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diff --git a/man5/proc.5 b/man5/proc.5 index 9a48841..ce072ee 100644 --- a/man5/proc.5 +++ b/man5/proc.5 @@ -1,40 +1,10 @@ -'\" t -.\" Copyright (C) 1994, 1995 by Daniel Quinlan (quinlan@yggdrasil.com) -.\" and Copyright (C) 2002-2008,2017 Michael Kerrisk <mtk.manpages@gmail.com> -.\" with networking additions from Alan Cox (A.Cox@swansea.ac.uk) -.\" and scsi additions from Michael Neuffer (neuffer@mail.uni-mainz.de) -.\" and sysctl additions from Andries Brouwer (aeb@cwi.nl) -.\" and System V IPC (as well as various other) additions from -.\" Michael Kerrisk <mtk.manpages@gmail.com> +.\" Copyright (C) 1994, 1995, Daniel Quinlan <quinlan@yggdrasil.com> +.\" Copyright (C) 2002-2008, 2017, Michael Kerrisk <mtk.manpages@gmail.com> +.\" Copyright (C) 2023, Alejandro Colomar <alx@kernel.org> .\" -.\" SPDX-License-Identifier: GPL-2.0-or-later +.\" SPDX-License-Identifier: GPL-3.0-or-later .\" -.\" Modified 1995-05-17 by faith@cs.unc.edu -.\" Minor changes by aeb and Marty Leisner (leisner@sdsp.mc.xerox.com). -.\" Modified 1996-04-13, 1996-07-22 by aeb@cwi.nl -.\" Modified 2001-12-16 by rwhron@earthlink.net -.\" Modified 2002-07-13 by jbelton@shaw.ca -.\" Modified 2002-07-22, 2003-05-27, 2004-04-06, 2004-05-25 -.\" by Michael Kerrisk <mtk.manpages@gmail.com> -.\" 2004-11-17, mtk -- updated notes on /proc/loadavg -.\" 2004-12-01, mtk, rtsig-max and rtsig-nr went away in Linux 2.6.8 -.\" 2004-12-14, mtk, updated 'statm', and fixed error in order of list -.\" 2005-05-12, mtk, updated 'stat' -.\" 2005-07-13, mtk, added /proc/sys/fs/mqueue/* -.\" 2005-09-16, mtk, Added /proc/sys/fs/suid_dumpable -.\" 2005-09-19, mtk, added /proc/zoneinfo -.\" 2005-03-01, mtk, moved /proc/sys/fs/mqueue/* material to mq_overview.7. -.\" 2008-06-05, mtk, Added /proc/[pid]/oom_score, /proc/[pid]/oom_adj, -.\" /proc/[pid]/limits, /proc/[pid]/mountinfo, /proc/[pid]/mountstats, -.\" and /proc/[pid]/fdinfo/*. -.\" 2008-06-19, mtk, Documented /proc/[pid]/status. -.\" 2008-07-15, mtk, added /proc/config.gz -.\" -.\" FIXME cross check against Documentation/filesystems/proc.txt -.\" to see what information could be imported from that file -.\" into this file. -.\" -.TH proc 5 2023-07-08 "Linux man-pages 6.05.01" +.TH proc 5 2023-10-31 "Linux man-pages 6.7" .SH NAME proc \- process information, system information, and sysctl pseudo-filesystem .SH DESCRIPTION @@ -46,13 +16,13 @@ It is commonly mounted at .IR /proc . Typically, it is mounted automatically by the system, but it can also be mounted manually using a command such as: -.PP +.P .in +4n .EX mount \-t proc proc /proc .EE .in -.PP +.P Most of the files in the .B proc filesystem are read-only, @@ -205,1741 +175,10 @@ directory. Various other files and subdirectories under .I /proc expose system-wide information. -.PP +.P All of the above are described in more detail below. .\" -.SS Files and directories -The following list provides details of many of the files and directories -under the -.I /proc -hierarchy. -.TP -.IR /proc/ pid -There is a numerical subdirectory for each running process; the -subdirectory is named by the process ID. -Each -.IR /proc/ pid -subdirectory contains the pseudo-files and directories described below. -.IP -The files inside each -.IR /proc/ pid -directory are normally owned by the effective user and -effective group ID of the process. -However, as a security measure, the ownership is made -.I root:root -if the process's "dumpable" attribute is set to a value other than 1. -.IP -Before Linux 4.11, -.\" commit 68eb94f16227336a5773b83ecfa8290f1d6b78ce -.I root:root -meant the "global" root user ID and group ID -(i.e., UID 0 and GID 0 in the initial user namespace). -Since Linux 4.11, -if the process is in a noninitial user namespace that has a -valid mapping for user (group) ID 0 inside the namespace, then -the user (group) ownership of the files under -.IR /proc/ pid -is instead made the same as the root user (group) ID of the namespace. -This means that inside a container, -things work as expected for the container "root" user. -.IP -The process's "dumpable" attribute may change for the following reasons: -.RS -.IP \[bu] 3 -The attribute was explicitly set via the -.BR prctl (2) -.B PR_SET_DUMPABLE -operation. -.IP \[bu] -The attribute was reset to the value in the file -.I /proc/sys/fs/suid_dumpable -(described below), for the reasons described in -.BR prctl (2). -.RE -.IP -Resetting the "dumpable" attribute to 1 reverts the ownership of the -.IR /proc/ pid /* -files to the process's effective UID and GID. -Note, however, that if the effective UID or GID is subsequently modified, -then the "dumpable" attribute may be reset, as described in -.BR prctl (2). -Therefore, it may be desirable to reset the "dumpable" attribute -.I after -making any desired changes to the process's effective UID or GID. -.TP -.IR /proc/ pid /attr -.\" https://lwn.net/Articles/28222/ -.\" From: Stephen Smalley <sds@epoch.ncsc.mil> -.\" To: LKML and others -.\" Subject: [RFC][PATCH] Process Attribute API for Security Modules -.\" Date: 08 Apr 2003 16:17:52 -0400 -.\" -.\" http://www.nsa.gov/research/_files/selinux/papers/module/x362.shtml -.\" -The files in this directory provide an API for security modules. -The contents of this directory are files that can be read and written -in order to set security-related attributes. -This directory was added to support SELinux, -but the intention was that the API be general enough to support -other security modules. -For the purpose of explanation, -examples of how SELinux uses these files are provided below. -.IP -This directory is present only if the kernel was configured with -.BR CONFIG_SECURITY . -.TP -.IR /proc/ pid /attr/current " (since Linux 2.6.0)" -The contents of this file represent the current -security attributes of the process. -.IP -In SELinux, this file is used to get the security context of a process. -Prior to Linux 2.6.11, this file could not be used to set the security -context (a write was always denied), since SELinux limited process security -transitions to -.BR execve (2) -(see the description of -.IR /proc/ pid /attr/exec , -below). -Since Linux 2.6.11, SELinux lifted this restriction and began supporting -"set" operations via writes to this node if authorized by policy, -although use of this operation is only suitable for applications that are -trusted to maintain any desired separation between the old and new security -contexts. -.IP -Prior to Linux 2.6.28, SELinux did not allow threads within a -multithreaded process to set their security context via this node -as it would yield an inconsistency among the security contexts of the -threads sharing the same memory space. -Since Linux 2.6.28, SELinux lifted -this restriction and began supporting "set" operations for threads within -a multithreaded process if the new security context is bounded by the old -security context, where the bounded relation is defined in policy and -guarantees that the new security context has a subset of the permissions -of the old security context. -.IP -Other security modules may choose to support "set" operations via -writes to this node. -.TP -.IR /proc/ pid /attr/exec " (since Linux 2.6.0)" -This file represents the attributes to assign to the -process upon a subsequent -.BR execve (2). -.IP -In SELinux, -this is needed to support role/domain transitions, and -.BR execve (2) -is the preferred point to make such transitions because it offers better -control over the initialization of the process in the new security label -and the inheritance of state. -In SELinux, this attribute is reset on -.BR execve (2) -so that the new program reverts to the default behavior for any -.BR execve (2) -calls that it may make. -In SELinux, a process can set -only its own -.IR /proc/ pid /attr/exec -attribute. -.TP -.IR /proc/ pid /attr/fscreate " (since Linux 2.6.0)" -This file represents the attributes to assign to files -created by subsequent calls to -.BR open (2), -.BR mkdir (2), -.BR symlink (2), -and -.BR mknod (2) -.IP -SELinux employs this file to support creation of a file -(using the aforementioned system calls) -in a secure state, -so that there is no risk of inappropriate access being obtained -between the time of creation and the time that attributes are set. -In SELinux, this attribute is reset on -.BR execve (2), -so that the new program reverts to the default behavior for -any file creation calls it may make, but the attribute will persist -across multiple file creation calls within a program unless it is -explicitly reset. -In SELinux, a process can set only its own -.IR /proc/ pid /attr/fscreate -attribute. -.TP -.IR /proc/ pid /attr/keycreate " (since Linux 2.6.18)" -.\" commit 4eb582cf1fbd7b9e5f466e3718a59c957e75254e -If a process writes a security context into this file, -all subsequently created keys -.RB ( add_key (2)) -will be labeled with this context. -For further information, see the kernel source file -.I Documentation/security/keys/core.rst -(or file -.\" commit b68101a1e8f0263dbc7b8375d2a7c57c6216fb76 -.I Documentation/security/keys.txt -between Linux 3.0 and Linux 4.13, or -.\" commit d410fa4ef99112386de5f218dd7df7b4fca910b4 -.I Documentation/keys.txt -before Linux 3.0). -.TP -.IR /proc/ pid /attr/prev " (since Linux 2.6.0)" -This file contains the security context of the process before the last -.BR execve (2); -that is, the previous value of -.IR /proc/ pid /attr/current . -.TP -.IR /proc/ pid /attr/socketcreate " (since Linux 2.6.18)" -.\" commit 42c3e03ef6b298813557cdb997bd6db619cd65a2 -If a process writes a security context into this file, -all subsequently created sockets will be labeled with this context. -.TP -.IR /proc/ pid /autogroup " (since Linux 2.6.38)" -.\" commit 5091faa449ee0b7d73bc296a93bca9540fc51d0a -See -.BR sched (7). -.TP -.IR /proc/ pid /auxv " (since Linux 2.6.0)" -.\" Precisely: Linux 2.6.0-test7 -This contains the contents of the ELF interpreter information passed -to the process at exec time. -The format is one \fIunsigned long\fP ID -plus one \fIunsigned long\fP value for each entry. -The last entry contains two zeros. -See also -.BR getauxval (3). -.IP -Permission to access this file is governed by a ptrace access mode -.B PTRACE_MODE_READ_FSCREDS -check; see -.BR ptrace (2). -.TP -.IR /proc/ pid /cgroup " (since Linux 2.6.24)" -See -.BR cgroups (7). -.TP -.IR /proc/ pid /clear_refs " (since Linux 2.6.22)" -.\" commit b813e931b4c8235bb42e301096ea97dbdee3e8fe (2.6.22) -.\" commit 398499d5f3613c47f2143b8c54a04efb5d7a6da9 (2.6.32) -.\" commit 040fa02077de01c7e08fa75be6125e4ca5636011 (3.11) -.\" -.\" "Clears page referenced bits shown in smaps output" -.\" write-only, writable only by the owner of the process -.IP -This is a write-only file, writable only by owner of the process. -.IP -The following values may be written to the file: -.RS -.TP -1 (since Linux 2.6.22) -.\" Internally: CLEAR_REFS_ALL -Reset the PG_Referenced and ACCESSED/YOUNG -bits for all the pages associated with the process. -(Before Linux 2.6.32, writing any nonzero value to this file -had this effect.) -.TP -2 (since Linux 2.6.32) -.\" Internally: CLEAR_REFS_ANON -Reset the PG_Referenced and ACCESSED/YOUNG -bits for all anonymous pages associated with the process. -.TP -3 (since Linux 2.6.32) -.\" Internally: CLEAR_REFS_MAPPED -Reset the PG_Referenced and ACCESSED/YOUNG -bits for all file-mapped pages associated with the process. -.RE -.IP -Clearing the PG_Referenced and ACCESSED/YOUNG bits provides a method -to measure approximately how much memory a process is using. -One first inspects the values in the "Referenced" fields -for the VMAs shown in -.IR /proc/ pid /smaps -to get an idea of the memory footprint of the -process. -One then clears the PG_Referenced and ACCESSED/YOUNG bits -and, after some measured time interval, -once again inspects the values in the "Referenced" fields -to get an idea of the change in memory footprint of the -process during the measured interval. -If one is interested only in inspecting the selected mapping types, -then the value 2 or 3 can be used instead of 1. -.IP -Further values can be written to affect different properties: -.RS -.TP -4 (since Linux 3.11) -Clear the soft-dirty bit for all the pages associated with the process. -.\" Internally: CLEAR_REFS_SOFT_DIRTY -This is used (in conjunction with -.IR /proc/ pid /pagemap ) -by the check-point restore system to discover which pages of a process -have been dirtied since the file -.IR /proc/ pid /clear_refs -was written to. -.TP -5 (since Linux 4.0) -.\" Internally: CLEAR_REFS_MM_HIWATER_RSS -Reset the peak resident set size ("high water mark") to the process's -current resident set size value. -.RE -.IP -Writing any value to -.IR /proc/ pid /clear_refs -other than those listed above has no effect. -.IP -The -.IR /proc/ pid /clear_refs -file is present only if the -.B CONFIG_PROC_PAGE_MONITOR -kernel configuration option is enabled. -.TP -.IR /proc/ pid /cmdline -This read-only file holds the complete command line for the process, -unless the process is a zombie. -.