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fea681da | 1 | .\" Copyright (C) 1994, 1995 by Daniel Quinlan (quinlan@yggdrasil.com) |
f352b560 | 2 | .\" and Copyright (C) 2002-2008,2017 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 | .\" |
4b8c67d9 | 55 | .TH PROC 5 2017-09-15 "Linux" "Linux Programmer's Manual" |
fea681da | 56 | .SH NAME |
9ee4a2b6 | 57 | proc \- process information pseudo-filesystem |
fea681da MK |
58 | .SH DESCRIPTION |
59 | The | |
31fa1fd2 | 60 | .B 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 . |
b574c52d MK |
65 | Typically, it is mounted automatically by the system, |
66 | but it can also be mounted manually using a command such as: | |
67 | .PP | |
68 | .in +4n | |
69 | .EX | |
70 | mount \-t proc proc /proc | |
71 | .EE | |
72 | .in | |
73 | .PP | |
7e174651 | 74 | Most of the files in the |
31fa1fd2 | 75 | .B proc |
7e174651 | 76 | filesystem are read-only, |
64165e01 | 77 | but some files are writable, allowing kernel variables to be changed. |
7e174651 | 78 | .\" |
fee59977 MK |
79 | .SS Mount options |
80 | The | |
31fa1fd2 | 81 | .B proc |
fee59977 MK |
82 | filesystem supports the following mount options: |
83 | .TP | |
84 | .BR hidepid "=\fIn\fP (since Linux 3.3)" | |
85 | .\" commit 0499680a42141d86417a8fbaa8c8db806bea1201 | |
86 | This option controls who can access the information in | |
87 | .IR /proc/[pid] | |
88 | directories. | |
89 | The argument, | |
90 | .IR n , | |
91 | is one of the following values: | |
92 | .RS | |
93 | .TP 4 | |
94 | 0 | |
95 | Everybody may access all | |
96 | .IR /proc/[pid] | |
97 | directories. | |
98 | This is the traditional behavior, | |
99 | and the default if this mount option is not specified. | |
100 | .TP | |
101 | 1 | |
102 | Users may not access files and subdirectories inside any | |
103 | .IR /proc/[pid] | |
104 | directories but their own (the | |
105 | .IR /proc/[pid] | |
106 | directories themselves remain visible). | |
107 | Sensitive files such as | |
97949440 | 108 | .IR /proc/[pid]/cmdline |
fee59977 | 109 | and |
97949440 | 110 | .IR /proc/[pid]/status |
fee59977 MK |
111 | are now protected against other users. |
112 | This makes it impossible to learn whether any user is running a | |
113 | specific program | |
114 | (so long as the program doesn't otherwise reveal itself by its behavior). | |
115 | .\" As an additional bonus, since | |
97949440 | 116 | .\" .IR /proc/[pid]/cmdline |
fee59977 MK |
117 | .\" is unaccessible for other users, |
118 | .\" poorly written programs passing sensitive information via | |
119 | .\" program arguments are now protected against local eavesdroppers. | |
120 | .TP | |
121 | 2 | |
122 | As for mode 1, but in addition the | |
123 | .IR /proc/[pid] | |
124 | directories belonging to other users become invisible. | |
125 | This means that | |
126 | .IR /proc/[pid] | |
127 | entries can no longer be used to discover the PIDs on the system. | |
128 | This doesn't hide the fact that a process with a specific PID value exists | |
9bc87ed0 | 129 | (it can be learned by other means, for example, by "kill \-0 $PID"), |
fee59977 MK |
130 | but it hides a process's UID and GID, |
131 | which could otherwise be learned by employing | |
132 | .BR stat (2) | |
133 | on a | |
134 | .IR /proc/[pid] | |
135 | directory. | |
136 | This greatly complicates an attacker's task of gathering | |
137 | information about running processes (e.g., discovering whether | |
138 | some daemon is running with elevated privileges, | |
139 | whether another user is running some sensitive program, | |
140 | whether other users are running any program at all, and so on). | |
141 | .RE | |
142 | .TP | |
143 | .BR gid "=\fIgid\fP (since Linux 3.3)" | |
144 | .\" commit 0499680a42141d86417a8fbaa8c8db806bea1201 | |
145 | Specifies the ID of a group whose members are authorized to | |
146 | learn process information otherwise prohibited by | |
147 | .BR hidepid | |
95b1c1d1 | 148 | (i.e., users in this group behave as though |
fee59977 MK |
149 | .I /proc |
150 | was mounted with | |
95b1c1d1 | 151 | .IR hidepid=0 ). |
fee59977 MK |
152 | This group should be used instead of approaches such as putting |
153 | nonroot users into the | |
154 | .BR sudoers (5) | |
155 | file. | |
3c7cfa32 MK |
156 | .\" |
157 | .SS Overview | |
158 | Underneath | |
159 | .IR /proc , | |
160 | there are the following general groups of files and subdirectories: | |
161 | .TP | |
162 | .IR /proc/[pid] " subdirectories" | |
163 | Each one of these subdirectories contains files and subdirectories | |
164 | exposing information about the process with the corresponding process ID. | |
165 | .IP | |
166 | Underneath each of the | |
167 | .I /proc/[pid] | |
168 | directories, a | |
7fe3b32b | 169 | .I task |
3c7cfa32 | 170 | subdirectory contains subdirectories of the form |
7fe3b32b | 171 | .IR task/[tid] , |
3c7cfa32 MK |
172 | which contain corresponding information about each of the threads |
173 | in the process, where | |
174 | .I tid | |
175 | is the kernel thread ID of the thread. | |
01df7b70 MK |
176 | .IP |
177 | The | |
178 | .I /proc/[pid] | |
179 | subdirectories are visible when iterating through | |
180 | .I /proc | |
181 | with | |
182 | .BR getdents (2) | |
183 | (and thus are visible when one uses | |
184 | .BR ls (1) | |
185 | to view the contents of | |
186 | .IR /proc ). | |
187 | .TP | |
188 | .IR /proc/[tid] " subdirectories" | |
189 | Each one of these subdirectories contains files and subdirectories | |
190 | exposing information about the thread with the corresponding thread ID. | |
37cd58d2 MK |
191 | The contents of these directories are the same as the corresponding |
192 | .IR /proc/[pid]/task/[tid] | |
193 | directories. | |
01df7b70 MK |
194 | .IP |
195 | The | |
196 | .I /proc/[tid] | |
197 | subdirectories are | |
198 | .I not | |
199 | visible when iterating through | |
200 | .I /proc | |
201 | with | |
202 | .BR getdents (2) | |
203 | (and thus are | |
204 | .I not | |
205 | visible when one uses | |
206 | .BR ls (1) | |
3c7cfa32 MK |
207 | to view the contents of |
208 | .IR /proc ). | |
209 | .TP | |
210 | .I /proc/self | |
211 | When a process accesses this magic symbolic link, | |
212 | it resolves to the process's own | |
213 | .I /proc/[pid] | |
214 | directory. | |
215 | .TP | |
216 | .I /proc/thread-self | |
217 | When a thread accesses this magic symbolic link, | |
218 | it resolves to the process's own | |
7fe3b32b | 219 | .I /proc/self/task/[tid] |
3c7cfa32 MK |
220 | directory. |
221 | .TP | |
222 | .I /proc/[a-z]* | |
223 | Various other files and subdirectories under | |
224 | .I /proc | |
225 | expose system-wide information. | |
226 | .PP | |
227 | All of the above are described in more detail below. | |
228 | .\" | |
fee59977 | 229 | .SS Files and directories |
71b36dc7 MK |
230 | The following list provides details of many of the files and directories |
231 | under the | |
743638fd MK |
232 | .I /proc |
233 | hierarchy. | |
fea681da | 234 | .TP |
69119dc7 | 235 | .I /proc/[pid] |
fea681da MK |
236 | There is a numerical subdirectory for each running process; the |
237 | subdirectory is named by the process ID. | |
1e6a8e2f MK |
238 | Each |
239 | .I /proc/[pid] | |
e96ad1fd MK |
240 | subdirectory contains the pseudo-files and directories described below. |
241 | .IP | |
242 | The files inside each | |
243 | .I /proc/[pid] | |
244 | directory are normally owned by the effective user and | |
3bdb8ec5 MK |
245 | effective group ID of the process. |
246 | However, as a security measure, the ownership is made | |
247 | .IR root:root | |
248 | if the process's "dumpable" attribute is set to a value other than 1. | |
fb49322d | 249 | .IP |
ae636827 MK |
250 | Before Linux 4.11, |
251 | .\" commit 68eb94f16227336a5773b83ecfa8290f1d6b78ce | |
252 | .IR root:root | |
253 | meant the "global" root user ID and group ID | |
254 | (i.e., UID 0 and GID 0 in the initial user namespace). | |
255 | Since Linux 4.11, | |
256 | if the process is in a noninitial user namespace that has a | |
257 | valid mapping for user (group) ID 0 inside the namespace, then | |
258 | the user (group) ownership of the files under | |
259 | .I /proc/[pid] | |
260 | is instead made the same as the root user (group) ID of the namespace. | |
261 | This means that inside a container, | |
262 | things work as expected for the container "root" user. | |
263 | .IP | |
fb49322d | 264 | The process's "dumpable" attribute may change for the following reasons: |
3bdb8ec5 MK |
265 | .RS |
266 | .IP * 3 | |
267 | The attribute was explicitly set via the | |
268 | .BR prctl (2) | |
269 | .B PR_SET_DUMPABLE | |
270 | operation. | |
271 | .IP * | |
272 | The attribute was reset to the value in the file | |
273 | .IR /proc/sys/fs/suid_dumpable | |
274 | (described below), for the reasons described in | |
275 | .BR prctl (2). | |
276 | .RE | |
277 | .IP | |
278 | Resetting the "dumpable" attribute to 1 reverts the ownership of the | |
279 | .IR /proc/[pid]/* | |
eada5570 | 280 | files to the process's effective UID and GID. |
b7a42567 MK |
281 | .TP |
282 | .I /proc/[pid]/attr | |
283 | .\" https://lwn.net/Articles/28222/ | |
284 | .\" From: Stephen Smalley <sds@epoch.ncsc.mil> | |
285 | .\" To: LKML and others | |
286 | .\" Subject: [RFC][PATCH] Process Attribute API for Security Modules | |
287 | .\" Date: 08 Apr 2003 16:17:52 -0400 | |
288 | .\" | |
b3fb99e8 MK |
289 | .\" http://www.nsa.gov/research/_files/selinux/papers/module/x362.shtml |
290 | .\" | |
b7a42567 MK |
291 | The files in this directory provide an API for security modules. |
292 | The contents of this directory are files that can be read and written | |
293 | in order to set security-related attributes. | |
294 | This directory was added to support SELinux, | |
295 | but the intention was that the API be general enough to support | |
296 | other security modules. | |
297 | For the purpose of explanation, | |
298 | examples of how SELinux uses these files are provided below. | |
2dad4c59 | 299 | .IP |
b7a42567 MK |
300 | This directory is present only if the kernel was configured with |
301 | .BR CONFIG_SECURITY . | |
302 | .TP | |
303 | .IR /proc/[pid]/attr/current " (since Linux 2.6.0)" | |
304 | The contents of this file represent the current | |
305 | security attributes of the process. | |
2dad4c59 | 306 | .IP |
fd44bdc7 TY |
307 | In SELinux, this file is used to get the security context of a process. |
308 | Prior to Linux 2.6.11, this file could not be used to set the security | |
309 | context (a write was always denied), since SELinux limited process security | |
310 | transitions to | |
b7a42567 MK |
311 | .BR execve (2) |
312 | (see the description of | |
313 | .IR /proc/[pid]/attr/exec , | |
314 | below). | |
fd44bdc7 TY |
315 | Since Linux 2.6.11, SELinux lifted this restriction and began supporting |
316 | "set" operations via writes to this node if authorized by policy, | |
317 | although use of this operation is only suitable for applications that are | |
318 | trusted to maintain any desired separation between the old and new security | |
b6620a25 MK |
319 | contexts. |
320 | Prior to Linux 2.6.28, SELinux did not allow threads within a | |
fd44bdc7 TY |
321 | multi-threaded process to set their security context via this node |
322 | as it would yield an inconsistency among the security contexts of the | |
b6620a25 MK |
323 | threads sharing the same memory space. |
324 | Since Linux 2.6.28, SELinux lifted | |
fd44bdc7 | 325 | this restriction and began supporting "set" operations for threads within |
b6620a25 | 326 | a multithreaded process if the new security context is bounded by the old |
fd44bdc7 TY |
327 | security context, where the bounded relation is defined in policy and |
328 | guarantees that the new security context has a subset of the permissions | |
329 | of the old security context. | |
b7a42567 MK |
330 | Other security modules may choose to support "set" operations via |
331 | writes to this node. | |
332 | .TP | |
333 | .IR /proc/[pid]/attr/exec " (since Linux 2.6.0)" | |
334 | This file represents the attributes to assign to the | |
335 | process upon a subsequent | |
336 | .BR execve (2). | |
2dad4c59 | 337 | .IP |
b7a42567 MK |
338 | In SELinux, |
339 | this is needed to support role/domain transitions, and | |
340 | .BR execve (2) | |
341 | is the preferred point to make such transitions because it offers better | |
342 | control over the initialization of the process in the new security label | |
343 | and the inheritance of state. | |
344 | In SELinux, this attribute is reset on | |
345 | .BR execve (2) | |
346 | so that the new program reverts to the default behavior for any | |
347 | .BR execve (2) | |
348 | calls that it may make. | |
349 | In SELinux, a process can set | |
350 | only its own | |
351 | .I /proc/[pid]/attr/exec | |
352 | attribute. | |
353 | .TP | |
354 | .IR /proc/[pid]/attr/fscreate " (since Linux 2.6.0)" | |
355 | This file represents the attributes to assign to files | |
356 | created by subsequent calls to | |
357 | .BR open (2), | |
358 | .BR mkdir (2), | |
359 | .BR symlink (2), | |
360 | and | |
361 | .BR mknod (2) | |
2dad4c59 | 362 | .IP |
b7a42567 MK |
363 | SELinux employs this file to support creation of a file |
364 | (using the aforementioned system calls) | |
365 | in a secure state, | |
366 | so that there is no risk of inappropriate access being obtained | |
367 | between the time of creation and the time that attributes are set. | |
368 | In SELinux, this attribute is reset on | |
369 | .BR execve (2), | |
370 | so that the new program reverts to the default behavior for | |
371 | any file creation calls it may make, but the attribute will persist | |
372 | across multiple file creation calls within a program unless it is | |
373 | explicitly reset. | |
374 | In SELinux, a process can set only its own | |
375 | .IR /proc/[pid]/attr/fscreate | |
376 | attribute. | |
377 | .TP | |
666db07e MK |
378 | .IR /proc/[pid]/attr/keycreate " (since Linux 2.6.18)" |
379 | .\" commit 4eb582cf1fbd7b9e5f466e3718a59c957e75254e | |
666db07e MK |
380 | If a process writes a security context into this file, |
381 | all subsequently created keys | |
382 | .RB ( add_key (2)) | |
383 | will be labeled with this context. | |
384 | For further information, see the kernel source file | |
6b3ead8f ES |
385 | .I Documentation/security/keys/core.rst |
386 | (or file | |
387 | .\" commit b68101a1e8f0263dbc7b8375d2a7c57c6216fb76 | |
388 | .I Documentation/security/keys.txt | |
389 | on Linux between 3.0 and 4.13, or | |
390 | .\" commit d410fa4ef99112386de5f218dd7df7b4fca910b4 | |
391 | .I Documentation/keys.txt | |
392 | before Linux 3.0). | |
2702dc21 | 393 | .TP |
93401860 MK |
394 | .IR /proc/[pid]/attr/prev " (since Linux 2.6.0)" |
395 | This file contains the security context of the process before the last | |
396 | .BR execve (2); | |
397 | that is, the previous value of | |
398 | .IR /proc/[pid]/attr/current . | |
399 | .TP | |
2702dc21 MK |
400 | .IR /proc/[pid]/attr/socketcreate " (since Linux 2.6.18)" |
401 | .\" commit 42c3e03ef6b298813557cdb997bd6db619cd65a2 | |
402 | If a process writes a security context into this file, | |
403 | all subsequently created sockets will be labeled with this context. | |
39b35179 MK |
404 | .TP |
405 | .IR /proc/[pid]/autogroup " (since Linux 2.6.38)" | |
406 | .\" commit 5091faa449ee0b7d73bc296a93bca9540fc51d0a | |
407 | See | |
408 | .BR sched (7). | |
fea681da | 409 | .TP |
d6bec36e MK |
410 | .IR /proc/[pid]/auxv " (since 2.6.0)" |
411 | .\" Precisely: Linux 2.6.0-test7 | |
857f1942 | 412 | This contains the contents of the ELF interpreter information passed |
c13182ef | 413 | to the process at exec time. |
857f1942 | 414 | The format is one \fIunsigned long\fP ID |
c13182ef | 415 | plus one \fIunsigned long\fP value for each entry. |
857f1942 | 416 | The last entry contains two zeros. |
4c69c692 MK |
417 | See also |
418 | .BR getauxval (3). | |
2dad4c59 | 419 | .IP |
82664739 MK |
420 | Permission to access this file is governed by a ptrace access mode |
421 | .B PTRACE_MODE_READ_FSCREDS | |
422 | check; see | |
423 | .BR ptrace (2). | |
b5d204d0 | 424 | .TP |
8d708d6b | 425 | .IR /proc/[pid]/cgroup " (since Linux 2.6.24)" |
5c2181ad MK |
426 | See |
427 | .BR cgroups (7). | |
76e0451c MK |
428 | .TP |
429 | .IR /proc/[pid]/clear_refs " (since Linux 2.6.22)" | |
430 | .\" commit b813e931b4c8235bb42e301096ea97dbdee3e8fe (2.6.22) | |
431 | .\" commit 398499d5f3613c47f2143b8c54a04efb5d7a6da9 (2.6.32) | |
432 | .\" commit 040fa02077de01c7e08fa75be6125e4ca5636011 (3.11) | |
b4e9ee8f | 433 | .\" |
b4e9ee8f | 434 | .\" "Clears page referenced bits shown in smaps output" |
76e0451c | 435 | .\" write-only, writable only by the owner of the process |
2dad4c59 | 436 | .IP |
76e0451c | 437 | This is a write-only file, writable only by owner of the process. |
2dad4c59 | 438 | .IP |
76e0451c MK |
439 | The following values may be written to the file: |
440 | .RS | |
441 | .TP | |
442 | 1 (since Linux 2.6.22) | |
443 | .\" Internally: CLEAR_REFS_ALL | |
444 | Reset the PG_Referenced and ACCESSED/YOUNG | |
445 | bits for all the pages associated with the process. | |
446 | (Before kernel 2.6.32, writing any nonzero value to this file | |
447 | had this effect.) | |
448 | .TP | |
449 | 2 (since Linux 2.6.32) | |
450 | .\" Internally: CLEAR_REFS_ANON | |
451 | Reset the PG_Referenced and ACCESSED/YOUNG | |
452 | bits for all anonymous pages associated with the process. | |
453 | .TP | |
454 | 3 (since Linux 2.6.32) | |
455 | .\" Internally: CLEAR_REFS_MAPPED | |
456 | Reset the PG_Referenced and ACCESSED/YOUNG | |
457 | bits for all file-mapped pages associated with the process. | |
458 | .RE | |
459 | .IP | |
460 | Clearing the PG_Referenced and ACCESSED/YOUNG bits provides a method | |
461 | to measure approximately how much memory a process is using. | |
322d49fb | 462 | One first inspects the values in the "Referenced" fields |
76e0451c MK |
463 | for the VMAs shown in |
464 | .IR /proc/[pid]/smaps | |
465 | to get an idea of the memory footprint of the | |
466 | process. | |
467 | One then clears the PG_Referenced and ACCESSED/YOUNG bits | |
468 | and, after some measured time interval, | |
322d49fb | 469 | once again inspects the values in the "Referenced" fields |
76e0451c MK |
470 | to get an idea of the change in memory footprint of the |
471 | process during the measured interval. | |
472 | If one is interested only in inspecting the selected mapping types, | |
473 | then the value 2 or 3 can be used instead of 1. | |
2dad4c59 | 474 | .IP |
dfdf642e | 475 | Further values can be written to affect different properties: |
76e0451c MK |
476 | .RS |
477 | .TP | |
478 | 4 (since Linux 3.11) | |
479 | Clear the soft-dirty bit for all the pages associated with the process. | |
480 | .\" Internally: CLEAR_REFS_SOFT_DIRTY | |
481 | This is used (in conjunction with | |
482 | .IR /proc/[pid]/pagemap ) | |
483 | by the check-point restore system to discover which pages of a process | |
484 | have been dirtied since the file | |
485 | .IR /proc/[pid]/clear_refs | |
486 | was written to. | |
dfdf642e NK |
487 | .TP |
488 | 5 (since Linux 4.0) | |
489 | .\" Internally: CLEAR_REFS_MM_HIWATER_RSS | |
0989246e MK |
490 | Reset the peak resident set size ("high water mark") to the process's |
491 | current resident set size value. | |
76e0451c MK |
492 | .RE |
493 | .IP | |
494 | Writing any value to | |
495 | .IR /proc/[pid]/clear_refs | |
496 | other than those listed above has no effect. | |
2dad4c59 | 497 | .IP |
76e0451c MK |
498 | The |
499 | .IR /proc/[pid]/clear_refs | |
500 | file is present only if the | |
501 | .B CONFIG_PROC_PAGE_MONITOR | |
502 | kernel configuration option is enabled. | |
857f1942 | 503 | .TP |
69119dc7 | 504 | .I /proc/[pid]/cmdline |
6975c16e | 505 | This read-only file holds the complete command line for the process, |
b447cd58 MK |
506 | unless the process is a zombie. |
507 | .\" In 2.3.26, this also used to be true if the process was swapped out. | |
508 | In the latter case, there is nothing in this file: | |
75b94dc3 | 509 | that is, a read on this file will return 0 characters. |
b447cd58 | 510 | The command-line arguments appear in this file as a set of |
6596d270 MK |
511 | strings separated by null bytes (\(aq\\0\(aq), |
512 | with a further null byte after the last string. | |
32d7ef00 MK |
513 | .TP |
514 | .IR /proc/[pid]/comm " (since Linux 2.6.33)" | |
515 | .\" commit 4614a696bd1c3a9af3a08f0e5874830a85b889d4 | |
516 | This file exposes the process's | |
517 | .I comm | |
518 | value\(emthat is, the command name associated with the process. | |
519 | Different threads in the same process may have different | |
520 | .I comm | |
521 | values, accessible via | |
522 | .IR /proc/[pid]/task/[tid]/comm . | |
523 | A thread may modify its | |
524 | .I comm | |
525 | value, or that of any of other thread in the same thread group (see | |
526 | the discussion of | |
527 | .B CLONE_THREAD | |
528 | in | |
529 | .BR clone (2)), | |
530 | by writing to the file | |
531 | .IR /proc/self/task/[tid]/comm . | |
532 | Strings longer than | |
533 | .B TASK_COMM_LEN | |
534 | (16) characters are silently truncated. | |
2dad4c59 | 535 | .IP |
ef4f4031 | 536 | This file provides a superset of the |
32d7ef00 MK |
537 | .BR prctl (2) |
538 | .B PR_SET_NAME | |
539 | and | |
540 | .B PR_GET_NAME | |
541 | operations, and is employed by | |
542 | .BR pthread_setname_np (3) | |
543 | when used to rename threads other than the caller. | |
fea681da | 544 | .TP |
7e07d950 | 545 | .IR /proc/[pid]/coredump_filter " (since Linux 2.6.23)" |
b4e9ee8f MK |
546 | See |
547 | .BR core (5). | |
5c411b17 | 548 | .TP |
7e07d950 MK |
549 | .IR /proc/[pid]/cpuset " (since Linux 2.6.12)" |
550 | .\" and/proc/[pid]/task/[tid]/cpuset | |
5c411b17 MK |
551 | See |
552 | .BR cpuset (7). | |
b4e9ee8f | 553 | .TP |
69119dc7 | 554 | .I /proc/[pid]/cwd |
c13182ef | 555 | This is a symbolic link to the current working directory of the process. |
59a40ed7 MK |
556 | To find out the current working directory of process 20, |
557 | for instance, you can do this: | |
2dad4c59 | 558 | .IP |
59a40ed7 | 559 | .in +4n |
37d5e699 | 560 | .EX |
b43a3b30 | 561 | .RB "$" " cd /proc/20/cwd; /bin/pwd" |
37d5e699 | 562 | .EE |
59a40ed7 | 563 | .in |
2dad4c59 | 564 | .IP |
c13182ef MK |
565 | Note that the |
566 | .I pwd | |
e7b489f0 | 567 | command is often a shell built-in, and might |
c13182ef | 568 | not work properly. |
743638fd MK |
569 | In |
570 | .BR bash (1), | |
571 | you may use | |
572 | .IR "pwd\ \-P" . | |
2dad4c59 | 573 | .IP |
afcaf646 | 574 | .\" The following was still true as at kernel 2.6.13 |
c13182ef MK |
575 | In a multithreaded process, the contents of this symbolic link |
576 | are not available if the main thread has already terminated | |
afcaf646 | 577 | (typically by calling |
59a40ed7 | 578 | .BR pthread_exit (3)). |
2dad4c59 | 579 | .IP |
b902fe18 MK |
580 | Permission to dereference or read |
581 | .RB ( readlink (2)) | |
582 | this symbolic link is governed by a ptrace access mode | |
583 | .B PTRACE_MODE_READ_FSCREDS | |
584 | check; see | |
585 | .BR ptrace (2). | |
fea681da | 586 | .TP |
69119dc7 | 587 | .I /proc/[pid]/environ |
09651080 MK |
588 | This file contains the initial environment that was set |
589 | when the currently executing program was started via | |
590 | .BR execve (2). | |
f81fb444 | 591 | The entries are separated by null bytes (\(aq\\0\(aq), |
b4e9ee8f | 592 | and there may be a null byte at the end. |
fea681da | 593 | Thus, to print out the environment of process 1, you would do: |
