |
3590 | It became optional in Linux 2.2 (available with | |
3591 | .B CONFIG_PCI_OLD_PROC | |
3592 | set at kernel compilation). | |
24b74457 | 3593 | It became once more nonoptionally enabled in Linux 2.4. |
2990d781 MK |
3594 | Next, it was deprecated in Linux 2.6 (still available with |
3595 | .B CONFIG_PCI_LEGACY_PROC | |
3596 | set), and finally removed altogether since Linux 2.6.17. | |
43d42cc0 | 3597 | .\" FIXME Document /proc/sched_debug (since Linux 2.6.23) |
69119dc7 | 3598 | .\" See also /proc/[pid]/sched |
caea7868 MK |
3599 | .TP |
3600 | .IR /proc/profile " (since Linux 2.4)" | |
3601 | This file is present only if the kernel was booted with the | |
3602 | .I profile=1 | |
3603 | command-line option. | |
3604 | It exposes kernel profiling information in a binary format for use by | |
3605 | .BR readprofile (1). | |
3606 | Writing (e.g., an empty string) to this file resets the profiling counters; | |
3607 | on some architectures, | |
3608 | writing a binary integer "profiling multiplier" of size | |
3609 | .IR sizeof(int) | |
8a3ac89a | 3610 | sets the profiling interrupt frequency. |
fea681da MK |
3611 | .TP |
3612 | .I /proc/scsi | |
59a40ed7 MK |
3613 | A directory with the |
3614 | .I scsi | |
3615 | mid-level pseudo-file and various SCSI low-level | |
2990d781 MK |
3616 | driver directories, |
3617 | which contain a file for each SCSI host in this system, all of | |
c13182ef MK |
3618 | which give the status of some part of the SCSI IO subsystem. |
3619 | These files contain ASCII structures and are, therefore, readable with | |
2990d781 | 3620 | .BR cat (1). |
fea681da | 3621 | |
c13182ef | 3622 | You can also write to some of the files to reconfigure the subsystem or |
59a40ed7 | 3623 | switch certain features on or off. |
fea681da MK |
3624 | .TP |
3625 | .I /proc/scsi/scsi | |
c13182ef | 3626 | This is a listing of all SCSI devices known to the kernel. |
59a40ed7 | 3627 | The listing is similar to the one seen during bootup. |
c13182ef | 3628 | scsi currently supports only the \fIadd-single-device\fP command which |
59a40ed7 MK |
3629 | allows root to add a hotplugged device to the list of known devices. |
3630 | ||
3631 | The command | |
3632 | .in +4n | |
3633 | .nf | |
3634 | ||
3635 | echo \(aqscsi add-single-device 1 0 5 0\(aq > /proc/scsi/scsi | |
fea681da | 3636 | |
59a40ed7 MK |
3637 | .fi |
3638 | .in | |
c13182ef MK |
3639 | will cause |
3640 | host scsi1 to scan on SCSI channel 0 for a device on ID 5 LUN 0. | |
3641 | If there | |
fea681da MK |
3642 | is already a device known on this address or the address is invalid, an |
3643 | error will be returned. | |
3644 | .TP | |
3645 | .I /proc/scsi/[drivername] | |
c13182ef MK |
3646 | \fI[drivername]\fP can currently be NCR53c7xx, aha152x, aha1542, aha1740, |
3647 | aic7xxx, buslogic, eata_dma, eata_pio, fdomain, in2000, pas16, qlogic, | |
3648 | scsi_debug, seagate, t128, u15-24f, ultrastore, or wd7000. | |
3649 | These directories show up for all drivers that registered at least one | |
59a40ed7 | 3650 | SCSI HBA. |
c13182ef | 3651 | Every directory contains one file per registered host. |
59a40ed7 | 3652 | Every host-file is named after the number the host was assigned during |
c13182ef | 3653 | initialization. |
fea681da | 3654 | |
c13182ef | 3655 | Reading these files will usually show driver and host configuration, |
f78ed33a | 3656 | statistics, and so on. |
fea681da MK |
3657 | |
3658 | Writing to these files allows different things on different hosts. | |