\" In Linux 2.3.26, this also used to be true if the process was swapped out. -In the latter case, there is nothing in this file: -that is, a read on this file will return 0 characters. -.IP -For processes which are still running, -the command-line arguments appear in this file -in the same layout as they do in process memory: -If the process is well-behaved, -it is a set of strings separated by null bytes (\[aq]\e0\[aq]), -with a further null byte after the last string. -.IP -This is the common case, -but processes have the freedom to -override the memory region and -break assumptions about the contents or format of the -.IR /proc/ pid /cmdline -file. -.IP -If, after an -.BR execve (2), -the process modifies its -.I argv -strings, those changes will show up here. -This is not the same thing as modifying the -.I argv -array. -.IP -Furthermore, a process may change the memory location that this file refers via -.BR prctl (2) -operations such as -.BR PR_SET_MM_ARG_START . -.IP -Think of this file as the command line that the process wants you to see. -.TP -.IR /proc/ pid /comm " (since Linux 2.6.33)" -.\" commit 4614a696bd1c3a9af3a08f0e5874830a85b889d4 -This file exposes the process's -.I comm -value\[em]that is, the command name associated with the process. -Different threads in the same process may have different -.I comm -values, accessible via -.IR /proc/ pid /task/ tid /comm . -A thread may modify its -.I comm -value, or that of any of other thread in the same thread group (see -the discussion of -.B CLONE_THREAD -in -.BR clone (2)), -by writing to the file -.IR /proc/self/task/ tid /comm . -Strings longer than -.B TASK_COMM_LEN -(16) characters (including the terminating null byte) are silently truncated. -.IP -This file provides a superset of the -.BR prctl (2) -.B PR_SET_NAME -and -.B PR_GET_NAME -operations, and is employed by -.BR pthread_setname_np (3) -when used to rename threads other than the caller. -The value in this file is used for the -.I %e -specifier in -.IR /proc/sys/kernel/core_pattern ; -see -.BR core (5). -.TP -.IR /proc/ pid /coredump_filter " (since Linux 2.6.23)" -See -.BR core (5). -.TP -.IR /proc/ pid /cpuset " (since Linux 2.6.12)" -.\" and/proc/[pid]/task/[tid]/cpuset -See -.BR cpuset (7). -.TP -.IR /proc/ pid /cwd -This is a symbolic link to the current working directory of the process. -To find out the current working directory of process 20, -for instance, you can do this: -.IP -.in +4n -.EX -.RB "$" " cd /proc/20/cwd; pwd \-P" -.EE -.in -.IP -.\" The following was still true as at kernel 2.6.13 -In a multithreaded process, the contents of this symbolic link -are not available if the main thread has already terminated -(typically by calling -.BR pthread_exit (3)). -.IP -Permission to dereference or read -.RB ( readlink (2)) -this symbolic link is governed by a ptrace access mode -.B PTRACE_MODE_READ_FSCREDS -check; see -.BR ptrace (2). -.TP -.IR /proc/ pid /environ -This file contains the initial environment that was set -when the currently executing program was started via -.BR execve (2). -The entries are separated by null bytes (\[aq]\e0\[aq]), -and there may be a null byte at the end. -Thus, to print out the environment of process 1, you would do: -.IP -.in +4n -.EX -.RB "$" " cat /proc/1/environ | tr \[aq]\e000\[aq] \[aq]\en\[aq]" -.EE -.in -.IP -If, after an -.BR execve (2), -the process modifies its environment -(e.g., by calling functions such as -.BR putenv (3) -or modifying the -.BR environ (7) -variable directly), -this file will -.I not -reflect those changes. -.IP -Furthermore, a process may change the memory location that this file refers via -.BR prctl (2) -operations such as -.BR PR_SET_MM_ENV_START . -.IP -Permission to access this file is governed by a ptrace access mode -.B PTRACE_MODE_READ_FSCREDS -check; see -.BR ptrace (2). -.TP -.IR /proc/ pid /exe -Under Linux 2.2 and later, this file is a symbolic link -containing the actual pathname of the executed command. -This symbolic link can be dereferenced normally; attempting to open -it will open the executable. -You can even type -.IR /proc/ pid /exe -to run another copy of the same executable that is being run by -process -.IR pid . -If the pathname has been unlinked, the symbolic link will contain the -string \[aq]\ (deleted)\[aq] appended to the original pathname. -.\" The following was still true as at kernel 2.6.13 -In a multithreaded process, the contents of this symbolic link -are not available if the main thread has already terminated -(typically by calling -.BR pthread_exit (3)). -.IP -Permission to dereference or read -.RB ( readlink (2)) -this symbolic link is governed by a ptrace access mode -.B PTRACE_MODE_READ_FSCREDS -check; see -.BR ptrace (2). -.IP -Under Linux 2.0 and earlier, -.IR /proc/ pid /exe -is a pointer to the binary which was executed, -and appears as a symbolic link. -A -.BR readlink (2) -call on this file under Linux 2.0 returns a string in the format: -.IP -.in +4n -.EX -[device]:inode -.EE -.in -.IP -For example, [0301]:1502 would be inode 1502 on device major 03 (IDE, -MFM, etc. drives) minor 01 (first partition on the first drive). -.IP -.BR find (1) -with the -.I \-inum -option can be used to locate the file. -.TP -.IR /proc/ pid /fd/ -This is a subdirectory containing one entry for each file which the -process has open, named by its file descriptor, and which is a -symbolic link to the actual file. -Thus, 0 is standard input, 1 standard output, 2 standard error, and so on. -.IP -For file descriptors for pipes and sockets, -the entries will be symbolic links whose content is the -file type with the inode. -A -.BR readlink (2) -call on this file returns a string in the format: -.IP -.in +4n -.EX -type:[inode] -.EE -.in -.IP -For example, -.I socket:[2248868] -will be a socket and its inode is 2248868. -For sockets, that inode can be used to find more information -in one of the files under -.IR /proc/net/ . -.IP -For file descriptors that have no corresponding inode -(e.g., file descriptors produced by -.BR bpf (2), -.BR epoll_create (2), -.BR eventfd (2), -.BR inotify_init (2), -.BR perf_event_open (2), -.BR signalfd (2), -.BR timerfd_create (2), -and -.BR userfaultfd (2)), -the entry will be a symbolic link with contents of the form -.IP -.in +4n -.EX -.RI anon_inode: file-type -.EE -.in -.IP -In many cases (but not all), the -.I file-type -is surrounded by square brackets. -.IP -For example, an epoll file descriptor will have a symbolic link -whose content is the string -.IR "anon_inode:[eventpoll]" . -.IP -.\"The following was still true as at kernel 2.6.13 -In a multithreaded process, the contents of this directory -are not available if the main thread has already terminated -(typically by calling -.BR pthread_exit (3)). -.IP -Programs that take a filename as a command-line argument, -but don't take input from standard input if no argument is supplied, -and programs that write to a file named as a command-line argument, -but don't send their output to standard output -if no argument is supplied, can nevertheless be made to use -standard input or standard output by using -.IR /proc/ pid /fd -files as command-line arguments. -For example, assuming that -.I \-i -is the flag designating an input file and -.I \-o -is the flag designating an output file: -.IP -.in +4n -.EX -.RB "$" " foobar \-i /proc/self/fd/0 \-o /proc/self/fd/1 ..." -.EE -.in -.IP -and you have a working filter. -.\" The following is not true in my tests (MTK): -.\" Note that this will not work for -.\" programs that seek on their files, as the files in the fd directory -.\" are not seekable. -.IP -.I /proc/self/fd/N -is approximately the same as -.I /dev/fd/N -in some UNIX and UNIX-like systems. -Most Linux MAKEDEV scripts symbolically link -.I /dev/fd -to -.IR /proc/self/fd , -in fact. -.IP -Most systems provide symbolic links -.IR /dev/stdin , -.IR /dev/stdout , -and -.IR /dev/stderr , -which respectively link to the files -.IR 0 , -.IR 1 , -and -.I 2 -in -.IR /proc/self/fd . -Thus the example command above could be written as: -.IP -.in +4n -.EX -.RB "$" " foobar \-i /dev/stdin \-o /dev/stdout ..." -.EE -.in -.IP -Permission to dereference or read -.RB ( readlink (2)) -the symbolic links in this directory is governed by a ptrace access mode -.B PTRACE_MODE_READ_FSCREDS -check; see -.BR ptrace (2). -.IP -Note that for file descriptors referring to inodes -(pipes and sockets, see above), -those inodes still have permission bits and ownership information -distinct from those of the -.IR /proc/ pid /fd -entry, -and that the owner may differ from the user and group IDs of the process. -An unprivileged process may lack permissions to open them, as in this example: -.IP -.in +4n -.EX -.RB "$" " echo test | sudo \-u nobody cat" -test -.RB "$" " echo test | sudo \-u nobody cat /proc/self/fd/0" -cat: /proc/self/fd/0: Permission denied -.EE -.in -.IP -File descriptor 0 refers to the pipe created by the shell -and owned by that shell's user, which is not -.IR nobody , -so -.B cat -does not have permission -to create a new file descriptor to read from that inode, -even though it can still read from its existing file descriptor 0. -.TP -.IR /proc/ pid /fdinfo/ " (since Linux 2.6.22)" -This is a subdirectory containing one entry for each file which the -process has open, named by its file descriptor. -The files in this directory are readable only by the owner of the process. -The contents of each file can be read to obtain information -about the corresponding file descriptor. -The content depends on the type of file referred to by the -corresponding file descriptor. -.IP -For regular files and directories, we see something like: -.IP -.in +4n -.EX -.RB "$" " cat /proc/12015/fdinfo/4" -pos: 1000 -flags: 01002002 -mnt_id: 21 -.EE -.in -.IP -The fields are as follows: -.RS -.TP -.I pos -This is a decimal number showing the file offset. -.TP -.I flags -This is an octal number that displays the -file access mode and file status flags (see -.BR open (2)). -If the close-on-exec file descriptor flag is set, then -.I flags -will also include the value -.BR O_CLOEXEC . -.IP -Before Linux 3.1, -.\" commit 1117f72ea0217ba0cc19f05adbbd8b9a397f5ab7 -this field incorrectly displayed the setting of -.B O_CLOEXEC -at the time the file was opened, -rather than the current setting of the close-on-exec flag. -.TP -.I -.I mnt_id -This field, present since Linux 3.15, -.\" commit 49d063cb353265c3af701bab215ac438ca7df36d -is the ID of the mount containing this file. -See the description of -.IR /proc/ pid /mountinfo . -.RE -.IP -For eventfd file descriptors (see -.BR eventfd (2)), -we see (since Linux 3.8) -.\" commit cbac5542d48127b546a23d816380a7926eee1c25 -the following fields: -.IP -.in +4n -.EX -pos: 0 -flags: 02 -mnt_id: 10 -eventfd\-count: 40 -.EE -.in -.IP -.I eventfd\-count -is the current value of the eventfd counter, in hexadecimal. -.IP -For epoll file descriptors (see -.BR epoll (7)), -we see (since Linux 3.8) -.\" commit 138d22b58696c506799f8de759804083ff9effae -the following fields: -.IP -.in +4n -.EX -pos: 0 -flags: 02 -mnt_id: 10 -tfd: 9 events: 19 data: 74253d2500000009 -tfd: 7 events: 19 data: 74253d2500000007 -.EE -.in -.IP -Each of the lines beginning -.I tfd -describes one of the file descriptors being monitored via -the epoll file descriptor (see -.BR epoll_ctl (2) -for some details). -The -.I tfd -field is the number of the file descriptor. -The -.I events -field is a hexadecimal mask of the events being monitored for this file -descriptor. -The -.I data -field is the data value associated with this file descriptor. -.IP -For signalfd file descriptors (see -.BR signalfd (2)), -we see (since Linux 3.8) -.\" commit 138d22b58696c506799f8de759804083ff9effae -the following fields: -.IP -.in +4n -.EX -pos: 0 -flags: 02 -mnt_id: 10 -sigmask: 0000000000000006 -.EE -.in -.IP -.I sigmask -is the hexadecimal mask of signals that are accepted via this -signalfd file descriptor. -(In this example, bits 2 and 3 are set, corresponding to the signals -.B SIGINT -and -.BR SIGQUIT ; -see -.BR signal (7).) -.IP -For inotify file descriptors (see -.BR inotify (7)), -we see (since Linux 3.8) -the following fields: -.IP -.in +4n -.EX -pos: 0 -flags: 00 -mnt_id: 11 -inotify wd:2 ino:7ef82a sdev:800001 mask:800afff ignored_mask:0 fhandle\-bytes:8 fhandle\-type:1 f_handle:2af87e00220ffd73 -inotify wd:1 ino:192627 sdev:800001 mask:800afff ignored_mask:0 fhandle\-bytes:8 fhandle\-type:1 f_handle:27261900802dfd73 -.EE -.in -.IP -Each of the lines beginning with "inotify" displays information about -one file or directory that is being monitored. -The fields in this line are as follows: -.RS -.TP -.I wd -A watch descriptor number (in decimal). -.TP -.I ino -The inode number of the target file (in hexadecimal). -.TP -.I sdev -The ID of the device where the target file resides (in hexadecimal). -.TP -.I mask -The mask of events being monitored for the target file (in hexadecimal). -.RE -.IP -If the kernel was built with exportfs support, the path to the target -file is exposed as a file handle, via three hexadecimal fields: -.IR fhandle\-bytes , -.IR fhandle\-type , -and -.IR f_handle . -.IP -For fanotify file descriptors (see -.BR fanotify (7)), -we see (since Linux 3.8) -the following fields: -.IP -.in +4n -.EX -pos: 0 -flags: 02 -mnt_id: 11 -fanotify flags:0 event\-flags:88002 -fanotify ino:19264f sdev:800001 mflags:0 mask:1 ignored_mask:0 fhandle\-bytes:8 fhandle\-type:1 f_handle:4f261900a82dfd73 -.EE -.in -.IP -The fourth line displays information defined when the fanotify group -was created via -.BR fanotify_init (2): -.RS -.TP -.I flags -The -.I flags -argument given to -.BR fanotify_init (2) -(expressed in hexadecimal). -.TP -.I event\-flags -The -.I event_f_flags -argument given to -.BR fanotify_init (2) -(expressed in hexadecimal). -.RE -.IP -Each additional line shown in the file contains information -about one of the marks in the fanotify group. -Most of these fields are as for inotify, except: -.RS -.TP -.I mflags -The flags associated with the mark -(expressed in hexadecimal). -.TP -.I mask -The events mask for this mark -(expressed in hexadecimal). -.TP -.I ignored_mask -The mask of events that are ignored for this mark -(expressed in hexadecimal). -.RE -.IP -For details on these fields, see -.BR fanotify_mark (2). -.IP -For timerfd file descriptors (see -.BR timerfd (2)), -we see (since Linux 3.17) -.