37d5e699 | 594 | .IP |
a08ea57c | 595 | .in +4n |
37d5e699 | 596 | .EX |
d1081b23 | 597 | .RB "$" " cat /proc/1/environ | tr \(aq\e000\(aq \(aq\en\(aq" |
37d5e699 | 598 | .EE |
a08ea57c | 599 | .in |
2dad4c59 | 600 | .IP |
09651080 MK |
601 | If, after an |
602 | .BR execve (2), | |
603 | the process modifies its environment | |
c187d2a1 | 604 | (e.g., by calling functions such as |
387e2438 MF |
605 | .BR putenv (3) |
606 | or modifying the | |
607 | .BR environ (7) | |
608 | variable directly), | |
09651080 MK |
609 | this file will |
610 | .I not | |
611 | reflect those changes. | |
2dad4c59 | 612 | .IP |
c187d2a1 | 613 | Furthermore, a process may change the memory location that this file refers via |
387e2438 | 614 | .BR prctl (2) |
c187d2a1 | 615 | operations such as |
387e2438 | 616 | .BR PR_SET_MM_ENV_START . |
2dad4c59 | 617 | .IP |
82664739 MK |
618 | Permission to access this file is governed by a ptrace access mode |
619 | .B PTRACE_MODE_READ_FSCREDS | |
620 | check; see | |
621 | .BR ptrace (2). | |
fea681da | 622 | .TP |
69119dc7 | 623 | .I /proc/[pid]/exe |
fea681da | 624 | Under Linux 2.2 and later, this file is a symbolic link |
2d7195b8 | 625 | containing the actual pathname of the executed command. |
c13182ef MK |
626 | This symbolic link can be dereferenced normally; attempting to open |
627 | it will open the executable. | |
628 | You can even type | |
69119dc7 | 629 | .I /proc/[pid]/exe |
06dd061c | 630 | to run another copy of the same executable that is being run by |
69119dc7 | 631 | process [pid]. |
7e3c767a GJ |
632 | If the pathname has been unlinked, the symbolic link will contain the |
633 | string \(aq(deleted)\(aq appended to the original pathname. | |
afcaf646 | 634 | .\" The following was still true as at kernel 2.6.13 |
c13182ef MK |
635 | In a multithreaded process, the contents of this symbolic link |
636 | are not available if the main thread has already terminated | |
afcaf646 MK |
637 | (typically by calling |
638 | .BR pthread_exit (3)). | |
2dad4c59 | 639 | .IP |
b902fe18 MK |
640 | Permission to dereference or read |
641 | .RB ( readlink (2)) | |
642 | this symbolic link is governed by a ptrace access mode | |
643 | .B PTRACE_MODE_READ_FSCREDS | |
644 | check; see | |
645 | .BR ptrace (2). | |
2dad4c59 | 646 | .IP |
eb9a0b2f | 647 | Under Linux 2.0 and earlier, |
69119dc7 | 648 | .I /proc/[pid]/exe |
c13182ef MK |
649 | is a pointer to the binary which was executed, |
650 | and appears as a symbolic link. | |
651 | A | |
fea681da MK |
652 | .BR readlink (2) |
653 | call on this file under Linux 2.0 returns a string in the format: | |
2dad4c59 | 654 | .IP |
59a40ed7 | 655 | [device]:inode |
2dad4c59 | 656 | .IP |
fea681da MK |
657 | For example, [0301]:1502 would be inode 1502 on device major 03 (IDE, |
658 | MFM, etc. drives) minor 01 (first partition on the first drive). | |
2dad4c59 | 659 | .IP |
fea681da | 660 | .BR find (1) |
59a40ed7 MK |
661 | with the |
662 | .I \-inum | |
663 | option can be used to locate the file. | |
fea681da | 664 | .TP |
d4529654 | 665 | .I /proc/[pid]/fd/ |
fea681da MK |
666 | This is a subdirectory containing one entry for each file which the |
667 | process has open, named by its file descriptor, and which is a | |
c13182ef | 668 | symbolic link to the actual file. |
f78ed33a | 669 | Thus, 0 is standard input, 1 standard output, 2 standard error, and so on. |
2dad4c59 | 670 | .IP |
f75715e0 MK |
671 | For file descriptors for pipes and sockets, |
672 | the entries will be symbolic links whose content is the | |
673 | file type with the inode. | |
d4529654 MF |
674 | A |
675 | .BR readlink (2) | |
676 | call on this file returns a string in the format: | |
2dad4c59 | 677 | .IP |
d4529654 | 678 | type:[inode] |
2dad4c59 | 679 | .IP |
f75715e0 MK |
680 | For example, |
681 | .I socket:[2248868] | |
682 | will be a socket and its inode is 2248868. | |
683 | For sockets, that inode can be used to find more information | |
684 | in one of the files under | |
d4529654 | 685 | .IR /proc/net/ . |
2dad4c59 | 686 | .IP |
2b7a2ac5 MK |
687 | For file descriptors that have no corresponding inode |
688 | (e.g., file descriptors produced by | |
89e284a2 | 689 | .BR bpf (2), |
2b7a2ac5 MK |
690 | .BR epoll_create (2), |
691 | .BR eventfd (2), | |
692 | .BR inotify_init (2), | |
89e284a2 | 693 | .BR perf_event_open (2), |
2b7a2ac5 | 694 | .BR signalfd (2), |
89e284a2 | 695 | .BR timerfd_create (2), |
2b7a2ac5 | 696 | and |
e8675558 | 697 | .BR userfaultfd (2)), |
2b7a2ac5 | 698 | the entry will be a symbolic link with contents of the form |
2dad4c59 | 699 | .IP |
2b7a2ac5 | 700 | anon_inode:<file-type> |
2dad4c59 | 701 | .IP |
e2a5929d | 702 | In many cases (but not all), the |
2b7a2ac5 MK |
703 | .I file-type |
704 | is surrounded by square brackets. | |
2dad4c59 | 705 | .IP |
2b7a2ac5 MK |
706 | For example, an epoll file descriptor will have a symbolic link |
707 | whose content is the string | |
708 | .IR "anon_inode:[eventpoll]" . | |
2dad4c59 | 709 | .IP |
d4529654 | 710 | .\"The following was still true as at kernel 2.6.13 |
afcaf646 | 711 | In a multithreaded process, the contents of this directory |
c13182ef | 712 | are not available if the main thread has already terminated |
afcaf646 MK |
713 | (typically by calling |
714 | .BR pthread_exit (3)). | |
2dad4c59 | 715 | .IP |
20c1a631 MK |
716 | Programs that take a filename as a command-line argument, |
717 | but don't take input from standard input if no argument is supplied, | |
718 | and programs that write to a file named as a command-line argument, | |
719 | but don't send their output to standard output | |
59a40ed7 | 720 | if no argument is supplied, can nevertheless be made to use |
20c1a631 MK |
721 | standard input or standard output by using |
722 | .IR /proc/[pid]/fd | |
723 | files as command-line arguments. | |
59a40ed7 MK |
724 | For example, assuming that |
725 | .I \-i | |
726 | is the flag designating an input file and | |
727 | .I \-o | |
728 | is the flag designating an output file: | |
37d5e699 | 729 | .IP |
a08ea57c | 730 | .in +4n |
37d5e699 | 731 | .EX |
b43a3b30 | 732 | .RB "$" " foobar \-i /proc/self/fd/0 \-o /proc/self/fd/1 ..." |
37d5e699 | 733 | .EE |
a08ea57c | 734 | .in |
2dad4c59 | 735 | .IP |
fea681da MK |
736 | and you have a working filter. |
737 | .\" The following is not true in my tests (MTK): | |
738 | .\" Note that this will not work for | |
739 | .\" programs that seek on their files, as the files in the fd directory | |
740 | .\" are not seekable. | |
2dad4c59 | 741 | .IP |
59a40ed7 MK |
742 | .I /proc/self/fd/N |
743 | is approximately the same as | |
744 | .I /dev/fd/N | |
008f1ecc | 745 | in some UNIX and UNIX-like systems. |
c13182ef | 746 | Most Linux MAKEDEV scripts symbolically link |
59a40ed7 MK |
747 | .I /dev/fd |
748 | to | |
749 | .IR /proc/self/fd , | |
750 | in fact. | |
2dad4c59 | 751 | .IP |
59a40ed7 MK |
752 | Most systems provide symbolic links |
753 | .IR /dev/stdin , | |
754 | .IR /dev/stdout , | |
755 | and | |
756 | .IR /dev/stderr , | |
757 | which respectively link to the files | |
758 | .IR 0 , | |
759 | .IR 1 , | |
760 | and | |
761 | .IR 2 | |
762 | in | |
763 | .IR /proc/self/fd . | |
764 | Thus the example command above could be written as: | |
d6bd89f3 | 765 | .IP |
59a40ed7 | 766 | .in +4n |
37d5e699 | 767 | .EX |
b43a3b30 | 768 | .RB "$" " foobar \-i /dev/stdin \-o /dev/stdout ..." |
37d5e699 | 769 | .EE |
59a40ed7 | 770 | .in |
138a191e MK |
771 | .IP |
772 | Permission to dereference or read | |
773 | .RB ( readlink (2)) | |
774 | the symbolic links in this directory is governed by a ptrace access mode | |
775 | .B PTRACE_MODE_READ_FSCREDS | |
776 | check; see | |
777 | .BR ptrace (2). | |
81c8aeb6 LW |
778 | .IP |
779 | Note that for file descriptors referring to inodes (pipes and sockets, see above), | |
780 | those inodes still have permission bits and ownership information | |
781 | distinct from those of the | |
782 | .I /proc/[pid]/fd | |
783 | entry, | |
784 | and that the owner may differ from the user and group IDs of the process. | |
785 | An unprivileged process may lack permissions to open them, as in this example: | |
786 | .IP | |
787 | .in +4n | |
788 | .EX | |
789 | .RB "$" " echo test | sudo -u nobody cat" | |
790 | test | |
791 | .RB "$" " echo test | sudo -u nobody cat /proc/self/fd/0" | |
792 | cat: /proc/self/fd/0: Permission denied | |
793 | .EE | |
794 | .in | |
795 | .IP | |
796 | File descriptor 0 refers to the pipe created by the shell | |
797 | and owned by that shell's user, which is not | |
798 | .IR nobody , | |
799 | so | |
800 | .B cat | |
801 | does not have permission to create a new file descriptor to read from that inode, | |
802 | even though it can still read from its existing file descriptor 0. | |
69ab425e | 803 | .TP |
7e07d950 | 804 | .IR /proc/[pid]/fdinfo/ " (since Linux 2.6.22)" |
69ab425e MK |
805 | This is a subdirectory containing one entry for each file which the |
806 | process has open, named by its file descriptor. | |
0275956d | 807 | The files in this directory are readable only by the owner of the process. |
69ab425e | 808 | The contents of each file can be read to obtain information |
0275956d MK |
809 | about the corresponding file descriptor. |
810 | The content depends on the type of file referred to by the | |
d9cb0d7d | 811 | corresponding file descriptor. |
2dad4c59 | 812 | .IP |
0275956d | 813 | For regular files and directories, we see something like: |
37d5e699 | 814 | .IP |
69ab425e | 815 | .in +4n |
37d5e699 | 816 | .EX |
69ab425e MK |
817 | .RB "$" " cat /proc/12015/fdinfo/4" |
818 | pos: 1000 | |
819 | flags: 01002002 | |
0275956d | 820 | mnt_id: 21 |
37d5e699 | 821 | .EE |
69ab425e | 822 | .in |
2dad4c59 | 823 | .IP |
9599cbb3 MK |
824 | The fields are as follows: |
825 | .RS | |
826 | .TP | |
69ab425e | 827 | .I pos |
9599cbb3 MK |
828 | This is a decimal number showing the file offset. |
829 | .TP | |
69ab425e | 830 | .I flags |
9599cbb3 | 831 | This is an octal number that displays the |
69ab425e MK |
832 | file access mode and file status flags (see |
833 | .BR open (2)). | |
d7e537ce MK |
834 | If the close-on-exec file descriptor flag is set, then |
835 | .I flags | |
836 | will also include the value | |
837 | .BR O_CLOEXEC . | |
2dad4c59 | 838 | .IP |
d7e537ce MK |
839 | Before Linux 3.1, |
840 | .\" commit 1117f72ea0217ba0cc19f05adbbd8b9a397f5ab7 | |
841 | this field incorrectly displayed the setting of | |
842 | .B O_CLOEXEC | |
843 | at the time the file was opened, | |
844 | rather than the current setting of the close-on-exec flag. | |
9599cbb3 MK |
845 | .TP |
846 | .I | |
0275956d | 847 | .I mnt_id |
9599cbb3 | 848 | This field, present since Linux 3.15, |
0275956d MK |
849 | .\" commit 49d063cb353265c3af701bab215ac438ca7df36d |
850 | is the ID of the mount point containing this file. | |
851 | See the description of | |
852 | .IR /proc/[pid]/mountinfo . | |
9599cbb3 MK |
853 | .RE |
854 | .IP | |
6e7622ee MK |
855 | For eventfd file descriptors (see |
856 | .BR eventfd (2)), | |
b6a7fd50 MK |
857 | we see (since Linux 3.8) |
858 | .\" commit cbac5542d48127b546a23d816380a7926eee1c25 | |
859 | the following fields: | |
2dad4c59 | 860 | .IP |
6e7622ee | 861 | .in +4n |
37d5e699 | 862 | .EX |
6e7622ee MK |
863 | pos: 0 |
864 | flags: 02 | |
865 | mnt_id: 10 | |
866 | eventfd-count: 40 | |
37d5e699 | 867 | .EE |
6e7622ee | 868 | .in |
2dad4c59 | 869 | .IP |
6e7622ee MK |
870 | .I eventfd-count |
871 | is the current value of the eventfd counter, in hexadecimal. | |
2dad4c59 | 872 | .IP |
58d375dd MK |
873 | For epoll file descriptors (see |
874 | .BR epoll (7)), | |
b6a7fd50 MK |
875 | we see (since Linux 3.8) |
876 | .\" commit 138d22b58696c506799f8de759804083ff9effae | |
877 | the following fields: | |
2dad4c59 | 878 | .IP |
58d375dd | 879 | .in +4n |
37d5e699 | 880 | .EX |
58d375dd MK |
881 | pos: 0 |
882 | flags: 02 | |
883 | mnt_id: 10 | |
884 | tfd: 9 events: 19 data: 74253d2500000009 | |
885 | tfd: 7 events: 19 data: 74253d2500000007 | |
37d5e699 | 886 | .EE |
58d375dd | 887 | .in |
2dad4c59 | 888 | .IP |
58d375dd MK |
889 | Each of the lines beginning |
890 | .I tfd | |
891 | describes one of the file descriptors being monitored via | |
892 | the epoll file descriptor (see | |
893 | .BR epoll_ctl (2) | |
894 | for some details). | |
895 | The | |
896 | .IR tfd | |
897 | field is the number of the file descriptor. | |
898 | The | |
899 | .I events | |
900 | field is a hexadecimal mask of the events being monitored for this file | |
901 | descriptor. | |
902 | The | |
903 | .I data | |
904 | field is the data value associated with this file descriptor. | |
2dad4c59 | 905 | .IP |
f8a14cac MK |
906 | For signalfd file descriptors (see |
907 | .BR signalfd (2)), | |
b6a7fd50 MK |
908 | we see (since Linux 3.8) |
909 | .\" commit 138d22b58696c506799f8de759804083ff9effae | |
910 | the following fields: | |
2dad4c59 | 911 | .IP |
f8a14cac | 912 | .in +4n |
37d5e699 | 913 | .EX |
f8a14cac MK |
914 | pos: 0 |
915 | flags: 02 | |
916 | mnt_id: 10 | |
917 | sigmask: 0000000000000006 | |
37d5e699 | 918 | .EE |
f8a14cac | 919 | .in |
2dad4c59 | 920 | .IP |
f8a14cac MK |
921 | .I sigmask |
922 | is the hexadecimal mask of signals that are accepted via this | |
923 | signalfd file descriptor. | |
924 | (In this example, bits 2 and 3 are set, corresponding to the signals | |
925 | .B SIGINT | |
926 | and | |
927 | .BR SIGQUIT ; | |
928 | see | |
929 | .BR signal (7).) | |
2dad4c59 | 930 | .IP |
4e77145c MK |
931 | For inotify file descriptors (see |
932 | .BR inotify (7)), | |
933 | we see (since Linux 3.8) | |
934 | the following fields: | |
2dad4c59 | 935 | .IP |
4e77145c | 936 | .in +4n |
37d5e699 | 937 | .EX |
4e77145c MK |
938 | pos: 0 |
939 | flags: 00 | |
940 | mnt_id: 11 | |
941 | inotify wd:2 ino:7ef82a sdev:800001 mask:800afff ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:2af87e00220ffd73 | |
942 | inotify wd:1 ino:192627 sdev:800001 mask:800afff ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:27261900802dfd73 | |
37d5e699 | 943 | .EE |
4e77145c | 944 | .in |
2dad4c59 | 945 | .IP |
4e77145c MK |
946 | Each of the lines beginning with "inotify" displays information about |
947 | one file or directory that is being monitored. | |
948 | The fields in this line are as follows: | |
949 | .RS | |
950 | .TP | |
951 | .I wd | |
952 | A watch descriptor number (in decimal). | |
953 | .TP | |
954 | .I ino | |
955 | The inode number of the target file (in hexadecimal). | |
956 | .TP | |
957 | .I sdev | |
958 | The ID of the device where the target file resides (in hexadecimal). | |
959 | .TP | |
960 | .I mask | |
961 | The mask of events being monitored for the target file (in hexadecimal). | |
962 | .RE | |
963 | .IP | |
964 | If the kernel was built with exportfs support, the path to the target | |
965 | file is exposed as a file handle, via three hexadecimal fields: | |
966 | .IR fhandle-bytes , | |
967 | .IR fhandle-type , | |
968 | and | |
969 | .IR f_handle . | |
2dad4c59 | 970 | .IP |
e2444bcb MK |
971 | For fanotify file descriptors (see |
972 | .BR fanotify (7)), | |
973 | we see (since Linux 3.8) | |
974 | the following fields: | |
2dad4c59 | 975 | .IP |
e2444bcb | 976 | .in +4n |
37d5e699 | 977 | .EX |
e2444bcb MK |
978 | pos: 0 |
979 | flags: 02 | |
980 | mnt_id: 11 | |
981 | fanotify flags:0 event-flags:88002 | |
982 | fanotify ino:19264f sdev:800001 mflags:0 mask:1 ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:4f261900a82dfd73 | |
37d5e699 | 983 | .EE |
e2444bcb | 984 | .in |
2dad4c59 | 985 | .IP |
e2444bcb MK |
986 | The fourth line displays information defined when the fanotify group |
987 | was created via | |
988 | .BR fanotify_init (2): | |
989 | .RS | |
990 | .TP | |
991 | .I flags | |
992 | The | |
993 | .I flags | |
994 | argument given to | |
995 | .BR fanotify_init (2) | |
996 | (expressed in hexadecimal). | |
997 | .TP | |
998 | .I event-flags | |
999 | The | |
1000 | .I event_f_flags | |
1001 | argument given to | |
1002 | .BR fanotify_init (2) | |
1003 | (expressed in hexadecimal). | |
1004 | .RE | |
1005 | .IP | |
1006 | Each additional line shown in the file contains information | |
1007 | about one of the marks in the fanotify group. | |
1008 | Most of these fields are as for inotify, except: | |
1009 | .RS | |
1010 | .TP | |
1011 | .I mflags | |
1012 | The flags associated with the mark | |
1013 | (expressed in hexadecimal). | |
1014 | .TP | |
1015 | .I mask | |
1016 | The events mask for this mark | |
1017 | (expressed in hexadecimal). | |
1018 | .TP | |
1019 | .I ignored_mask | |
1020 | The mask of events that are ignored for this mark | |
1021 | (expressed in hexadecimal). | |
1022 | .RE | |
1023 | .IP | |
1024 | For details on these fields, see | |
1025 | .BR fanotify_mark (2). | |
340a16a6 LW |
1026 | .IP |
1027 | For timerfd file descriptors (see | |
1028 | .BR timerfd (2)), | |
1029 | we see (since Linux 3.17) | |
cd595f62 | 1030 | .\" commit af9c4957cf212ad9cf0bee34c95cb11de5426e85 |
340a16a6 LW |
1031 | the following fields: |
1032 | .IP | |
1033 | .in +4n | |
1034 | .EX | |
1035 | pos: 0 | |
1036 | flags: 02004002 | |
1037 | mnt_id: 13 | |
1038 | clockid: 0 | |
1039 | ticks: 0 | |
1040 | settime flags: 03 | |
1041 | it_value: (7695568592, 640020877) | |
1042 | it_interval: (0, 0) | |
1043 | .EE | |
1044 | .in | |
1cdbc3a6 MK |
1045 | .RS |
1046 | .TP | |
340a16a6 | 1047 | .I clockid |
1cdbc3a6 | 1048 | This is the numeric value of the clock ID |
734ec506 MK |
1049 | (corresponding to one of the |
1050 | .B CLOCK_* | |
1051 | constants defined via | |
a6425049 | 1052 | .IR <time.h> ) |
cb5a67a4 | 1053 | that is used to mark the progress of the timer (in this example, 0 is |
340a16a6 | 1054 | .BR CLOCK_REALTIME ). |
1cdbc3a6 | 1055 | .TP |
340a16a6 | 1056 | .I ticks |
1cdbc3a6 MK |
1057 | This is the number of timer expirations that have occurred, |
1058 | (i.e., the value that | |
340a16a6 | 1059 | .BR read (2) |
1cdbc3a6 MK |
1060 | on it would return). |
1061 | .TP | |
340a16a6 | 1062 | .I settime flags |
1cdbc3a6 | 1063 | This field lists the flags with which the timerfd was last armed (see |
340a16a6 LW |
1064 | .BR timerfd_settime (2)), |
1065 | in octal | |
1066 | (in this example, both | |
1067 | .B TFD_TIMER_ABSTIME | |
1068 | and | |
1069 | .B TFD_TIMER_CANCEL_ON_SET | |
1070 | are set). | |
1cdbc3a6 | 1071 | .TP |
340a16a6 | 1072 | .I it_value |
1cdbc3a6 MK |
1073 | This field contains the amount of time until the timer will next expire, |
1074 | expressed in seconds and nanoseconds. | |
734ec506 MK |
1075 | This is always expressed as a relative value, |
1076 | regardless of whether the timer was created using the | |
1077 | .B TFD_TIMER_ABSTIME | |
1078 | flag. | |
1cdbc3a6 | 1079 | .TP |
340a16a6 | 1080 | .I it_interval |
1cdbc3a6 MK |
1081 | This field contains the interval of the timer, |
1082 | in seconds and nanoseconds. | |
1083 | (The | |
1084 | .I it_value | |
1085 | and | |
1086 | .I it_interval | |
1087 | fields contain the values that | |
340a16a6 | 1088 | .BR timerfd_gettime (2) |
1cdbc3a6 MK |
1089 | on this file descriptor would return.) |
1090 | .RE | |
0ca2fc4d | 1091 | .TP |
93401860 MK |
1092 | .IR /proc/[pid]/gid_map " (since Linux 3.5)" |
1093 | See | |
1094 | .BR user_namespaces (7). | |
1095 | .TP | |
0ca2fc4d | 1096 | .IR /proc/[pid]/io " (since kernel 2.6.20)" |
68f11066 MK |
1097 | .\" commit 7c3ab7381e79dfc7db14a67c6f4f3285664e1ec2 |
1098 | This file contains I/O statistics for the process, for example: | |
37d5e699 | 1099 | .IP |
0ca2fc4d | 1100 | .in +4n |
37d5e699 | 1101 | .EX |
0ca2fc4d PS |
1102 | .RB "#" " cat /proc/3828/io" |
1103 | rchar: 323934931 | |
1104 | wchar: 323929600 | |
1105 | syscr: 632687 | |
1106 | syscw: 632675 | |
1107 | read_bytes: 0 | |
1108 | write_bytes: 323932160 | |
1109 | cancelled_write_bytes: 0 | |
37d5e699 | 1110 | .EE |
0ca2fc4d | 1111 | .in |
2dad4c59 | 1112 | .IP |
0ca2fc4d PS |
1113 | The fields are as follows: |
1114 | .RS | |
68f11066 MK |
1115 | .TP |
1116 | .IR rchar ": characters read" | |
0ca2fc4d PS |
1117 | The number of bytes which this task has caused to be read from storage. |
1118 | This is simply the sum of bytes which this process passed to | |
1119 | .BR read (2) | |
68f11066 | 1120 | and similar system calls. |
11256884 | 1121 | It includes things such as terminal I/O and |
68f11066 MK |
1122 | is unaffected by whether or not actual |
1123 | physical disk I/O was required (the read might have been satisfied from | |
0ca2fc4d | 1124 | pagecache). |
68f11066 MK |
1125 | .TP |
1126 | .IR wchar ": characters written" | |
0ca2fc4d PS |
1127 | The number of bytes which this task has caused, or shall cause to be written |
1128 | to disk. | |
1129 | Similar caveats apply here as with | |
1130 | .IR rchar . | |
68f11066 MK |
1131 | .TP |
1132 | .IR syscr ": read syscalls" | |
1133 | Attempt to count the number of read I/O operations\(emthat is, | |
1134 | system calls such as | |
0ca2fc4d PS |
1135 | .BR read (2) |
1136 | and | |
1137 | .BR pread (2). | |
68f11066 MK |
1138 | .TP |
1139 | .IR syscw ": write syscalls" | |
1140 | Attempt to count the number of write I/O operations\(emthat is, | |
1141 | system calls such as | |
0ca2fc4d PS |
1142 | .BR write (2) |
1143 | and | |
1144 | .BR pwrite (2). | |
68f11066 MK |
1145 | .TP |
1146 | .IR read_bytes ": bytes read" | |
0ca2fc4d PS |
1147 | Attempt to count the number of bytes which this process really did cause to |
1148 | be fetched from the storage layer. | |
1149 | This is accurate for block-backed filesystems. | |
68f11066 MK |
1150 | .TP |
1151 | .IR write_bytes ": bytes written" | |
0ca2fc4d PS |
1152 | Attempt to count the number of bytes which this process caused to be sent to |
1153 | the storage layer. | |
68f11066 | 1154 | .TP |
0ca2fc4d | 1155 | .IR cancelled_write_bytes : |
0ca2fc4d PS |
1156 | The big inaccuracy here is truncate. |
1157 | If a process writes 1MB to a file and then deletes the file, | |
1158 | it will in fact perform no writeout. | |
1159 | But it will have been accounted as having caused 1MB of write. | |
68f11066 | 1160 | In other words: this field represents the number of bytes which this process |
0ca2fc4d | 1161 | caused to not happen, by truncating pagecache. |
68f11066 | 1162 | A task can cause "negative" I/O too. |
0ca2fc4d | 1163 | If this task truncates some dirty pagecache, |
68f11066 MK |
1164 | some I/O which another task has been accounted for |
1165 | (in its | |
1166 | .IR write_bytes ) | |
1167 | will not be happening. | |
1168 | .RE | |
0ca2fc4d PS |
1169 | .IP |
1170 | .IR Note : | |
68f11066 | 1171 | In the current implementation, things are a bit racy on 32-bit systems: |
0ca2fc4d PS |
1172 | if process A reads process B's |
1173 | .I /proc/[pid]/io | |
68f11066 | 1174 | while process B is updating one of these 64-bit counters, |
0ca2fc4d | 1175 | process A could see an intermediate result. |
2dad4c59 | 1176 | .IP |
d8e2972a MK |
1177 | Permission to access this file is governed by a ptrace access mode |
1178 | .B PTRACE_MODE_READ_FSCREDS | |
1179 | check; see | |
1180 | .BR ptrace (2). | |
f6e17121 | 1181 | .TP |
7e07d950 | 1182 | .IR /proc/[pid]/limits " (since Linux 2.6.24)" |
69ab425e MK |
1183 | This file displays the soft limit, hard limit, and units of measurement |
1184 | for each of the process's resource limits (see | |
1185 | .BR getrlimit (2)). | |
1186 | Up to and including Linux 2.6.35, | |
1187 | this file is protected to allow reading only by the real UID of the process. | |
1188 | Since Linux 2.6.36, | |
1189 | .\" commit 3036e7b490bf7878c6dae952eec5fb87b1106589 | |
1190 | this file is readable by all users on the system. | |
df2a8576 MK |