3659 | For example, with the \fIlatency\fP and \fInolatency\fP commands, | |
3660 | root can switch on and off command latency measurement code in the | |
c13182ef MK |
3661 | eata_dma driver. |
3662 | With the \fIlockup\fP and \fIunlock\fP commands, | |
3663 | root can control bus lockups simulated by the scsi_debug driver. | |
fea681da MK |
3664 | .TP |
3665 | .I /proc/self | |
59a40ed7 MK |
3666 | This directory refers to the process accessing the |
3667 | .I /proc | |
9ee4a2b6 | 3668 | filesystem, |
59a40ed7 MK |
3669 | and is identical to the |
3670 | .I /proc | |
3671 | directory named by the process ID of the same process. | |
fea681da MK |
3672 | .TP |
3673 | .I /proc/slabinfo | |
c13182ef | 3674 | Information about kernel caches. |
90878f7c | 3675 | Since Linux 2.6.16 this file is present only if the |
821643a8 MK |
3676 | .B CONFIG_SLAB |
3677 | kernel configuration option is enabled. | |
350038ff | 3678 | The columns in |
38f76cd2 | 3679 | .I /proc/slabinfo |
350038ff | 3680 | are: |
a08ea57c | 3681 | .in +4n |
fea681da | 3682 | .nf |
a08ea57c | 3683 | |
fea681da MK |
3684 | cache-name |
3685 | num-active-objs | |
3686 | total-objs | |
3687 | object-size | |
3688 | num-active-slabs | |
3689 | total-slabs | |
3690 | num-pages-per-slab | |
3691 | .fi | |
a08ea57c MK |
3692 | .in |
3693 | ||
c13182ef | 3694 | See |
fea681da MK |
3695 | .BR slabinfo (5) |
3696 | for details. | |
3697 | .TP | |
3698 | .I /proc/stat | |
c13182ef MK |
3699 | kernel/system statistics. |
3700 | Varies with architecture. | |
3701 | Common | |
fea681da MK |
3702 | entries include: |
3703 | .RS | |
3704 | .TP | |
3705 | \fIcpu 3357 0 4313 1362393\fP | |
bfbfcd18 | 3706 | The amount of time, measured in units of |
268f000b MK |
3707 | USER_HZ (1/100ths of a second on most architectures, use |
3708 | .IR sysconf(_SC_CLK_TCK) | |
3709 | to obtain the right value), | |
b81087ab | 3710 | .\" 1024 on Alpha and ia64 |
ae3b8047 MK |
3711 | that the system spent in various states: |
3712 | .RS | |
3713 | .TP | |
3714 | .I user | |
ea0841f6 | 3715 | (1) Time spent in user mode. |
ae3b8047 MK |
3716 | .TP |
3717 | .I nice | |
0633f951 | 3718 | (2) Time spent in user mode with low priority (nice). |
9f1b9726 | 3719 | .TP |
ae3b8047 | 3720 | .I system |
0633f951 | 3721 | (3) Time spent in system mode. |
ae3b8047 MK |
3722 | .TP |
3723 | .I idle | |
ea0841f6 | 3724 | (4) Time spent in the idle task. |
bea08fec | 3725 | .\" FIXME . Actually, the following info about the /proc/stat 'cpu' field |
e04a1f93 MK |
3726 | .\" does not seem to be quite right (at least in 2.6.12 or 3.6): |
3727 | .\" the idle time in /proc/uptime does not quite match this value | |
3728 | This value should be USER_HZ times the | |
4cb1deb7 MK |
3729 | second entry in the |
3730 | .I /proc/uptime | |
3731 | pseudo-file. | |
ae3b8047 MK |
3732 | .TP |
3733 | .IR iowait " (since Linux 2.5.41)" | |
ea0841f6 | 3734 | (5) Time waiting for I/O to complete. |
ae3b8047 MK |
3735 | .TP |
3736 | .IR irq " (since Linux 2.6.0-test4)" | |
ea0841f6 | 3737 | (6) Time servicing interrupts. |
ae3b8047 | 3738 | .TP |
0633f951 | 3739 | .IR softirq " (since Linux 2.6.0-test4)" |
ea0841f6 | 3740 | (7) Time servicing softirqs. |
ae3b8047 MK |
3741 | .TP |
3742 | .IR steal " (since Linux 2.6.11)" | |
ea0841f6 | 3743 | (8) Stolen time, which is the time spent in other operating systems when |
9de1f6cc | 3744 | running in a virtualized environment |
ae3b8047 MK |
3745 | .TP |
3746 | .IR guest " (since Linux 2.6.24)" | |