\" commit af9c4957cf212ad9cf0bee34c95cb11de5426e85 -the following fields: -.IP -.in +4n -.EX -pos: 0 -flags: 02004002 -mnt_id: 13 -clockid: 0 -ticks: 0 -settime flags: 03 -it_value: (7695568592, 640020877) -it_interval: (0, 0) -.EE -.in -.RS -.TP -.I clockid -This is the numeric value of the clock ID -(corresponding to one of the -.B CLOCK_* -constants defined via -.IR <time.h> ) -that is used to mark the progress of the timer (in this example, 0 is -.BR CLOCK_REALTIME ). -.TP -.I ticks -This is the number of timer expirations that have occurred, -(i.e., the value that -.BR read (2) -on it would return). -.TP -.I settime flags -This field lists the flags with which the timerfd was last armed (see -.BR timerfd_settime (2)), -in octal -(in this example, both -.B TFD_TIMER_ABSTIME -and -.B TFD_TIMER_CANCEL_ON_SET -are set). -.TP -.I it_value -This field contains the amount of time until the timer will next expire, -expressed in seconds and nanoseconds. -This is always expressed as a relative value, -regardless of whether the timer was created using the -.B TFD_TIMER_ABSTIME -flag. -.TP -.I it_interval -This field contains the interval of the timer, -in seconds and nanoseconds. -(The -.I it_value -and -.I it_interval -fields contain the values that -.BR timerfd_gettime (2) -on this file descriptor would return.) -.RE -.TP -.IR /proc/ pid /gid_map " (since Linux 3.5)" -See -.BR user_namespaces (7). -.TP -.IR /proc/ pid /io " (since Linux 2.6.20)" -.\" commit 7c3ab7381e79dfc7db14a67c6f4f3285664e1ec2 -This file contains I/O statistics for the process, for example: -.IP -.in +4n -.EX -.RB "#" " cat /proc/3828/io" -rchar: 323934931 -wchar: 323929600 -syscr: 632687 -syscw: 632675 -read_bytes: 0 -write_bytes: 323932160 -cancelled_write_bytes: 0 -.EE -.in -.IP -The fields are as follows: -.RS -.TP -.IR rchar ": characters read" -The number of bytes which this task has caused to be read from storage. -This is simply the sum of bytes which this process passed to -.BR read (2) -and similar system calls. -It includes things such as terminal I/O and -is unaffected by whether or not actual -physical disk I/O was required (the read might have been satisfied from -pagecache). -.TP -.IR wchar ": characters written" -The number of bytes which this task has caused, or shall cause to be written -to disk. -Similar caveats apply here as with -.IR rchar . -.TP -.IR syscr ": read syscalls" -Attempt to count the number of read I/O operations\[em]that is, -system calls such as -.BR read (2) -and -.BR pread (2). -.TP -.IR syscw ": write syscalls" -Attempt to count the number of write I/O operations\[em]that is, -system calls such as -.BR write (2) -and -.BR pwrite (2). -.TP -.IR read_bytes ": bytes read" -Attempt to count the number of bytes which this process really did cause to -be fetched from the storage layer. -This is accurate for block-backed filesystems. -.TP -.IR write_bytes ": bytes written" -Attempt to count the number of bytes which this process caused to be sent to -the storage layer. -.TP -.IR cancelled_write_bytes : -The big inaccuracy here is truncate. -If a process writes 1 MB to a file and then deletes the file, -it will in fact perform no writeout. -But it will have been accounted as having caused 1 MB of write. -In other words: this field represents the number of bytes which this process -caused to not happen, by truncating pagecache. -A task can cause "negative" I/O too. -If this task truncates some dirty pagecache, -some I/O which another task has been accounted for -(in its -.IR write_bytes ) -will not be happening. -.RE -.IP -.IR Note : -In the current implementation, things are a bit racy on 32-bit systems: -if process A reads process B's -.IR /proc/ pid /io -while process B is updating one of these 64-bit counters, -process A could see an intermediate result. -.IP -Permission to access this file is governed by a ptrace access mode -.B PTRACE_MODE_READ_FSCREDS -check; see -.BR ptrace (2). -.TP -.IR /proc/ pid /limits " (since Linux 2.6.24)" -This file displays the soft limit, hard limit, and units of measurement -for each of the process's resource limits (see -.BR getrlimit (2)). -Up to and including Linux 2.6.35, -this file is protected to allow reading only by the real UID of the process. -Since Linux 2.6.36, -.\" commit 3036e7b490bf7878c6dae952eec5fb87b1106589 -this file is readable by all users on the system. -.\" FIXME Describe /proc/[pid]/loginuid -.\" Added in Linux 2.6.11; updating requires CAP_AUDIT_CONTROL -.\" CONFIG_AUDITSYSCALL -.TP -.IR /proc/ pid /map_files/ " (since Linux 3.3)" -.\" commit 640708a2cff7f81e246243b0073c66e6ece7e53e -This subdirectory contains entries corresponding to memory-mapped -files (see -.BR mmap (2)). -Entries are named by memory region start and end -address pair (expressed as hexadecimal numbers), -and are symbolic links to the mapped files themselves. -Here is an example, -with the output wrapped and reformatted to fit on an 80-column display: -.IP -.in +4n -.EX -.RB "#" " ls \-l /proc/self/map_files/" -lr\-\-\-\-\-\-\-\-. 1 root root 64 Apr 16 21:31 - 3252e00000\-3252e20000 \-> /usr/lib64/ld\-2.15.so -\&... -.EE -.in -.IP -Although these entries are present for memory regions that were -mapped with the -.B MAP_FILE -flag, the way anonymous shared memory (regions created with the -.B MAP_ANON | MAP_SHARED -flags) -is implemented in Linux -means that such regions also appear on this directory. -Here is an example where the target file is the deleted -.I /dev/zero -one: -.IP -.in +4n -.EX -lrw\-\-\-\-\-\-\-. 1 root root 64 Apr 16 21:33 - 7fc075d2f000\-7fc075e6f000 \-> /dev/zero (deleted) -.EE -.in -.IP -Permission to access this file is governed by a ptrace access mode -.B PTRACE_MODE_READ_FSCREDS -check; see -.BR ptrace (2). -.IP -Until Linux 4.3, -.\" commit bdb4d100afe9818aebd1d98ced575c5ef143456c -this directory appeared only if the -.B CONFIG_CHECKPOINT_RESTORE -kernel configuration option was enabled. -.IP -Capabilities are required to read the contents of the symbolic links in -this directory: before Linux 5.9, the reading process requires -.B CAP_SYS_ADMIN -in the initial user namespace; -since Linux 5.9, the reading process must have either -.B CAP_SYS_ADMIN -or -.B CAP_CHECKPOINT_RESTORE -in the initial (i.e. root) user namespace. -.TP -.IR /proc/ pid /maps -A file containing the currently mapped memory regions and their access -permissions. -See -.BR mmap (2) -for some further information about memory mappings. -.IP -Permission to access this file is governed by a ptrace access mode -.B PTRACE_MODE_READ_FSCREDS -check; see -.BR ptrace (2). -.IP -The format of the file is: -.IP -.in +4n -.EX -.I "address perms offset dev inode pathname" -00400000\-00452000 r\-xp 00000000 08:02 173521 /usr/bin/dbus\-daemon -00651000\-00652000 r\-\-p 00051000 08:02 173521 /usr/bin/dbus\-daemon -00652000\-00655000 rw\-p 00052000 08:02 173521 /usr/bin/dbus\-daemon -00e03000\-00e24000 rw\-p 00000000 00:00 0 [heap] -00e24000\-011f7000 rw\-p 00000000 00:00 0 [heap] -\&... -35b1800000\-35b1820000 r\-xp 00000000 08:02 135522 /usr/lib64/ld\-2.15.so -35b1a1f000\-35b1a20000 r\-\-p 0001f000 08:02 135522 /usr/lib64/ld\-2.15.so -35b1a20000\-35b1a21000 rw\-p 00020000 08:02 135522 /usr/lib64/ld\-2.15.so -35b1a21000\-35b1a22000 rw\-p 00000000 00:00 0 -35b1c00000\-35b1dac000 r\-xp 00000000 08:02 135870 /usr/lib64/libc\-2.15.so -35b1dac000\-35b1fac000 \-\-\-p 001ac000 08:02 135870 /usr/lib64/libc\-2.15.so -35b1fac000\-35b1fb0000 r\-\-p 001ac000 08:02 135870 /usr/lib64/libc\-2.15.so -35b1fb0000\-35b1fb2000 rw\-p 001b0000 08:02 135870 /usr/lib64/libc\-2.15.so -\&... -f2c6ff8c000\-7f2c7078c000 rw\-p 00000000 00:00 0 [stack:986] -\&... -7fffb2c0d000\-7fffb2c2e000 rw\-p 00000000 00:00 0 [stack] -7fffb2d48000\-7fffb2d49000 r\-xp 00000000 00:00 0 [vdso] -.EE -.in -.IP -The -.I address -field is the address space in the process that the mapping occupies. -The -.I perms -field is a set of permissions: -.IP -.in +4n -.EX -r = read -w = write -x = execute -s = shared -p = private (copy on write) -.EE -.in -.IP -The -.I offset -field is the offset into the file/whatever; -.I dev -is the device -(major:minor); -.I inode -is the inode on that device. -0 indicates that no inode is associated with the memory region, -as would be the case with BSS (uninitialized data). -.IP -The -.I pathname -field will usually be the file that is backing the mapping. -For ELF files, -you can easily coordinate with the -.I offset -field by looking at the -Offset field in the ELF program headers -.RI ( "readelf\ \-l" ). -.IP -There are additional helpful pseudo-paths: -.RS -.TP -.I [stack] -The initial process's (also known as the main thread's) stack. -.TP -.IR [stack: tid ] " (from Linux 3.4 to Linux 4.4)" -.\" commit b76437579d1344b612cf1851ae610c636cec7db0 (added) -.\" commit 65376df582174ffcec9e6471bf5b0dd79ba05e4a (removed) -A thread's stack (where the -.I tid -is a thread ID). -It corresponds to the -.IR /proc/ pid /task/ tid / -path. -This field was removed in Linux 4.5, since providing this information -for a process with large numbers of threads is expensive. -.TP -.I [vdso] -The virtual dynamically linked shared object. -See -.BR vdso (7). -.TP -.I [heap] -The process's heap. -.TP -.IR [anon: name ] " (since Linux 5.17)" -.\" Commit 9a10064f5625d5572c3626c1516e0bebc6c9fe9b -A named private anonymous mapping. -Set with -.BR prctl (2) -.BR PR_SET_VMA_ANON_NAME . -.TP -.IR [anon_shmem: name ] " (since Linux 6.2)" -.\" Commit d09e8ca6cb93bb4b97517a18fbbf7eccb0e9ff43 -A named shared anonymous mapping. -Set with -.BR prctl (2) -.BR PR_SET_VMA_ANON_NAME . -.in -.RE -.IP -If the -.I pathname -field is blank, -this is an anonymous mapping as obtained via -.BR mmap (2). -There is no easy way to coordinate this back to a process's source, -short of running it through -.BR gdb (1), -.BR strace (1), -or similar. -.IP -.I pathname -is shown unescaped except for newline characters, which are replaced -with an octal escape sequence. -As a result, it is not possible to determine whether the original -pathname contained a newline character or the literal -.I \e012 -character sequence. -.IP -If the mapping is file-backed and the file has been deleted, the string -" (deleted)" is appended to the pathname. -Note that this is ambiguous too. -.IP -Under Linux 2.0, there is no field giving pathname. -.TP -.IR /proc/ pid /mem -This file can be used to access the pages of a process's memory through -.BR open (2), -.BR read (2), -and -.BR lseek (2). -.IP -Permission to access this file is governed by a ptrace access mode -.B PTRACE_MODE_ATTACH_FSCREDS -check; see -.BR ptrace (2). -.TP -.IR /proc/ pid /mountinfo " (since Linux 2.6.26)" -.\" This info adapted from Documentation/filesystems/proc.txt -.\" commit 2d4d4864ac08caff5c204a752bd004eed4f08760 -This file contains information about mounts -in the process's mount namespace (see -.BR mount_namespaces (7)). -It supplies various information -(e.g., propagation state, root of mount for bind mounts, -identifier for each mount and its parent) that is missing from the (older) -.IR /proc/ pid /mounts -file, and fixes various other problems with that file -(e.g., nonextensibility, -failure to distinguish per-mount versus per-superblock options). -.IP -The file contains lines of the form: -.IP -.EX -36 35 98:0 /mnt1 /mnt2 rw,noatime master:1 \- ext3 /dev/root rw,errors=continue -(1)(2)(3) (4) (5) (6) (7) (8) (9) (10) (11) -.EE -.IP -The numbers in parentheses are labels for the descriptions below: -.RS 7 -.TP 5 -(1) -mount ID: a unique ID for the mount (may be reused after -.BR umount (2)). -.TP -(2) -parent ID: the ID of the parent mount -(or of self for the root of this mount namespace's mount tree). -.IP -If a new mount is stacked on top of a previous existing mount -(so that it hides the existing mount) at pathname P, -then the parent of the new mount is the previous mount at that location. -Thus, when looking at all the mounts stacked at a particular location, -the top-most mount is the one that is not the parent -of any other mount at the same location. -(Note, however, that this top-most mount will be accessible only if -the longest path subprefix of P that is a mount point -is not itself hidden by a stacked mount.) -.IP -If the parent mount lies outside the process's root directory (see -.BR chroot (2)), -the ID shown here won't have a corresponding record in -.I mountinfo -whose mount ID (field 1) matches this parent mount ID -(because mounts that lie outside the process's root directory -are not shown in -.IR mountinfo ). -As a special case of this point, -the process's root mount may have a parent mount -(for the initramfs filesystem) that lies -.