1191 | .\" FIXME Describe /proc/[pid]/loginuid |
1192 | .\" Added in 2.6.11; updating requires CAP_AUDIT_CONTROL | |
1193 | .\" CONFIG_AUDITSYSCALL | |
b4f89985 PE |
1194 | .TP |
1195 | .IR /proc/[pid]/map_files/ " (since kernel 3.3) | |
18cdd0ac MK |
1196 | .\" commit 640708a2cff7f81e246243b0073c66e6ece7e53e |
1197 | This subdirectory contains entries corresponding to memory-mapped | |
b4f89985 PE |
1198 | files (see |
1199 | .BR mmap (2)). | |
18cdd0ac MK |
1200 | Entries are named by memory region start and end |
1201 | address pair (expressed as hexadecimal numbers), | |
1202 | and are symbolic links to the mapped files themselves. | |
1203 | Here is an example, with the output wrapped and reformatted to fit on an 80-column display: | |
37d5e699 | 1204 | .IP |
b4f89985 | 1205 | .in +4n |
37d5e699 | 1206 | .EX |
f2aa4dcc | 1207 | .RB "#" " ls -l /proc/self/map_files/" |
18cdd0ac | 1208 | lr\-\-\-\-\-\-\-\-. 1 root root 64 Apr 16 21:31 |
9bc87ed0 | 1209 | 3252e00000\-3252e20000 \-> /usr/lib64/ld\-2.15.so |
b4f89985 | 1210 | \&... |
37d5e699 | 1211 | .EE |
b4f89985 | 1212 | .in |
2dad4c59 | 1213 | .IP |
b4f89985 | 1214 | Although these entries are present for memory regions that were |
d6a56978 | 1215 | mapped with the |
b4f89985 | 1216 | .BR MAP_FILE |
18cdd0ac | 1217 | flag, the way anonymous shared memory (regions created with the |
b4f89985 PE |
1218 | .B MAP_ANON | MAP_SHARED |
1219 | flags) | |
1220 | is implemented in Linux | |
18cdd0ac MK |
1221 | means that such regions also appear on this directory. |
1222 | Here is an example where the target file is the deleted | |
1223 | .I /dev/zero | |
1224 | one: | |
37d5e699 | 1225 | .IP |
b4f89985 | 1226 | .in +4n |
37d5e699 | 1227 | .EX |
18cdd0ac MK |
1228 | lrw\-\-\-\-\-\-\-. 1 root root 64 Apr 16 21:33 |
1229 | 7fc075d2f000\-7fc075e6f000 \-> /dev/zero (deleted) | |
37d5e699 | 1230 | .EE |
b4f89985 | 1231 | .in |
2dad4c59 | 1232 | .IP |
b4f89985 PE |
1233 | This directory appears only if the |
1234 | .B CONFIG_CHECKPOINT_RESTORE | |
1235 | kernel configuration option is enabled. | |
f2aa4dcc MK |
1236 | Privilege |
1237 | .RB ( CAP_SYS_ADMIN ) | |
1238 | .\" FIXME | |
1239 | .\" This may change. See the mail thread | |
43d42cc0 | 1240 | .\" "[RFC][PATCH v2] procfs: Always expose /proc/<pid>/map_files/ and make it readable" |
f2aa4dcc MK |
1241 | .\" from Jan 2015 |
1242 | is required to view the contents of this directory. | |
fea681da | 1243 | .TP |
69119dc7 | 1244 | .I /proc/[pid]/maps |
fea681da MK |
1245 | A file containing the currently mapped memory regions and their access |
1246 | permissions. | |
bbf9f397 MK |
1247 | See |
1248 | .BR mmap (2) | |
1249 | for some further information about memory mappings. | |
2dad4c59 | 1250 | .IP |
aee2f0bf MK |
1251 | Permission to access this file is governed by a ptrace access mode |
1252 | .B PTRACE_MODE_READ_FSCREDS | |
1253 | check; see | |
1254 | .BR ptrace (2). | |
2dad4c59 | 1255 | .IP |
dd0c3b96 | 1256 | The format of the file is: |
c1a022dc MK |
1257 | .IP |
1258 | .in 4n | |
1259 | .EX | |
21781757 | 1260 | .I "address perms offset dev inode pathname" |
9bc87ed0 MK |
1261 | 00400000\-00452000 r-xp 00000000 08:02 173521 /usr/bin/dbus-daemon |
1262 | 00651000\-00652000 r--p 00051000 08:02 173521 /usr/bin/dbus-daemon | |
1263 | 00652000\-00655000 rw-p 00052000 08:02 173521 /usr/bin/dbus-daemon | |
1264 | 00e03000\-00e24000 rw-p 00000000 00:00 0 [heap] | |
1265 | 00e24000\-011f7000 rw-p 00000000 00:00 0 [heap] | |
182090db | 1266 | \&... |
9bc87ed0 MK |
1267 | 35b1800000\-35b1820000 r-xp 00000000 08:02 135522 /usr/lib64/ld\-2.15.so |
1268 | 35b1a1f000\-35b1a20000 r--p 0001f000 08:02 135522 /usr/lib64/ld\-2.15.so | |
1269 | 35b1a20000\-35b1a21000 rw-p 00020000 08:02 135522 /usr/lib64/ld\-2.15.so | |
1270 | 35b1a21000\-35b1a22000 rw-p 00000000 00:00 0 | |
1271 | 35b1c00000\-35b1dac000 r-xp 00000000 08:02 135870 /usr/lib64/libc\-2.15.so | |
1272 | 35b1dac000\-35b1fac000 ---p 001ac000 08:02 135870 /usr/lib64/libc\-2.15.so | |
1273 | 35b1fac000\-35b1fb0000 r--p 001ac000 08:02 135870 /usr/lib64/libc\-2.15.so | |
1274 | 35b1fb0000\-35b1fb2000 rw-p 001b0000 08:02 135870 /usr/lib64/libc\-2.15.so | |
182090db | 1275 | \&... |
9bc87ed0 | 1276 | f2c6ff8c000\-7f2c7078c000 rw-p 00000000 00:00 0 [stack:986] |
182090db | 1277 | \&... |
9bc87ed0 MK |
1278 | 7fffb2c0d000\-7fffb2c2e000 rw-p 00000000 00:00 0 [stack] |
1279 | 7fffb2d48000\-7fffb2d49000 r-xp 00000000 00:00 0 [vdso] | |
c1a022dc | 1280 | .EE |
21781757 | 1281 | .in |
c1a022dc | 1282 | .IP |
7d2e6d74 | 1283 | The |
3eb8c588 MK |
1284 | .I address |
1285 | field is the address space in the process that the mapping occupies. | |
1286 | The | |
1287 | .I perms | |
1288 | field is a set of permissions: | |
2dad4c59 | 1289 | .IP |
37d5e699 MK |
1290 | .in +4 |
1291 | .EX | |
fea681da MK |
1292 | r = read |
1293 | w = write | |
1294 | x = execute | |
1295 | s = shared | |
1296 | p = private (copy on write) | |
37d5e699 | 1297 | .EE |
fea681da | 1298 | .in |
2dad4c59 | 1299 | .IP |
3eb8c588 MK |
1300 | The |
1301 | .I offset | |
b844cf04 | 1302 | field is the offset into the file/whatever; |
3eb8c588 MK |
1303 | .I dev |
1304 | is the device | |
dd0c3b96 | 1305 | (major:minor); |
3eb8c588 MK |
1306 | .I inode |
1307 | is the inode on that device. | |
59a40ed7 | 1308 | 0 indicates that no inode is associated with the memory region, |
16e64bae | 1309 | as would be the case with BSS (uninitialized data). |
2dad4c59 | 1310 | .IP |
3eb8c588 MK |
1311 | The |
1312 | .I pathname | |
1313 | field will usually be the file that is backing the mapping. | |
491ea6f1 | 1314 | For ELF files, |
3eb8c588 MK |
1315 | you can easily coordinate with the |
1316 | .I offset | |
1317 | field by looking at the | |
491ea6f1 MK |
1318 | Offset field in the ELF program headers |
1319 | .RI ( "readelf\ \-l" ). | |
2dad4c59 | 1320 | .IP |
491ea6f1 | 1321 | There are additional helpful pseudo-paths: |
61b0b1f4 MK |
1322 | .RS 12 |
1323 | .TP | |
1324 | .IR [stack] | |
16e64bae | 1325 | The initial process's (also known as the main thread's) stack. |
61b0b1f4 | 1326 | .TP |
bca7fbb5 MK |
1327 | .IR [stack:<tid>] " (from Linux 3.4 to 4.4)" |
1328 | .\" commit b76437579d1344b612cf1851ae610c636cec7db0 (added) | |
1329 | .\" commit 65376df582174ffcec9e6471bf5b0dd79ba05e4a (removed) | |
61b0b1f4 | 1330 | A thread's stack (where the |
3eb8c588 | 1331 | .IR <tid> |
61b0b1f4 | 1332 | is a thread ID). |
491ea6f1 | 1333 | It corresponds to the |
3eb8c588 | 1334 | .IR /proc/[pid]/task/[tid]/ |
37d32c38 | 1335 | path. |
bca7fbb5 MK |
1336 | This field was removed in Linux 4.5, since providing this information |
1337 | for a process with large numbers of threads is expensive. | |
61b0b1f4 | 1338 | .TP |
7d2e6d74 | 1339 | .IR [vdso] |
61b0b1f4 | 1340 | The virtual dynamically linked shared object. |
c56a0185 MK |
1341 | See |
1342 | .BR vdso (7). | |
61b0b1f4 | 1343 | .TP |
7d2e6d74 | 1344 | .IR [heap] |
61b0b1f4 MK |
1345 | The process's heap. |
1346 | .in | |
61b0b1f4 MK |
1347 | .RE |
1348 | .IP | |
3eb8c588 MK |
1349 | If the |
1350 | .I pathname | |
1351 | field is blank, | |
40382e5e MK |
1352 | this is an anonymous mapping as obtained via |
1353 | .BR mmap (2). | |
61b0b1f4 MK |
1354 | There is no easy way to coordinate this back to a process's source, |
1355 | short of running it through | |
491ea6f1 MK |
1356 | .BR gdb (1), |
1357 | .BR strace (1), | |
1358 | or similar. | |
2dad4c59 | 1359 | .IP |
b6547479 EK |
1360 | .I pathname |
1361 | is shown unescaped except for newline characters, which are replaced | |
d512e7b4 MK |
1362 | with an octal escape sequence. |
1363 | As a result, it is not possible to determine whether the original | |
1364 | pathname contained a newline character or the literal | |
b6547479 EK |
1365 | .I \\\012 |
1366 | character sequence. | |
1367 | .IP | |
1368 | If the mapping is file-backed and the file has been deleted, the string | |
d512e7b4 MK |
1369 | " (deleted)" is appended to the pathname. |
1370 | Note that this is ambiguous too. | |
b6547479 | 1371 | .IP |
eb9a0b2f | 1372 | Under Linux 2.0, there is no field giving pathname. |
fea681da | 1373 | .TP |
69119dc7 | 1374 | .I /proc/[pid]/mem |
fea681da MK |
1375 | This file can be used to access the pages of a process's memory through |
1376 | .BR open (2), | |
1377 | .BR read (2), | |
1378 | and | |
ccb2bb0d | 1379 | .BR lseek (2). |
2dad4c59 | 1380 | .IP |
aee2f0bf MK |
1381 | Permission to access this file is governed by a ptrace access mode |
1382 | .B PTRACE_MODE_ATTACH_FSCREDS | |
1383 | check; see | |
1384 | .BR ptrace (2). | |
b4e9ee8f | 1385 | .TP |
69119dc7 | 1386 | .IR /proc/[pid]/mountinfo " (since Linux 2.6.26)" |
b4e9ee8f | 1387 | .\" This info adapted from Documentation/filesystems/proc.txt |
fb4bdaa1 | 1388 | .\" commit 2d4d4864ac08caff5c204a752bd004eed4f08760 |
ef5b47f6 MK |
1389 | This file contains information about mount points |
1390 | in the process's mount namespace (see | |
1391 | .BR mount_namespaces (7)). | |
fb4bdaa1 MK |
1392 | It supplies various information |
1393 | (e.g., propagation state, root of mount for bind mounts, | |
1394 | identifier for each mount and its parent) that is missing from the (older) | |
1395 | .IR /proc/[pid]/mounts | |
1396 | file, and fixes various other problems with that file | |
1397 | (e.g., nonextensibility, | |
1398 | failure to distinguish per-mount versus per-superblock options). | |
2dad4c59 | 1399 | .IP |
fb4bdaa1 | 1400 | The file contains lines of the form: |
c1a022dc MK |
1401 | .IP |
1402 | .in 0n | |
1403 | .EX | |
0f619d1f | 1404 | 36 35 98:0 /mnt1 /mnt2 rw,noatime master:1 \- ext3 /dev/root rw,errors=continue |
b4e9ee8f | 1405 | (1)(2)(3) (4) (5) (6) (7) (8) (9) (10) (11) |
c1a022dc MK |
1406 | .in |
1407 | .EE | |
b4e9ee8f MK |
1408 | .IP |
1409 | The numbers in parentheses are labels for the descriptions below: | |
3bc960c2 | 1410 | .RS 7 |
b4e9ee8f MK |
1411 | .TP 5 |
1412 | (1) | |
0f619d1f | 1413 | mount ID: a unique ID for the mount (may be reused after |
b4e9ee8f MK |
1414 | .BR umount (2)). |
1415 | .TP | |
1416 | (2) | |
29270550 MK |
1417 | parent ID: the ID of the parent mount |
1418 | (or of self for the root of this mount namespace's mount tree). | |
1419 | .IP | |
8c420ed8 MK |
1420 | If a new mount is stacked on top of a previous existing mount |
1421 | (so that it hides the existing mount) at pathname P, | |
1422 | then the parent of the new mount is the previous mount at that location. | |
1423 | Thus, when looking at all the mounts stacked at a particular location, | |
1424 | the top-most mount is the one that is not the parent | |
1425 | of any other mount at the same location. | |
1426 | (Note, however, that this top-most mount will be accessible only if | |
1427 | the longest path subprefix of P that is a mount point | |
1428 | is not itself hidden by a stacked mount.) | |
1429 | .IP | |
29270550 MK |
1430 | If the parent mount point lies outside the process's root directory (see |
1431 | .BR chroot (2)), | |
1432 | the ID shown here won't have a corresponding record in | |
35cf1b93 | 1433 | .I mountinfo |
29270550 MK |
1434 | whose mount ID (field 1) matches this parent mount ID |
1435 | (because mount points that lie outside the process's root directory | |
1436 | are not shown in | |
1437 | .IR mountinfo ). | |
1438 | As a special case of this point, | |
1439 | the process's root mount point may have a parent mount | |
1440 | (for the initramfs filesystem) that lies | |
1441 | .\" Miklos Szeredi, Nov 2017: The hidden one is the initramfs, I believe | |
1442 | .\" mtk: In the initial mount namespace, this hidden ID has the value 0 | |
1443 | outside the process's root directory, | |
1444 | and an entry for that mount point will not appear in | |
1445 | .IR mountinfo . | |
b4e9ee8f MK |
1446 | .TP |
1447 | (3) | |
0f619d1f | 1448 | major:minor: the value of |
b4e9ee8f | 1449 | .I st_dev |
0f619d1f | 1450 | for files on this filesystem (see |
b4e9ee8f MK |
1451 | .BR stat (2)). |
1452 | .TP | |
1453 | (4) | |
0f619d1f | 1454 | root: the pathname of the directory in the filesystem |
8d857fcb | 1455 | which forms the root of this mount. |
b4e9ee8f MK |
1456 | .TP |
1457 | (5) | |
ebdc66e2 | 1458 | mount point: the pathname of the mount point relative |
0f619d1f | 1459 | to the process's root directory. |
b4e9ee8f MK |
1460 | .TP |
1461 | (6) | |
adab7ac8 MK |
1462 | mount options: per-mount options (see |
1463 | .BR mount (2)). | |
b4e9ee8f MK |
1464 | .TP |
1465 | (7) | |
0f619d1f | 1466 | optional fields: zero or more fields of the form "tag[:value]"; see below. |
b4e9ee8f MK |
1467 | .TP |
1468 | (8) | |
0f619d1f | 1469 | separator: the end of the optional fields is marked by a single hyphen. |
b4e9ee8f MK |
1470 | .TP |
1471 | (9) | |
0f619d1f | 1472 | filesystem type: the filesystem type in the form "type[.subtype]". |
b4e9ee8f MK |
1473 | .TP |
1474 | (10) | |
9ee4a2b6 | 1475 | mount source: filesystem-specific information or "none". |
b4e9ee8f MK |
1476 | .TP |
1477 | (11) | |
adab7ac8 MK |
1478 | super options: per-superblock options (see |
1479 | .BR mount (2)). | |
b4e9ee8f MK |
1480 | .RE |
1481 | .IP | |
966b5839 MK |
1482 | Currently, the possible optional fields are |
1483 | .IR shared , | |
1484 | .IR master , | |
1485 | .IR propagate_from , | |
1486 | and | |
1487 | .IR unbindable . | |
1488 | See | |
1489 | .BR mount_namespaces (7) | |
1490 | for a description of these fields. | |
0f619d1f MK |
1491 | Parsers should ignore all unrecognized optional fields. |
1492 | .IP | |
b4e9ee8f MK |
1493 | For more information on mount propagation see: |
1494 | .I Documentation/filesystems/sharedsubtree.txt | |
66a9882e | 1495 | in the Linux kernel source tree. |
b4e9ee8f | 1496 | .TP |
cea61382 | 1497 | .IR /proc/[pid]/mounts " (since Linux 2.4.19)" |
226cb3a8 | 1498 | This file lists all the filesystems currently mounted in the |
ef5b47f6 MK |
1499 | process's mount namespace (see |
1500 | .BR mount_namespaces (7)). | |
cea61382 MK |
1501 | The format of this file is documented in |
1502 | .BR fstab (5). | |
2dad4c59 | 1503 | .IP |
cea61382 MK |
1504 | Since kernel version 2.6.15, this file is pollable: |
1505 | after opening the file for reading, a change in this file | |
9ee4a2b6 | 1506 | (i.e., a filesystem mount or unmount) causes |
cea61382 | 1507 | .BR select (2) |
226cb3a8 | 1508 | to mark the file descriptor as having an exceptional condition, and |
cea61382 MK |
1509 | .BR poll (2) |
1510 | and | |
1511 | .BR epoll_wait (2) | |
226cb3a8 MK |
1512 | mark the file as having a priority event |
1513 | .RB ( POLLPRI ). | |
1514 | (Before Linux 2.6.30, | |
1515 | a change in this file was indicated by the file descriptor | |
1516 | being marked as readable for | |
1517 | .BR select (2), | |
1518 | and being marked as having an error condition for | |
1519 | .BR poll (2) | |
1520 | and | |
1521 | .BR epoll_wait (2).) | |
cea61382 | 1522 | .TP |
69119dc7 | 1523 | .IR /proc/[pid]/mountstats " (since Linux 2.6.17)" |
783a6233 | 1524 | This file exports information (statistics, configuration information) |
ef5b47f6 MK |
1525 | about the mount points in the process's mount namespace (see |
1526 | .BR mount_namespaces (7)). | |
b4e9ee8f | 1527 | Lines in this file have the form: |
37d5e699 MK |
1528 | .IP |
1529 | .in +4n | |
1530 | .EX | |
b4e9ee8f MK |
1531 | device /dev/sda7 mounted on /home with fstype ext3 [statistics] |
1532 | ( 1 ) ( 2 ) (3 ) (4) | |
37d5e699 MK |
1533 | .EE |
1534 | .in | |
b4e9ee8f MK |
1535 | .IP |
1536 | The fields in each line are: | |
3bc960c2 | 1537 | .RS 7 |
b4e9ee8f MK |
1538 | .TP 5 |
1539 | (1) | |
1540 | The name of the mounted device | |
1541 | (or "nodevice" if there is no corresponding device). | |
1542 | .TP | |
1543 | (2) | |
9ee4a2b6 | 1544 | The mount point within the filesystem tree. |
b4e9ee8f MK |
1545 | .TP |
1546 | (3) | |
9ee4a2b6 | 1547 | The filesystem type. |
b4e9ee8f MK |
1548 | .TP |
1549 | (4) | |
1550 | Optional statistics and configuration information. | |
9ee4a2b6 | 1551 | Currently (as at Linux 2.6.26), only NFS filesystems export |
b4e9ee8f MK |
1552 | information via this field. |
1553 | .RE | |
1554 | .IP | |
90878f7c | 1555 | This file is readable only by the owner of the process. |
b4e9ee8f | 1556 | .TP |
2d3fb75b | 1557 | .IR /proc/[pid]/net " (since Linux 2.6.25)" |
9fb88bc8 MK |
1558 | See the description of |
1559 | .IR /proc/net . | |
1560 | .TP | |
b4a185e5 | 1561 | .IR /proc/[pid]/ns/ " (since Linux 3.0)" |
2c4201f0 | 1562 | .\" See commit 6b4e306aa3dc94a0545eb9279475b1ab6209a31f |
b4a185e5 EB |
1563 | This is a subdirectory containing one entry for each namespace that |
1564 | supports being manipulated by | |
80e63655 | 1565 | .BR setns (2). |
cf8bfe6d MK |
1566 | For more information, see |
1567 | .BR namespaces (7). | |
b4a185e5 | 1568 | .TP |
69119dc7 | 1569 | .IR /proc/[pid]/numa_maps " (since Linux 2.6.14)" |
610f75cc MK |
1570 | See |
1571 | .BR numa (7). | |
7388733a | 1572 | .TP |
69119dc7 | 1573 | .IR /proc/[pid]/oom_adj " (since Linux 2.6.11)" |
b4e9ee8f | 1574 | This file can be used to adjust the score used to select which process |
0425de01 | 1575 | should be killed in an out-of-memory (OOM) situation. |
b4e9ee8f MK |
1576 | The kernel uses this value for a bit-shift operation of the process's |
1577 | .IR oom_score | |
1578 | value: | |
5b8dbfd4 MK |
1579 | valid values are in the range \-16 to +15, |
1580 | plus the special value \-17, | |
b4e9ee8f MK |
1581 | which disables OOM-killing altogether for this process. |
1582 | A positive score increases the likelihood of this | |
1583 | process being killed by the OOM-killer; | |
1584 | a negative score decreases the likelihood. | |
de8e9cc1 | 1585 | .IP |
b4e9ee8f MK |
1586 | The default value for this file is 0; |
1587 | a new process inherits its parent's | |
1588 | .I oom_adj | |
1589 | setting. | |
1590 | A process must be privileged | |
1591 | .RB ( CAP_SYS_RESOURCE ) | |
1592 | to update this file. | |
f2c8b197 MK |
1593 | .IP |
1594 | Since Linux 2.6.36, use of this file is deprecated in favor of | |
1595 | .IR /proc/[pid]/oom_score_adj . | |
b4e9ee8f | 1596 | .TP |
69119dc7 | 1597 | .IR /proc/[pid]/oom_score " (since Linux 2.6.11)" |
5753354a MF |
1598 | .\" See mm/oom_kill.c::badness() in pre 2.6.36 sources |
1599 | .\" See mm/oom_kill.c::oom_badness() after 2.6.36 | |
1600 | .\" commit a63d83f427fbce97a6cea0db2e64b0eb8435cd10 | |
b4e9ee8f MK |
1601 | This file displays the current score that the kernel gives to |
1602 | this process for the purpose of selecting a process | |
1603 | for the OOM-killer. | |
1604 | A higher score means that the process is more likely to be | |
1605 | selected by the OOM-killer. | |
1606 | The basis for this score is the amount of memory used by the process, | |
1607 | with increases (+) or decreases (\-) for factors including: | |
5753354a MF |
1608 | .\" See mm/oom_kill.c::badness() in pre 2.6.36 sources |
1609 | .\" See mm/oom_kill.c::oom_badness() after 2.6.36 | |
1610 | .\" commit a63d83f427fbce97a6cea0db2e64b0eb8435cd10 | |
1611 | .RS | |
1612 | .IP * 2 | |
9b0e3937 | 1613 | whether the process is privileged (\-). |
5753354a MF |
1614 | .\" More precisely, if it has CAP_SYS_ADMIN or (pre 2.6.36) CAP_SYS_RESOURCE |
1615 | .RE | |
1616 | .IP | |
1617 | Before kernel 2.6.36 the following factors were also used in the calculation of oom_score: | |
b4e9ee8f MK |
1618 | .RS |
1619 | .IP * 2 | |
1620 | whether the process creates a lot of children using | |
1621 | .BR fork (2) | |
1622 | (+); | |
1623 | .IP * | |
1624 | whether the process has been running a long time, | |
1625 | or has used a lot of CPU time (\-); | |
1626 | .IP * | |
5753354a | 1627 | whether the process has a low nice value (i.e., > 0) (+); and |
b4e9ee8f MK |
1628 | .IP * |
1629 | whether the process is making direct hardware access (\-). | |
1630 | .\" More precisely, if it has CAP_SYS_RAWIO | |
1631 | .RE | |
1632 | .IP | |
1633 | The | |
1634 | .I oom_score | |
f2c8b197 MK |
1635 | also reflects the adjustment specified by the |
1636 | .I oom_score_adj | |
1637 | or | |
b4e9ee8f MK |
1638 | .I oom_adj |
1639 | setting for the process. | |
f2c8b197 MK |
1640 | .TP |
1641 | .IR /proc/[pid]/oom_score_adj " (since Linux 2.6.36)" | |
1642 | .\" Text taken from 3.7 Documentation/filesystems/proc.txt | |
1643 | This file can be used to adjust the badness heuristic used to select which | |
1644 | process gets killed in out-of-memory conditions. | |
2dad4c59 | 1645 | .IP |
f2c8b197 MK |
1646 | The badness heuristic assigns a value to each candidate task ranging from 0 |
1647 | (never kill) to 1000 (always kill) to determine which process is targeted. | |
1648 | The units are roughly a proportion along that range of | |
1649 | allowed memory the process may allocate from, | |
1650 | based on an estimation of its current memory and swap use. | |
1651 | For example, if a task is using all allowed memory, | |
1652 | its badness score will be 1000. | |
1653 | If it is using half of its allowed memory, its score will be 500. | |
2dad4c59 | 1654 | .IP |
f2c8b197 MK |
1655 | There is an additional factor included in the badness score: root |
1656 | processes are given 3% extra memory over other tasks. | |
2dad4c59 | 1657 | .IP |
f2c8b197 | 1658 | The amount of "allowed" memory depends on the context |
0633f951 | 1659 | in which the OOM-killer was called. |
f2c8b197 MK |
1660 | If it is due to the memory assigned to the allocating task's cpuset |
1661 | being exhausted, | |
1662 | the allowed memory represents the set of mems assigned to that | |
1663 | cpuset (see | |
1664 | .BR cpuset (7)). | |
1665 | If it is due to a mempolicy's node(s) being exhausted, | |
1666 | the allowed memory represents the set of mempolicy nodes. | |
1667 | If it is due to a memory limit (or swap limit) being reached, | |
1668 | the allowed memory is that configured limit. | |
1669 | Finally, if it is due to the entire system being out of memory, the | |
1670 | allowed memory represents all allocatable resources. | |
2dad4c59 | 1671 | .IP |
f2c8b197 | 1672 | The value of |
0633f951 | 1673 | .I oom_score_adj |
f2c8b197 MK |
1674 | is added to the badness score before it |
1675 | is used to determine which task to kill. | |
1676 | Acceptable values range from \-1000 | |
1677 | (OOM_SCORE_ADJ_MIN) to +1000 (OOM_SCORE_ADJ_MAX). | |
0633f951 | 1678 | This allows user space to control the preference for OOM-killing, |
f2c8b197 | 1679 | ranging from always preferring a certain |
f082ada4 | 1680 | task or completely disabling it from OOM killing. |
f2c8b197 | 1681 | The lowest possible value, \-1000, is |
0633f951 | 1682 | equivalent to disabling OOM-killing entirely for that task, |
f2c8b197 | 1683 | since it will always report a badness score of 0. |
2dad4c59 | 1684 | .IP |
f2c8b197 MK |
1685 | Consequently, it is very simple for user space to define |
1686 | the amount of memory to consider for each task. | |
48ac01a7 | 1687 | Setting an |
f2c8b197 MK |
1688 | .I oom_score_adj |
1689 | value of +500, for example, | |
1690 | is roughly equivalent to allowing the remainder of tasks sharing the | |
1691 | same system, cpuset, mempolicy, or memory controller resources | |
1692 | to use at least 50% more memory. | |
1693 | A value of \-500, on the other hand, would be roughly | |
1694 | equivalent to discounting 50% of the task's | |
1695 | allowed memory from being considered as scoring against the task. | |
2dad4c59 | 1696 | .IP |
0633f951 | 1697 | For backward compatibility with previous kernels, |
f2c8b197 MK |
1698 | .I /proc/[pid]/oom_adj |
1699 | can still be used to tune the badness score. | |
1700 | Its value is | |
9f1b9726 | 1701 | scaled linearly with |