0633f951 | 3747 | (9) Time spent running a virtual CPU for guest |
afef1764 | 3748 | operating systems under the control of the Linux kernel. |
14c06953 | 3749 | .\" See Changelog entry for 5e84cfde51cf303d368fcb48f22059f37b3872de |
d4fd4120 MK |
3750 | .TP |
3751 | .IR guest_nice " (since Linux 2.6.33)" | |
3752 | .\" commit ce0e7b28fb75cb003cfc8d0238613aaf1c55e797 | |
3753 | (10) Time spent running a niced guest (virtual CPU for guest | |
3754 | operating systems under the control of the Linux kernel). | |
ae3b8047 | 3755 | .RE |
fea681da MK |
3756 | .TP |
3757 | \fIpage 5741 1808\fP | |
3758 | The number of pages the system paged in and the number that were paged | |
3759 | out (from disk). | |
3760 | .TP | |
3761 | \fIswap 1 0\fP | |
3762 | The number of swap pages that have been brought in and out. | |
3763 | .TP | |
bea08fec | 3764 | .\" FIXME . The following is not the full picture for the 'intr' of |
777f5a9e | 3765 | .\" /proc/stat on 2.6: |
fea681da | 3766 | \fIintr 1462898\fP |
bfbfcd18 MK |
3767 | This line shows counts of interrupts serviced since boot time, |
3768 | for each of the possible system interrupts. | |
d63ff76e | 3769 | The first column is the total of all interrupts serviced |
d6a56978 MK |
3770 | including unnumbered architecture specific interrupts; |
3771 | each subsequent column is the total for that particular numbered interrupt. | |
d63ff76e | 3772 | Unnumbered interrupts are not shown, only summed into the total. |
fea681da MK |
3773 | .TP |
3774 | \fIdisk_io: (2,0):(31,30,5764,1,2) (3,0):\fP... | |
636297e9 | 3775 | (major,disk_idx):(noinfo, read_io_ops, blks_read, write_io_ops, blks_written) |
bfbfcd18 MK |
3776 | .br |
3777 | (Linux 2.4 only) | |
fea681da MK |
3778 | .TP |
3779 | \fIctxt 115315\fP | |
3780 | The number of context switches that the system underwent. | |
3781 | .TP | |
3782 | \fIbtime 769041601\fP | |
f49c451a | 3783 | boot time, in seconds since the Epoch, 1970-01-01 00:00:00 +0000 (UTC). |
fea681da MK |
3784 | .TP |
3785 | \fIprocesses 86031\fP | |
3786 | Number of forks since boot. | |
bfbfcd18 MK |
3787 | .TP |
3788 | \fIprocs_running 6\fP | |
3789 | Number of processes in runnable state. | |
5fab2e7c | 3790 | (Linux 2.5.45 onward.) |
bfbfcd18 MK |
3791 | .TP |
3792 | \fIprocs_blocked 2\fP | |
3793 | Number of processes blocked waiting for I/O to complete. | |
5fab2e7c | 3794 | (Linux 2.5.45 onward.) |
fea681da MK |
3795 | .RE |
3796 | .TP | |
3797 | .I /proc/swaps | |
c13182ef MK |
3798 | Swap areas in use. |
3799 | See also | |
fea681da MK |
3800 | .BR swapon (8). |
3801 | .TP | |
3802 | .I /proc/sys | |
3803 | This directory (present since 1.3.57) contains a number of files | |
3804 | and subdirectories corresponding to kernel variables. | |
3805 | These variables can be read and sometimes modified using | |
9ee4a2b6 | 3806 | the \fI/proc\fP filesystem, and the (deprecated) |
fea681da | 3807 | .BR sysctl (2) |
c13182ef | 3808 | system call. |
84ff8c1e | 3809 | |
e8aa7100 | 3810 | String values may be terminated by either \(aq\\0\(aq or \(aq\\n\(aq. |
84ff8c1e HS |
3811 | |
3812 | Integer and long values may be written either in decimal or in | |
3813 | hexadecimal notation (e.g. 0x3FFF). | |
e8aa7100 MK |
3814 | When writing multiple integer or long values, these may be separated |
3815 | by any of the following whitespace characters: | |
3816 | \(aq\ \(aq, \(aq\\t\(aq, or \(aq\\n\(aq. | |
3817 | Using other separators leads to the error | |
84ff8c1e | 3818 | .BR EINVAL . |
fea681da | 3819 | .TP |