\" Miklos Szeredi, Nov 2017: The hidden one is the initramfs, I believe -.\" mtk: In the initial mount namespace, this hidden ID has the value 0 -outside the process's root directory, -and an entry for that mount will not appear in -.IR mountinfo . -.TP -(3) -major:minor: the value of -.I st_dev -for files on this filesystem (see -.BR stat (2)). -.TP -(4) -root: the pathname of the directory in the filesystem -which forms the root of this mount. -.TP -(5) -mount point: the pathname of the mount point relative -to the process's root directory. -.TP -(6) -mount options: per-mount options (see -.BR mount (2)). -.TP -(7) -optional fields: zero or more fields of the form "tag[:value]"; see below. -.TP -(8) -separator: the end of the optional fields is marked by a single hyphen. -.TP -(9) -filesystem type: the filesystem type in the form "type[.subtype]". -.TP -(10) -mount source: filesystem-specific information or "none". -.TP -(11) -super options: per-superblock options (see -.BR mount (2)). -.RE -.IP -Currently, the possible optional fields are -.IR shared , -.IR master , -.IR propagate_from , -and -.IR unbindable . -See -.BR mount_namespaces (7) -for a description of these fields. -Parsers should ignore all unrecognized optional fields. -.IP -For more information on mount propagation see -.I Documentation/filesystems/sharedsubtree.rst -(or -.I Documentation/filesystems/sharedsubtree.txt -before Linux 5.8) -in the Linux kernel source tree. -.TP -.IR /proc/ pid /mounts " (since Linux 2.4.19)" -This file lists all the filesystems currently mounted in the -process's mount namespace (see -.BR mount_namespaces (7)). -The format of this file is documented in -.BR fstab (5). -.IP -Since Linux 2.6.15, this file is pollable: -after opening the file for reading, a change in this file -(i.e., a filesystem mount or unmount) causes -.BR select (2) -to mark the file descriptor as having an exceptional condition, and -.BR poll (2) -and -.BR epoll_wait (2) -mark the file as having a priority event -.RB ( POLLPRI ). -(Before Linux 2.6.30, -a change in this file was indicated by the file descriptor -being marked as readable for -.BR select (2), -and being marked as having an error condition for -.BR poll (2) -and -.BR epoll_wait (2).) -.TP -.IR /proc/ pid /mountstats " (since Linux 2.6.17)" -This file exports information (statistics, configuration information) -about the mounts in the process's mount namespace (see -.BR mount_namespaces (7)). -Lines in this file have the form: -.IP -.in +4n -.EX -device /dev/sda7 mounted on /home with fstype ext3 [stats] -( 1 ) ( 2 ) (3 ) ( 4 ) -.EE -.in -.IP -The fields in each line are: -.RS 7 -.TP 5 -(1) -The name of the mounted device -(or "nodevice" if there is no corresponding device). -.TP -(2) -The mount point within the filesystem tree. -.TP -(3) -The filesystem type. -.TP -(4) -Optional statistics and configuration information. -Currently (as at Linux 2.6.26), only NFS filesystems export -information via this field. -.RE -.IP -This file is readable only by the owner of the process. -.TP -.IR /proc/ pid /net " (since Linux 2.6.25)" -See the description of -.IR /proc/net . -.TP -.IR /proc/ pid /ns/ " (since Linux 3.0)" -.\" See commit 6b4e306aa3dc94a0545eb9279475b1ab6209a31f -This is a subdirectory containing one entry for each namespace that -supports being manipulated by -.BR setns (2). -For more information, see -.BR namespaces (7). -.TP -.IR /proc/ pid /numa_maps " (since Linux 2.6.14)" -See -.BR numa (7). -.TP -.IR /proc/ pid /oom_adj " (since Linux 2.6.11)" -This file can be used to adjust the score used to select which process -should be killed in an out-of-memory (OOM) situation. -The kernel uses this value for a bit-shift operation of the process's -.I oom_score -value: -valid values are in the range \-16 to +15, -plus the special value \-17, -which disables OOM-killing altogether for this process. -A positive score increases the likelihood of this -process being killed by the OOM-killer; -a negative score decreases the likelihood. -.IP -The default value for this file is 0; -a new process inherits its parent's -.I oom_adj -setting. -A process must be privileged -.RB ( CAP_SYS_RESOURCE ) -to update this file, -although a process can always increase its own -.I oom_adj -setting (since Linux 2.6.20). -.IP -Since Linux 2.6.36, use of this file is deprecated in favor of -.IR /proc/ pid /oom_score_adj , -and finally removed in Linux 3.7. -.TP -.IR /proc/ pid /oom_score " (since Linux 2.6.11)" -.\" See mm/oom_kill.c::badness() before Linux 2.6.36 sources -.\" See mm/oom_kill.c::oom_badness() after Linux 2.6.36 -.\" commit a63d83f427fbce97a6cea0db2e64b0eb8435cd10 -This file displays the current score that the kernel gives to -this process for the purpose of selecting a process -for the OOM-killer. -A higher score means that the process is more likely to be -selected by the OOM-killer. -The basis for this score is the amount of memory used by the process, -with increases (+) or decreases (\-) for factors including: -.\" See mm/oom_kill.c::badness() before Linux 2.6.36 sources -.\" See mm/oom_kill.c::oom_badness() after Linux 2.6.36 -.\" commit a63d83f427fbce97a6cea0db2e64b0eb8435cd10 -.RS -.IP \[bu] 3 -whether the process is privileged (\-). -.\" More precisely, if it has CAP_SYS_ADMIN or (pre 2.6.36) CAP_SYS_RESOURCE -.RE -.IP -Before Linux 2.6.36 -the following factors were also used in the calculation of oom_score: -.RS -.IP \[bu] 3 -whether the process creates a lot of children using -.BR fork (2) -(+); -.IP \[bu] -whether the process has been running a long time, -or has used a lot of CPU time (\-); -.IP \[bu] -whether the process has a low nice value (i.e., > 0) (+); and -.IP \[bu] -whether the process is making direct hardware access (\-). -.\" More precisely, if it has CAP_SYS_RAWIO -.RE -.IP -The -.I oom_score -also reflects the adjustment specified by the -.I oom_score_adj -or -.I oom_adj -setting for the process. -.TP -.IR /proc/ pid /oom_score_adj " (since Linux 2.6.36)" -.\" Text taken from Linux 3.7 Documentation/filesystems/proc.txt -This file can be used to adjust the badness heuristic used to select which -process gets killed in out-of-memory conditions. -.IP -The badness heuristic assigns a value to each candidate task ranging from 0 -(never kill) to 1000 (always kill) to determine which process is targeted. -The units are roughly a proportion along that range of -allowed memory the process may allocate from, -based on an estimation of its current memory and swap use. -For example, if a task is using all allowed memory, -its badness score will be 1000. -If it is using half of its allowed memory, its score will be 500. -.IP -There is an additional factor included in the badness score: root -processes are given 3% extra memory over other tasks. -.IP -The amount of "allowed" memory depends on the context -in which the OOM-killer was called. -If it is due to the memory assigned to the allocating task's cpuset -being exhausted, -the allowed memory represents the set of mems assigned to that -cpuset (see -.BR cpuset (7)). -If it is due to a mempolicy's node(s) being exhausted, -the allowed memory represents the set of mempolicy nodes. -If it is due to a memory limit (or swap limit) being reached, -the allowed memory is that configured limit. -Finally, if it is due to the entire system being out of memory, the -allowed memory represents all allocatable resources. -.IP -The value of -.I oom_score_adj -is added to the badness score before it -is used to determine which task to kill. -Acceptable values range from \-1000 -(OOM_SCORE_ADJ_MIN) to +1000 (OOM_SCORE_ADJ_MAX). -This allows user space to control the preference for OOM-killing, -ranging from always preferring a certain -task or completely disabling it from OOM-killing. -The lowest possible value, \-1000, is -equivalent to disabling OOM-killing entirely for that task, -since it will always report a badness score of 0. -.IP -Consequently, it is very simple for user space to define -the amount of memory to consider for each task. -Setting an -.I oom_score_adj -value of +500, for example, -is roughly equivalent to allowing the remainder of tasks sharing the -same system, cpuset, mempolicy, or memory controller resources -to use at least 50% more memory. -A value of \-500, on the other hand, would be roughly -equivalent to discounting 50% of the task's -allowed memory from being considered as scoring against the task. -.IP -For backward compatibility with previous kernels, -.IR /proc/ pid /oom_adj -can still be used to tune the badness score. -Its value is -scaled linearly with -.IR oom_score_adj . -.IP -Writing to -.IR /proc/ pid /oom_score_adj -or -.IR /proc/ pid /oom_adj -will change the other with its scaled value. -.IP -The -.BR choom (1) -program provides a command-line interface for adjusting the -.I oom_score_adj -value of a running process or a newly executed command. -.TP -.IR /proc/ pid /pagemap " (since Linux 2.6.25)" -This file shows the mapping of each of the process's virtual pages -into physical page frames or swap area. -It contains one 64-bit value for each virtual page, -with the bits set as follows: -.RS -.TP -63 -If set, the page is present in RAM. -.TP -62 -If set, the page is in swap space -.TP -61 (since Linux 3.5) -The page is a file-mapped page or a shared anonymous page. -.TP -60\[en]58 (since Linux 3.11) -Zero -.\" Not quite true; see commit 541c237c0923f567c9c4cabb8a81635baadc713f -.TP -57 (since Linux 5.14) -If set, the page is write-protected through -.BR userfaultfd (2). -.TP -56 (since Linux 4.2) -.\" commit 77bb499bb60f4b79cca7d139c8041662860fcf87 -.\" commit 83b4b0bb635eee2b8e075062e4e008d1bc110ed7 -The page is exclusively mapped. -.TP -55 (since Linux 3.11) -PTE is soft-dirty -(see the kernel source file -.IR Documentation/admin\-guide/mm/soft\-dirty.rst ). -.TP -54\[en]0 -If the page is present in RAM (bit 63), then these bits -provide the page frame number, which can be used to index -.I /proc/kpageflags -and -.IR /proc/kpagecount . -If the page is present in swap (bit 62), -then bits 4\[en]0 give the swap type, and bits 54\[en]5 encode the swap offset. -.RE -.IP -Before Linux 3.11, bits 60\[en]55 were -used to encode the base-2 log of the page size. -.IP -To employ -.IR /proc/ pid /pagemap -efficiently, use -.IR /proc/ pid /maps -to determine which areas of memory are actually mapped and seek -to skip over unmapped regions. -.IP -The -.IR /proc/ pid /pagemap -file is present only if the -.B CONFIG_PROC_PAGE_MONITOR -kernel configuration option is enabled. -.IP -Permission to access this file is governed by a ptrace access mode -.B PTRACE_MODE_READ_FSCREDS -check; see -.BR ptrace (2). -.TP -.IR /proc/ pid /personality " (since Linux 2.6.28)" -.\" commit 478307230810d7e2a753ed220db9066dfdf88718 -This read-only file exposes the process's execution domain, as set by -.BR personality (2). -The value is displayed in hexadecimal notation. -.IP -Permission to access this file is governed by a ptrace access mode -.B PTRACE_MODE_ATTACH_FSCREDS -check; see -.BR ptrace (2). -.TP -.IR /proc/ pid /root -UNIX and Linux support the idea of a per-process root of the -filesystem, set by the -.BR chroot (2) -system call. -This file is a symbolic link that points to the process's -root directory, and behaves in the same way as -.IR exe , -and -.IR fd/* . -.IP -Note however that this file is not merely a symbolic link. -It provides the same view of the filesystem (including namespaces and the -set of per-process mounts) as the process itself. -An example illustrates this point. -In one terminal, we start a shell in new user and mount namespaces, -and in that shell we create some new mounts: -.IP -.in +4n -.EX -$ \fBPS1=\[aq]sh1# \[aq] unshare \-Urnm\fP -sh1# \fBmount \-t tmpfs tmpfs /etc\fP # Mount empty tmpfs at /etc -sh1# \fBmount \-\-bind /usr /dev\fP # Mount /usr at /dev -sh1# \fBecho $$\fP -27123 -.EE -.in -.IP -In a second terminal window, in the initial mount namespace, -we look at the contents of the corresponding mounts in -the initial and new namespaces: -.IP -.in +4n -.EX -$ \fBPS1=\[aq]sh2# \[aq] sudo sh\fP -sh2# \fBls /etc | wc \-l\fP # In initial NS -309 -sh2# \fBls /proc/27123/root/etc | wc \-l\fP # /etc in other NS -0 # The empty tmpfs dir -sh2# \fBls /dev | wc \-l\fP # In initial NS -205 -sh2# \fBls /proc/27123/root/dev | wc \-l\fP # /dev in other NS -11 # Actually bind - # mounted to /usr -sh2# \fBls /usr | wc \-l\fP # /usr in initial NS -11 -.EE -.in -.IP -.\" The following was still true as at kernel 2.6.13 -In a multithreaded process, the contents of the -.IR /proc/ pid /root -symbolic link are not available if the main thread has already terminated -(typically by calling -.BR pthread_exit (3)). -.IP -Permission to dereference or read -.RB ( readlink (2)) -this symbolic link is governed by a ptrace access mode -.B PTRACE_MODE_READ_FSCREDS -check; see -.BR ptrace (2). -.TP -.IR /proc/ pid /projid_map " (since Linux 3.7)" -.