f2c8b197 | 1702 | .IR oom_score_adj . |
2dad4c59 | 1703 | .IP |
f2c8b197 MK |
1704 | Writing to |
1705 | .IR /proc/[pid]/oom_score_adj | |
1706 | or | |
1707 | .IR /proc/[pid]/oom_adj | |
1708 | will change the other with its scaled value. | |
6f752251 MK |
1709 | .IP |
1710 | The | |
1711 | .BR choom (1) | |
1712 | program provides a command-line interface for adjusting the | |
1713 | .I oom_score_adj | |
1714 | value of a running process or a newly executed command. | |
b0aa1e51 MK |
1715 | .TP |
1716 | .IR /proc/[pid]/pagemap " (since Linux 2.6.25)" | |
1717 | This file shows the mapping of each of the process's virtual pages | |
1718 | into physical page frames or swap area. | |
1719 | It contains one 64-bit value for each virtual page, | |
1720 | with the bits set as follows: | |
1721 | .RS 12 | |
1722 | .TP | |
1723 | 63 | |
1724 | If set, the page is present in RAM. | |
1725 | .TP | |
1726 | 62 | |
1727 | If set, the page is in swap space | |
1728 | .TP | |
1729 | 61 (since Linux 3.5) | |
1730 | The page is a file-mapped page or a shared anonymous page. | |
1731 | .TP | |
2e84528d | 1732 | 60\(en57 (since Linux 3.11) |
b0aa1e51 MK |
1733 | Zero |
1734 | .\" Not quite true; see commit 541c237c0923f567c9c4cabb8a81635baadc713f | |
1735 | .TP | |
2e84528d | 1736 | 56 (since Linux 4.2) |
abfbcb56 MK |
1737 | .\" commit 77bb499bb60f4b79cca7d139c8041662860fcf87 |
1738 | .\" commit 83b4b0bb635eee2b8e075062e4e008d1bc110ed7 | |
2e84528d OE |
1739 | The page is exclusively mapped. |
1740 | .TP | |
b5301584 | 1741 | 55 (since Linux 3.11) |
b0aa1e51 MK |
1742 | PTE is soft-dirty |
1743 | (see the kernel source file | |
f9326a24 | 1744 | .IR Documentation/admin-guide/mm/soft-dirty.rst ). |
b0aa1e51 | 1745 | .TP |
9bc87ed0 | 1746 | 54\(en0 |
b0aa1e51 MK |
1747 | If the page is present in RAM (bit 63), then these bits |
1748 | provide the page frame number, which can be used to index | |
1749 | .IR /proc/kpageflags | |
1750 | and | |
1751 | .IR /proc/kpagecount . | |
1752 | If the page is present in swap (bit 62), | |
9bc87ed0 | 1753 | then bits 4\(en0 give the swap type, and bits 54\(en5 encode the swap offset. |
b0aa1e51 MK |
1754 | .RE |
1755 | .IP | |
9bc87ed0 | 1756 | Before Linux 3.11, bits 60\(en55 were |
b0aa1e51 MK |
1757 | used to encode the base-2 log of the page size. |
1758 | .IP | |
1759 | To employ | |
1760 | .IR /proc/[pid]/pagemap | |
1761 | efficiently, use | |
1762 | .IR /proc/[pid]/maps | |
1763 | to determine which areas of memory are actually mapped and seek | |
1764 | to skip over unmapped regions. | |
1765 | .IP | |
1766 | The | |
1767 | .IR /proc/[pid]/pagemap | |
1768 | file is present only if the | |
1769 | .B CONFIG_PROC_PAGE_MONITOR | |
1770 | kernel configuration option is enabled. | |
2dad4c59 | 1771 | .IP |
aee2f0bf MK |
1772 | Permission to access this file is governed by a ptrace access mode |
1773 | .B PTRACE_MODE_READ_FSCREDS | |
1774 | check; see | |
1775 | .BR ptrace (2). | |
7c2905d1 MK |
1776 | .TP |
1777 | .IR /proc/[pid]/personality " (since Linux 2.6.28)" | |
1778 | .\" commit 478307230810d7e2a753ed220db9066dfdf88718 | |
1779 | This read-only file exposes the process's execution domain, as set by | |
1780 | .BR personality (2). | |
1781 | The value is displayed in hexadecimal notation. | |
2dad4c59 | 1782 | .IP |
4834ae91 MK |
1783 | Permission to access this file is governed by a ptrace access mode |
1784 | .B PTRACE_MODE_ATTACH_FSCREDS | |
1785 | check; see | |
1786 | .BR ptrace (2). | |
fea681da | 1787 | .TP |
69119dc7 | 1788 | .I /proc/[pid]/root |
008f1ecc | 1789 | UNIX and Linux support the idea of a per-process root of the |
9ee4a2b6 | 1790 | filesystem, set by the |
fea681da | 1791 | .BR chroot (2) |
c13182ef MK |
1792 | system call. |
1793 | This file is a symbolic link that points to the process's | |
14d70713 MK |
1794 | root directory, and behaves in the same way as |
1795 | .IR exe , | |
1796 | and | |
1797 | .IR fd/* . | |
2dad4c59 | 1798 | .IP |
948f0ff4 | 1799 | Note however that this file is not merely a symbolic link. |
2b312241 MF |
1800 | It provides the same view of the filesystem (including namespaces and the |
1801 | set of per-process mounts) as the process itself. | |
a77efd58 MK |
1802 | An example illustrates this point. |
1803 | In one terminal, we start a shell in new user and mount namespaces, | |
1804 | and in that shell we create some new mount points: | |
2dad4c59 | 1805 | .IP |
a77efd58 | 1806 | .in +4n |
37d5e699 | 1807 | .EX |
a77efd58 MK |
1808 | $ \fBPS1='sh1# ' unshare \-Urnm\fP |
1809 | sh1# \fBmount \-t tmpfs tmpfs /etc\fP # Mount empty tmpfs at /etc | |
1810 | sh1# \fBmount \-\-bind /usr /dev\fP # Mount /usr at /dev | |
89f92905 | 1811 | sh1# \fBecho $$\fP |
a77efd58 | 1812 | 27123 |
37d5e699 | 1813 | .EE |
a77efd58 | 1814 | .in |
2dad4c59 | 1815 | .IP |
a77efd58 MK |
1816 | In a second terminal window, in the initial mount namespace, |
1817 | we look at the contents of the corresponding mounts in | |
1818 | the initial and new namespaces: | |
2dad4c59 | 1819 | .IP |
a77efd58 | 1820 | .in +4n |
37d5e699 | 1821 | .EX |
89f92905 | 1822 | $ \fBPS1='sh2# ' sudo sh\fP |
a77efd58 MK |
1823 | sh2# \fBls /etc | wc \-l\fP # In initial NS |
1824 | 309 | |
1825 | sh2# \fBls /proc/27123/root/etc | wc \-l\fP # /etc in other NS | |
1826 | 0 # The empty tmpfs dir | |
1827 | sh2# \fBls /dev | wc \-l\fP # In initial NS | |
1828 | 205 | |
1829 | sh2# \fBls /proc/27123/root/dev | wc \-l\fP # /dev in other NS | |
1830 | 11 # Actually bind | |
1831 | # mounted to /usr | |
1832 | sh2# \fBls /usr | wc \-l\fP # /usr in initial NS | |
1833 | 11 | |
37d5e699 | 1834 | .EE |
a77efd58 | 1835 | .in |
2dad4c59 | 1836 | .IP |
afcaf646 | 1837 | .\" The following was still true as at kernel 2.6.13 |
3ed7270e MK |
1838 | In a multithreaded process, the contents of the |
1839 | .I /proc/[pid]/root | |
1840 | symbolic link are not available if the main thread has already terminated | |
afcaf646 MK |
1841 | (typically by calling |
1842 | .BR pthread_exit (3)). | |
2dad4c59 | 1843 | .IP |
b902fe18 MK |
1844 | Permission to dereference or read |
1845 | .RB ( readlink (2)) | |
1846 | this symbolic link is governed by a ptrace access mode | |
1847 | .B PTRACE_MODE_READ_FSCREDS | |
1848 | check; see | |
1849 | .BR ptrace (2). | |
f34f0182 | 1850 | .\" FIXME Describe /proc/[pid]/projid_map |
43d42cc0 MK |
1851 | .\" Added in 3.7 |
1852 | .\" commit f76d207a66c3a53defea67e7d36c3eb1b7d6d61d | |
15869389 MK |
1853 | .TP |
1854 | .IR /proc/[pid]/seccomp " (Linux 2.6.12 to 2.6.22)" | |
1855 | This file can be used to read and change the process's | |
1856 | secure computing (seccomp) mode setting. | |
1857 | It contains the value 0 if the process is not in seccomp mode, | |
1858 | and 1 if the process is in strict seccomp mode (see | |
1859 | .BR seccomp (2)). | |
1860 | Writing 1 to this file places the process irreversibly in strict seccomp mode. | |
1861 | (Further attempts to write to the file fail with the | |
1862 | .B EPERM | |
1863 | error.) | |
2dad4c59 | 1864 | .IP |
15869389 MK |
1865 | In Linux 2.6.23, |
1866 | this file went away, to be replaced by the | |
1867 | .BR prctl (2) | |
1868 | .BR PR_GET_SECCOMP | |
1869 | and | |
1870 | .BR PR_SET_SECCOMP | |
1871 | operations (and later by | |
1872 | .BR seccomp (2) | |
1873 | and the | |
1874 | .I Seccomp | |
1875 | field in | |
1876 | .IR /proc/[pid]/status ). | |
69119dc7 | 1877 | .\" FIXME Describe /proc/[pid]/sessionid |
b3fb99e8 | 1878 | .\" commit 1e0bd7550ea9cf474b1ad4c6ff5729a507f75fdc |
b4e9ee8f | 1879 | .\" CONFIG_AUDITSYSCALL |
43d42cc0 | 1880 | .\" Added in 2.6.25; read-only; only readable by real UID |
bea08fec | 1881 | .\" |
69119dc7 | 1882 | .\" FIXME Describe /proc/[pid]/sched |
b4e9ee8f MK |
1883 | .\" Added in 2.6.23 |
1884 | .\" CONFIG_SCHED_DEBUG, and additional fields if CONFIG_SCHEDSTATS | |
1885 | .\" Displays various scheduling parameters | |
1886 | .\" This file can be written, to reset stats | |
ef4f4031 | 1887 | .\" The set of fields exposed by this file have changed |
b3fb99e8 MK |
1888 | .\" significantly over time. |
1889 | .\" commit 43ae34cb4cd650d1eb4460a8253a8e747ba052ac | |
1890 | .\" | |
69119dc7 MK |
1891 | .\" FIXME Describe /proc/[pid]/schedstats and |
1892 | .\" /proc/[pid]/task/[tid]/schedstats | |
b4e9ee8f MK |
1893 | .\" Added in 2.6.9 |
1894 | .\" CONFIG_SCHEDSTATS | |
fea681da | 1895 | .TP |
5c92b1b7 | 1896 | .IR /proc/[pid]/setgroups " (since Linux 3.19)" |
ab28dba9 MK |
1897 | See |
1898 | .BR user_namespaces (7). | |
d520465b | 1899 | .TP |
69119dc7 | 1900 | .IR /proc/[pid]/smaps " (since Linux 2.6.14)" |
b07b19c4 | 1901 | This file shows memory consumption for each of the process's mappings. |
859503c3 MK |
1902 | (The |
1903 | .BR pmap (1) | |
1904 | command displays similar information, | |
1905 | in a form that may be easier for parsing.) | |
1f0add28 | 1906 | For each mapping there is a series of lines such as the following: |
37d5e699 | 1907 | .IP |
a08ea57c | 1908 | .in +4n |
37d5e699 | 1909 | .EX |
9bc87ed0 | 1910 | 00400000\-0048a000 r\-xp 00000000 fd:03 960637 /bin/bash |
95fe794d PG |
1911 | Size: 552 kB |
1912 | Rss: 460 kB | |
1913 | Pss: 100 kB | |
1914 | Shared_Clean: 452 kB | |
1915 | Shared_Dirty: 0 kB | |
1916 | Private_Clean: 8 kB | |
1917 | Private_Dirty: 0 kB | |
1918 | Referenced: 460 kB | |
1919 | Anonymous: 0 kB | |
1920 | AnonHugePages: 0 kB | |
4ad958e1 MK |
1921 | ShmemHugePages: 0 kB |
1922 | ShmemPmdMapped: 0 kB | |
95fe794d PG |
1923 | Swap: 0 kB |
1924 | KernelPageSize: 4 kB | |
1925 | MMUPageSize: 4 kB | |
6861f8f0 MK |
1926 | KernelPageSize: 4 kB |
1927 | MMUPageSize: 4 kB | |
95fe794d | 1928 | Locked: 0 kB |
2f057281 | 1929 | ProtectionKey: 0 |
eb848708 | 1930 | VmFlags: rd ex mr mw me dw |
37d5e699 | 1931 | .EE |
a08ea57c | 1932 | .in |
2d3fb75b | 1933 | .IP |
b07b19c4 MK |
1934 | The first of these lines shows the same information as is displayed |
1935 | for the mapping in | |
69119dc7 | 1936 | .IR /proc/[pid]/maps . |
c3d59262 | 1937 | The following lines show the size of the mapping, |
95fe794d | 1938 | the amount of the mapping that is currently resident in RAM ("Rss"), |
a5a3e91b | 1939 | the process's proportional share of this mapping ("Pss"), |
1f0add28 | 1940 | the number of clean and dirty shared pages in the mapping, |
c7ce200d | 1941 | and the number of clean and dirty private pages in the mapping. |
95fe794d | 1942 | "Referenced" indicates the amount of memory currently marked as |
1f0add28 MK |
1943 | referenced or accessed. |
1944 | "Anonymous" shows the amount of memory | |
1945 | that does not belong to any file. | |
1946 | "Swap" shows how much | |
95fe794d | 1947 | would-be-anonymous memory is also used, but out on swap. |
2dad4c59 | 1948 | .IP |
6861f8f0 MK |
1949 | The "KernelPageSize" line (available since Linux 2.6.29) |
1950 | is the page size used by the kernel to back the virtual memory area. | |
1f0add28 MK |
1951 | This matches the size used by the MMU in the majority of cases. |
1952 | However, one counter-example occurs on PPC64 kernels | |
6861f8f0 | 1953 | whereby a kernel using 64kB as a base page size may still use 4kB |
1f0add28 | 1954 | pages for the MMU on older processors. |
6861f8f0 MK |
1955 | To distinguish the two attributes, the "MMUPageSize" line |
1956 | (also available since Linux 2.6.29) | |
1957 | reports the page size used by the MMU. | |
2dad4c59 | 1958 | .IP |
95fe794d PG |
1959 | The "Locked" indicates whether the mapping is locked in memory |
1960 | or not. | |
2dad4c59 | 1961 | .IP |
9b780b06 MK |
1962 | The "ProtectionKey" line (available since Linux 4.9, on x86 only) |
1963 | contains the memory protection key (see | |
1964 | .BR pkeys (7)) | |
1965 | associated with the virtual memory area. | |
1966 | This entry is present only if the kernel was built with the | |
1967 | .B CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS | |
1968 | configuration option. | |
2dad4c59 | 1969 | .IP |
eb848708 MK |
1970 | The "VmFlags" line (available since Linux 3.8) |
1971 | represents the kernel flags associated with the virtual memory area, | |
1972 | encoded using the following two-letter codes: | |
2dad4c59 | 1973 | .IP |
95fe794d | 1974 | rd - readable |
1f0add28 | 1975 | wr - writable |
95fe794d PG |
1976 | ex - executable |
1977 | sh - shared | |
1978 | mr - may read | |
1979 | mw - may write | |
1980 | me - may execute | |
1981 | ms - may share | |
723e333c | 1982 | gd - stack segment grows down |
95fe794d PG |
1983 | pf - pure PFN range |
1984 | dw - disabled write to the mapped file | |
1985 | lo - pages are locked in memory | |
1986 | io - memory mapped I/O area | |
1987 | sr - sequential read advise provided | |
1988 | rr - random read advise provided | |
1989 | dc - do not copy area on fork | |
1990 | de - do not expand area on remapping | |
1991 | ac - area is accountable | |
1992 | nr - swap space is not reserved for the area | |
1993 | ht - area uses huge tlb pages | |
1994 | nl - non-linear mapping | |
1995 | ar - architecture specific flag | |
1996 | dd - do not include area into core dump | |
1997 | sd - soft-dirty flag | |
1998 | mm - mixed map area | |
1999 | hg - huge page advise flag | |
2000 | nh - no-huge page advise flag | |
b5408a0f | 2001 | mg - mergeable advise flag |
2dad4c59 | 2002 | .IP |
be729d66 DH |
2003 | "ProtectionKey" field contains the memory protection key (see |
2004 | .BR pkeys (5)) | |
2005 | associated with the virtual memory area. | |
f12f1b9b | 2006 | Present only if the kernel was built with the |
be729d66 DH |
2007 | .B CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS |
2008 | configuration option. (since Linux 4.6) | |
2dad4c59 | 2009 | .IP |
e618d945 MK |
2010 | The |
2011 | .IR /proc/[pid]/smaps | |
2012 | file is present only if the | |
2013 | .B CONFIG_PROC_PAGE_MONITOR | |
2014 | kernel configuration option is enabled. | |
b07b19c4 | 2015 | .TP |
67aac6fb MK |
2016 | .IR /proc/[pid]/stack " (since Linux 2.6.29)" |
2017 | .\" 2ec220e27f5040aec1e88901c1b6ea3d135787ad | |
2018 | This file provides a symbolic trace of the function calls in this | |
2019 | process's kernel stack. | |
2020 | This file is provided only if the kernel was built with the | |
2021 | .B CONFIG_STACKTRACE | |
2022 | configuration option. | |
2dad4c59 | 2023 | .IP |
4834ae91 MK |
2024 | Permission to access this file is governed by a ptrace access mode |
2025 | .B PTRACE_MODE_ATTACH_FSCREDS | |
2026 | check; see | |
2027 | .BR ptrace (2). | |
67aac6fb | 2028 | .TP |
69119dc7 | 2029 | .I /proc/[pid]/stat |
c13182ef MK |
2030 | Status information about the process. |
2031 | This is used by | |
2032 | .BR ps (1). | |
082bf5b8 MK |
2033 | It is defined in the kernel source file |
2034 | .IR fs/proc/array.c "." | |
2dad4c59 | 2035 | .IP |
fea681da MK |
2036 | The fields, in order, with their proper |
2037 | .BR scanf (3) | |
b02b4b74 MK |
2038 | format specifiers, are listed below. |
2039 | Whether or not certain of these fields display valid information is governed by | |
2040 | a ptrace access mode | |
2041 | .BR PTRACE_MODE_READ_FSCREDS "\ |\ " PTRACE_MODE_NOAUDIT | |
2042 | check (refer to | |
2043 | .BR ptrace (2)). | |
2044 | If the check denies access, then the field value is displayed as 0. | |
2045 | The affected fields are indicated with the marking [PT]. | |
2dad4c59 | 2046 | .IP |
fea681da | 2047 | .RS |
62e4a418 MK |
2048 | .TP 10 |
2049 | (1) \fIpid\fP \ %d | |
2050 | .br | |
2051 | The process ID. | |
fea681da | 2052 | .TP |
62e4a418 MK |
2053 | (2) \fIcomm\fP \ %s |
2054 | The filename of the executable, in parentheses. | |
c13182ef | 2055 | This is visible whether or not the executable is swapped out. |
fea681da | 2056 | .TP |
62e4a418 | 2057 | (3) \fIstate\fP \ %c |
31293f37 MK |
2058 | One of the following characters, indicating process state: |
2059 | .RS | |
2060 | .IP R 3 | |
2061 | Running | |
2062 | .IP S | |
2063 | Sleeping in an interruptible wait | |
2064 | .IP D | |
2065 | Waiting in uninterruptible | |
2066 | disk sleep | |
2067 | .IP Z | |
2068 | Zombie | |
2069 | .IP T | |
2070 | Stopped (on a signal) or (before Linux 2.6.33) trace stopped | |
2071 | .IP t | |
2072 | .\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29 | |
2073 | Tracing stop (Linux 2.6.33 onward) | |
2074 | .IP W | |
2075 | Paging (only before Linux 2.6.0) | |
2076 | .IP X | |
ef4f4031 | 2077 | Dead (from Linux 2.6.0 onward) |
31293f37 MK |
2078 | .IP x |
2079 | .\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29 | |
2080 | Dead (Linux 2.6.33 to | |
2081 | .\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457 | |
2082 | 3.13 only) | |
2083 | .IP K | |
2084 | .\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29 | |
2085 | Wakekill (Linux 2.6.33 to | |
2086 | .\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457 | |
2087 | 3.13 only) | |
2088 | .IP W | |
2089 | .\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29 | |
2090 | Waking (Linux 2.6.33 to | |
2091 | .\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457 | |
2092 | 3.13 only) | |
2093 | .IP P | |
2094 | .\" commit f2530dc71cf0822f90bb63ea4600caaef33a66bb | |
2095 | Parked (Linux 3.9 to | |
2096 | .\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457 | |
2097 | 3.13 only) | |
2098 | .RE | |
fea681da | 2099 | .TP |
62e4a418 | 2100 | (4) \fIppid\fP \ %d |
e0fdc57c | 2101 | The PID of the parent of this process. |
fea681da | 2102 | .TP |
62e4a418 MK |
2103 | (5) \fIpgrp\fP \ %d |
2104 | The process group ID of the process. | |
fea681da | 2105 | .TP |
62e4a418 MK |
2106 | (6) \fIsession\fP \ %d |
2107 | The session ID of the process. | |
fea681da | 2108 | .TP |
62e4a418 MK |
2109 | (7) \fItty_nr\fP \ %d |
2110 | The controlling terminal of the process. | |
59a40ed7 MK |
2111 | (The minor device number is contained in the combination of bits |
2112 | 31 to 20 and 7 to 0; | |
b97deb97 | 2113 | the major device number is in bits 15 to 8.) |
fea681da | 2114 | .TP |
62e4a418 | 2115 | (8) \fItpgid\fP \ %d |
fea681da | 2116 | .\" This field and following, up to and including wchan added 0.99.1 |
62e4a418 | 2117 | The ID of the foreground process group of the controlling |
59a40ed7 | 2118 | terminal of the process. |
fea681da | 2119 | .TP |
62e4a418 MK |
2120 | (9) \fIflags\fP \ %u |
2121 | The kernel flags word of the process. | |
c13182ef | 2122 | For bit meanings, |
66a9882e | 2123 | see the PF_* defines in the Linux kernel source file |
00702acc | 2124 | .IR include/linux/sched.h . |
fea681da | 2125 | Details depend on the kernel version. |
2dad4c59 | 2126 | .IP |
62e4a418 | 2127 | The format for this field was %lu before Linux 2.6. |
fea681da | 2128 | .TP |
ee566744 | 2129 | (10) \fIminflt\fP \ %lu |
62e4a418 | 2130 | The number of minor faults the process has made which have not |
fea681da MK |
2131 | required loading a memory page from disk. |
2132 | .TP | |
62e4a418 MK |
2133 | (11) \fIcminflt\fP \ %lu |
2134 | The number of minor faults that the process's | |
fea681da MK |
2135 | waited-for children have made. |
2136 | .TP | |
62e4a418 MK |
2137 | (12) \fImajflt\fP \ %lu |
2138 | The number of major faults the process has made which have | |
fea681da MK |
2139 | required loading a memory page from disk. |
2140 | .TP | |
62e4a418 MK |
2141 | (13) \fIcmajflt\fP \ %lu |
2142 | The number of major faults that the process's | |
fea681da MK |
2143 | waited-for children have made. |
2144 | .TP | |
62e4a418 MK |
2145 | (14) \fIutime\fP \ %lu |
2146 | Amount of time that this process has been scheduled in user mode, | |
7a017e24 | 2147 | measured in clock ticks (divide by |
67914165 | 2148 | .IR sysconf(_SC_CLK_TCK) ). |
a1c9dc59 MK |
2149 | This includes guest time, \fIguest_time\fP |
2150 | (time spent running a virtual CPU, see below), | |
2151 | so that applications that are not aware of the guest time field | |
2152 | do not lose that time from their calculations. | |
fea681da | 2153 | .TP |
62e4a418 MK |
2154 | (15) \fIstime\fP \ %lu |
2155 | Amount of time that this process has been scheduled in kernel mode, | |
7a017e24 | 2156 | measured in clock ticks (divide by |
67914165 | 2157 | .IR sysconf(_SC_CLK_TCK) ). |
fea681da | 2158 | .TP |
62e4a418 MK |
2159 | (16) \fIcutime\fP \ %ld |
2160 | Amount of time that this process's | |
7a017e24 MK |
2161 | waited-for children have been scheduled in user mode, |
2162 | measured in clock ticks (divide by | |
67914165 | 2163 | .IR sysconf(_SC_CLK_TCK) ). |
c13182ef | 2164 | (See also |
fea681da | 2165 | .BR times (2).) |
a1c9dc59 MK |
2166 | This includes guest time, \fIcguest_time\fP |
2167 | (time spent running a virtual CPU, see below). | |
fea681da | 2168 | .TP |
62e4a418 MK |
2169 | (17) \fIcstime\fP \ %ld |
2170 | Amount of time that this process's | |
7a017e24 MK |
2171 | waited-for children have been scheduled in kernel mode, |
2172 | measured in clock ticks (divide by | |
67914165 | 2173 | .IR sysconf(_SC_CLK_TCK) ). |
fea681da | 2174 | .TP |
62e4a418 MK |
2175 | (18) \fIpriority\fP \ %ld |
2176 | (Explanation for Linux 2.6) | |
59a40ed7 MK |
2177 | For processes running a real-time scheduling policy |
2178 | .RI ( policy | |
2179 | below; see | |
2180 | .BR sched_setscheduler (2)), | |
2181 | this is the negated scheduling priority, minus one; | |
2182 | that is, a number in the range \-2 to \-100, | |
2183 | corresponding to real-time priorities 1 to 99. | |
2184 | For processes running under a non-real-time scheduling policy, | |
2185 | this is the raw nice value | |
2186 | .RB ( setpriority (2)) | |
2187 | as represented in the kernel. | |
2188 | The kernel stores nice values as numbers | |
2189 | in the range 0 (high) to 39 (low), | |
2190 | corresponding to the user-visible nice range of \-20 to 19. | |
2dad4c59 | 2191 | .IP |
59a40ed7 MK |
2192 | Before Linux 2.6, this was a scaled value based on |
2193 | the scheduler weighting given to this process. | |
2194 | .\" And back in kernel 1.2 days things were different again. | |
fea681da | 2195 | .TP |
62e4a418 MK |
2196 | (19) \fInice\fP \ %ld |
2197 | The nice value (see | |
59a40ed7 MK |
2198 | .BR setpriority (2)), |
2199 | a value in the range 19 (low priority) to \-20 (high priority). | |
2200 | .\" Back in kernel 1.2 days things were different. | |
fea681da MK |
2201 | .\" .TP |
2202 | .\" \fIcounter\fP %ld | |
2203 | .\" The current maximum size in jiffies of the process's next timeslice, | |
2204 | .\" or what is currently left of its current timeslice, if it is the | |
2205 | .\" currently running process. | |
2206 | .\" .TP | |
2207 | .\" \fItimeout\fP %u | |
2208 | .\" The time in jiffies of the process's next timeout. | |
0e94f77b | 2209 | .\" timeout was removed sometime around 2.1/2.2 |
aa610245 | 2210 | .TP |
62e4a418 MK |
2211 | (20) \fInum_threads\fP \ %ld |
2212 | Number of threads in this process (since Linux 2.6). | |
bb83d1b9 | 2213 | Before kernel 2.6, this field was hard coded to 0 as a placeholder |
0e94f77b | 2214 | for an earlier removed field. |
fea681da | 2215 | .TP |
62e4a418 MK |
2216 | (21) \fIitrealvalue\fP \ %ld |
2217 | The time in jiffies before the next | |
8bd58774 MK |
2218 | .B SIGALRM |
2219 | is sent to the process due to an interval timer. | |
0e94f77b MK |
2220 | Since kernel 2.6.17, this field is no longer maintained, |
2221 | and is hard coded as 0. | |
fea681da | 2222 | .TP |
62e4a418 MK |
2223 | (22) \fIstarttime\fP \ %llu |
2224 | The time the process started after system boot. | |
055024ed MK |
2225 | In kernels before Linux 2.6, this value was expressed in jiffies. |
2226 | Since Linux 2.6, the value is expressed in clock ticks (divide by | |
2227 | .IR sysconf(_SC_CLK_TCK) ). | |
2dad4c59 | 2228 | .IP |
62e4a418 | 2229 | The format for this field was %lu before Linux 2.6. |