6ab7c0aa | 3820 | .IR /proc/sys/abi " (since Linux 2.4.10)" |
fea681da | 3821 | This directory may contain files with application binary information. |
6ab7c0aa | 3822 | .\" On some systems, it is not present. |
66a9882e | 3823 | See the Linux kernel source file |
6ab7c0aa MK |
3824 | .I Documentation/sysctl/abi.txt |
3825 | for more information. | |
fea681da MK |
3826 | .TP |
3827 | .I /proc/sys/debug | |
3828 | This directory may be empty. | |
3829 | .TP | |
3830 | .I /proc/sys/dev | |
e2badfdf | 3831 | This directory contains device-specific information (e.g., |
9a67332e | 3832 | .IR dev/cdrom/info ). |
fea681da MK |
3833 | On |
3834 | some systems, it may be empty. | |
3835 | .TP | |
3836 | .I /proc/sys/fs | |
49236d3c | 3837 | This directory contains the files and subdirectories for kernel variables |
9ee4a2b6 | 3838 | related to filesystems. |
fea681da MK |
3839 | .TP |
3840 | .I /proc/sys/fs/binfmt_misc | |
c13182ef | 3841 | Documentation for files in this directory can be found |
66a9882e | 3842 | in the Linux kernel sources in |
fea681da MK |
3843 | .IR Documentation/binfmt_misc.txt . |
3844 | .TP | |
59a40ed7 MK |
3845 | .IR /proc/sys/fs/dentry-state " (since Linux 2.2)" |
3846 | This file contains information about the status of the | |
3847 | directory cache (dcache). | |
3848 | The file contains six numbers, | |
c13182ef | 3849 | .IR nr_dentry ", " nr_unused ", " age_limit " (age in seconds), " |
59a40ed7 | 3850 | .I want_pages |
fea681da | 3851 | (pages requested by system) and two dummy values. |
59a40ed7 MK |
3852 | .RS |
3853 | .IP * 2 | |
3854 | .I nr_dentry | |
3855 | is the number of allocated dentries (dcache entries). | |
3856 | This field is unused in Linux 2.2. | |
3857 | .IP * | |
3858 | .I nr_unused | |
3859 | is the number of unused dentries. | |
3860 | .IP * | |
3861 | .I age_limit | |
3862 | .\" looks like this is unused in kernels 2.2 to 2.6 | |
3863 | is the age in seconds after which dcache entries | |
3864 | can be reclaimed when memory is short. | |
3865 | .IP * | |
3866 | .I want_pages | |
3867 | .\" looks like this is unused in kernels 2.2 to 2.6 | |
c7094399 | 3868 | is nonzero when the kernel has called shrink_dcache_pages() and the |
fea681da | 3869 | dcache isn't pruned yet. |
59a40ed7 | 3870 | .RE |
fea681da MK |
3871 | .TP |
3872 | .I /proc/sys/fs/dir-notify-enable | |
3873 | This file can be used to disable or enable the | |
3874 | .I dnotify | |
3875 | interface described in | |
3876 | .BR fcntl (2) | |
3877 | on a system-wide basis. | |
3878 | A value of 0 in this file disables the interface, | |
3879 | and a value of 1 enables it. | |
3880 | .TP | |
3881 | .I /proc/sys/fs/dquot-max | |
3882 | This file shows the maximum number of cached disk quota entries. | |
3883 | On some (2.4) systems, it is not present. | |
3884 | If the number of free cached disk quota entries is very low and | |
3885 | you have some awesome number of simultaneous system users, | |
3886 | you might want to raise the limit. | |
3887 | .TP | |
3888 | .I /proc/sys/fs/dquot-nr | |
3889 | This file shows the number of allocated disk quota | |
3890 | entries and the number of free disk quota entries. | |
3891 | .TP | |
24cb4a4b | 3892 | .IR /proc/sys/fs/epoll " (since Linux 2.6.28)" |
242b46af MK |
3893 | This directory contains the file |
3894 | .IR max_user_watches , | |
24cb4a4b MK |
3895 | which can be used to limit the amount of kernel memory consumed by the |
3896 | .I epoll | |
3897 | interface. | |
3898 | For further details, see | |