\" commit f76d207a66c3a53defea67e7d36c3eb1b7d6d61d -See -.BR user_namespaces (7). -.TP -.IR /proc/ pid /seccomp " (Linux 2.6.12 to Linux 2.6.22)" -This file can be used to read and change the process's -secure computing (seccomp) mode setting. -It contains the value 0 if the process is not in seccomp mode, -and 1 if the process is in strict seccomp mode (see -.BR seccomp (2)). -Writing 1 to this file places the process irreversibly in strict seccomp mode. -(Further attempts to write to the file fail with the -.B EPERM -error.) -.IP -In Linux 2.6.23, -this file went away, to be replaced by the -.BR prctl (2) -.B PR_GET_SECCOMP -and -.B PR_SET_SECCOMP -operations (and later by -.BR seccomp (2) -and the -.I Seccomp -field in -.IR /proc/ pid /status ). +.\" .SH FILES .\" FIXME Describe /proc/[pid]/sessionid .\" commit 1e0bd7550ea9cf474b1ad4c6ff5729a507f75fdc .\" CONFIG_AUDITSYSCALL @@ -1958,4970 +197,25 @@ field in .\" /proc/[pid]/task/[tid]/schedstats .\" Added in Linux 2.6.9 .\" CONFIG_SCHEDSTATS -.TP -.IR /proc/ pid /setgroups " (since Linux 3.19)" -See -.BR user_namespaces (7). -.TP -.IR /proc/ pid /smaps " (since Linux 2.6.14)" -This file shows memory consumption for each of the process's mappings. -(The -.BR pmap (1) -command displays similar information, -in a form that may be easier for parsing.) -For each mapping there is a series of lines such as the following: -.IP -.in +4n -.EX -00400000\-0048a000 r\-xp 00000000 fd:03 960637 /bin/bash -Size: 552 kB -Rss: 460 kB -Pss: 100 kB -Shared_Clean: 452 kB -Shared_Dirty: 0 kB -Private_Clean: 8 kB -Private_Dirty: 0 kB -Referenced: 460 kB -Anonymous: 0 kB -AnonHugePages: 0 kB -ShmemHugePages: 0 kB -ShmemPmdMapped: 0 kB -Swap: 0 kB -KernelPageSize: 4 kB -MMUPageSize: 4 kB -Locked: 0 kB -ProtectionKey: 0 -VmFlags: rd ex mr mw me dw -.EE -.in -.IP -The first of these lines shows the same information as is displayed -for the mapping in -.IR /proc/ pid /maps . -The following lines show the size of the mapping, -the amount of the mapping that is currently resident in RAM ("Rss"), -the process's proportional share of this mapping ("Pss"), -the number of clean and dirty shared pages in the mapping, -and the number of clean and dirty private pages in the mapping. -"Referenced" indicates the amount of memory currently marked as -referenced or accessed. -"Anonymous" shows the amount of memory -that does not belong to any file. -"Swap" shows how much -would-be-anonymous memory is also used, but out on swap. -.IP -The "KernelPageSize" line (available since Linux 2.6.29) -is the page size used by the kernel to back the virtual memory area. -This matches the size used by the MMU in the majority of cases. -However, one counter-example occurs on PPC64 kernels -whereby a kernel using 64 kB as a base page size may still use 4 kB -pages for the MMU on older processors. -To distinguish the two attributes, the "MMUPageSize" line -(also available since Linux 2.6.29) -reports the page size used by the MMU. -.IP -The "Locked" indicates whether the mapping is locked in memory -or not. -.IP -The "ProtectionKey" line (available since Linux 4.9, on x86 only) -contains the memory protection key (see -.BR pkeys (7)) -associated with the virtual memory area. -This entry is present only if the kernel was built with the -.B CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS -configuration option (since Linux 4.6). -.IP -The "VmFlags" line (available since Linux 3.8) -represents the kernel flags associated with the virtual memory area, -encoded using the following two-letter codes: -.RS -.IP -.TS -l l l. -rd - readable -wr - writable -ex - executable -sh - shared -mr - may read -mw - may write -me - may execute -ms - may share -gd - stack segment grows down -pf - pure PFN range -dw - disabled write to the mapped file -lo - pages are locked in memory -io - memory mapped I/O area -sr - sequential read advise provided -rr - random read advise provided -dc - do not copy area on fork -de - do not expand area on remapping -ac - area is accountable -nr - swap space is not reserved for the area -ht - area uses huge tlb pages -sf - perform synchronous page faults (since Linux 4.15) -nl - non-linear mapping (removed in Linux 4.0) -ar - architecture specific flag -wf - wipe on fork (since Linux 4.14) -dd - do not include area into core dump -sd - soft-dirty flag (since Linux 3.13) -mm - mixed map area -hg - huge page advise flag -nh - no-huge page advise flag -mg - mergeable advise flag -um - userfaultfd missing pages tracking (since Linux 4.3) -uw - userfaultfd wprotect pages tracking (since Linux 4.3) -.TE -.RE -.IP -The -.IR /proc/ pid /smaps -file is present only if the -.B CONFIG_PROC_PAGE_MONITOR -kernel configuration option is enabled. -.TP -.IR /proc/ pid /stack " (since Linux 2.6.29)" -.\" 2ec220e27f5040aec1e88901c1b6ea3d135787ad -This file provides a symbolic trace of the function calls in this -process's kernel stack. -This file is provided only if the kernel was built with the -.B CONFIG_STACKTRACE -configuration option. -.IP -Permission to access this file is governed by a ptrace access mode -.B PTRACE_MODE_ATTACH_FSCREDS -check; see -.BR ptrace (2). -.TP -.IR /proc/ pid /stat -Status information about the process. -This is used by -.BR ps (1). -It is defined in the kernel source file -.IR fs/proc/array.c "." -.IP -The fields, in order, with their proper -.BR scanf (3) -format specifiers, are listed below. -Whether or not certain of these fields display valid information is governed by -a ptrace access mode -.BR PTRACE_MODE_READ_FSCREDS " | " PTRACE_MODE_NOAUDIT -check (refer to -.BR ptrace (2)). -If the check denies access, then the field value is displayed as 0. -The affected fields are indicated with the marking [PT]. -.RS -.TP -(1) \fIpid\fP \ %d -.br -The process ID. -.TP -(2) \fIcomm\fP \ %s -The filename of the executable, in parentheses. -Strings longer than -.B TASK_COMM_LEN -(16) characters (including the terminating null byte) are silently truncated. -This is visible whether or not the executable is swapped out. -.TP -(3) \fIstate\fP \ %c -One of the following characters, indicating process state: -.RS -.TP -R -Running -.TP -S -Sleeping in an interruptible wait -.TP -D -Waiting in uninterruptible -disk sleep -.TP -Z -Zombie -.TP -T -Stopped (on a signal) or (before Linux 2.6.33) trace stopped -.TP -t -.\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29 -Tracing stop (Linux 2.6.33 onward) -.TP -W -Paging (only before Linux 2.6.0) -.TP -X -Dead (from Linux 2.6.0 onward) -.TP -x -.\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29 -Dead (Linux 2.6.33 to -.\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457 -3.13 only) -.TP -K -.\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29 -Wakekill (Linux 2.6.33 to -.\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457 -3.13 only) -.TP -W -.\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29 -Waking (Linux 2.6.33 to -.\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457 -3.13 only) -.TP -P -.\" commit f2530dc71cf0822f90bb63ea4600caaef33a66bb -Parked (Linux 3.9 to -.\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457 -3.13 only) -.TP -I -.\" commit 06eb61844d841d0032a9950ce7f8e783ee49c0d0 -Idle (Linux 4.14 onward) -.RE -.TP -(4) \fIppid\fP \ %d -The PID of the parent of this process. -.TP -(5) \fIpgrp\fP \ %d -The process group ID of the process. -.TP -(6) \fIsession\fP \ %d -The session ID of the process. -.TP -(7) \fItty_nr\fP \ %d -The controlling terminal of the process. -(The minor device number is contained in the combination of bits -31 to 20 and 7 to 0; -the major device number is in bits 15 to 8.) -.TP -(8) \fItpgid\fP \ %d -.\" This field and following, up to and including wchan added 0.99.1 -The ID of the foreground process group of the controlling -terminal of the process. -.TP -(9) \fIflags\fP \ %u -The kernel flags word of the process. -For bit meanings, -see the PF_* defines in the Linux kernel source file -.IR include/linux/sched.h . -Details depend on the kernel version. -.IP -The format for this field was %lu before Linux 2.6. -.TP -(10) \fIminflt\fP \ %lu -The number of minor faults the process has made which have not -required loading a memory page from disk. -.TP -(11) \fIcminflt\fP \ %lu -The number of minor faults that the process's -waited-for children have made. -.TP -(12) \fImajflt\fP \ %lu -The number of major faults the process has made which have -required loading a memory page from disk. -.TP -(13) \fIcmajflt\fP \ %lu -The number of major faults that the process's -waited-for children have made. -.TP -(14) \fIutime\fP \ %lu -Amount of time that this process has been scheduled in user mode, -measured in clock ticks (divide by -.IR sysconf(_SC_CLK_TCK) ). -This includes guest time, \fIguest_time\fP -(time spent running a virtual CPU, see below), -so that applications that are not aware of the guest time field -do not lose that time from their calculations. -.TP -(15) \fIstime\fP \ %lu -Amount of time that this process has been scheduled in kernel mode, -measured in clock ticks (divide by -.IR sysconf(_SC_CLK_TCK) ). -.TP -(16) \fIcutime\fP \ %ld -Amount of time that this process's -waited-for children have been scheduled in user mode, -measured in clock ticks (divide by -.IR sysconf(_SC_CLK_TCK) ). -(See also -.BR times (2).) -This includes guest time, \fIcguest_time\fP -(time spent running a virtual CPU, see below). -.TP -(17) \fIcstime\fP \ %ld -Amount of time that this process's -waited-for children have been scheduled in kernel mode, -measured in clock ticks (divide by -.IR sysconf(_SC_CLK_TCK) ). -.TP -(18) \fIpriority\fP \ %ld -(Explanation for Linux 2.6) -For processes running a real-time scheduling policy -.RI ( policy -below; see -.BR sched_setscheduler (2)), -this is the negated scheduling priority, minus one; -that is, a number in the range \-2 to \-100, -corresponding to real-time priorities 1 to 99. -For processes running under a non-real-time scheduling policy, -this is the raw nice value -.RB ( setpriority (2)) -as represented in the kernel. -The kernel stores nice values as numbers -in the range 0 (high) to 39 (low), -corresponding to the user-visible nice range of \-20 to 19. -.IP -Before Linux 2.6, this was a scaled value based on -the scheduler weighting given to this process. -.\" And back in Linux 1.2 days things were different again. -.TP -(19) \fInice\fP \ %ld -The nice value (see -.BR setpriority (2)), -a value in the range 19 (low priority) to \-20 (high priority). -.\" Back in Linux 1.2 days things were different. -.\" .TP -.\" \fIcounter\fP %ld -.\" The current maximum size in jiffies of the process's next timeslice, -.\" or what is currently left of its current timeslice, if it is the -.\" currently running process. -.\" .TP -.\" \fItimeout\fP %u -.\" The time in jiffies of the process's next timeout. -.\" timeout was removed sometime around 2.1/2.2 -.TP -(20) \fInum_threads\fP \ %ld -Number of threads in this process (since Linux 2.6). -Before Linux 2.6, this field was hard coded to 0 as a placeholder -for an earlier removed field. -.TP -(21) \fIitrealvalue\fP \ %ld -The time in jiffies before the next -.B SIGALRM -is sent to the process due to an interval timer. -Since Linux 2.6.17, this field is no longer maintained, -and is hard coded as 0. -.TP -(22) \fIstarttime\fP \ %llu -The time the process started after system boot. -Before Linux 2.6, this value was expressed in jiffies. -Since Linux 2.6, the value is expressed in clock ticks (divide by -.IR sysconf(_SC_CLK_TCK) ). -.IP -The format for this field was %lu before Linux 2.6. -.TP -(23) \fIvsize\fP \ %lu -Virtual memory size in bytes. -.TP -(24) \fIrss\fP \ %ld -Resident Set Size: number of pages the process has in real memory. -This is just the pages which -count toward text, data, or stack space. -This does not include pages -which have not been demand-loaded in, or which are swapped out. -This value is inaccurate; see -.IR /proc/ pid /statm -below. -.TP -(25) \fIrsslim\fP \ %lu -Current soft limit in bytes on the rss of the process; -see the description of -.B RLIMIT_RSS -in -.BR getrlimit (2). -.TP -(26) \fIstartcode\fP \ %lu \ [PT] -The address above which program text can run. -.TP -(27) \fIendcode\fP \ %lu \ [PT] -The address below which program text can run. -.TP -(28) \fIstartstack\fP \ %lu \ [PT] -The address of the start (i.e., bottom) of the stack. -.TP -(29) \fIkstkesp\fP \ %lu \ [PT] -The current value of ESP (stack pointer), as found in the -kernel stack page for the process. -.TP -(30) \fIkstkeip\fP \ %lu \ [PT] -The current EIP (instruction pointer). -.TP -(31) \fIsignal\fP \ %lu -The bitmap of pending signals, displayed as a decimal number. -Obsolete, because it does not provide information on real-time signals; use -.IR /proc/ pid /status -instead. -.TP -(32) \fIblocked\fP \ %lu -The bitmap of blocked signals, displayed as a decimal number. -Obsolete, because it does not provide information on real-time signals; use -.IR /proc/ pid /status -instead. -.TP -(33) \fIsigignore\fP \ %lu -The bitmap of ignored signals, displayed as a decimal number. -Obsolete, because it does not provide information on real-time signals; use -.IR /proc/ pid /status -instead. -.TP -(34) \fIsigcatch\fP \ %lu -The bitmap of caught signals, displayed as a decimal number. -Obsolete, because it does not provide information on real-time signals; use -.IR /proc/ pid /status -instead. -.TP -(35) \fIwchan\fP \ %lu \ [PT] -This is the "channel" in which the process is waiting. -It is the address of a location in the kernel where the process is sleeping. -The corresponding symbolic name can be found in -.IR /proc/ pid /wchan . -.TP -(36) \fInswap\fP \ %lu -.