fea681da | 2230 | .TP |
62e4a418 MK |
2231 | (23) \fIvsize\fP \ %lu |
2232 | Virtual memory size in bytes. | |
fea681da | 2233 | .TP |
62e4a418 MK |
2234 | (24) \fIrss\fP \ %ld |
2235 | Resident Set Size: number of pages the process has in real memory. | |
c13182ef | 2236 | This is just the pages which |
5fab2e7c | 2237 | count toward text, data, or stack space. |
c13182ef | 2238 | This does not include pages |
fea681da MK |
2239 | which have not been demand-loaded in, or which are swapped out. |
2240 | .TP | |
62e4a418 MK |
2241 | (25) \fIrsslim\fP \ %lu |
2242 | Current soft limit in bytes on the rss of the process; | |
59a40ed7 MK |
2243 | see the description of |
2244 | .B RLIMIT_RSS | |
2245 | in | |
2b5407af | 2246 | .BR getrlimit (2). |
fea681da | 2247 | .TP |
b02b4b74 | 2248 | (26) \fIstartcode\fP \ %lu \ [PT] |
62e4a418 | 2249 | The address above which program text can run. |
fea681da | 2250 | .TP |
b02b4b74 | 2251 | (27) \fIendcode\fP \ %lu \ [PT] |
62e4a418 | 2252 | The address below which program text can run. |
fea681da | 2253 | .TP |
b02b4b74 | 2254 | (28) \fIstartstack\fP \ %lu \ [PT] |
62e4a418 | 2255 | The address of the start (i.e., bottom) of the stack. |
fea681da | 2256 | .TP |
b02b4b74 | 2257 | (29) \fIkstkesp\fP \ %lu \ [PT] |
62e4a418 | 2258 | The current value of ESP (stack pointer), as found in the |
fea681da MK |
2259 | kernel stack page for the process. |
2260 | .TP | |
b02b4b74 | 2261 | (30) \fIkstkeip\fP \ %lu \ [PT] |
62e4a418 | 2262 | The current EIP (instruction pointer). |
fea681da | 2263 | .TP |
62e4a418 MK |
2264 | (31) \fIsignal\fP \ %lu |
2265 | The bitmap of pending signals, displayed as a decimal number. | |
59a40ed7 | 2266 | Obsolete, because it does not provide information on real-time signals; use |
69119dc7 | 2267 | .I /proc/[pid]/status |
59a40ed7 | 2268 | instead. |
fea681da | 2269 | .TP |
62e4a418 MK |
2270 | (32) \fIblocked\fP \ %lu |
2271 | The bitmap of blocked signals, displayed as a decimal number. | |
59a40ed7 | 2272 | Obsolete, because it does not provide information on real-time signals; use |
69119dc7 | 2273 | .I /proc/[pid]/status |
59a40ed7 | 2274 | instead. |
fea681da | 2275 | .TP |
62e4a418 MK |
2276 | (33) \fIsigignore\fP \ %lu |
2277 | The bitmap of ignored signals, displayed as a decimal number. | |
59a40ed7 | 2278 | Obsolete, because it does not provide information on real-time signals; use |
69119dc7 | 2279 | .I /proc/[pid]/status |
59a40ed7 | 2280 | instead. |
fea681da | 2281 | .TP |
62e4a418 MK |
2282 | (34) \fIsigcatch\fP \ %lu |
2283 | The bitmap of caught signals, displayed as a decimal number. | |
59a40ed7 | 2284 | Obsolete, because it does not provide information on real-time signals; use |
69119dc7 | 2285 | .I /proc/[pid]/status |
59a40ed7 | 2286 | instead. |
fea681da | 2287 | .TP |
b02b4b74 | 2288 | (35) \fIwchan\fP \ %lu \ [PT] |
62e4a418 | 2289 | This is the "channel" in which the process is waiting. |
2054f761 MK |
2290 | It is the address of a location in the kernel where the process is sleeping. |
2291 | The corresponding symbolic name can be found in | |
2292 | .IR /proc/[pid]/wchan . | |
fea681da | 2293 | .TP |
62e4a418 | 2294 | (36) \fInswap\fP \ %lu |
0633f951 | 2295 | .\" nswap was added in 2.0 |
4d9b6984 | 2296 | Number of pages swapped (not maintained). |
fea681da | 2297 | .TP |
62e4a418 | 2298 | (37) \fIcnswap\fP \ %lu |
0633f951 | 2299 | .\" cnswap was added in 2.0 |
4d9b6984 | 2300 | Cumulative \fInswap\fP for child processes (not maintained). |
fea681da | 2301 | .TP |
62e4a418 MK |
2302 | (38) \fIexit_signal\fP \ %d \ (since Linux 2.1.22) |
2303 | Signal to be sent to parent when we die. | |
fea681da | 2304 | .TP |
62e4a418 MK |
2305 | (39) \fIprocessor\fP \ %d \ (since Linux 2.2.8) |
2306 | CPU number last executed on. | |
568105c6 | 2307 | .TP |
62e4a418 MK |
2308 | (40) \fIrt_priority\fP \ %u \ (since Linux 2.5.19) |
2309 | Real-time scheduling priority, a number in the range 1 to 99 for | |
59a40ed7 MK |
2310 | processes scheduled under a real-time policy, |
2311 | or 0, for non-real-time processes (see | |
568105c6 MK |
2312 | .BR sched_setscheduler (2)). |
2313 | .TP | |
62e4a418 MK |
2314 | (41) \fIpolicy\fP \ %u \ (since Linux 2.5.19) |
2315 | Scheduling policy (see | |
568105c6 | 2316 | .BR sched_setscheduler (2)). |
cd60dedd | 2317 | Decode using the SCHED_* constants in |
59a40ed7 | 2318 | .IR linux/sched.h . |
2dad4c59 | 2319 | .IP |
62e4a418 | 2320 | The format for this field was %lu before Linux 2.6.22. |
167450d6 | 2321 | .TP |
62e4a418 MK |
2322 | (42) \fIdelayacct_blkio_ticks\fP \ %llu \ (since Linux 2.6.18) |
2323 | Aggregated block I/O delays, measured in clock ticks (centiseconds). | |
14c06953 | 2324 | .TP |
62e4a418 MK |
2325 | (43) \fIguest_time\fP \ %lu \ (since Linux 2.6.24) |
2326 | Guest time of the process (time spent running a virtual CPU | |
7a017e24 | 2327 | for a guest operating system), measured in clock ticks (divide by |
67914165 | 2328 | .IR sysconf(_SC_CLK_TCK) ). |
14c06953 | 2329 | .TP |
62e4a418 MK |
2330 | (44) \fIcguest_time\fP \ %ld \ (since Linux 2.6.24) |
2331 | Guest time of the process's children, measured in clock ticks (divide by | |
67914165 | 2332 | .IR sysconf(_SC_CLK_TCK) ). |
fea681da | 2333 | .TP |
b02b4b74 | 2334 | (45) \fIstart_data\fP \ %lu \ (since Linux 3.3) \ [PT] |
0be30a54 | 2335 | .\" commit b3f7f573a20081910e34e99cbc91831f4f02f1ff |
62e4a418 | 2336 | Address above which program initialized and |
426bc8d7 | 2337 | uninitialized (BSS) data are placed. |
12449ae3 | 2338 | .TP |
b02b4b74 | 2339 | (46) \fIend_data\fP \ %lu \ (since Linux 3.3) \ [PT] |
0be30a54 | 2340 | .\" commit b3f7f573a20081910e34e99cbc91831f4f02f1ff |
62e4a418 | 2341 | Address below which program initialized and |
426bc8d7 | 2342 | uninitialized (BSS) data are placed. |
12449ae3 | 2343 | .TP |
b02b4b74 | 2344 | (47) \fIstart_brk\fP \ %lu \ (since Linux 3.3) \ [PT] |
0be30a54 | 2345 | .\" commit b3f7f573a20081910e34e99cbc91831f4f02f1ff |
62e4a418 | 2346 | Address above which program heap can be expanded with |
426bc8d7 | 2347 | .BR brk (2). |
12449ae3 | 2348 | .TP |
b02b4b74 | 2349 | (48) \fIarg_start\fP \ %lu \ (since Linux 3.5) \ [PT] |
0be30a54 | 2350 | .\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3 |
62e4a418 | 2351 | Address above which program command-line arguments |
426bc8d7 MK |
2352 | .RI ( argv ) |
2353 | are placed. | |
12449ae3 | 2354 | .TP |
b02b4b74 | 2355 | (49) \fIarg_end\fP \ %lu \ (since Linux 3.5) \ [PT] |
0be30a54 | 2356 | .\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3 |
62e4a418 | 2357 | Address below program command-line arguments |
426bc8d7 MK |
2358 | .RI ( argv ) |
2359 | are placed. | |
12449ae3 | 2360 | .TP |
b02b4b74 | 2361 | (50) \fIenv_start\fP \ %lu \ (since Linux 3.5) \ [PT] |
0be30a54 | 2362 | .\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3 |
62e4a418 | 2363 | Address above which program environment is placed. |
12449ae3 | 2364 | .TP |
b02b4b74 | 2365 | (51) \fIenv_end\fP \ %lu \ (since Linux 3.5) \ [PT] |
0be30a54 | 2366 | .\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3 |
62e4a418 | 2367 | Address below which program environment is placed. |
12449ae3 | 2368 | .TP |
b02b4b74 | 2369 | (52) \fIexit_code\fP \ %d \ (since Linux 3.5) \ [PT] |
0be30a54 | 2370 | .\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3 |
62e4a418 | 2371 | The thread's exit status in the form reported by |
426bc8d7 | 2372 | .BR waitpid (2). |
12449ae3 | 2373 | .RE |
2374 | .TP | |
69119dc7 | 2375 | .I /proc/[pid]/statm |
59a40ed7 | 2376 | Provides information about memory usage, measured in pages. |
c13182ef | 2377 | The columns are: |
37d5e699 | 2378 | .IP |
a08ea57c | 2379 | .in +4n |
37d5e699 | 2380 | .EX |
cb42fb56 | 2381 | size (1) total program size |
69119dc7 | 2382 | (same as VmSize in \fI/proc/[pid]/status\fP) |
cb42fb56 | 2383 | resident (2) resident set size |
69119dc7 | 2384 | (same as VmRSS in \fI/proc/[pid]/status\fP) |
4e6fa352 MK |
2385 | shared (3) number of resident shared pages (i.e., backed by a file) |
2386 | (same as RssFile+RssShmem in \fI/proc/[pid]/status\fP) | |
cb42fb56 | 2387 | text (4) text (code) |
59a40ed7 | 2388 | .\" (not including libs; broken, includes data segment) |
d133b9b3 | 2389 | lib (5) library (unused since Linux 2.6; always 0) |
cb42fb56 | 2390 | data (6) data + stack |
59a40ed7 | 2391 | .\" (including libs; broken, includes library text) |
d133b9b3 | 2392 | dt (7) dirty pages (unused since Linux 2.6; always 0) |
37d5e699 | 2393 | .EE |
a08ea57c | 2394 | .in |
fea681da | 2395 | .TP |
69119dc7 | 2396 | .I /proc/[pid]/status |
fea681da | 2397 | Provides much of the information in |
69119dc7 | 2398 | .I /proc/[pid]/stat |
fea681da | 2399 | and |
69119dc7 | 2400 | .I /proc/[pid]/statm |
fea681da | 2401 | in a format that's easier for humans to parse. |
16b5f7ba | 2402 | Here's an example: |
37d5e699 | 2403 | .IP |
16b5f7ba | 2404 | .in +4n |
37d5e699 | 2405 | .EX |
b43a3b30 | 2406 | .RB "$" " cat /proc/$$/status" |
16b5f7ba | 2407 | Name: bash |
a79343e9 | 2408 | Umask: 0022 |
16b5f7ba | 2409 | State: S (sleeping) |
aac0b30f | 2410 | Tgid: 17248 |
2d2dfb69 | 2411 | Ngid: 0 |
aac0b30f MK |
2412 | Pid: 17248 |
2413 | PPid: 17200 | |
16b5f7ba MK |
2414 | TracerPid: 0 |
2415 | Uid: 1000 1000 1000 1000 | |
2416 | Gid: 100 100 100 100 | |
2417 | FDSize: 256 | |
2418 | Groups: 16 33 100 | |
aac0b30f MK |
2419 | NStgid: 17248 |
2420 | NSpid: 17248 | |
2421 | NSpgid: 17248 | |
2422 | NSsid: 17200 | |
06b7cee0 MK |
2423 | VmPeak: 131168 kB |
2424 | VmSize: 131168 kB | |
2425 | VmLck: 0 kB | |
2426 | VmPin: 0 kB | |
2427 | VmHWM: 13484 kB | |
2428 | VmRSS: 13484 kB | |
e546617e MK |
2429 | RssAnon: 10264 kB |
2430 | RssFile: 3220 kB | |
2431 | RssShmem: 0 kB | |
06b7cee0 MK |
2432 | VmData: 10332 kB |
2433 | VmStk: 136 kB | |
2434 | VmExe: 992 kB | |
2435 | VmLib: 2104 kB | |
2436 | VmPTE: 76 kB | |
2437 | VmPMD: 12 kB | |
2438 | VmSwap: 0 kB | |
4084d612 | 2439 | HugetlbPages: 0 kB # 4.4 |
4641c596 | 2440 | CoreDumping: 0 # 4.15 |
16b5f7ba MK |
2441 | Threads: 1 |
2442 | SigQ: 0/3067 | |
2443 | SigPnd: 0000000000000000 | |
2444 | ShdPnd: 0000000000000000 | |
2445 | SigBlk: 0000000000010000 | |
2446 | SigIgn: 0000000000384004 | |
2447 | SigCgt: 000000004b813efb | |
2448 | CapInh: 0000000000000000 | |
2449 | CapPrm: 0000000000000000 | |
2450 | CapEff: 0000000000000000 | |
2451 | CapBnd: ffffffffffffffff | |
6112ea97 | 2452 | CapAmb: 0000000000000000 |
6c0ed873 | 2453 | NoNewPrivs: 0 |
039b6546 | 2454 | Seccomp: 0 |
bf8fc275 | 2455 | Speculation_Store_Bypass: vulnerable |
16b5f7ba MK |
2456 | Cpus_allowed: 00000001 |
2457 | Cpus_allowed_list: 0 | |
2458 | Mems_allowed: 1 | |
2459 | Mems_allowed_list: 0 | |
2460 | voluntary_ctxt_switches: 150 | |
2461 | nonvoluntary_ctxt_switches: 545 | |
37d5e699 | 2462 | .EE |
16b5f7ba MK |
2463 | .in |
2464 | .IP | |
2465 | The fields are as follows: | |
2466 | .RS | |
2467 | .IP * 2 | |
2468 | .IR Name : | |
2469 | Command run by this process. | |
2470 | .IP * | |
a79343e9 | 2471 | .IR Umask : |
53473996 MK |
2472 | Process umask, expressed in octal with a leading zero; see |
2473 | .BR umask (2). | |
a79343e9 MK |
2474 | (Since Linux 4.7.) |
2475 | .IP * | |
16b5f7ba | 2476 | .IR State : |
4175f999 MK |
2477 | Current state of the process. |
2478 | One of | |
16b5f7ba MK |
2479 | "R (running)", |
2480 | "S (sleeping)", | |
2481 | "D (disk sleep)", | |
2482 | "T (stopped)", | |
2483 | "T (tracing stop)", | |
2484 | "Z (zombie)", | |
2485 | or | |
2486 | "X (dead)". | |
2487 | .IP * | |
2488 | .IR Tgid : | |
2489 | Thread group ID (i.e., Process ID). | |
2490 | .IP * | |
2d2dfb69 MK |
2491 | .IR Ngid : |
2492 | NUMA group ID (0 if none; since Linux 3.13). | |
2493 | .IP * | |
16b5f7ba MK |
2494 | .IR Pid : |
2495 | Thread ID (see | |
2496 | .BR gettid (2)). | |
2497 | .IP * | |
a1bc91d5 MK |
2498 | .IR PPid : |
2499 | PID of parent process. | |
2500 | .IP * | |
16b5f7ba MK |
2501 | .IR TracerPid : |
2502 | PID of process tracing this process (0 if not being traced). | |
2503 | .IP * | |
2504 | .IR Uid ", " Gid : | |
9ee4a2b6 | 2505 | Real, effective, saved set, and filesystem UIDs (GIDs). |
16b5f7ba MK |
2506 | .IP * |
2507 | .IR FDSize : | |
2508 | Number of file descriptor slots currently allocated. | |
2509 | .IP * | |
2510 | .IR Groups : | |
2511 | Supplementary group list. | |
2512 | .IP * | |
b84a64f4 | 2513 | .IR NStgid : |
aac0b30f MK |
2514 | Thread group ID (i.e., PID) in each of the PID namespaces of which |
2515 | .I [pid] | |
2516 | is a member. | |
2517 | The leftmost entry shows the value with respect to the PID namespace | |
0aae4092 KF |
2518 | of the process that mounted this procfs (or the root namespace |
2519 | if mounted by the kernel), | |
aac0b30f MK |
2520 | followed by the value in successively nested inner namespaces. |
2521 | .\" commit e4bc33245124db69b74a6d853ac76c2976f472d5 | |
2522 | (Since Linux 4.1.) | |
2523 | .IP * | |
b84a64f4 | 2524 | .IR NSpid : |
aac0b30f MK |
2525 | Thread ID in each of the PID namespaces of which |
2526 | .I [pid] | |
2527 | is a member. | |
2528 | The fields are ordered as for | |
2529 | .IR NStgid . | |
2530 | (Since Linux 4.1.) | |
2531 | .IP * | |
ecc9535d | 2532 | .IR NSpgid : |
aac0b30f MK |
2533 | Process group ID in each of the PID namespaces of which |
2534 | .I [pid] | |
2535 | is a member. | |
2536 | The fields are ordered as for | |
2537 | .IR NStgid . | |
2538 | (Since Linux 4.1.) | |
2539 | .IP * | |
ecc9535d | 2540 | .IR NSsid : |
aac0b30f MK |
2541 | descendant namespace session ID hierarchy |
2542 | Session ID in each of the PID namespaces of which | |
2543 | .I [pid] | |
2544 | is a member. | |
2545 | The fields are ordered as for | |
2546 | .IR NStgid . | |
2547 | (Since Linux 4.1.) | |
2548 | .IP * | |
16b5f7ba MK |
2549 | .IR VmPeak : |
2550 | Peak virtual memory size. | |
2551 | .IP * | |
2552 | .IR VmSize : | |
2553 | Virtual memory size. | |
2554 | .IP * | |
2555 | .IR VmLck : | |
fde39195 | 2556 | Locked memory size (see |
f8bfb68e | 2557 | .BR mlock (2)). |
16b5f7ba | 2558 | .IP * |
15789039 TY |
2559 | .IR VmPin : |
2560 | Pinned memory size | |
2561 | .\" commit bc3e53f682d93df677dbd5006a404722b3adfe18 | |
2562 | (since Linux 3.2). | |
2563 | These are pages that can't be moved because something needs to | |
2564 | directly access physical memory. | |
2565 | .IP * | |
16b5f7ba MK |
2566 | .IR VmHWM : |
2567 | Peak resident set size ("high water mark"). | |
2568 | .IP * | |
2569 | .IR VmRSS : | |
2570 | Resident set size. | |
e546617e MK |
2571 | Note that the value here is the sum of |
2572 | .IR RssAnon , | |
2573 | .IR RssFile , | |
2574 | and | |
2575 | .IR RssShmem . | |
2576 | .IP * | |
2577 | .IR RssAnon : | |
2578 | Size of resident anonymous memory. | |
2579 | .\" commit bf9683d6990589390b5178dafe8fd06808869293 | |
2580 | (since Linux 4.5). | |
2581 | .IP * | |
2582 | .IR RssFile : | |
2583 | Size of resident file mappings. | |
2584 | .\" commit bf9683d6990589390b5178dafe8fd06808869293 | |
2585 | (since Linux 4.5). | |
2586 | .IP * | |
2587 | .IR RssShmem : | |
78230722 | 2588 | Size of resident shared memory (includes System V shared memory, |
4e07c70f MK |
2589 | mappings from |
2590 | .BR tmpfs (5), | |
2591 | and shared anonymous mappings). | |
e546617e MK |
2592 | .\" commit bf9683d6990589390b5178dafe8fd06808869293 |
2593 | (since Linux 4.5). | |
16b5f7ba MK |
2594 | .IP * |
2595 | .IR VmData ", " VmStk ", " VmExe : | |
2596 | Size of data, stack, and text segments. | |
2597 | .IP * | |
2598 | .IR VmLib : | |
2599 | Shared library code size. | |
2600 | .IP * | |
2601 | .IR VmPTE : | |
2602 | Page table entries size (since Linux 2.6.10). | |
2603 | .IP * | |
e28af9cd MK |
2604 | .IR VmPMD : |
2605 | .\" commit dc6c9a35b66b520cf67e05d8ca60ebecad3b0479 | |
fcfac78d | 2606 | Size of second-level page tables (added in Linux 4.0; removed in Linux 4.15). |
e28af9cd | 2607 | .IP * |
ac4b0eb3 | 2608 | .IR VmSwap : |
1ddc1665 | 2609 | .\" commit b084d4353ff99d824d3bc5a5c2c22c70b1fba722 |
fce21149 MK |
2610 | Swapped-out virtual memory size by anonymous private pages; |
2611 | shmem swap usage is not included (since Linux 2.6.34). | |
49f6dda7 | 2612 | .IP * |
4084d612 | 2613 | .IR HugetlbPages : |
422425ff | 2614 | Size of hugetlb memory portions |
4084d612 MK |
2615 | .\" commit 5d317b2b6536592a9b51fe65faed43d65ca9158e |
2616 | (since Linux 4.4). | |
2617 | .IP * | |
4641c596 MK |
2618 | .IR CoreDumping : |
2619 | Contains the value 1 if the process is currently dumping core, | |
2620 | and 0 if it is not | |
2621 | .\" commit c643401218be0f4ab3522e0c0a63016596d6e9ca | |
2622 | (since Linux 4.15). | |
2623 | This information can be used by a monitoring process to avoid killing | |
2624 | a process that is currently dumping core, | |
2625 | which could result in a corrupted core dump file. | |
2626 | .IP * | |
16b5f7ba MK |
2627 | .IR Threads : |
2628 | Number of threads in process containing this thread. | |
2629 | .IP * | |
6ee625eb MK |
2630 | .IR SigQ : |
2631 | This field contains two slash-separated numbers that relate to | |
2632 | queued signals for the real user ID of this process. | |
2633 | The first of these is the number of currently queued | |
2634 | signals for this real user ID, and the second is the | |
2635 | resource limit on the number of queued signals for this process | |
2636 | (see the description of | |
2637 | .BR RLIMIT_SIGPENDING | |
2638 | in | |
2639 | .BR getrlimit (2)). | |
2640 | .IP * | |
16b5f7ba MK |
2641 | .IR SigPnd ", " ShdPnd : |
2642 | Number of signals pending for thread and for process as a whole (see | |
2643 | .BR pthreads (7) | |
2644 | and | |
2645 | .BR signal (7)). | |
2646 | .IP * | |
2647 | .IR SigBlk ", " SigIgn ", " SigCgt : | |
2648 | Masks indicating signals being blocked, ignored, and caught (see | |
2649 | .BR signal (7)). | |
2650 | .IP * | |
2651 | .IR CapInh ", " CapPrm ", " CapEff : | |
2652 | Masks of capabilities enabled in inheritable, permitted, and effective sets | |
2653 | (see | |
2654 | .BR capabilities (7)). | |
2655 | .IP * | |
2656 | .IR CapBnd : | |
2657 | Capability Bounding set | |
7e07d950 | 2658 | (since Linux 2.6.26, see |
16b5f7ba MK |
2659 | .BR capabilities (7)). |
2660 | .IP * | |
6112ea97 MK |
2661 | .IR CapAmb : |
2662 | Ambient capability set | |
2663 | (since Linux 4.3, see | |
2664 | .BR capabilities (7)). | |
2665 | .IP * | |
6c0ed873 MK |
2666 | .IR NoNewPrivs : |
2667 | .\" commit af884cd4a5ae62fcf5e321fecf0ec1014730353d | |
2668 | Value of the | |
2669 | .I no_new_privs | |
2670 | bit | |
2671 | (since Linux 4.10, see | |
2672 | .BR prctl (2)). | |
2673 | .IP * | |
039b6546 MK |
2674 | .IR Seccomp : |
2675 | .\" commit 2f4b3bf6b2318cfaa177ec5a802f4d8d6afbd816 | |
2676 | Seccomp mode of the process | |
2677 | (since Linux 3.8, see | |
2678 | .BR seccomp (2)). | |
2679 | 0 means | |
2680 | .BR SECCOMP_MODE_DISABLED ; | |
2681 | 1 means | |
2682 | .BR SECCOMP_MODE_STRICT ; | |
2683 | 2 means | |
2684 | .BR SECCOMP_MODE_FILTER . | |
2685 | This field is provided only if the kernel was built with the | |
2686 | .BR CONFIG_SECCOMP | |
2687 | kernel configuration option enabled. | |
2688 | .IP * | |
bf8fc275 NF |
2689 | .IR Speculation_Store_Bypass : |
2690 | .\" commit fae1fa0fc6cca8beee3ab8ed71d54f9a78fa3f64 | |
2691 | Speculation flaw mitigation state | |
2692 | (since Linux 4.17, see | |
2693 | .BR prctl (2)). | |
2694 | .IP * | |
16b5f7ba MK |
2695 | .IR Cpus_allowed : |
2696 | Mask of CPUs on which this process may run | |
2697 | (since Linux 2.6.24, see | |
2698 | .BR cpuset (7)). | |
2699 | .IP * | |
2700 | .IR Cpus_allowed_list : | |
2701 | Same as previous, but in "list format" | |
2702 | (since Linux 2.6.26, see | |
2703 | .BR cpuset (7)). | |
2704 | .IP * | |
2705 | .IR Mems_allowed : | |
2706 | Mask of memory nodes allowed to this process | |
2707 | (since Linux 2.6.24, see | |
2708 | .BR cpuset (7)). | |
2709 | .IP * | |
2710 | .IR Mems_allowed_list : | |
2711 | Same as previous, but in "list format" | |
2712 | (since Linux 2.6.26, see | |
2713 | .BR cpuset (7)). | |
2714 | .IP * | |
7c82878a | 2715 | .IR voluntary_ctxt_switches ", " nonvoluntary_ctxt_switches : |
16b5f7ba MK |
2716 | Number of voluntary and involuntary context switches (since Linux 2.6.23). |
2717 | .RE | |
afb7b014 MK |
2718 | .TP |
2719 | .IR /proc/[pid]/syscall " (since Linux 2.6.27)" | |
2720 | .\" commit ebcb67341fee34061430f3367f2e507e52ee051b | |
2721 | This file exposes the system call number and argument registers for the | |
2722 | system call currently being executed by the process, | |
2723 | followed by the values of the stack pointer and program counter registers. | |
2724 | The values of all six argument registers are exposed, | |
2725 | although most system calls use fewer registers. | |
2dad4c59 | 2726 | .IP |
afb7b014 | 2727 | If the process is blocked, but not in a system call, |
1fb61947 | 2728 | then the file displays \-1 in place of the system call number, |
afb7b014 | 2729 | followed by just the values of the stack pointer and program counter. |
64fcb6e1 | 2730 | If process is not blocked, then the file contains just the string "running". |
2dad4c59 | 2731 | .IP |
afb7b014 MK |
2732 | This file is present only if the kernel was configured with |
2733 | .BR CONFIG_HAVE_ARCH_TRACEHOOK . | |
2dad4c59 | 2734 | .IP |
4834ae91 MK |
2735 | Permission to access this file is governed by a ptrace access mode |
2736 | .B PTRACE_MODE_ATTACH_FSCREDS | |
2737 | check; see | |
2738 | .BR ptrace (2). | |
fea681da | 2739 | .TP |
d6bec36e MK |
2740 | .IR /proc/[pid]/task " (since Linux 2.6.0)" |
2741 | .\" Precisely: Linux 2.6.0-test6 | |
afcaf646 MK |
2742 | This is a directory that contains one subdirectory |
2743 | for each thread in the process. | |
69119dc7 MK |
2744 | The name of each subdirectory is the numerical thread ID |
2745 | .RI ( [tid] ) | |
2746 | of the thread (see | |
afcaf646 | 2747 | .BR gettid (2)). |
eb8567a5 | 2748 | .IP |
afcaf646 MK |
2749 | Within each of these subdirectories, there is a set of |
2750 | files with the same names and contents as under the | |
69119dc7 | 2751 | .I /proc/[pid] |
afcaf646 MK |
2752 | directories. |
2753 | For attributes that are shared by all threads, the contents for | |
2754 | each of the files under the | |
69119dc7 | 2755 | .I task/[tid] |
afcaf646 | 2756 | subdirectories will be the same as in the corresponding |
c13182ef | 2757 | file in the parent |
69119dc7 | 2758 | .I /proc/[pid] |
afcaf646 | 2759 | directory |
c13182ef | 2760 | (e.g., in a multithreaded process, all of the |
69119dc7 | 2761 | .I task/[tid]/cwd |
c13182ef | 2762 | files will have the same value as the |
69119dc7 | 2763 | .I /proc/[pid]/cwd |
c13182ef | 2764 | file in the parent directory, since all of the threads in a process |
afcaf646 MK |
2765 | share a working directory). |
2766 | For attributes that are distinct for each thread, | |
c13182ef | 2767 | the corresponding files under |
69119dc7 | 2768 | .I task/[tid] |
afcaf646 | 2769 | may have different values (e.g., various fields in each of the |
69119dc7 | 2770 | .I task/[tid]/status |
4a40c703 JH |
2771 | files may be different for each thread), |
2772 | .\" in particular: "children" :/ | |
2773 | or they might not exist in | |
2774 | .I /proc/[pid] | |
2775 | at all. | |
eb8567a5 | 2776 | .IP |
afcaf646 MK |
2777 | .\" The following was still true as at kernel 2.6.13 |
2778 | In a multithreaded process, the contents of the | |
69119dc7 | 2779 | .I /proc/[pid]/task |
c13182ef | 2780 | directory are not available if the main thread has already terminated |
afcaf646 MK |
2781 | (typically by calling |
2782 | .BR pthread_exit (3)). | |
2dad4c59 | 2783 | .IP |
4a40c703 JH |