\" nswap was added in Linux 2.0 -Number of pages swapped (not maintained). -.TP -(37) \fIcnswap\fP \ %lu -.\" cnswap was added in Linux 2.0 -Cumulative \fInswap\fP for child processes (not maintained). -.TP -(38) \fIexit_signal\fP \ %d \ (since Linux 2.1.22) -Signal to be sent to parent when we die. -.TP -(39) \fIprocessor\fP \ %d \ (since Linux 2.2.8) -CPU number last executed on. -.TP -(40) \fIrt_priority\fP \ %u \ (since Linux 2.5.19) -Real-time scheduling priority, a number in the range 1 to 99 for -processes scheduled under a real-time policy, -or 0, for non-real-time processes (see -.BR sched_setscheduler (2)). -.TP -(41) \fIpolicy\fP \ %u \ (since Linux 2.5.19) -Scheduling policy (see -.BR sched_setscheduler (2)). -Decode using the SCHED_* constants in -.IR linux/sched.h . -.IP -The format for this field was %lu before Linux 2.6.22. -.TP -(42) \fIdelayacct_blkio_ticks\fP \ %llu \ (since Linux 2.6.18) -Aggregated block I/O delays, measured in clock ticks (centiseconds). -.TP -(43) \fIguest_time\fP \ %lu \ (since Linux 2.6.24) -Guest time of the process (time spent running a virtual CPU -for a guest operating system), measured in clock ticks (divide by -.IR sysconf(_SC_CLK_TCK) ). -.TP -(44) \fIcguest_time\fP \ %ld \ (since Linux 2.6.24) -Guest time of the process's children, measured in clock ticks (divide by -.IR sysconf(_SC_CLK_TCK) ). -.TP -(45) \fIstart_data\fP \ %lu \ (since Linux 3.3) \ [PT] -.\" commit b3f7f573a20081910e34e99cbc91831f4f02f1ff -Address above which program initialized and -uninitialized (BSS) data are placed. -.TP -(46) \fIend_data\fP \ %lu \ (since Linux 3.3) \ [PT] -.\" commit b3f7f573a20081910e34e99cbc91831f4f02f1ff -Address below which program initialized and -uninitialized (BSS) data are placed. -.TP -(47) \fIstart_brk\fP \ %lu \ (since Linux 3.3) \ [PT] -.\" commit b3f7f573a20081910e34e99cbc91831f4f02f1ff -Address above which program heap can be expanded with -.BR brk (2). -.TP -(48) \fIarg_start\fP \ %lu \ (since Linux 3.5) \ [PT] -.\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3 -Address above which program command-line arguments -.RI ( argv ) -are placed. -.TP -(49) \fIarg_end\fP \ %lu \ (since Linux 3.5) \ [PT] -.\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3 -Address below program command-line arguments -.RI ( argv ) -are placed. -.TP -(50) \fIenv_start\fP \ %lu \ (since Linux 3.5) \ [PT] -.\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3 -Address above which program environment is placed. -.TP -(51) \fIenv_end\fP \ %lu \ (since Linux 3.5) \ [PT] -.\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3 -Address below which program environment is placed. -.TP -(52) \fIexit_code\fP \ %d \ (since Linux 3.5) \ [PT] -.\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3 -The thread's exit status in the form reported by -.BR waitpid (2). -.RE -.TP -.IR /proc/ pid /statm -Provides information about memory usage, measured in pages. -The columns are: -.IP -.in +4n -.EX -size (1) total program size - (same as VmSize in \fI/proc/\fPpid\fI/status\fP) -resident (2) resident set size - (inaccurate; same as VmRSS in \fI/proc/\fPpid\fI/status\fP) -shared (3) number of resident shared pages - (i.e., backed by a file) - (inaccurate; same as RssFile+RssShmem in - \fI/proc/\fPpid\fI/status\fP) -text (4) text (code) -.\" (not including libs; broken, includes data segment) -lib (5) library (unused since Linux 2.6; always 0) -data (6) data + stack -.\" (including libs; broken, includes library text) -dt (7) dirty pages (unused since Linux 2.6; always 0) -.EE -.in -.IP -.\" See SPLIT_RSS_COUNTING in the kernel. -.\" Inaccuracy is bounded by TASK_RSS_EVENTS_THRESH. -Some of these values are inaccurate because -of a kernel-internal scalability optimization. -If accurate values are required, use -.IR /proc/ pid /smaps -or -.IR /proc/ pid /smaps_rollup -instead, which are much slower but provide accurate, detailed information. -.TP -.IR /proc/ pid /status -Provides much of the information in -.IR /proc/ pid /stat -and -.IR /proc/ pid /statm -in a format that's easier for humans to parse. -Here's an example: -.IP -.in +4n -.EX -.RB "$" " cat /proc/$$/status" -Name: bash -Umask: 0022 -State: S (sleeping) -Tgid: 17248 -Ngid: 0 -Pid: 17248 -PPid: 17200 -TracerPid: 0 -Uid: 1000 1000 1000 1000 -Gid: 100 100 100 100 -FDSize: 256 -Groups: 16 33 100 -NStgid: 17248 -NSpid: 17248 -NSpgid: 17248 -NSsid: 17200 -VmPeak: 131168 kB -VmSize: 131168 kB -VmLck: 0 kB -VmPin: 0 kB -VmHWM: 13484 kB -VmRSS: 13484 kB -RssAnon: 10264 kB -RssFile: 3220 kB -RssShmem: 0 kB -VmData: 10332 kB -VmStk: 136 kB -VmExe: 992 kB -VmLib: 2104 kB -VmPTE: 76 kB -VmPMD: 12 kB -VmSwap: 0 kB -HugetlbPages: 0 kB # 4.4 -CoreDumping: 0 # 4.15 -Threads: 1 -SigQ: 0/3067 -SigPnd: 0000000000000000 -ShdPnd: 0000000000000000 -SigBlk: 0000000000010000 -SigIgn: 0000000000384004 -SigCgt: 000000004b813efb -CapInh: 0000000000000000 -CapPrm: 0000000000000000 -CapEff: 0000000000000000 -CapBnd: ffffffffffffffff -CapAmb: 0000000000000000 -NoNewPrivs: 0 -Seccomp: 0 -Speculation_Store_Bypass: vulnerable -Cpus_allowed: 00000001 -Cpus_allowed_list: 0 -Mems_allowed: 1 -Mems_allowed_list: 0 -voluntary_ctxt_switches: 150 -nonvoluntary_ctxt_switches: 545 -.EE -.in -.IP -The fields are as follows: -.RS -.TP -.I Name -Command run by this process. -Strings longer than -.B TASK_COMM_LEN -(16) characters (including the terminating null byte) are silently truncated. -.TP -.I Umask -Process umask, expressed in octal with a leading zero; see -.BR umask (2). -(Since Linux 4.7.) -.TP -.I State -Current state of the process. -One of -"R (running)", -"S (sleeping)", -"D (disk sleep)", -"T (stopped)", -"t (tracing stop)", -"Z (zombie)", -or -"X (dead)". -.TP -.I Tgid -Thread group ID (i.e., Process ID). -.TP -.I Ngid -NUMA group ID (0 if none; since Linux 3.13). -.TP -.I Pid -Thread ID (see -.BR gettid (2)). -.TP -.I PPid -PID of parent process. -.TP -.I TracerPid -PID of process tracing this process (0 if not being traced). -.TP -.IR Uid ", " Gid -Real, effective, saved set, and filesystem UIDs (GIDs). -.TP -.I FDSize -Number of file descriptor slots currently allocated. -.TP -.I Groups -Supplementary group list. -.TP -.I NStgid -Thread group ID (i.e., PID) in each of the PID namespaces of which -.I pid -is a member. -The leftmost entry shows the value with respect to the PID namespace -of the process that mounted this procfs (or the root namespace -if mounted by the kernel), -followed by the value in successively nested inner namespaces. -.\" commit e4bc33245124db69b74a6d853ac76c2976f472d5 -(Since Linux 4.1.) -.TP -.I NSpid -Thread ID in each of the PID namespaces of which -.I pid -is a member. -The fields are ordered as for -.IR NStgid . -(Since Linux 4.1.) -.TP -.I NSpgid -Process group ID in each of the PID namespaces of which -.I pid -is a member. -The fields are ordered as for -.IR NStgid . -(Since Linux 4.1.) -.TP -.I NSsid -descendant namespace session ID hierarchy -Session ID in each of the PID namespaces of which -.I pid -is a member. -The fields are ordered as for -.IR NStgid . -(Since Linux 4.1.) -.TP -.I VmPeak -Peak virtual memory size. -.TP -.I VmSize -Virtual memory size. -.TP -.I VmLck -Locked memory size (see -.BR mlock (2)). -.TP -.I VmPin -Pinned memory size -.\" commit bc3e53f682d93df677dbd5006a404722b3adfe18 -(since Linux 3.2). -These are pages that can't be moved because something needs to -directly access physical memory. -.TP -.I VmHWM -Peak resident set size ("high water mark"). -This value is inaccurate; see -.IR /proc/ pid /statm -above. -.TP -.I VmRSS -Resident set size. -Note that the value here is the sum of -.IR RssAnon , -.IR RssFile , -and -.IR RssShmem . -This value is inaccurate; see -.IR /proc/ pid /statm -above. -.TP -.I RssAnon -Size of resident anonymous memory. -.\" commit bf9683d6990589390b5178dafe8fd06808869293 -(since Linux 4.5). -This value is inaccurate; see -.IR /proc/ pid /statm -above. -.TP -.I RssFile -Size of resident file mappings. -.\" commit bf9683d6990589390b5178dafe8fd06808869293 -(since Linux 4.5). -This value is inaccurate; see -.IR /proc/ pid /statm -above. -.TP -.I RssShmem -Size of resident shared memory (includes System V shared memory, -mappings from -.BR tmpfs (5), -and shared anonymous mappings). -.\" commit bf9683d6990589390b5178dafe8fd06808869293 -(since Linux 4.5). -.TP -.IR VmData ", " VmStk ", " VmExe -Size of data, stack, and text segments. -This value is inaccurate; see -.IR /proc/ pid /statm -above. -.TP -.I VmLib -Shared library code size. -.TP -.I VmPTE -Page table entries size (since Linux 2.6.10). -.TP -.I VmPMD -.\" commit dc6c9a35b66b520cf67e05d8ca60ebecad3b0479 -Size of second-level page tables (added in Linux 4.0; removed in Linux 4.15). -.TP -.I VmSwap -.\" commit b084d4353ff99d824d3bc5a5c2c22c70b1fba722 -Swapped-out virtual memory size by anonymous private pages; -shmem swap usage is not included (since Linux 2.6.34). -This value is inaccurate; see -.IR /proc/ pid /statm -above. -.TP -.I HugetlbPages -Size of hugetlb memory portions -.\" commit 5d317b2b6536592a9b51fe65faed43d65ca9158e -(since Linux 4.4). -.TP -.I CoreDumping -Contains the value 1 if the process is currently dumping core, -and 0 if it is not -.\" commit c643401218be0f4ab3522e0c0a63016596d6e9ca -(since Linux 4.15). -This information can be used by a monitoring process to avoid killing -a process that is currently dumping core, -which could result in a corrupted core dump file. -.TP -.I Threads -Number of threads in process containing this thread. -.TP -.I SigQ -This field contains two slash-separated numbers that relate to -queued signals for the real user ID of this process. -The first of these is the number of currently queued -signals for this real user ID, and the second is the -resource limit on the number of queued signals for this process -(see the description of -.B RLIMIT_SIGPENDING -in -.BR getrlimit (2)). -.TP -.IR SigPnd ", " ShdPnd -Mask (expressed in hexadecimal) -of signals pending for thread and for process as a whole (see -.BR pthreads (7) -and -.BR signal (7)). -.TP -.IR SigBlk ", " SigIgn ", " SigCgt -Masks (expressed in hexadecimal) -indicating signals being blocked, ignored, and caught (see -.BR signal (7)). -.TP -.IR CapInh ", " CapPrm ", " CapEff -Masks (expressed in hexadecimal) -of capabilities enabled in inheritable, permitted, and effective sets -(see -.BR capabilities (7)). -.TP -.I CapBnd -Capability bounding set, expressed in hexadecimal -(since Linux 2.6.26, see -.BR capabilities (7)). -.TP -.I CapAmb -Ambient capability set, expressed in hexadecimal -(since Linux 4.3, see -.BR capabilities (7)). -.TP -.I NoNewPrivs -.\" commit af884cd4a5ae62fcf5e321fecf0ec1014730353d -Value of the -.I no_new_privs -bit -(since Linux 4.10, see -.BR prctl (2)). -.TP -.I Seccomp -.\" commit 2f4b3bf6b2318cfaa177ec5a802f4d8d6afbd816 -Seccomp mode of the process -(since Linux 3.8, see -.BR seccomp (2)). -0 means -.BR SECCOMP_MODE_DISABLED ; -1 means -.BR SECCOMP_MODE_STRICT ; -2 means -.BR SECCOMP_MODE_FILTER . -This field is provided only if the kernel was built with the -.B CONFIG_SECCOMP -kernel configuration option enabled. -.TP -.I Speculation_Store_Bypass -.\" commit fae1fa0fc6cca8beee3ab8ed71d54f9a78fa3f64 -Speculation flaw mitigation state -(since Linux 4.17, see -.BR prctl (2)). -.TP -.I Cpus_allowed -Hexadecimal mask of CPUs on which this process may run -(since Linux 2.6.24, see -.BR cpuset (7)). -.TP -.I Cpus_allowed_list -Same as previous, but in "list format" -(since Linux 2.6.26, see -.BR cpuset (7)). -.TP -.I Mems_allowed -Mask of memory nodes allowed to this process -(since Linux 2.6.24, see -.BR cpuset (7)). -.TP -.I Mems_allowed_list -Same as previous, but in "list format" -(since Linux 2.6.26, see -.BR cpuset (7)). -.TP -.IR voluntary_ctxt_switches ", " nonvoluntary_ctxt_switches -Number of voluntary and involuntary context switches (since Linux 2.6.23). -.RE -.TP -.IR /proc/ pid /syscall " (since Linux 2.6.27)" -.\" commit ebcb67341fee34061430f3367f2e507e52ee051b -This file exposes the system call number and argument registers for the -system call currently being executed by the process, -followed by the values of the stack pointer and program counter registers. -The values of all six argument registers are exposed, -although most system calls use fewer registers. -.IP -If the process is blocked, but not in a system call, -then the file displays \-1 in place of the system call number, -followed by just the values of the stack pointer and program counter. -If process is not blocked, then the file contains just the string "running". -.IP -This file is present only if the kernel was configured with -.BR CONFIG_HAVE_ARCH_TRACEHOOK . -.IP -Permission to access this file is governed by a ptrace access mode -.B PTRACE_MODE_ATTACH_FSCREDS -check; see -.BR ptrace (2). -.TP -.IR /proc/ pid /task " (since Linux 2.6.0)" -.