2784 | .TP |
2785 | .IR /proc/[pid]/task/[tid]/children " (since Linux 3.5)" | |
2786 | .\" commit 818411616baf46ceba0cff6f05af3a9b294734f7 | |
2787 | A space-separated list of child tasks of this task. | |
2788 | Each child task is represented by its TID. | |
2dad4c59 | 2789 | .IP |
4a40c703 | 2790 | .\" see comments in get_children_pid() in fs/proc/array.c |
45dd5092 MK |
2791 | This option is intended for use by the checkpoint-restore (CRIU) system, |
2792 | and reliably provides a list of children only if all of the child processes | |
2793 | are stopped or frozen. | |
2794 | It does not work properly if children of the target task exit while | |
4a40c703 | 2795 | the file is being read! |
45dd5092 | 2796 | Exiting children may cause non-exiting children to be omitted from the list. |
4a40c703 | 2797 | This makes this interface even more unreliable than classic PID-based |
45dd5092 MK |
2798 | approaches if the inspected task and its children aren't frozen, |
2799 | and most code should probably not use this interface. | |
2dad4c59 | 2800 | .IP |
7ded2db4 MK |
2801 | Until Linux 4.2, the presence of this file was governed by the |
2802 | .B CONFIG_CHECKPOINT_RESTORE | |
2803 | kernel configuration option. | |
2804 | Since Linux 4.2, | |
2805 | .\" commit 2e13ba54a2682eea24918b87ad3edf70c2cf085b | |
ae34c521 | 2806 | it is governed by the |
7ded2db4 MK |
2807 | .B CONFIG_PROC_CHILDREN |
2808 | option. | |
afcaf646 | 2809 | .TP |
1509ca0e MK |
2810 | .IR /proc/[pid]/timers " (since Linux 3.10)" |
2811 | .\" commit 5ed67f05f66c41e39880a6d61358438a25f9fee5 | |
2812 | .\" commit 48f6a7a511ef8823fdff39afee0320092d43a8a0 | |
2813 | A list of the POSIX timers for this process. | |
93691c1e | 2814 | Each timer is listed with a line that starts with the string "ID:". |
1509ca0e | 2815 | For example: |
2dad4c59 | 2816 | .IP |
1509ca0e | 2817 | .in +4n |
37d5e699 | 2818 | .EX |
1509ca0e MK |
2819 | ID: 1 |
2820 | signal: 60/00007fff86e452a8 | |
2821 | notify: signal/pid.2634 | |
2822 | ClockID: 0 | |
2823 | ID: 0 | |
2824 | signal: 60/00007fff86e452a8 | |
2825 | notify: signal/pid.2634 | |
2826 | ClockID: 1 | |
37d5e699 | 2827 | .EE |
1509ca0e | 2828 | .in |
2dad4c59 | 2829 | .IP |
1509ca0e MK |
2830 | The lines shown for each timer have the following meanings: |
2831 | .RS | |
2832 | .TP | |
2833 | .I ID | |
2834 | The ID for this timer. | |
2835 | This is not the same as the timer ID returned by | |
2836 | .BR timer_create (2); | |
2837 | rather, it is the same kernel-internal ID that is available via the | |
2838 | .I si_timerid | |
2839 | field of the | |
2840 | .IR siginfo_t | |
2841 | structure (see | |
2842 | .BR sigaction (2)). | |
2843 | .TP | |
2844 | .I signal | |
2845 | This is the signal number that this timer uses to deliver notifications | |
2846 | followed by a slash, and then the | |
7f1ea8fb | 2847 | .I sigev_value |
1509ca0e MK |
2848 | value supplied to the signal handler. |
2849 | Valid only for timers that notify via a signal. | |
2850 | .TP | |
2851 | .I notify | |
2852 | The part before the slash specifies the mechanism | |
2853 | that this timer uses to deliver notifications, | |
2854 | and is one of "thread", "signal", or "none". | |
2855 | Immediately following the slash is either the string "tid" for timers | |
2856 | with | |
2857 | .B SIGEV_THREAD_ID | |
2858 | notification, or "pid" for timers that notify by other mechanisms. | |
dbe6f88b MK |
2859 | Following the "." is the PID of the process |
2860 | (or the kernel thread ID of the thread) that will be delivered | |
1509ca0e MK |
2861 | a signal if the timer delivers notifications via a signal. |
2862 | .TP | |
2863 | .I ClockID | |
2864 | This field identifies the clock that the timer uses for measuring time. | |
2865 | For most clocks, this is a number that matches one of the user-space | |
2866 | .BR CLOCK_* | |
9d54c087 | 2867 | constants exposed via |
1509ca0e MK |
2868 | .IR <time.h> . |
2869 | .B CLOCK_PROCESS_CPUTIME_ID | |
9bc87ed0 | 2870 | timers display with a value of \-6 |
1509ca0e MK |
2871 | in this field. |
2872 | .B CLOCK_THREAD_CPUTIME_ID | |
9bc87ed0 | 2873 | timers display with a value of \-2 |
1509ca0e MK |
2874 | in this field. |
2875 | .RE | |
5734da6d MK |
2876 | .IP |
2877 | This file is available only when the kernel was configured with | |
2878 | .BR CONFIG_CHECKPOINT_RESTORE . | |
1509ca0e | 2879 | .TP |
11f60142 MK |
2880 | .IR /proc/[pid]/timerslack_ns " (since Linux 4.6)" |
2881 | .\" commit da8b44d5a9f8bf26da637b7336508ca534d6b319 | |
2882 | .\" commit 5de23d435e88996b1efe0e2cebe242074ce67c9e | |
2883 | This file exposes the process's "current" timer slack value, | |
2884 | expressed in nanoseconds. | |
2885 | The file is writable, | |
2886 | allowing the process's timer slack value to be changed. | |
2887 | Writing 0 to this file resets the "current" timer slack to the | |
2888 | "default" timer slack value. | |
2889 | For further details, see the discussion of | |
2890 | .BR PR_SET_TIMERSLACK | |
2891 | in | |
2892 | .BR prctl (2). | |
2dad4c59 | 2893 | .IP |
5daae264 MK |
2894 | Initially, |
2895 | permission to access this file was governed by a ptrace access mode | |
a62e0e01 | 2896 | .B PTRACE_MODE_ATTACH_FSCREDS |
5daae264 MK |
2897 | check (see |
2898 | .BR ptrace (2)). | |
2899 | However, this was subsequently deemed too strict a requirement | |
2900 | (and had the side effect that requiring a process to have the | |
2901 | .B CAP_SYS_PTRACE | |
2902 | capability would also allow it to view and change any process's memory). | |
2903 | Therefore, since Linux 4.9, | |
2904 | .\" commit 7abbaf94049914f074306d960b0f968ffe52e59f | |
2905 | only the (weaker) | |
2906 | .B CAP_SYS_NICE | |
2907 | capability is required to access this file. | |
11f60142 | 2908 | .TP |
b1aad373 MK |
2909 | .IR /proc/[pid]/uid_map ", " /proc/[pid]/gid_map " (since Linux 3.5)" |
2910 | See | |
2911 | .BR user_namespaces (7). | |
2912 | .TP | |
2913 | .IR /proc/[pid]/wchan " (since Linux 2.6.0)" | |
2914 | The symbolic name corresponding to the location | |
2915 | in the kernel where the process is sleeping. | |
2dad4c59 | 2916 | .IP |
82664739 MK |
2917 | Permission to access this file is governed by a ptrace access mode |
2918 | .B PTRACE_MODE_READ_FSCREDS | |
2919 | check; see | |
2920 | .BR ptrace (2). | |
b1aad373 | 2921 | .TP |
01df7b70 MK |
2922 | .IR /proc/[tid] |
2923 | There is a numerical subdirectory for each running thread | |
2924 | that is not a thread group leader | |
2925 | (i.e., a thread whose thread ID is not the same as its process ID); | |
2926 | the subdirectory is named by the thread ID. | |
2927 | Each one of these subdirectories contains files and subdirectories | |
2928 | exposing information about the thread with the thread ID | |
2929 | .IR tid . | |
2930 | The contents of these directories are the same as the corresponding | |
71190ded | 2931 | .IR /proc/[pid]/task/[tid] |
01df7b70 MK |
2932 | directories. |
2933 | .IP | |
2934 | The | |
2935 | .I /proc/[tid] | |
2936 | subdirectories are | |
2937 | .I not | |
2938 | visible when iterating through | |
2939 | .I /proc | |
2940 | with | |
2941 | .BR getdents (2) | |
2942 | (and thus are | |
2943 | .I not | |
2944 | visible when one uses | |
2945 | .BR ls (1) | |
2946 | to view the contents of | |
2947 | .IR /proc ). | |
37cd58d2 MK |
2948 | However, the pathnames of these directories are visible to |
2949 | (i.e., usable as arguments in) | |
2950 | system calls that operate on pathnames. | |
01df7b70 | 2951 | .TP |
b1aad373 MK |
2952 | .I /proc/apm |
2953 | Advanced power management version and battery information when | |
2954 | .B CONFIG_APM | |
2955 | is defined at kernel compilation time. | |
2956 | .TP | |
2957 | .I /proc/buddyinfo | |
2958 | This file contains information which is used for diagnosing memory | |
2959 | fragmentation issues. | |
2960 | Each line starts with the identification of the node and the name | |
2961 | of the zone which together identify a memory region | |
2962 | This is then | |
2963 | followed by the count of available chunks of a certain order in | |
2964 | which these zones are split. | |
2965 | The size in bytes of a certain order is given by the formula: | |
2dad4c59 | 2966 | .IP |
b1aad373 | 2967 | (2^order)\ *\ PAGE_SIZE |
2dad4c59 | 2968 | .IP |
b1aad373 MK |
2969 | The binary buddy allocator algorithm inside the kernel will split |
2970 | one chunk into two chunks of a smaller order (thus with half the | |
2971 | size) or combine two contiguous chunks into one larger chunk of | |
2972 | a higher order (thus with double the size) to satisfy allocation | |
2973 | requests and to counter memory fragmentation. | |
2974 | The order matches the column number, when starting to count at zero. | |
2dad4c59 | 2975 | .IP |
b5b0d21e | 2976 | For example on an x86-64 system: |
2dad4c59 | 2977 | .IP |
b1aad373 | 2978 | .in -12n |
37d5e699 | 2979 | .EX |
b1aad373 MK |
2980 | Node 0, zone DMA 1 1 1 0 2 1 1 0 1 1 3 |
2981 | Node 0, zone DMA32 65 47 4 81 52 28 13 10 5 1 404 | |
2982 | Node 0, zone Normal 216 55 189 101 84 38 37 27 5 3 587 | |
37d5e699 | 2983 | .EE |
b1aad373 | 2984 | .in |
2dad4c59 | 2985 | .IP |
b1aad373 MK |
2986 | In this example, there is one node containing three zones and there |
2987 | are 11 different chunk sizes. | |
2988 | If the page size is 4 kilobytes, then the first zone called | |
2989 | .I DMA | |
2990 | (on x86 the first 16 megabyte of memory) has 1 chunk of 4 kilobytes | |
2991 | (order 0) available and has 3 chunks of 4 megabytes (order 10) available. | |
2dad4c59 | 2992 | .IP |
b1aad373 MK |
2993 | If the memory is heavily fragmented, the counters for higher |
2994 | order chunks will be zero and allocation of large contiguous areas | |
2995 | will fail. | |
2dad4c59 | 2996 | .IP |
b1aad373 MK |
2997 | Further information about the zones can be found in |
2998 | .IR /proc/zoneinfo . | |
2999 | .TP | |
3000 | .I /proc/bus | |
3001 | Contains subdirectories for installed busses. | |
3002 | .TP | |
3003 | .I /proc/bus/pccard | |
3004 | Subdirectory for PCMCIA devices when | |
3005 | .B CONFIG_PCMCIA | |
3006 | is set at kernel compilation time. | |
3007 | .TP | |
fea681da MK |
3008 | .I /proc/bus/pccard/drivers |
3009 | .TP | |
3010 | .I /proc/bus/pci | |
c13182ef | 3011 | Contains various bus subdirectories and pseudo-files containing |
59a40ed7 | 3012 | information about PCI busses, installed devices, and device |
c13182ef MK |
3013 | drivers. |
3014 | Some of these files are not ASCII. | |
fea681da MK |
3015 | .TP |
3016 | .I /proc/bus/pci/devices | |
59a40ed7 | 3017 | Information about PCI devices. |
c13182ef | 3018 | They may be accessed through |
fea681da MK |
3019 | .BR lspci (8) |
3020 | and | |
3021 | .BR setpci (8). | |
3022 | .TP | |
12b23dfe MK |
3023 | .IR /proc/cgroups " (since Linux 2.6.24)" |
3024 | See | |
3025 | .BR cgroups (7). | |
3026 | .TP | |
fea681da | 3027 | .I /proc/cmdline |
c13182ef MK |
3028 | Arguments passed to the Linux kernel at boot time. |
3029 | Often done via a boot manager such as | |
59a40ed7 MK |
3030 | .BR lilo (8) |
3031 | or | |
3032 | .BR grub (8). | |
f6e524c4 MK |
3033 | .TP |
3034 | .IR /proc/config.gz " (since Linux 2.6)" | |
3035 | This file exposes the configuration options that were used | |
c3d9780d | 3036 | to build the currently running kernel, |
f6e524c4 MK |
3037 | in the same format as they would be shown in the |
3038 | .I .config | |
3039 | file that resulted when configuring the kernel (using | |
3040 | .IR "make xconfig" , | |
3041 | .IR "make config" , | |
3042 | or similar). | |
3043 | The file contents are compressed; view or search them using | |
f78ed33a MK |
3044 | .BR zcat (1) |
3045 | and | |
3046 | .BR zgrep (1). | |
f6e524c4 | 3047 | As long as no changes have been made to the following file, |
250e01ec MK |
3048 | the contents of |
3049 | .I /proc/config.gz | |
37d5e699 MK |
3050 | are the same as those provided by: |
3051 | .IP | |
f6e524c4 | 3052 | .in +4n |
37d5e699 | 3053 | .EX |
c3074d70 | 3054 | cat /lib/modules/$(uname \-r)/build/.config |
37d5e699 | 3055 | .EE |
f6e524c4 | 3056 | .in |
250e01ec MK |
3057 | .IP |
3058 | .I /proc/config.gz | |
90878f7c | 3059 | is provided only if the kernel is configured with |
250e01ec | 3060 | .BR CONFIG_IKCONFIG_PROC . |
fea681da | 3061 | .TP |
577c0e20 MK |
3062 | .I /proc/crypto |
3063 | A list of the ciphers provided by the kernel crypto API. | |
3064 | For details, see the kernel | |
3065 | .I "Linux Kernel Crypto API" | |
3066 | documentation available under the kernel source directory | |
e94de168 ES |
3067 | .I Documentation/crypto/ |
3068 | .\" commit 3b72c814a8e8cd638e1ba0da4dfce501e9dff5af | |
3069 | (or | |
3070 | .I Documentation/DocBook | |
3071 | before 4.10; | |
3072 | the documentation can be built using a command such as | |
577c0e20 | 3073 | .IR "make htmldocs" |
e94de168 | 3074 | in the root directory of the kernel source tree). |
577c0e20 | 3075 | .TP |
fea681da MK |
3076 | .I /proc/cpuinfo |
3077 | This is a collection of CPU and system architecture dependent items, | |
3078 | for each supported architecture a different list. | |
3079 | Two common entries are \fIprocessor\fP which gives CPU number and | |
c13182ef MK |
3080 | \fIbogomips\fP; a system constant that is calculated |
3081 | during kernel initialization. | |
3082 | SMP machines have information for | |
fea681da | 3083 | each CPU. |
a091f002 MK |
3084 | The |
3085 | .BR lscpu (1) | |
3086 | command gathers its information from this file. | |
fea681da MK |
3087 | .TP |
3088 | .I /proc/devices | |
c13182ef MK |
3089 | Text listing of major numbers and device groups. |
3090 | This can be used by MAKEDEV scripts for consistency with the kernel. | |
fea681da MK |
3091 | .TP |
3092 | .IR /proc/diskstats " (since Linux 2.5.69)" | |
3093 | This file contains disk I/O statistics for each disk device. | |
66a9882e | 3094 | See the Linux kernel source file |
fea681da MK |
3095 | .I Documentation/iostats.txt |
3096 | for further information. | |
3097 | .TP | |
3098 | .I /proc/dma | |
c13182ef | 3099 | This is a list of the registered \fIISA\fP DMA (direct memory access) |
fea681da MK |
3100 | channels in use. |
3101 | .TP | |
3102 | .I /proc/driver | |
3103 | Empty subdirectory. | |
3104 | .TP | |
3105 | .I /proc/execdomains | |
3106 | List of the execution domains (ABI personalities). | |
3107 | .TP | |
3108 | .I /proc/fb | |
097585ed MK |
3109 | Frame buffer information when |
3110 | .B CONFIG_FB | |
3111 | is defined during kernel compilation. | |
fea681da MK |
3112 | .TP |
3113 | .I /proc/filesystems | |
9ee4a2b6 MK |
3114 | A text listing of the filesystems which are supported by the kernel, |
3115 | namely filesystems which were compiled into the kernel or whose kernel | |
6387216b MK |
3116 | modules are currently loaded. |
3117 | (See also | |
fb477da2 | 3118 | .BR filesystems (5).) |
9ee4a2b6 | 3119 | If a filesystem is marked with "nodev", |
809d0164 | 3120 | this means that it does not require a block device to be mounted |
9ee4a2b6 | 3121 | (e.g., virtual filesystem, network filesystem). |
2dad4c59 | 3122 | .IP |
809d0164 MK |
3123 | Incidentally, this file may be used by |
3124 | .BR mount (8) | |
9ee4a2b6 MK |
3125 | when no filesystem is specified and it didn't manage to determine the |
3126 | filesystem type. | |
3127 | Then filesystems contained in this file are tried | |
809d0164 | 3128 | (excepted those that are marked with "nodev"). |
fea681da MK |
3129 | .TP |
3130 | .I /proc/fs | |
df352acc | 3131 | .\" FIXME Much more needs to be said about /proc/fs |
91085d85 | 3132 | .\" |
df352acc MK |
3133 | Contains subdirectories that in turn contain files |
3134 | with information about (certain) mounted filesystems. | |
fea681da MK |
3135 | .TP |
3136 | .I /proc/ide | |
3137 | This directory | |
59a40ed7 MK |
3138 | exists on systems with the IDE bus. |
3139 | There are directories for each IDE channel and attached device. | |
c13182ef | 3140 | Files include: |
2dad4c59 | 3141 | .IP |
a08ea57c | 3142 | .in +4n |
37d5e699 | 3143 | .EX |
fea681da MK |
3144 | cache buffer size in KB |
3145 | capacity number of sectors | |
3146 | driver driver version | |
3147 | geometry physical and logical geometry | |
9fdfa163 | 3148 | identify in hexadecimal |
fea681da MK |
3149 | media media type |
3150 | model manufacturer's model number | |
3151 | settings drive settings | |
9fdfa163 MK |
3152 | smart_thresholds in hexadecimal |
3153 | smart_values in hexadecimal | |
37d5e699 | 3154 | .EE |
a08ea57c | 3155 | .in |
2dad4c59 | 3156 | .IP |
c13182ef | 3157 | The |
fea681da MK |
3158 | .BR hdparm (8) |
3159 | utility provides access to this information in a friendly format. | |
3160 | .TP | |
3161 | .I /proc/interrupts | |
23ec6ff0 MK |
3162 | This is used to record the number of interrupts per CPU per IO device. |
3163 | Since Linux 2.6.24, | |
9ea5bc66 | 3164 | for the i386 and x86-64 architectures, at least, this also includes |
23ec6ff0 MK |
3165 | interrupts internal to the system (that is, not associated with a device |
3166 | as such), such as NMI (nonmaskable interrupt), LOC (local timer interrupt), | |
3167 | and for SMP systems, TLB (TLB flush interrupt), RES (rescheduling | |
3168 | interrupt), CAL (remote function call interrupt), and possibly others. | |
3169 | Very easy to read formatting, done in ASCII. | |
fea681da MK |
3170 | .TP |
3171 | .I /proc/iomem | |
3172 | I/O memory map in Linux 2.4. | |
3173 | .TP | |
3174 | .I /proc/ioports | |
c13182ef | 3175 | This is a list of currently registered Input-Output port regions that |
fea681da MK |
3176 | are in use. |
3177 | .TP | |
3178 | .IR /proc/kallsyms " (since Linux 2.5.71)" | |
3179 | This holds the kernel exported symbol definitions used by the | |
3180 | .BR modules (X) | |
3181 | tools to dynamically link and bind loadable modules. | |
3182 | In Linux 2.5.47 and earlier, a similar file with slightly different syntax | |
3183 | was named | |
3184 | .IR ksyms . | |
3185 | .TP | |
3186 | .I /proc/kcore | |
3187 | This file represents the physical memory of the system and is stored | |
c13182ef MK |
3188 | in the ELF core file format. |
3189 | With this pseudo-file, and an unstripped | |
9a67332e MK |
3190 | kernel |
3191 | .RI ( /usr/src/linux/vmlinux ) | |
3192 | binary, GDB can be used to | |
fea681da | 3193 | examine the current state of any kernel data structures. |
2dad4c59 | 3194 | .IP |
fea681da | 3195 | The total length of the file is the size of physical memory (RAM) plus |
ee8655b5 | 3196 | 4\ KiB. |
fea681da | 3197 | .TP |
653836fb MK |
3198 | .IR /proc/keys " (since Linux 2.6.10)" |
3199 | See | |
3200 | .BR keyrings (7). | |
3201 | .TP | |
3202 | .IR /proc/key-users " (since Linux 2.6.10)" | |
3203 | See | |
3204 | .BR keyrings (7). | |
3205 | .TP | |
fea681da MK |
3206 | .I /proc/kmsg |
3207 | This file can be used instead of the | |
3208 | .BR syslog (2) | |
c13182ef MK |
3209 | system call to read kernel messages. |
3210 | A process must have superuser | |
fea681da | 3211 | privileges to read this file, and only one process should read this |
c13182ef MK |
3212 | file. |
3213 | This file should not be read if a syslog process is running | |
fea681da MK |
3214 | which uses the |
3215 | .BR syslog (2) | |
3216 | system call facility to log kernel messages. | |
2dad4c59 | 3217 | .IP |
fea681da | 3218 | Information in this file is retrieved with the |
c4517613 | 3219 | .BR dmesg (1) |
fea681da MK |
3220 | program. |
3221 | .TP | |
55d68a94 | 3222 | .IR /proc/kpagecgroup " (since Linux 4.3)" |
0e462d71 | 3223 | .\" commit 80ae2fdceba8313b0433f899bdd9c6c463291a17 |
55d68a94 OE |
3224 | This file contains a 64-bit inode number of |
3225 | the memory cgroup each page is charged to, | |
3226 | indexed by page frame number (see the discussion of | |
3227 | .IR /proc/[pid]/pagemap ). | |
3228 | .IP | |
3229 | The | |
3230 | .IR /proc/kpagecgroup | |
3231 | file is present only if the | |
3232 | .B CONFIG_MEMCG | |
3233 | kernel configuration option is enabled. | |
3234 | .TP | |
ff56ac8b MK |
3235 | .IR /proc/kpagecount " (since Linux 2.6.25)" |
3236 | This file contains a 64-bit count of the number of | |
3237 | times each physical page frame is mapped, | |
3238 | indexed by page frame number (see the discussion of | |
3239 | .IR /proc/[pid]/pagemap ). | |
3240 | .IP | |
3241 | The | |
3242 | .IR /proc/kpagecount | |
3243 | file is present only if the | |
3244 | .B CONFIG_PROC_PAGE_MONITOR | |
59d566a9 MK |
3245 | kernel configuration option is enabled. |
3246 | .TP | |
3247 | .IR /proc/kpageflags " (since Linux 2.6.25)" | |
ef4f4031 | 3248 | This file contains 64-bit masks corresponding to each physical page frame; |
59d566a9 MK |
3249 | it is indexed by page frame number (see the discussion of |
3250 | .IR /proc/[pid]/pagemap ). | |
3251 | The bits are as follows: | |
2dad4c59 | 3252 | .IP |
59d566a9 MK |
3253 | 0 - KPF_LOCKED |
3254 | 1 - KPF_ERROR | |
3255 | 2 - KPF_REFERENCED | |
3256 | 3 - KPF_UPTODATE | |
3257 | 4 - KPF_DIRTY | |
3258 | 5 - KPF_LRU | |
3259 | 6 - KPF_ACTIVE | |
3260 | 7 - KPF_SLAB | |
3261 | 8 - KPF_WRITEBACK | |
3262 | 9 - KPF_RECLAIM | |
3263 | 10 - KPF_BUDDY | |
3264 | 11 - KPF_MMAP (since Linux 2.6.31) | |
3265 | 12 - KPF_ANON (since Linux 2.6.31) | |
3266 | 13 - KPF_SWAPCACHE (since Linux 2.6.31) | |
3267 | 14 - KPF_SWAPBACKED (since Linux 2.6.31) | |
3268 | 15 - KPF_COMPOUND_HEAD (since Linux 2.6.31) | |
3269 | 16 - KPF_COMPOUND_TAIL (since Linux 2.6.31) | |
d0ffc687 | 3270 | 17 - KPF_HUGE (since Linux 2.6.31) |
59d566a9 MK |
3271 | 18 - KPF_UNEVICTABLE (since Linux 2.6.31) |
3272 | 19 - KPF_HWPOISON (since Linux 2.6.31) | |
3273 | 20 - KPF_NOPAGE (since Linux 2.6.31) | |
3274 | 21 - KPF_KSM (since Linux 2.6.32) | |
3275 | 22 - KPF_THP (since Linux 3.4) | |
5487da4c MK |
3276 | 23 - KPF_BALLOON (since Linux 3.18) |
3277 | .\" KPF_BALLOON: commit 09316c09dde33aae14f34489d9e3d243ec0d5938 | |
f38dfdf1 | 3278 | 24 - KPF_ZERO_PAGE (since Linux 4.0) |
c6f182bc | 3279 | .\" KPF_ZERO_PAGE: commit 56873f43abdcd574b25105867a990f067747b2f4 |
f38dfdf1 | 3280 | 25 - KPF_IDLE (since Linux 4.3) |
c6f182bc | 3281 | .\" KPF_IDLE: commit f074a8f49eb87cde95ac9d040ad5e7ea4f029738 |
2dad4c59 | 3282 | .IP |
59d566a9 MK |
3283 | For further details on the meanings of these bits, |
3284 | see the kernel source file | |
a2463bae | 3285 | .IR Documentation/admin-guide/mm/pagemap.rst . |
59d566a9 MK |
3286 | Before kernel 2.6.29, |
3287 | .\" commit ad3bdefe877afb47480418fdb05ecd42842de65e | |
3288 | .\" commit e07a4b9217d1e97d2f3a62b6b070efdc61212110 | |
3289 | .BR KPF_WRITEBACK , | |
3290 | .BR KPF_RECLAIM , | |
3291 | .BR KPF_BUDDY , | |
3292 | and | |
3293 | .BR KPF_LOCKED | |
3294 | did not report correctly. | |
3295 | .IP | |
3296 | The | |
3297 | .IR /proc/kpageflags | |
3298 | file is present only if the | |
3299 | .B CONFIG_PROC_PAGE_MONITOR | |
ff56ac8b MK |
3300 | kernel configuration option is enabled. |
3301 | .TP | |
93f18cbb | 3302 | .IR /proc/ksyms " (Linux 1.1.23\(en2.5.47)" |
fea681da MK |
3303 | See |
3304 | .IR /proc/kallsyms . | |
3305 | .TP | |
3306 | .I /proc/loadavg | |
6b05dc38 MK |
3307 | The first three fields in this file are load average figures |
3308 | giving the number of jobs in the run queue (state R) | |
fea681da MK |
3309 | or waiting for disk I/O (state D) averaged over 1, 5, and 15 minutes. |
3310 | They are the same as the load average numbers given by | |
3311 | .BR uptime (1) | |
3312 | and other programs. | |
6b05dc38 | 3313 | The fourth field consists of two numbers separated by a slash (/). |
78fc91ec EDB |
3314 | The first of these is the number of currently runnable kernel |
3315 | scheduling entities (processes, threads). | |
6b05dc38 MK |
3316 | The value after the slash is the number of kernel scheduling entities |
3317 | that currently exist on the system. | |
3318 | The fifth field is the PID of the process that was most | |
3319 | recently created on the system. | |
fea681da MK |
3320 | .TP |
3321 | .I /proc/locks | |
3322 | This file shows current file locks | |
3323 | .RB ( flock "(2) and " fcntl (2)) | |
3324 | and leases | |
3325 | .RB ( fcntl (2)). | |
f352b560 MK |
3326 | .IP |
3327 | An example of the content shown in this file is the following: | |
3328 | .IP | |
3329 | .in +4n | |
3330 | .EX | |
3331 | 1: POSIX ADVISORY READ 5433 08:01:7864448 128 128 | |
3332 | 2: FLOCK ADVISORY WRITE 2001 08:01:7864554 0 EOF | |
3333 | 3: FLOCK ADVISORY WRITE 1568 00:2f:32388 0 EOF | |
3334 | 4: POSIX ADVISORY WRITE 699 00:16:28457 0 EOF | |
3335 | 5: POSIX ADVISORY WRITE 764 00:16:21448 0 0 | |
3336 | 6: POSIX ADVISORY READ 3548 08:01:7867240 1 1 | |
3337 | 7: POSIX ADVISORY READ 3548 08:01:7865567 1826 2335 | |
3338 | 8: OFDLCK ADVISORY WRITE -1 08:01:8713209 128 191 | |
3339 | .EE | |
3340 | .in | |
3341 | .IP | |
3342 | The fields shown in each line are as follows: | |
3343 | .RS | |
3344 | .IP (1) 4 | |
3345 | The ordinal position of the lock in the list. | |
3346 | .IP (2) | |
3347 | The lock type. | |
3348 | Values that may appear here include: | |
3349 | .RS | |
3350 | .TP | |
3351 | .B FLOCK | |
3352 | This is a BSD file lock created using | |
3353 | .BR flock (2). | |
3354 | .TP | |
3355 | .B OFDLCK | |
3356 | This is an open file description (OFD) lock created using | |
3357 | .BR fcntl (2). | |
3358 | .TP | |
3359 | .B POSIX | |
3360 | This is a POSIX byte-range lock created using | |
3361 | .BR fcntl (2). | |
3362 | .RE | |
3363 | .IP (3) | |
3364 | Among the strings that can appear here are the following: | |
3365 | .RS | |
3366 | .TP | |
3367 | .B ADVISORY | |
3368 | This is an advisory lock. | |
3369 | .TP | |
3370 | .B MANDATORY | |
3371 | This is a mandatory lock. | |
3372 | .RE | |
3373 | .IP (4) | |
3374 | The type of lock. | |
3375 | Values that can appear here are: | |
3376 | .RS | |
3377 | .TP | |
3378 | .B READ | |
3379 | This is a POSIX or OFD read lock, or a BSD shared lock. | |
3380 | .TP | |
3381 | .B WRITE | |
3382 | This is a POSIX or OFD write lock, or a BSD exclusive lock. | |
3383 | .RE | |
3384 | .IP (5) | |
3385 | The PID of the process that owns the lock. | |
3386 | .IP | |
3387 | Because OFD locks are not owned by a single process | |
3388 | (since multiple processes may have file descriptors that | |
3389 | refer to the same open file description), | |
3390 | the value \-1 is displayed in this field for OFD locks. | |
3391 | (Before kernel 4.14, | |
52f842a5 | 3392 | .\" commit 9d5b86ac13c573795525ecac6ed2db39ab23e2a8 |
f352b560 MK |
3393 | a bug meant that the PID of the process that |
3394 | initially acquired the lock was displayed instead of the value \-1.) | |
3395 | .IP (6) | |
3396 | Three colon-separated subfields that identify the major and minor device | |
3397 | ID of the device containing the filesystem where the locked file resides, | |
3398 | followed by the inode number of the locked file. | |
3399 | .IP (7) | |
3400 | The byte offset of the first byte of the lock. | |
3401 | For BSD locks, this value is always 0. | |
3402 | .IP (8) | |
3403 | The byte offset of the last byte of the lock. | |
3404 | .B EOF | |
3405 | in this field means that the lock extends to the end of the file. | |
3406 | For BSD locks, the value shown is always | |
3407 | .IR EOF . | |
3408 | .RE | |
3409 | .IP | |
8fb9b45a MK |
3410 | Since Linux 4.9, |
3411 | .\" commit d67fd44f697dff293d7cdc29af929241b669affe | |
3412 | the list of locks shown in | |
3413 | .I /proc/locks | |
3414 | is filtered to show just the locks for the processes in the PID | |
3415 | namespace (see | |
3416 | .BR pid_namespaces (7)) | |
3417 | for which the | |
3418 | .I /proc | |
3419 | filesystem was mounted. | |
1dbe854b | 3420 | (In the initial PID namespace, |
8fb9b45a MK |
3421 | there is no filtering of the records shown in this file.) |
3422 | .IP | |
9f1002a1 MK |
3423 | The |
3424 | .BR lslocks (8) | |
3425 | command provides a bit more information about each lock. | |
fea681da | 3426 | .TP |
89dd5f8a | 3427 | .IR /proc/malloc " (only up to and including Linux 2.2)" |
59a40ed7 | 3428 | .\" It looks like this only ever did something back in 1.0 days |
90878f7c | 3429 | This file is present only if |
89dd5f8a | 3430 | .B CONFIG_DEBUG_MALLOC |
097585ed | 3431 | was defined during compilation. |
fea681da MK |
3432 | .TP |
3433 | .I /proc/meminfo | |
77b802ec MK |
3434 | This file reports statistics about memory usage on the system. |
3435 | It is used by | |
fea681da MK |
3436 | .BR free (1) |
3437 | to report the amount of free and used memory (both physical and swap) | |
3438 | on the system as well as the shared memory and buffers used by the | |
3439 | kernel. | |
3ba3d5b1 MK |
3440 | Each line of the file consists of a parameter name, followed by a colon, |
3441 | the value of the parameter, and an option unit of measurement (e.g., "kB"). | |
3442 | The list below describes the parameter names and | |
3443 | the format specifier required to read the field value. | |
3444 | Except as noted below, | |
3445 | all of the fields have been present since at least Linux 2.6.0. | |
86cf87d7 | 3446 | Some fields are displayed only if the kernel was configured |
3ba3d5b1 MK |
3447 | with various options; those dependencies are noted in the list. |
3448 | .RS | |
3449 | .TP | |
3450 | .IR MemTotal " %lu" | |
449dd4e2 | 3451 | Total usable RAM (i.e., physical RAM minus a few reserved |
99e91586 | 3452 | bits and the kernel binary code). |
3ba3d5b1 MK |
3453 | .TP |
3454 | .IR MemFree " %lu" | |
7bccb7d4 DP |
3455 | The sum of |
3456 | .IR LowFree + HighFree . | |
3ba3d5b1 | 3457 | .TP |
8b4b1f68 MK |
3458 | .IR MemAvailable " %lu (since Linux 3.14)" |
3459 | An estimate of how much memory is available for starting new | |
3460 | applications, without swapping. | |
3461 | .TP | |
3ba3d5b1 | 3462 | .IR Buffers " %lu" |
99e91586 | 3463 | Relatively temporary storage for raw disk blocks that |
3ba3d5b1 MK |
3464 | shouldn't get tremendously large (20MB or so). |
3465 | .TP | |
3466 | .IR Cached " %lu" | |
3467 | In-memory cache for files read from the disk (the page cache). | |
3468 | Doesn't include | |
3469 | .IR SwapCached . | |
3470 | .TP | |
3471 | .IR SwapCached " %lu" | |
3472 | Memory that once was swapped out, is swapped back in but | |
3473 | still also is in the swap file. | |
fa1d2749 | 3474 | (If memory pressure is high, these pages |
3ba3d5b1 | 3475 | don't need to be swapped out again because they are already |
99e91586 | 3476 | in the swap file. |
3ba3d5b1 MK |
3477 | This saves I/O.) |
3478 | .TP | |
3479 | .IR Active " %lu" | |
3480 | Memory that has been used more recently and usually not | |
3481 | reclaimed unless absolutely necessary. | |
3482 | .TP | |
3483 | .IR Inactive " %lu" | |
3484 | Memory which has been less recently used. | |
3485 | It is more eligible to be reclaimed for other purposes. | |
3486 | .TP | |
3487 | .IR Active(anon) " %lu (since Linux 2.6.28)" | |
3488 | [To be documented.] | |
3489 | .TP | |
3490 | .IR Inactive(anon) " %lu (since Linux 2.6.28)" | |
3491 | [To be documented.] | |
3492 | .TP | |
3493 | .IR Active(file) " %lu (since Linux 2.6.28)" | |
3494 | [To be documented.] | |
3495 | .TP | |
3496 | .IR Inactive(file) " %lu (since Linux 2.6.28)" | |
3497 | [To be documented.] | |
3498 | .TP | |
3499 | .IR Unevictable " %lu (since Linux 2.6.28)" | |
3500 | (From Linux 2.6.28 to 2.6.30, | |
3501 | \fBCONFIG_UNEVICTABLE_LRU\fP was required.) | |
3502 | [To be documented.] | |
3503 | .TP | |
46fbfc07 | 3504 | .IR Mlocked " %lu (since Linux 2.6.28)" |
3ba3d5b1 MK |
3505 | (From Linux 2.6.28 to 2.6.30, |
3506 | \fBCONFIG_UNEVICTABLE_LRU\fP was required.) | |
3507 | [To be documented.] | |
3508 | .TP | |
3509 | .IR HighTotal " %lu" | |
3510 | (Starting with Linux 2.6.19, \fBCONFIG_HIGHMEM\fP is required.) | |
3511 | Total amount of highmem. | |
99e91586 | 3512 | Highmem is all memory above ~860MB of physical memory. |
3ba3d5b1 MK |
3513 | Highmem areas are for use by user-space programs, |
3514 | or for the page cache. | |
3515 | The kernel must use tricks to access | |
3516 | this memory, making it slower to access than lowmem. | |
3517 | .TP | |
3518 | .IR HighFree " %lu | |
3519 | (Starting with Linux 2.6.19, \fBCONFIG_HIGHMEM\fP is required.) | |
3520 | Amount of free highmem. | |
3521 | .TP | |
3522 | .IR LowTotal " %lu | |
3523 | (Starting with Linux 2.6.19, \fBCONFIG_HIGHMEM\fP is required.) | |
3524 | Total amount of lowmem. | |
3525 | Lowmem is memory which can be used for everything that | |
3526 | highmem can be used for, but it is also available for the | |
3527 | kernel's use for its own data structures. | |
3528 | Among many other things, | |
99e91586 | 3529 | it is where everything from |
7bccb7d4 DP |
3530 | .I Slab |
3531 | is allocated. | |
3ba3d5b1 MK |
3532 | Bad things happen when you're out of lowmem. |
3533 | .TP | |
3534 | .IR LowFree " %lu | |
3535 | (Starting with Linux 2.6.19, \fBCONFIG_HIGHMEM\fP is required.) | |
3536 | Amount of free lowmem. | |
3537 | .TP | |
3538 | .IR MmapCopy " %lu (since Linux 2.6.29)" | |
99e91586 DP |
3539 | .RB ( CONFIG_MMU |
3540 | is required.) | |
3ba3d5b1 MK |
3541 | [To be documented.] |
3542 | .TP | |
3543 | .IR SwapTotal " %lu" | |
3544 | Total amount of swap space available. | |
3545 | .TP | |
3546 | .IR SwapFree " %lu" | |
c16d4f25 | 3547 | Amount of swap space that is currently unused. |
3ba3d5b1 MK |
3548 | .TP |
3549 | .IR Dirty " %lu" | |
3550 | Memory which is waiting to get written back to the disk. | |
3551 | .TP | |
3552 | .IR Writeback " %lu" | |
3553 | Memory which is actively being written back to the disk. | |
3554 | .TP | |
3555 | .IR AnonPages " %lu (since Linux 2.6.18)" | |
3556 | Non-file backed pages mapped into user-space page tables. | |
3557 | .TP | |
3558 | .IR Mapped " %lu" | |
fda70f5b MK |
3559 | Files which have been mapped into memory (with |
3560 | .BR mmap (2)), | |
3561 | such as libraries. | |
3ba3d5b1 MK |
3562 | .TP |
3563 | .IR Shmem " %lu (since Linux 2.6.32)" | |
eb775c04 MK |
3564 | Amount of memory consumed in |
3565 | .BR tmpfs (5) | |
3566 | filesystems. | |
3ba3d5b1 | 3567 | .TP |
7375eaab MK |
3568 | .IR KReclaimable " %lu (since Linux 4.20)" |
3569 | Kernel allocations that the kernel will attempt to reclaim | |
3570 | under memory pressure. | |
3571 | Includes | |
3572 | .I SReclaimable | |
3573 | (below), and other direct allocations with a shrinker. | |
3574 | .TP | |
3ba3d5b1 MK |
3575 | .IR Slab " %lu" |
3576 | In-kernel data structures cache. | |
5a5bde70 MK |
3577 | (See |
3578 | .BR slabinfo (5).) | |
3ba3d5b1 MK |
3579 | .TP |
3580 | .IR SReclaimable " %lu (since Linux 2.6.19)" | |
7bccb7d4 DP |
3581 | Part of |
3582 | .IR Slab , | |
3583 | that might be reclaimed, such as caches. | |
3ba3d5b1 MK |
3584 | .TP |
3585 | .IR SUnreclaim " %lu (since Linux 2.6.19)" | |
7bccb7d4 DP |
3586 | Part of |
3587 | .IR Slab , | |
3588 | that cannot be reclaimed on memory pressure. | |
3ba3d5b1 MK |
3589 | .TP |
3590 | .IR KernelStack " %lu (since Linux 2.6.32)" | |
3591 | Amount of memory allocated to kernel stacks. | |
3592 | .TP | |
3593 | .IR PageTables " %lu (since Linux 2.6.18)" | |
3594 | Amount of memory dedicated to the lowest level of page tables. | |
3595 | .TP | |
3596 | .IR Quicklists " %lu (since Linux 2.6.27)" | |
3597 | (\fBCONFIG_QUICKLIST\fP is required.) | |
3598 | [To be documented.] | |
3599 | .TP | |
3600 | .IR NFS_Unstable " %lu (since Linux 2.6.18)" | |
3601 | NFS pages sent to the server, but not yet committed to stable storage. | |
3602 | .TP | |
3603 | .IR Bounce " %lu (since Linux 2.6.18)" | |
3604 | Memory used for block device "bounce buffers". | |
3605 | .TP | |
3606 | .IR WritebackTmp " %lu (since Linux 2.6.26)" | |
3607 | Memory used by FUSE for temporary writeback buffers. | |
3608 | .TP | |
3609 | .IR CommitLimit " %lu (since Linux 2.6.10)" | |
cd7b6c40 MK |
3610 | This is the total amount of memory currently available to |
3611 | be allocated on the system, expressed in kilobytes. | |
90878f7c MK |
3612 | This limit is adhered to |
3613 | only if strict overcommit accounting is enabled (mode 2 in | |
cd7b6c40 MK |
3614 | .IR /proc/sys/vm/overcommit_memory ). |
3615 | The limit is calculated according to the formula described under | |
3616 | .IR /proc/sys/vm/overcommit_memory . | |
3617 | For further details, see the kernel source file | |
a2463bae | 3618 | .IR Documentation/vm/overcommit-accounting.rst . |
3ba3d5b1 MK |
3619 | .TP |
3620 | .IR Committed_AS " %lu" | |
3621 | The amount of memory presently allocated on the system. | |
3622 | The committed memory is a sum of all of the memory which | |
3623 | has been allocated by processes, even if it has not been | |
3624 | "used" by them as of yet. | |
3625 | A process which allocates 1GB of memory (using | |
3626 | .BR malloc (3) | |
33a0ccb2 | 3627 | or similar), but touches only 300MB of that memory will show up |
90878f7c | 3628 | as using only 300MB of memory even if it has the address space |
3ba3d5b1 | 3629 | allocated for the entire 1GB. |
2dad4c59 | 3630 | .IP |
3ba3d5b1 MK |
3631 | This 1GB is memory which has been "committed" to by the VM |
3632 | and can be used at any time by the allocating application. | |
cd7b6c40 | 3633 | With strict overcommit enabled on the system (mode 2 in |
d9e0f03d | 3634 | .IR /proc/sys/vm/overcommit_memory ), |
3ba3d5b1 MK |
3635 | allocations which would exceed the |
3636 | .I CommitLimit | |
cd7b6c40 | 3637 | will not be permitted. |
3ba3d5b1 MK |
3638 | This is useful if one needs to guarantee that processes will not |
3639 | fail due to lack of memory once that memory has been successfully allocated. | |
3640 | .TP | |
3641 | .IR VmallocTotal " %lu" | |
3642 | Total size of vmalloc memory area. | |
3643 | .TP | |
3644 | .IR VmallocUsed " %lu" | |
2fc546f9 MK |
3645 | Amount of vmalloc area which is used. |
3646 | Since Linux 4.4, | |
3647 | .\" commit a5ad88ce8c7fae7ddc72ee49a11a75aa837788e0 | |
3648 | this field is no longer calculated, and is hard coded as 0. | |
3649 | See | |
bfe9256a | 3650 | .IR /proc/vmallocinfo . |
3ba3d5b1 MK |
3651 | .TP |
3652 | .IR VmallocChunk " %lu" | |
2fc546f9 MK |
3653 | Largest contiguous block of vmalloc area which is free. |
3654 | Since Linux 4.4, | |
3655 | .\" commit a5ad88ce8c7fae7ddc72ee49a11a75aa837788e0 | |
3656 | this field is no longer calculated and is hard coded as 0. | |
3657 | See | |
bfe9256a | 3658 | .IR /proc/vmallocinfo . |
3ba3d5b1 MK |
3659 | .TP |
3660 | .IR HardwareCorrupted " %lu (since Linux 2.6.32)" | |
3661 | (\fBCONFIG_MEMORY_FAILURE\fP is required.) | |
3662 | [To be documented.] | |
3663 | .TP | |
f7bbc79d MK |
3664 | .IR LazyFree " %lu (since Linux 4.12)" |
3665 | Shows the amount of memory marked by | |
3666 | .BR madvise (2) | |
3667 | .BR MADV_FREE . | |
3668 | .TP | |
3ba3d5b1 MK |
3669 | .IR AnonHugePages " %lu (since Linux 2.6.38)" |
3670 | (\fBCONFIG_TRANSPARENT_HUGEPAGE\fP is required.) | |
7fac88a9 | 3671 | Non-file backed huge pages mapped into user-space page tables. |
3ba3d5b1 | 3672 | .TP |
4ad958e1 MK |
3673 | .IR ShmemHugePages " %lu (since Linux 4.8)" |
3674 | (\fBCONFIG_TRANSPARENT_HUGEPAGE\fP is required.) | |
4e07c70f MK |
3675 | Memory used by shared memory (shmem) and |
3676 | .BR tmpfs (5) | |
3677 | allocated with huge pages | |
4ad958e1 MK |
3678 | .TP |
3679 | .IR ShmemPmdMapped " %lu (since Linux 4.8)" | |
3680 | (\fBCONFIG_TRANSPARENT_HUGEPAGE\fP is required.) | |
956e74b4 | 3681 | Shared memory mapped into user space with huge pages. |
4ad958e1 | 3682 | .TP |
43179f55 MK |
3683 | .IR CmaTotal " %lu (since Linux 3.1)" |
3684 | Total CMA (Contiguous Memory Allocator) pages. | |
3685 | (\fBCONFIG_CMA\fP is required.) | |
3686 | .TP | |
3687 | .IR CmaFree " %lu (since Linux 3.1)" | |
3688 | Free CMA (Contiguous Memory Allocator) pages. | |
3689 | (\fBCONFIG_CMA\fP is required.) | |
3690 | .TP | |
3ba3d5b1 MK |
3691 | .IR HugePages_Total " %lu" |
3692 | (\fBCONFIG_HUGETLB_PAGE\fP is required.) | |
3693 | The size of the pool of huge pages. | |
3694 | .TP | |
3695 | .IR HugePages_Free " %lu" | |
3696 | (\fBCONFIG_HUGETLB_PAGE\fP is required.) | |
3697 | The number of huge pages in the pool that are not yet allocated. | |
3698 | .TP | |
3699 | .IR HugePages_Rsvd " %lu (since Linux 2.6.17)" | |
3700 | (\fBCONFIG_HUGETLB_PAGE\fP is required.) | |
3701 | This is the number of huge pages for | |
3702 | which a commitment to allocate from the pool has been made, | |
3703 | but no allocation has yet been made. | |
3704 | These reserved huge pages | |
3705 | guarantee that an application will be able to allocate a | |
3706 | huge page from the pool of huge pages at fault time. | |
3707 | .TP | |
aa8a6b4f | 3708 | .IR HugePages_Surp " %lu (since Linux 2.6.24)" |
3ba3d5b1 MK |
3709 | (\fBCONFIG_HUGETLB_PAGE\fP is required.) |
3710 | This is the number of huge pages in | |
3711 | the pool above the value in | |
3712 | .IR /proc/sys/vm/nr_hugepages . | |
3713 | The maximum number of surplus huge pages is controlled by | |
3714 | .IR /proc/sys/vm/nr_overcommit_hugepages . | |
3715 | .TP | |
3716 | .IR Hugepagesize " %lu" | |
3717 | (\fBCONFIG_HUGETLB_PAGE\fP is required.) | |
3718 | The size of huge pages. | |
d5268de1 MK |
3719 | .TP |
3720 | .IR DirectMap4k " %lu (since Linux 2.6.27)" | |
3721 | Number of bytes of RAM linearly mapped by kernel in 4kB pages. | |
3722 | (x86.) | |
3723 | .TP | |
3724 | .IR DirectMap4M " %lu (since Linux 2.6.27)" | |
3725 | Number of bytes of RAM linearly mapped by kernel in 4MB pages. | |
3726 | (x86 with | |
3727 | .BR CONFIG_X86_64 | |
3728 | or | |
3729 | .BR CONFIG_X86_PAE | |
3730 | enabled.) | |
3731 | .TP | |
3732 | .IR DirectMap2M " %lu (since Linux 2.6.27)" | |
3733 | Number of bytes of RAM linearly mapped by kernel in 2MB pages. | |
3734 | (x86 with neither | |
3735 | .BR CONFIG_X86_64 | |
3736 | nor | |
3737 | .BR CONFIG_X86_PAE | |
3738 | enabled.) | |
3739 | .TP | |
3740 | .IR DirectMap1G " %lu (since Linux 2.6.27)" | |
3741 | (x86 with | |
3742 | .BR CONFIG_X86_64 | |
3743 | and | |
3744 | .B CONFIG_X86_DIRECT_GBPAGES | |
3745 | enabled.) | |
3ba3d5b1 | 3746 | .RE |
fea681da | 3747 | .TP |
aa341984 MK |
3748 | .I /proc/modules |
3749 | A text list of the modules that have been loaded by the system. | |
3750 | See also | |
3751 | .BR lsmod (8). | |
3752 | .TP | |
fea681da | 3753 | .I /proc/mounts |
c1eea65a | 3754 | Before kernel 2.4.19, this file was a list |
9ee4a2b6 | 3755 | of all the filesystems currently mounted on the system. |
ef5b47f6 MK |
3756 | With the introduction of per-process mount namespaces in Linux 2.4.19 (see |
3757 | .BR mount_namespaces (7)), | |
3758 | this file became a link to | |
c1eea65a | 3759 | .IR /proc/self/mounts , |
732e54dd | 3760 | which lists the mount points of the process's own mount namespace. |
fea681da | 3761 | The format of this file is documented in |
31e9a9ec | 3762 | .BR fstab (5). |
fea681da | 3763 | .TP |
fea681da | 3764 | .I /proc/mtrr |
c13182ef | 3765 | Memory Type Range Registers. |
66a9882e | 3766 | See the Linux kernel source file |
a8999e1f ES |
3767 | .I Documentation/x86/mtrr.txt |
3768 | .\" commit 7225e75144b9718cbbe1820d9c011c809d5773fd | |
3769 | (or | |
cfe70b66 | 3770 | .I Documentation/mtrr.txt |
a8999e1f | 3771 | before Linux 2.6.28) |
fea681da MK |
3772 | for details. |
3773 | .TP | |
3774 | .I /proc/net | |
ccb4bcdc MK |
3775 | This directory contains various files and subdirectories containing |
3776 | information about the networking layer. | |
3777 | The files contain ASCII structures and are, | |
59a40ed7 MK |
3778 | therefore, readable with |
3779 | .BR cat (1). | |
c13182ef | 3780 | However, the standard |
fea681da MK |
3781 | .BR netstat (8) |
3782 | suite provides much cleaner access to these files. | |
2dad4c59 | 3783 | .IP |
9fb88bc8 MK |
3784 | With the advent of network namespaces, |
3785 | various information relating to the network stack is virtualized (see | |
3786 | .BR namespaces (7)). | |
3787 | Thus, since Linux 2.6.25, | |
3788 | .\" commit e9720acd728a46cb40daa52c99a979f7c4ff195c | |
3789 | .IR /proc/net | |
3790 | is a symbolic link to the directory | |
3791 | .IR /proc/self/net , | |
3792 | which contains the same files and directories as listed below. | |
3793 | However, these files and directories now expose information | |
3794 | for the network namespace of which the process is a member. | |
fea681da MK |
3795 | .TP |
3796 | .I /proc/net/arp | |
3797 | This holds an ASCII readable dump of the kernel ARP table used for | |
c13182ef | 3798 | address resolutions. |
01d0a447 | 3799 | It will show both dynamically learned and preprogrammed ARP entries. |
c13182ef | 3800 | The format is: |
c1a022dc MK |
3801 | .IP |
3802 | .in 7n | |
3803 | .EX | |
fea681da MK |
3804 | IP address HW type Flags HW address Mask Device |
3805 | 192.168.0.50 0x1 0x2 00:50:BF:25:68:F3 * eth0 | |
3806 | 192.168.0.250 0x1 0xc 00:00:00:00:00:00 * eth0 | |
c1a022dc | 3807 | .EE |
fea681da | 3808 | .in |
c1a022dc | 3809 | .IP |
6c04f928 | 3810 | Here "IP address" is the IPv4 address of the machine and the "HW type" |
c13182ef MK |
3811 | is the hardware type of the address from RFC\ 826. |
3812 | The flags are the internal | |
9a67332e MK |
3813 | flags of the ARP structure (as defined in |
3814 | .IR /usr/include/linux/if_arp.h ) | |
3815 | and | |
6c04f928 | 3816 | the "HW address" is the data link layer mapping for that IP address if |
fea681da MK |
3817 | it is known. |
3818 | .TP | |
3819 | .I /proc/net/dev | |
c13182ef MK |
3820 | The dev pseudo-file contains network device status information. |
3821 | This gives | |
3822 | the number of received and sent packets, the number of errors and | |
fea681da | 3823 | collisions |
c13182ef MK |
3824 | and other basic statistics. |
3825 | These are used by the | |
fea681da | 3826 | .BR ifconfig (8) |
c13182ef MK |
3827 | program to report device status. |
3828 | The format is: | |
c1a022dc | 3829 | .IP |
fea681da | 3830 | .in 1n |
c1a022dc | 3831 | .EX |
fea681da MK |
3832 | Inter-| Receive | Transmit |
3833 | face |bytes packets errs drop fifo frame compressed multicast|bytes packets errs drop fifo colls carrier compressed | |
3834 | lo: 2776770 11307 0 0 0 0 0 0 2776770 11307 0 0 0 0 0 0 | |
3835 | eth0: 1215645 2751 0 0 0 0 0 0 1782404 4324 0 0 0 427 0 0 | |
3836 | ppp0: 1622270 5552 1 0 0 0 0 0 354130 5669 0 0 0 0 0 0 | |
3837 | tap0: 7714 81 0 0 0 0 0 0 7714 81 0 0 0 0 0 0 | |
c1a022dc | 3838 | .EE |
fea681da | 3839 | .in |
fea681da MK |
3840 | .\" .TP |
3841 | .\" .I /proc/net/ipx | |
3842 | .\" No information. | |
3843 | .\" .TP | |
3844 | .\" .I /proc/net/ipx_route | |
3845 | .\" No information. | |
3846 | .TP | |
3847 | .I /proc/net/dev_mcast | |
3848 | Defined in | |
3849 | .IR /usr/src/linux/net/core/dev_mcast.c : | |
37d5e699 MK |
3850 | .IP |
3851 | .in +4 | |
3852 | .EX | |
9fdfa163 | 3853 | indx interface_name dmi_u dmi_g dmi_address |
fea681da MK |
3854 | 2 eth0 1 0 01005e000001 |
3855 | 3 eth1 1 0 01005e000001 | |
3856 | 4 eth2 1 0 01005e000001 | |
37d5e699 | 3857 | .EE |
fea681da | 3858 | .in |
fea681da MK |
3859 | .TP |
3860 | .I /proc/net/igmp | |
c13182ef MK |
3861 | Internet Group Management Protocol. |
3862 | Defined in | |
fea681da MK |
3863 | .IR /usr/src/linux/net/core/igmp.c . |
3864 | .TP | |
3865 | .I /proc/net/rarp | |
3866 | This file uses the same format as the | |
3867 | .I arp | |
3868 | file and contains the current reverse mapping database used to provide | |