\" Precisely: Linux 2.6.0-test6 -This is a directory that contains one subdirectory -for each thread in the process. -The name of each subdirectory is the numerical thread ID -.RI ( tid ) -of the thread (see -.BR gettid (2)). -.IP -Within each of these subdirectories, there is a set of -files with the same names and contents as under the -.IR /proc/ pid -directories. -For attributes that are shared by all threads, the contents for -each of the files under the -.IR task/ tid -subdirectories will be the same as in the corresponding -file in the parent -.IR /proc/ pid -directory -(e.g., in a multithreaded process, all of the -.IR task/ tid /cwd -files will have the same value as the -.IR /proc/ pid /cwd -file in the parent directory, since all of the threads in a process -share a working directory). -For attributes that are distinct for each thread, -the corresponding files under -.IR task/ tid -may have different values (e.g., various fields in each of the -.IR task/ tid /status -files may be different for each thread), -.\" in particular: "children" :/ -or they might not exist in -.IR /proc/ pid -at all. -.IP -.\" The following was still true as at kernel 2.6.13 -In a multithreaded process, the contents of the -.IR /proc/ pid /task -directory are not available if the main thread has already terminated -(typically by calling -.BR pthread_exit (3)). -.TP -.IR /proc/ pid /task/ tid /children " (since Linux 3.5)" -.\" commit 818411616baf46ceba0cff6f05af3a9b294734f7 -A space-separated list of child tasks of this task. -Each child task is represented by its TID. -.IP -.\" see comments in get_children_pid() in fs/proc/array.c -This option is intended for use by the checkpoint-restore (CRIU) system, -and reliably provides a list of children only if all of the child processes -are stopped or frozen. -It does not work properly if children of the target task exit while -the file is being read! -Exiting children may cause non-exiting children to be omitted from the list. -This makes this interface even more unreliable than classic PID-based -approaches if the inspected task and its children aren't frozen, -and most code should probably not use this interface. -.IP -Until Linux 4.2, the presence of this file was governed by the -.B CONFIG_CHECKPOINT_RESTORE -kernel configuration option. -Since Linux 4.2, -.\" commit 2e13ba54a2682eea24918b87ad3edf70c2cf085b -it is governed by the -.B CONFIG_PROC_CHILDREN -option. -.TP -.IR /proc/ pid /timers " (since Linux 3.10)" -.\" commit 5ed67f05f66c41e39880a6d61358438a25f9fee5 -.\" commit 48f6a7a511ef8823fdff39afee0320092d43a8a0 -A list of the POSIX timers for this process. -Each timer is listed with a line that starts with the string "ID:". -For example: -.IP -.in +4n -.EX -ID: 1 -signal: 60/00007fff86e452a8 -notify: signal/pid.2634 -ClockID: 0 -ID: 0 -signal: 60/00007fff86e452a8 -notify: signal/pid.2634 -ClockID: 1 -.EE -.in -.IP -The lines shown for each timer have the following meanings: -.RS -.TP -.I ID -The ID for this timer. -This is not the same as the timer ID returned by -.BR timer_create (2); -rather, it is the same kernel-internal ID that is available via the -.I si_timerid -field of the -.I siginfo_t -structure (see -.BR sigaction (2)). -.TP -.I signal -This is the signal number that this timer uses to deliver notifications -followed by a slash, and then the -.I sigev_value -value supplied to the signal handler. -Valid only for timers that notify via a signal. -.TP -.I notify -The part before the slash specifies the mechanism -that this timer uses to deliver notifications, -and is one of "thread", "signal", or "none". -Immediately following the slash is either the string "tid" for timers -with -.B SIGEV_THREAD_ID -notification, or "pid" for timers that notify by other mechanisms. -Following the "." is the PID of the process -(or the kernel thread ID of the thread) that will be delivered -a signal if the timer delivers notifications via a signal. -.TP -.I ClockID -This field identifies the clock that the timer uses for measuring time. -For most clocks, this is a number that matches one of the user-space -.B CLOCK_* -constants exposed via -.IR <time.h> . -.B CLOCK_PROCESS_CPUTIME_ID -timers display with a value of \-6 -in this field. -.B CLOCK_THREAD_CPUTIME_ID -timers display with a value of \-2 -in this field. -.RE -.IP -This file is available only when the kernel was configured with -.BR CONFIG_CHECKPOINT_RESTORE . -.TP -.IR /proc/ pid /timerslack_ns " (since Linux 4.6)" -.\" commit da8b44d5a9f8bf26da637b7336508ca534d6b319 -.\" commit 5de23d435e88996b1efe0e2cebe242074ce67c9e -This file exposes the process's "current" timer slack value, -expressed in nanoseconds. -The file is writable, -allowing the process's timer slack value to be changed. -Writing 0 to this file resets the "current" timer slack to the -"default" timer slack value. -For further details, see the discussion of -.B PR_SET_TIMERSLACK -in -.BR prctl (2). -.IP -Initially, -permission to access this file was governed by a ptrace access mode -.B PTRACE_MODE_ATTACH_FSCREDS -check (see -.BR ptrace (2)). -However, this was subsequently deemed too strict a requirement -(and had the side effect that requiring a process to have the -.B CAP_SYS_PTRACE -capability would also allow it to view and change any process's memory). -Therefore, since Linux 4.9, -.\" commit 7abbaf94049914f074306d960b0f968ffe52e59f -only the (weaker) -.B CAP_SYS_NICE -capability is required to access this file. -.TP -.IR /proc/ pid /uid_map " (since Linux 3.5)" -See -.BR user_namespaces (7). -.TP -.IR /proc/ pid /wchan " (since Linux 2.6.0)" -The symbolic name corresponding to the location -in the kernel where the process is sleeping. -.IP -Permission to access this file is governed by a ptrace access mode -.B PTRACE_MODE_READ_FSCREDS -check; see -.BR ptrace (2). -.TP -.IR /proc/ tid -There is a numerical subdirectory for each running thread -that is not a thread group leader -(i.e., a thread whose thread ID is not the same as its process ID); -the subdirectory is named by the thread ID. -Each one of these subdirectories contains files and subdirectories -exposing information about the thread with the thread ID -.IR tid . -The contents of these directories are the same as the corresponding -.IR /proc/ pid /task/ tid -directories. -.IP -The -.IR /proc/ tid -subdirectories are -.I not -visible when iterating through -.I /proc -with -.BR getdents (2) -(and thus are -.I not -visible when one uses -.BR ls (1) -to view the contents of -.IR /proc ). -However, the pathnames of these directories are visible to -(i.e., usable as arguments in) -system calls that operate on pathnames. -.TP -.I /proc/apm -Advanced power management version and battery information when -.B CONFIG_APM -is defined at kernel compilation time. -.TP -.I /proc/buddyinfo -This file contains information which is used for diagnosing memory -fragmentation issues. -Each line starts with the identification of the node and the name -of the zone which together identify a memory region. -This is then -followed by the count of available chunks of a certain order in -which these zones are split. -The size in bytes of a certain order is given by the formula: -.IP -.in +4n -.EX -(2\[ha]order)\ *\ PAGE_SIZE -.EE -.in -.IP -The binary buddy allocator algorithm inside the kernel will split -one chunk into two chunks of a smaller order (thus with half the -size) or combine two contiguous chunks into one larger chunk of -a higher order (thus with double the size) to satisfy allocation -requests and to counter memory fragmentation. -The order matches the column number, when starting to count at zero. -.IP -For example on an x86-64 system: -.RS -12 -.EX -Node 0, zone DMA 1 1 1 0 2 1 1 0 1 1 3 -Node 0, zone DMA32 65 47 4 81 52 28 13 10 5 1 404 -Node 0, zone Normal 216 55 189 101 84 38 37 27 5 3 587 -.EE -.RE -.IP -In this example, there is one node containing three zones and there -are 11 different chunk sizes. -If the page size is 4 kilobytes, then the first zone called -.I DMA -(on x86 the first 16 megabyte of memory) has 1 chunk of 4 kilobytes -(order 0) available and has 3 chunks of 4 megabytes (order 10) available. -.IP -If the memory is heavily fragmented, the counters for higher -order chunks will be zero and allocation of large contiguous areas -will fail. -.IP -Further information about the zones can be found in -.IR /proc/zoneinfo . -.TP -.I /proc/bus -Contains subdirectories for installed buses. -.TP -.I /proc/bus/pccard -Subdirectory for PCMCIA devices when -.B CONFIG_PCMCIA -is set at kernel compilation time. -.TP -.I /proc/bus/pccard/drivers -.TP -.I /proc/bus/pci -Contains various bus subdirectories and pseudo-files containing -information about PCI buses, installed devices, and device -drivers. -Some of these files are not ASCII. -.TP -.I /proc/bus/pci/devices -Information about PCI devices. -They may be accessed through -.BR lspci (8) -and -.BR setpci (8). -.TP -.IR /proc/cgroups " (since Linux 2.6.24)" -See -.BR cgroups (7). -.TP -.I /proc/cmdline -Arguments passed to the Linux kernel at boot time. -Often done via a boot manager such as -.BR lilo (8) -or -.BR grub (8). -Any arguments embedded in the kernel image or initramfs via -.B CONFIG_BOOT_CONFIG -will also be displayed. -.TP -.IR /proc/config.gz " (since Linux 2.6)" -This file exposes the configuration options that were used -to build the currently running kernel, -in the same format as they would be shown in the -.I .config -file that resulted when configuring the kernel (using -.IR "make xconfig" , -.IR "make config" , -or similar). -The file contents are compressed; view or search them using -.BR zcat (1) -and -.BR zgrep (1). -As long as no changes have been made to the following file, -the contents of -.I /proc/config.gz -are the same as those provided by: -.IP -.in +4n -.EX -cat /lib/modules/$(uname \-r)/build/.config -.EE -.in -.IP -.I /proc/config.gz -is provided only if the kernel is configured with -.BR CONFIG_IKCONFIG_PROC . -.TP -.I /proc/crypto -A list of the ciphers provided by the kernel crypto API. -For details, see the kernel -.I "Linux Kernel Crypto API" -documentation available under the kernel source directory -.I Documentation/crypto/ -.\" commit 3b72c814a8e8cd638e1ba0da4dfce501e9dff5af -(or -.I Documentation/DocBook -before Linux 4.10; -the documentation can be built using a command such as -.I make htmldocs -in the root directory of the kernel source tree). -.TP -.I /proc/cpuinfo -This is a collection of CPU and system architecture dependent items, -for each supported architecture a different list. -Two common entries are \fIprocessor\fP which gives CPU number and -\fIbogomips\fP; a system constant that is calculated -during kernel initialization. -SMP machines have information for -each CPU. -The -.BR lscpu (1) -command gathers its information from this file. -.TP -.I /proc/devices -Text listing of major numbers and device groups. -This can be used by MAKEDEV scripts for consistency with the kernel. -.TP -.IR /proc/diskstats " (since Linux 2.5.69)" -This file contains disk I/O statistics for each disk device. -See the Linux kernel source file -.I Documentation/admin\-guide/iostats.rst -(or -.I Documentation/iostats.txt -before Linux 5.3) -for further information. -.TP -.I /proc/dma -This is a list of the registered \fIISA\fP DMA (direct memory access) -channels in use. -.TP -.I /proc/driver -Empty subdirectory. -.TP -.I /proc/execdomains -Used to list ABI personalities before Linux 4.1; -now contains a constant string for userspace compatibility. -.TP -.I /proc/fb -Frame buffer information when -.B CONFIG_FB -is defined during kernel compilation. -.TP -.I /proc/filesystems -A text listing of the filesystems which are supported by the kernel, -namely filesystems which were compiled into the kernel or whose kernel -modules are currently loaded. -(See also -.BR filesystems (5).) -If a filesystem is marked with "nodev", -this means that it does not require a block device to be mounted -(e.g., virtual filesystem, network filesystem). -.IP -Incidentally, this file may be used by -.BR mount (8) -when no filesystem is specified and it didn't manage to determine the -filesystem type. -Then filesystems contained in this file are tried -(excepted those that are marked with "nodev"). -.TP -.I /proc/fs -.\" FIXME Much more needs to be said about /proc/fs -.