3869 | .BR rarp (8) | |
c13182ef MK |
3870 | reverse address lookup services. |
3871 | If RARP is not configured into the | |
fea681da MK |
3872 | kernel, |
3873 | this file will not be present. | |
3874 | .TP | |
3875 | .I /proc/net/raw | |
c13182ef MK |
3876 | Holds a dump of the RAW socket table. |
3877 | Much of the information is not of | |
fea681da | 3878 | use |
c13182ef | 3879 | apart from debugging. |
6c04f928 | 3880 | The "sl" value is the kernel hash slot for the |
fea681da | 3881 | socket, |
6c04f928 MK |
3882 | the "local_address" is the local address and protocol number pair. |
3883 | \&"St" is | |
c13182ef MK |
3884 | the internal status of the socket. |
3885 | The "tx_queue" and "rx_queue" are the | |
fea681da | 3886 | outgoing and incoming data queue in terms of kernel memory usage. |
94e9d9fe | 3887 | The "tr", "tm\->when", and "rexmits" fields are not used by RAW. |
fdc196f5 MK |
3888 | The "uid" |
3889 | field holds the effective UID of the creator of the socket. | |
fea681da MK |
3890 | .\" .TP |
3891 | .\" .I /proc/net/route | |
3892 | .\" No information, but looks similar to | |
3893 | .\" .BR route (8). | |
3894 | .TP | |
3895 | .I /proc/net/snmp | |
c13182ef | 3896 | This file holds the ASCII data needed for the IP, ICMP, TCP, and UDP |
fea681da | 3897 | management |
763f0e47 | 3898 | information bases for an SNMP agent. |
fea681da MK |
3899 | .TP |
3900 | .I /proc/net/tcp | |
c13182ef MK |
3901 | Holds a dump of the TCP socket table. |
3902 | Much of the information is not | |
3903 | of use apart from debugging. | |
3904 | The "sl" value is the kernel hash slot | |
6beb1671 MK |
3905 | for the socket, the "local_address" is the local address and port number pair. |
3906 | The "rem_address" is the remote address and port number pair | |
6c04f928 MK |
3907 | (if connected). |
3908 | \&"St" is the internal status of the socket. | |
3909 | The "tx_queue" and "rx_queue" are the | |
fea681da | 3910 | outgoing and incoming data queue in terms of kernel memory usage. |
94e9d9fe | 3911 | The "tr", "tm\->when", and "rexmits" fields hold internal information of |
f33774c4 | 3912 | the kernel socket state and are useful only for debugging. |
fdc196f5 MK |
3913 | The "uid" |
3914 | field holds the effective UID of the creator of the socket. | |
fea681da MK |
3915 | .TP |
3916 | .I /proc/net/udp | |
c13182ef MK |
3917 | Holds a dump of the UDP socket table. |
3918 | Much of the information is not of | |
3919 | use apart from debugging. | |
3920 | The "sl" value is the kernel hash slot for the | |
6beb1671 MK |
3921 | socket, the "local_address" is the local address and port number pair. |
3922 | The "rem_address" is the remote address and port number pair | |
f2d607ee MK |
3923 | (if connected). |
3924 | "St" is the internal status of the socket. | |
fea681da | 3925 | The "tx_queue" and "rx_queue" are the outgoing and incoming data queue |
c13182ef | 3926 | in terms of kernel memory usage. |
94e9d9fe | 3927 | The "tr", "tm\->when", and "rexmits" fields |
c13182ef | 3928 | are not used by UDP. |
fdc196f5 MK |
3929 | The "uid" |
3930 | field holds the effective UID of the creator of the socket. | |
fea681da | 3931 | The format is: |
c1a022dc | 3932 | .IP |
fea681da | 3933 | .in 1n |
c1a022dc | 3934 | .EX |
94e9d9fe | 3935 | sl local_address rem_address st tx_queue rx_queue tr rexmits tm\->when uid |
fea681da MK |
3936 | 1: 01642C89:0201 0C642C89:03FF 01 00000000:00000001 01:000071BA 00000000 0 |
3937 | 1: 00000000:0801 00000000:0000 0A 00000000:00000000 00:00000000 6F000100 0 | |
3938 | 1: 00000000:0201 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 | |
c1a022dc | 3939 | .EE |
fea681da | 3940 | .in |
c1a022dc | 3941 | .IP |
fea681da MK |
3942 | .TP |
3943 | .I /proc/net/unix | |
008f1ecc | 3944 | Lists the UNIX domain sockets present within the system and their |
c13182ef MK |
3945 | status. |
3946 | The format is: | |
c1a022dc MK |
3947 | .IP |
3948 | .in 1n | |
3949 | .EX | |
fea681da MK |
3950 | Num RefCount Protocol Flags Type St Path |
3951 | 0: 00000002 00000000 00000000 0001 03 | |
3952 | 1: 00000001 00000000 00010000 0001 01 /dev/printer | |
c1a022dc MK |
3953 | .EE |
3954 | .in | |
3955 | .IP | |
756f55f6 MK |
3956 | The fields are as follows: |
3957 | .RS | |
3958 | .TP 10 | |
3959 | .IR Num : | |
3960 | the kernel table slot number. | |
3961 | .TP | |
3962 | .IR RefCount : | |
3963 | the number of users of the socket. | |
3964 | .TP | |
3965 | .IR Protocol : | |
3966 | currently always 0. | |
3967 | .TP | |
3968 | .IR Flags : | |
3969 | the internal kernel flags holding the status of the socket. | |
3970 | .TP | |
3971 | .IR Type : | |
a405066e MK |
3972 | the socket type. |
3973 | For | |
3974 | .BR SOCK_STREAM | |
3975 | sockets, this is 0001; for | |
3976 | .BR SOCK_DGRAM | |
3977 | sockets, it is 0002; and for | |
3978 | .BR SOCK_SEQPACKET | |
3979 | sockets, it is 0005. | |
756f55f6 MK |
3980 | .TP |
3981 | .IR St : | |
3982 | the internal state of the socket. | |
3983 | .TP | |
3984 | .IR Path : | |
590ba7e5 | 3985 | the bound pathname (if any) of the socket. |
8f8a46fb MK |
3986 | Sockets in the abstract namespace are included in the list, |
3987 | and are shown with a | |
3988 | .I Path | |
3989 | that commences with the character '@'. | |
756f55f6 | 3990 | .RE |
fea681da | 3991 | .TP |
ed8de0e4 | 3992 | .I /proc/net/netfilter/nfnetlink_queue |
6f858d5c | 3993 | This file contains information about netfilter user-space queueing, if used. |
f2d607ee MK |
3994 | Each line represents a queue. |
3995 | Queues that have not been subscribed to | |
6f858d5c | 3996 | by user space are not shown. |
37d5e699 MK |
3997 | .IP |
3998 | .in +4n | |
3999 | .EX | |
ed8de0e4 FW |
4000 | 1 4207 0 2 65535 0 0 0 1 |
4001 | (1) (2) (3)(4) (5) (6) (7) (8) | |
37d5e699 MK |
4002 | .EE |
4003 | .in | |
ed8de0e4 FW |
4004 | .IP |
4005 | The fields in each line are: | |
4006 | .RS 7 | |
4007 | .TP 5 | |
4008 | (1) | |
f2d607ee MK |
4009 | The ID of the queue. |
4010 | This matches what is specified in the | |
ed8de0e4 FW |
4011 | .B \-\-queue\-num |
4012 | or | |
4013 | .B \-\-queue\-balance | |
4014 | options to the | |
4015 | .BR iptables (8) | |
f2d607ee MK |
4016 | NFQUEUE target. |
4017 | See | |
ed8de0e4 FW |
4018 | .BR iptables-extensions (8) |
4019 | for more information. | |
4020 | .TP | |
4021 | (2) | |
7672e08e | 4022 | The netlink port ID subscribed to the queue. |
ed8de0e4 FW |
4023 | .TP |
4024 | (3) | |
4025 | The number of packets currently queued and waiting to be processed by | |
4026 | the application. | |
4027 | .TP | |
4028 | (4) | |
f2d607ee MK |
4029 | The copy mode of the queue. |
4030 | It is either 1 (metadata only) or 2 | |
6f858d5c | 4031 | (also copy payload data to user space). |
ed8de0e4 FW |
4032 | .TP |
4033 | (5) | |
1dea597b | 4034 | Copy range; that is, how many bytes of packet payload should be copied to |
6f858d5c | 4035 | user space at most. |
ed8de0e4 FW |
4036 | .TP |
4037 | (6) | |
f2d607ee MK |
4038 | queue dropped. |
4039 | Number of packets that had to be dropped by the kernel because | |
6f858d5c | 4040 | too many packets are already waiting for user space to send back the mandatory |
ed8de0e4 FW |
4041 | accept/drop verdicts. |
4042 | .TP | |
4043 | (7) | |
f2d607ee MK |
4044 | queue user dropped. |
4045 | Number of packets that were dropped within the netlink | |
4046 | subsystem. | |
4047 | Such drops usually happen when the corresponding socket buffer is | |
6f858d5c | 4048 | full; that is, user space is not able to read messages fast enough. |
ed8de0e4 FW |
4049 | .TP |
4050 | (8) | |
f2d607ee MK |
4051 | sequence number. |
4052 | Every queued packet is associated with a (32-bit) | |
ed8de0e4 FW |
4053 | monotonically-increasing sequence number. |
4054 | This shows the ID of the most recent packet queued. | |
4055 | .RE | |
4056 | .IP | |
f33774c4 | 4057 | The last number exists only for compatibility reasons and is always 1. |
ed8de0e4 | 4058 | .TP |
fea681da | 4059 | .I /proc/partitions |
f042d149 MK |
4060 | Contains the major and minor numbers of each partition as well as the number |
4061 | of 1024-byte blocks and the partition name. | |
fea681da MK |
4062 | .TP |
4063 | .I /proc/pci | |
4064 | This is a listing of all PCI devices found during kernel initialization | |
4065 | and their configuration. | |
2dad4c59 | 4066 | .IP |
59a40ed7 MK |
4067 | This file has been deprecated in favor of a new |
4068 | .I /proc | |
2990d781 MK |
4069 | interface for PCI |
4070 | .RI ( /proc/bus/pci ). | |
4071 | It became optional in Linux 2.2 (available with | |
4072 | .B CONFIG_PCI_OLD_PROC | |
4073 | set at kernel compilation). | |
24b74457 | 4074 | It became once more nonoptionally enabled in Linux 2.4. |
2990d781 MK |
4075 | Next, it was deprecated in Linux 2.6 (still available with |
4076 | .B CONFIG_PCI_LEGACY_PROC | |
4077 | set), and finally removed altogether since Linux 2.6.17. | |
43d42cc0 | 4078 | .\" FIXME Document /proc/sched_debug (since Linux 2.6.23) |
69119dc7 | 4079 | .\" See also /proc/[pid]/sched |
caea7868 MK |
4080 | .TP |
4081 | .IR /proc/profile " (since Linux 2.4)" | |
4082 | This file is present only if the kernel was booted with the | |
4083 | .I profile=1 | |
4084 | command-line option. | |
4085 | It exposes kernel profiling information in a binary format for use by | |
4086 | .BR readprofile (1). | |
4087 | Writing (e.g., an empty string) to this file resets the profiling counters; | |
4088 | on some architectures, | |
4089 | writing a binary integer "profiling multiplier" of size | |
4090 | .IR sizeof(int) | |
8a3ac89a | 4091 | sets the profiling interrupt frequency. |
fea681da MK |
4092 | .TP |
4093 | .I /proc/scsi | |
59a40ed7 MK |
4094 | A directory with the |
4095 | .I scsi | |
4096 | mid-level pseudo-file and various SCSI low-level | |
2990d781 MK |
4097 | driver directories, |
4098 | which contain a file for each SCSI host in this system, all of | |
c13182ef MK |
4099 | which give the status of some part of the SCSI IO subsystem. |
4100 | These files contain ASCII structures and are, therefore, readable with | |
2990d781 | 4101 | .BR cat (1). |
2dad4c59 | 4102 | .IP |
c13182ef | 4103 | You can also write to some of the files to reconfigure the subsystem or |
59a40ed7 | 4104 | switch certain features on or off. |
fea681da MK |
4105 | .TP |
4106 | .I /proc/scsi/scsi | |
c13182ef | 4107 | This is a listing of all SCSI devices known to the kernel. |
59a40ed7 | 4108 | The listing is similar to the one seen during bootup. |
c13182ef | 4109 | scsi currently supports only the \fIadd-single-device\fP command which |
59a40ed7 | 4110 | allows root to add a hotplugged device to the list of known devices. |
2dad4c59 | 4111 | .IP |
59a40ed7 | 4112 | The command |
37d5e699 | 4113 | .IP |
59a40ed7 | 4114 | .in +4n |
37d5e699 | 4115 | .EX |
59a40ed7 | 4116 | echo \(aqscsi add-single-device 1 0 5 0\(aq > /proc/scsi/scsi |
37d5e699 | 4117 | .EE |
59a40ed7 | 4118 | .in |
37d5e699 | 4119 | .IP |
c13182ef MK |
4120 | will cause |
4121 | host scsi1 to scan on SCSI channel 0 for a device on ID 5 LUN 0. | |
4122 | If there | |
fea681da MK |
4123 | is already a device known on this address or the address is invalid, an |
4124 | error will be returned. | |
4125 | .TP | |
4126 | .I /proc/scsi/[drivername] | |
c13182ef MK |
4127 | \fI[drivername]\fP can currently be NCR53c7xx, aha152x, aha1542, aha1740, |
4128 | aic7xxx, buslogic, eata_dma, eata_pio, fdomain, in2000, pas16, qlogic, | |
4129 | scsi_debug, seagate, t128, u15-24f, ultrastore, or wd7000. | |
4130 | These directories show up for all drivers that registered at least one | |
59a40ed7 | 4131 | SCSI HBA. |
c13182ef | 4132 | Every directory contains one file per registered host. |
59a40ed7 | 4133 | Every host-file is named after the number the host was assigned during |
c13182ef | 4134 | initialization. |
2dad4c59 | 4135 | .IP |
c13182ef | 4136 | Reading these files will usually show driver and host configuration, |
f78ed33a | 4137 | statistics, and so on. |
2dad4c59 | 4138 | .IP |
fea681da MK |
4139 | Writing to these files allows different things on different hosts. |
4140 | For example, with the \fIlatency\fP and \fInolatency\fP commands, | |
4141 | root can switch on and off command latency measurement code in the | |
c13182ef MK |
4142 | eata_dma driver. |
4143 | With the \fIlockup\fP and \fIunlock\fP commands, | |
4144 | root can control bus lockups simulated by the scsi_debug driver. | |
fea681da MK |
4145 | .TP |
4146 | .I /proc/self | |
59a40ed7 MK |
4147 | This directory refers to the process accessing the |
4148 | .I /proc | |
9ee4a2b6 | 4149 | filesystem, |
59a40ed7 MK |
4150 | and is identical to the |
4151 | .I /proc | |
4152 | directory named by the process ID of the same process. | |
fea681da MK |
4153 | .TP |
4154 | .I /proc/slabinfo | |
c13182ef | 4155 | Information about kernel caches. |
c13182ef | 4156 | See |
fea681da MK |
4157 | .BR slabinfo (5) |
4158 | for details. | |
4159 | .TP | |
4160 | .I /proc/stat | |
c13182ef MK |
4161 | kernel/system statistics. |
4162 | Varies with architecture. | |
4163 | Common | |
fea681da MK |
4164 | entries include: |
4165 | .RS | |
4166 | .TP | |
46f6dbe8 ES |
4167 | .I cpu 10132153 290696 3084719 46828483 16683 0 25195 0 175628 0 |
4168 | .TQ | |
4169 | .I cpu0 1393280 32966 572056 13343292 6130 0 17875 0 23933 0 | |
bfbfcd18 | 4170 | The amount of time, measured in units of |
268f000b MK |
4171 | USER_HZ (1/100ths of a second on most architectures, use |
4172 | .IR sysconf(_SC_CLK_TCK) | |
4173 | to obtain the right value), | |
b81087ab | 4174 | .\" 1024 on Alpha and ia64 |
46f6dbe8 ES |
4175 | that the system ("cpu" line) or the specific CPU ("cpu\fIN\fR" line) |
4176 | spent in various states: | |
ae3b8047 MK |
4177 | .RS |
4178 | .TP | |
4179 | .I user | |
ea0841f6 | 4180 | (1) Time spent in user mode. |
ae3b8047 MK |
4181 | .TP |
4182 | .I nice | |
0633f951 | 4183 | (2) Time spent in user mode with low priority (nice). |
9f1b9726 | 4184 | .TP |
ae3b8047 | 4185 | .I system |
0633f951 | 4186 | (3) Time spent in system mode. |
ae3b8047 MK |
4187 | .TP |
4188 | .I idle | |
ea0841f6 | 4189 | (4) Time spent in the idle task. |
bea08fec | 4190 | .\" FIXME . Actually, the following info about the /proc/stat 'cpu' field |
e04a1f93 MK |
4191 | .\" does not seem to be quite right (at least in 2.6.12 or 3.6): |
4192 | .\" the idle time in /proc/uptime does not quite match this value | |
4193 | This value should be USER_HZ times the | |
4cb1deb7 MK |
4194 | second entry in the |
4195 | .I /proc/uptime | |
4196 | pseudo-file. | |
ae3b8047 MK |
4197 | .TP |
4198 | .IR iowait " (since Linux 2.5.41)" | |
ea0841f6 | 4199 | (5) Time waiting for I/O to complete. |
e0a73a31 MK |
4200 | This value is not reliable, for the following reasons: |
4201 | .\" See kernel commit 9c240d757658a3ae9968dd309e674c61f07c7f48 | |
4202 | .RS | |
4203 | .IP 1. 3 | |
4204 | The CPU will not wait for I/O to complete; | |
4205 | iowait is the time that a task is waiting for I/O to complete. | |
4206 | When a CPU goes into idle state for outstanding task I/O, | |
4207 | another task will be scheduled on this CPU. | |
4208 | .IP 2. | |
4209 | On a multi-core CPU, | |
4210 | the task waiting for I/O to complete is not running on any CPU, | |
4211 | so the iowait of each CPU is difficult to calculate. | |
4212 | .IP 3. | |
4213 | The value in this field may | |
4214 | .I decrease | |
4215 | in certain conditions. | |
2d3fb75b | 4216 | .RE |
ae3b8047 | 4217 | .TP |
d6bec36e MK |
4218 | .IR irq " (since Linux 2.6.0)" |
4219 | .\" Precisely: Linux 2.6.0-test4 | |
ea0841f6 | 4220 | (6) Time servicing interrupts. |
ae3b8047 | 4221 | .TP |
d6bec36e MK |
4222 | .IR softirq " (since Linux 2.6.0" |
4223 | .\" Precisely: Linux 2.6.0-test4 | |
ea0841f6 | 4224 | (7) Time servicing softirqs. |
ae3b8047 MK |
4225 | .TP |
4226 | .IR steal " (since Linux 2.6.11)" | |
ea0841f6 | 4227 | (8) Stolen time, which is the time spent in other operating systems when |
9de1f6cc | 4228 | running in a virtualized environment |
ae3b8047 MK |
4229 | .TP |
4230 | .IR guest " (since Linux 2.6.24)" | |
0633f951 | 4231 | (9) Time spent running a virtual CPU for guest |
afef1764 | 4232 | operating systems under the control of the Linux kernel. |
14c06953 | 4233 | .\" See Changelog entry for 5e84cfde51cf303d368fcb48f22059f37b3872de |
d4fd4120 MK |
4234 | .TP |
4235 | .IR guest_nice " (since Linux 2.6.33)" | |
4236 | .\" commit ce0e7b28fb75cb003cfc8d0238613aaf1c55e797 | |
4237 | (10) Time spent running a niced guest (virtual CPU for guest | |
4238 | operating systems under the control of the Linux kernel). | |
ae3b8047 | 4239 | .RE |
fea681da MK |
4240 | .TP |
4241 | \fIpage 5741 1808\fP | |
4242 | The number of pages the system paged in and the number that were paged | |
4243 | out (from disk). | |
4244 | .TP | |
4245 | \fIswap 1 0\fP | |
4246 | The number of swap pages that have been brought in and out. | |
4247 | .TP | |
bea08fec | 4248 | .\" FIXME . The following is not the full picture for the 'intr' of |
777f5a9e | 4249 | .\" /proc/stat on 2.6: |
fea681da | 4250 | \fIintr 1462898\fP |
bfbfcd18 MK |
4251 | This line shows counts of interrupts serviced since boot time, |
4252 | for each of the possible system interrupts. | |
d63ff76e | 4253 | The first column is the total of all interrupts serviced |
d6a56978 MK |
4254 | including unnumbered architecture specific interrupts; |
4255 | each subsequent column is the total for that particular numbered interrupt. | |
d63ff76e | 4256 | Unnumbered interrupts are not shown, only summed into the total. |
fea681da MK |
4257 | .TP |
4258 | \fIdisk_io: (2,0):(31,30,5764,1,2) (3,0):\fP... | |
636297e9 | 4259 | (major,disk_idx):(noinfo, read_io_ops, blks_read, write_io_ops, blks_written) |
bfbfcd18 MK |
4260 | .br |
4261 | (Linux 2.4 only) | |
fea681da MK |
4262 | .TP |
4263 | \fIctxt 115315\fP | |
4264 | The number of context switches that the system underwent. | |
4265 | .TP | |
4266 | \fIbtime 769041601\fP | |
f49c451a | 4267 | boot time, in seconds since the Epoch, 1970-01-01 00:00:00 +0000 (UTC). |
fea681da MK |
4268 | .TP |
4269 | \fIprocesses 86031\fP | |
4270 | Number of forks since boot. | |
bfbfcd18 MK |
4271 | .TP |
4272 | \fIprocs_running 6\fP | |
4273 | Number of processes in runnable state. | |
5fab2e7c | 4274 | (Linux 2.5.45 onward.) |
bfbfcd18 MK |
4275 | .TP |
4276 | \fIprocs_blocked 2\fP | |
4277 | Number of processes blocked waiting for I/O to complete. | |
5fab2e7c | 4278 | (Linux 2.5.45 onward.) |
76f6f102 ES |
4279 | .TP |
4280 | .I softirq 229245889 94 60001584 13619 5175704 2471304 28 51212741 59130143 0 51240672 | |
4281 | .\" commit d3d64df21d3d0de675a0d3ffa7c10514f3644b30 | |
4282 | This line shows the number of softirq for all CPUs. | |
4283 | The first column is the total of all softirqs and | |
4284 | each subsequent column is the total for particular softirq. | |
d7f23d0b | 4285 | (Linux 2.6.31 onward.) |
fea681da MK |
4286 | .RE |
4287 | .TP | |
4288 | .I /proc/swaps | |
c13182ef MK |
4289 | Swap areas in use. |
4290 | See also | |
fea681da MK |
4291 | .BR swapon (8). |
4292 | .TP | |
4293 | .I /proc/sys | |
4294 | This directory (present since 1.3.57) contains a number of files | |
4295 | and subdirectories corresponding to kernel variables. | |
4296 | These variables can be read and sometimes modified using | |
9ee4a2b6 | 4297 | the \fI/proc\fP filesystem, and the (deprecated) |
fea681da | 4298 | .BR sysctl (2) |
c13182ef | 4299 | system call. |
2dad4c59 | 4300 | .IP |
e8aa7100 | 4301 | String values may be terminated by either \(aq\\0\(aq or \(aq\\n\(aq. |
2dad4c59 | 4302 | .IP |
84ff8c1e HS |
4303 | Integer and long values may be written either in decimal or in |
4304 | hexadecimal notation (e.g. 0x3FFF). | |
e8aa7100 MK |
4305 | When writing multiple integer or long values, these may be separated |
4306 | by any of the following whitespace characters: | |
4307 | \(aq\ \(aq, \(aq\\t\(aq, or \(aq\\n\(aq. | |
4308 | Using other separators leads to the error | |
84ff8c1e | 4309 | .BR EINVAL . |
fea681da | 4310 | .TP |
6ab7c0aa | 4311 | .IR /proc/sys/abi " (since Linux 2.4.10)" |
fea681da | 4312 | This directory may contain files with application binary information. |
6ab7c0aa | 4313 | .\" On some systems, it is not present. |
66a9882e | 4314 | See the Linux kernel source file |
6ab7c0aa MK |
4315 | .I Documentation/sysctl/abi.txt |
4316 | for more information. | |
fea681da MK |
4317 | .TP |
4318 | .I /proc/sys/debug | |
4319 | This directory may be empty. | |
4320 | .TP | |
4321 | .I /proc/sys/dev | |
e2badfdf | 4322 | This directory contains device-specific information (e.g., |
9a67332e | 4323 | .IR dev/cdrom/info ). |
fea681da MK |
4324 | On |
4325 | some systems, it may be empty. | |
4326 | .TP | |
4327 | .I /proc/sys/fs | |
49236d3c | 4328 | This directory contains the files and subdirectories for kernel variables |
9ee4a2b6 | 4329 | related to filesystems. |
fea681da MK |
4330 | .TP |
4331 | .I /proc/sys/fs/binfmt_misc | |
c13182ef | 4332 | Documentation for files in this directory can be found |
a2923df0 MK |
4333 | in the Linux kernel source in the file |
4334 | .IR Documentation/admin-guide/binfmt-misc.rst | |
4335 | (or in | |
4336 | .IR Documentation/binfmt_misc.txt | |
4337 | on older kernels). | |
fea681da | 4338 | .TP |
59a40ed7 MK |
4339 | .IR /proc/sys/fs/dentry-state " (since Linux 2.2)" |
4340 | This file contains information about the status of the | |
4341 | directory cache (dcache). | |
4342 | The file contains six numbers, | |
c13182ef | 4343 | .IR nr_dentry ", " nr_unused ", " age_limit " (age in seconds), " |
59a40ed7 | 4344 | .I want_pages |
fea681da | 4345 | (pages requested by system) and two dummy values. |
59a40ed7 MK |
4346 | .RS |
4347 | .IP * 2 | |
4348 | .I nr_dentry | |
4349 | is the number of allocated dentries (dcache entries). | |
4350 | This field is unused in Linux 2.2. | |
4351 | .IP * | |
4352 | .I nr_unused | |
4353 | is the number of unused dentries. | |
4354 | .IP * | |
4355 | .I age_limit | |
4356 | .\" looks like this is unused in kernels 2.2 to 2.6 | |
4357 | is the age in seconds after which dcache entries | |
4358 | can be reclaimed when memory is short. | |
4359 | .IP * | |
4360 | .I want_pages | |
4361 | .\" looks like this is unused in kernels 2.2 to 2.6 | |
c7094399 | 4362 | is nonzero when the kernel has called shrink_dcache_pages() and the |
fea681da | 4363 | dcache isn't pruned yet. |
59a40ed7 | 4364 | .RE |
fea681da MK |
4365 | .TP |
4366 | .I /proc/sys/fs/dir-notify-enable | |
4367 | This file can be used to disable or enable the | |
4368 | .I dnotify | |
4369 | interface described in | |
4370 | .BR fcntl (2) | |
4371 | on a system-wide basis. | |
4372 | A value of 0 in this file disables the interface, | |
4373 | and a value of 1 enables it. | |
4374 | .TP | |
4375 | .I /proc/sys/fs/dquot-max | |
4376 | This file shows the maximum number of cached disk quota entries. | |
4377 | On some (2.4) systems, it is not present. | |
4378 | If the number of free cached disk quota entries is very low and | |
4379 | you have some awesome number of simultaneous system users, | |
4380 | you might want to raise the limit. | |
4381 | .TP | |
4382 | .I /proc/sys/fs/dquot-nr | |
4383 | This file shows the number of allocated disk quota | |
4384 | entries and the number of free disk quota entries. | |
4385 | .TP | |
24cb4a4b | 4386 | .IR /proc/sys/fs/epoll " (since Linux 2.6.28)" |
242b46af MK |
4387 | This directory contains the file |
4388 | .IR max_user_watches , | |
24cb4a4b MK |
4389 | which can be used to limit the amount of kernel memory consumed by the |
4390 | .I epoll | |
4391 | interface. | |
4392 | For further details, see | |