\" -Contains subdirectories that in turn contain files -with information about (certain) mounted filesystems. -.TP -.I /proc/ide -This directory -exists on systems with the IDE bus. -There are directories for each IDE channel and attached device. -Files include: -.IP -.in +4n -.EX -cache buffer size in KB -capacity number of sectors -driver driver version -geometry physical and logical geometry -identify in hexadecimal -media media type -model manufacturer\[aq]s model number -settings drive settings -smart_thresholds IDE disk management thresholds (in hex) -smart_values IDE disk management values (in hex) -.EE -.in -.IP -The -.BR hdparm (8) -utility provides access to this information in a friendly format. -.TP -.I /proc/interrupts -This is used to record the number of interrupts per CPU per IO device. -Since Linux 2.6.24, -for the i386 and x86-64 architectures, at least, this also includes -interrupts internal to the system (that is, not associated with a device -as such), such as NMI (nonmaskable interrupt), LOC (local timer interrupt), -and for SMP systems, TLB (TLB flush interrupt), RES (rescheduling -interrupt), CAL (remote function call interrupt), and possibly others. -Very easy to read formatting, done in ASCII. -.TP -.I /proc/iomem -I/O memory map in Linux 2.4. -.TP -.I /proc/ioports -This is a list of currently registered Input-Output port regions that -are in use. -.TP -.IR /proc/kallsyms " (since Linux 2.5.71)" -This holds the kernel exported symbol definitions used by the -.BR modules (X) -tools to dynamically link and bind loadable modules. -In Linux 2.5.47 and earlier, a similar file with slightly different syntax -was named -.IR ksyms . -.TP -.I /proc/kcore -This file represents the physical memory of the system and is stored -in the ELF core file format. -With this pseudo-file, and an unstripped -kernel -.RI ( /usr/src/linux/vmlinux ) -binary, GDB can be used to -examine the current state of any kernel data structures. -.IP -The total length of the file is the size of physical memory (RAM) plus -4\ KiB. -.TP -.IR /proc/keys " (since Linux 2.6.10)" -See -.BR keyrings (7). -.TP -.IR /proc/key\-users " (since Linux 2.6.10)" -See -.BR keyrings (7). -.TP -.I /proc/kmsg -This file can be used instead of the -.BR syslog (2) -system call to read kernel messages. -A process must have superuser -privileges to read this file, and only one process should read this -file. -This file should not be read if a syslog process is running -which uses the -.BR syslog (2) -system call facility to log kernel messages. -.IP -Information in this file is retrieved with the -.BR dmesg (1) -program. -.TP -.IR /proc/kpagecgroup " (since Linux 4.3)" -.\" commit 80ae2fdceba8313b0433f899bdd9c6c463291a17 -This file contains a 64-bit inode number of -the memory cgroup each page is charged to, -indexed by page frame number (see the discussion of -.IR /proc/ pid /pagemap ). -.IP -The -.I /proc/kpagecgroup -file is present only if the -.B CONFIG_MEMCG -kernel configuration option is enabled. -.TP -.IR /proc/kpagecount " (since Linux 2.6.25)" -This file contains a 64-bit count of the number of -times each physical page frame is mapped, -indexed by page frame number (see the discussion of -.IR /proc/ pid /pagemap ). -.IP -The -.I /proc/kpagecount -file is present only if the -.B CONFIG_PROC_PAGE_MONITOR -kernel configuration option is enabled. -.TP -.IR /proc/kpageflags " (since Linux 2.6.25)" -This file contains 64-bit masks corresponding to each physical page frame; -it is indexed by page frame number (see the discussion of -.IR /proc/ pid /pagemap ). -The bits are as follows: -.RS -.IP -.TS -r l l l. -0 - KPF_LOCKED -1 - KPF_ERROR -2 - KPF_REFERENCED -3 - KPF_UPTODATE -4 - KPF_DIRTY -5 - KPF_LRU -6 - KPF_ACTIVE -7 - KPF_SLAB -8 - KPF_WRITEBACK -9 - KPF_RECLAIM -10 - KPF_BUDDY -11 - KPF_MMAP (since Linux 2.6.31) -12 - KPF_ANON (since Linux 2.6.31) -13 - KPF_SWAPCACHE (since Linux 2.6.31) -14 - KPF_SWAPBACKED (since Linux 2.6.31) -15 - KPF_COMPOUND_HEAD (since Linux 2.6.31) -16 - KPF_COMPOUND_TAIL (since Linux 2.6.31) -17 - KPF_HUGE (since Linux 2.6.31) -18 - KPF_UNEVICTABLE (since Linux 2.6.31) -19 - KPF_HWPOISON (since Linux 2.6.31) -20 - KPF_NOPAGE (since Linux 2.6.31) -21 - KPF_KSM (since Linux 2.6.32) -22 - KPF_THP (since Linux 3.4) -23 - KPF_BALLOON (since Linux 3.18) -.\" KPF_BALLOON: commit 09316c09dde33aae14f34489d9e3d243ec0d5938 -24 - KPF_ZERO_PAGE (since Linux 4.0) -.\" KPF_ZERO_PAGE: commit 56873f43abdcd574b25105867a990f067747b2f4 -25 - KPF_IDLE (since Linux 4.3) -.\" KPF_IDLE: commit f074a8f49eb87cde95ac9d040ad5e7ea4f029738 -26 - KPF_PGTABLE (since Linux 4.18) -.\" KPF_PGTABLE: commit 1d40a5ea01d53251c23c7be541d3f4a656cfc537 -.TE -.RE -.IP -For further details on the meanings of these bits, -see the kernel source file -.IR Documentation/admin\-guide/mm/pagemap.rst . -Before Linux 2.6.29, -.\" commit ad3bdefe877afb47480418fdb05ecd42842de65e -.\" commit e07a4b9217d1e97d2f3a62b6b070efdc61212110 -.BR KPF_WRITEBACK , -.BR KPF_RECLAIM , -.BR KPF_BUDDY , -and -.B KPF_LOCKED -did not report correctly. -.IP -The -.I /proc/kpageflags -file is present only if the -.B CONFIG_PROC_PAGE_MONITOR -kernel configuration option is enabled. -.TP -.IR /proc/ksyms " (Linux 1.1.23\[en]2.5.47)" -See -.IR /proc/kallsyms . -.TP -.I /proc/loadavg -The first three fields in this file are load average figures -giving the number of jobs in the run queue (state R) -or waiting for disk I/O (state D) averaged over 1, 5, and 15 minutes. -They are the same as the load average numbers given by -.BR uptime (1) -and other programs. -The fourth field consists of two numbers separated by a slash (/). -The first of these is the number of currently runnable kernel -scheduling entities (processes, threads). -The value after the slash is the number of kernel scheduling entities -that currently exist on the system. -The fifth field is the PID of the process that was most -recently created on the system. -.TP -.I /proc/locks -This file shows current file locks -.RB ( flock "(2) and " fcntl (2)) -and leases -.RB ( fcntl (2)). -.IP -An example of the content shown in this file is the following: -.IP -.in +4n -.EX -1: POSIX ADVISORY READ 5433 08:01:7864448 128 128 -2: FLOCK ADVISORY WRITE 2001 08:01:7864554 0 EOF -3: FLOCK ADVISORY WRITE 1568 00:2f:32388 0 EOF -4: POSIX ADVISORY WRITE 699 00:16:28457 0 EOF -5: POSIX ADVISORY WRITE 764 00:16:21448 0 0 -6: POSIX ADVISORY READ 3548 08:01:7867240 1 1 -7: POSIX ADVISORY READ 3548 08:01:7865567 1826 2335 -8: OFDLCK ADVISORY WRITE \-1 08:01:8713209 128 191 -.EE -.in -.IP -The fields shown in each line are as follows: -.RS -.IP [1] 5 -The ordinal position of the lock in the list. -.IP [2] -The lock type. -Values that may appear here include: -.RS -.TP -.B FLOCK -This is a BSD file lock created using -.BR flock (2). -.TP -.B OFDLCK -This is an open file description (OFD) lock created using -.BR fcntl (2). -.TP -.B POSIX -This is a POSIX byte-range lock created using -.BR fcntl (2). -.RE -.IP [3] -Among the strings that can appear here are the following: -.RS -.TP -.B ADVISORY -This is an advisory lock. -.TP -.B MANDATORY -This is a mandatory lock. -.RE -.IP [4] -The type of lock. -Values that can appear here are: -.RS -.TP -.B READ -This is a POSIX or OFD read lock, or a BSD shared lock. -.TP -.B WRITE -This is a POSIX or OFD write lock, or a BSD exclusive lock. -.RE -.IP [5] -The PID of the process that owns the lock. -.IP -Because OFD locks are not owned by a single process -(since multiple processes may have file descriptors that -refer to the same open file description), -the value \-1 is displayed in this field for OFD locks. -(Before Linux 4.14, -.\" commit 9d5b86ac13c573795525ecac6ed2db39ab23e2a8 -a bug meant that the PID of the process that -initially acquired the lock was displayed instead of the value \-1.) -.IP [6] -Three colon-separated subfields that identify the major and minor device -ID of the device containing the filesystem where the locked file resides, -followed by the inode number of the locked file. -.IP [7] -The byte offset of the first byte of the lock. -For BSD locks, this value is always 0. -.IP [8] -The byte offset of the last byte of the lock. -.B EOF -in this field means that the lock extends to the end of the file. -For BSD locks, the value shown is always -.IR EOF . -.RE -.IP -Since Linux 4.9, -.\" commit d67fd44f697dff293d7cdc29af929241b669affe -the list of locks shown in -.I /proc/locks -is filtered to show just the locks for the processes in the PID -namespace (see -.BR pid_namespaces (7)) -for which the -.I /proc -filesystem was mounted. -(In the initial PID namespace, -there is no filtering of the records shown in this file.) -.IP -The -.BR lslocks (8) -command provides a bit more information about each lock. -.TP -.IR /proc/malloc " (only up to and including Linux 2.2)" -.\" It looks like this only ever did something back in 1.0 days -This file is present only if -.B CONFIG_DEBUG_MALLOC -was defined during compilation. -.TP -.I /proc/meminfo -This file reports statistics about memory usage on the system. -It is used by -.BR free (1) -to report the amount of free and used memory (both physical and swap) -on the system as well as the shared memory and buffers used by the -kernel. -Each line of the file consists of a parameter name, followed by a colon, -the value of the parameter, and an option unit of measurement (e.g., "kB"). -The list below describes the parameter names and -the format specifier required to read the field value. -Except as noted below, -all of the fields have been present since at least Linux 2.6.0. -Some fields are displayed only if the kernel was configured -with various options; those dependencies are noted in the list. -.RS -.TP -.IR MemTotal " %lu" -Total usable RAM (i.e., physical RAM minus a few reserved -bits and the kernel binary code). -.TP -.IR MemFree " %lu" -The sum of -.IR LowFree + HighFree . -.TP -.IR MemAvailable " %lu (since Linux 3.14)" -An estimate of how much memory is available for starting new -applications, without swapping. -.TP -.IR Buffers " %lu" -Relatively temporary storage for raw disk blocks that -shouldn't get tremendously large (20 MB or so). -.TP -.IR Cached " %lu" -In-memory cache for files read from the disk (the page cache). -Doesn't include -.IR SwapCached . -.TP -.IR SwapCached " %lu" -Memory that once was swapped out, is swapped back in but -still also is in the swap file. -(If memory pressure is high, these pages -don't need to be swapped out again because they are already -in the swap file. -This saves I/O.) -.TP -.IR Active " %lu" -Memory that has been used more recently and usually not -reclaimed unless absolutely necessary. -.TP -.IR Inactive " %lu" -Memory which has been less recently used. -It is more eligible to be reclaimed for other purposes. -.TP -.IR Active(anon) " %lu (since Linux 2.6.28)" -[To be documented.] -.TP -.IR Inactive(anon) " %lu (since Linux 2.6.28)" -[To be documented.] -.TP -.IR Active(file) " %lu (since Linux 2.6.28)" -[To be documented.] -.TP -.IR Inactive(file) " %lu (since Linux 2.6.28)" -[To be documented.] -.TP -.IR Unevictable " %lu (since Linux 2.6.28)" -(From Linux 2.6.28 to Linux 2.6.30, -\fBCONFIG_UNEVICTABLE_LRU\fP was required.) -[To be documented.] -.TP -.IR Mlocked " %lu (since Linux 2.6.28)" -(From Linux 2.6.28 to Linux 2.6.30, -\fBCONFIG_UNEVICTABLE_LRU\fP was required.) -[To be documented.] -.TP -.IR HighTotal " %lu" -(Starting with Linux 2.6.19, \fBCONFIG_HIGHMEM\fP is required.) -Total amount of highmem. -Highmem is all memory above \[ti]860 MB of physical memory. -Highmem areas are for use by user-space programs, -or for the page cache. -The kernel must use tricks to access -this memory, making it slower to access than lowmem. -.TP -.IR HighFree " %lu" -(Starting with Linux 2.6.19, \fBCONFIG_HIGHMEM\fP is required.) -Amount of free highmem. -.TP -.IR LowTotal " %lu" -(Starting with Linux 2.6.19, \fBCONFIG_HIGHMEM\fP is required.) -Total amount of lowmem. -Lowmem is memory which can be used for everything that -highmem can be used for, but it is also available for the -kernel's use for its own data structures. -Among many other things, -it is where everything from -.I Slab -is allocated. -Bad things happen when you're out of lowmem. -.TP -.IR LowFree " %lu" -(Starting with Linux 2.6.19, \fBCONFIG_HIGHMEM\fP is required.) -Amount of free lowmem. -.TP -.IR MmapCopy " %lu (since Linux 2.6.29)" -.RB ( CONFIG_MMU -is required.) -[To be documented.] -.TP -.IR SwapTotal " %lu" -Total amount of swap space available. -.TP -.IR SwapFree " %lu" -Amount of swap space that is currently unused. -.TP -.IR Dirty " %lu" -Memory which is waiting to get written back to the disk. -.TP -.IR Writeback " %lu" -Memory which is actively being written back to the disk. -.TP -.IR AnonPages " %lu (since Linux 2.6.18)" -Non-file backed pages mapped into user-space page tables. -.TP -.IR Mapped " %lu" -Files which have been mapped into memory (with -.BR mmap (2)), -such as libraries. -.TP -.IR Shmem " %lu (since Linux 2.6.32)" -Amount of memory consumed in -.BR tmpfs (5) -filesystems. -.TP -.IR KReclaimable " %lu (since Linux 4.20)" -Kernel allocations that the kernel will attempt to reclaim -under memory pressure. -Includes -.I SReclaimable -(below), and other direct allocations with a shrinker. -.TP -.IR Slab " %lu" -In-kernel data structures cache. -(See -.BR slabinfo (5).) -.TP -.IR SReclaimable " %lu (since Linux 2.6.19)" -Part of -.IR Slab , -that might be reclaimed, such as caches. -.TP -.IR SUnreclaim " %lu (since Linux 2.6.19)" -Part of -.IR Slab , -that cannot be reclaimed on memory pressure. -.TP -.IR KernelStack " %lu (since Linux 2.6.32)" -Amount of memory allocated to kernel stacks. -.TP -.IR PageTables " %lu (since Linux 2.6.18)" -Amount of memory dedicated to the lowest level of page tables. -.TP -.IR Quicklists " %lu (since Linux 2.6.27)" -(\fBCONFIG_QUICKLIST\fP is required.) -[To be documented.] -.TP -.IR NFS_Unstable " %lu (since Linux 2.6.18)" -NFS pages sent to the server, but not yet committed to stable storage. -.TP -.IR Bounce " %lu (since Linux 2.6.18)" -Memory used for block device "bounce buffers". -.TP -.IR WritebackTmp " %lu (since Linux 2.6.26)" -Memory used by FUSE for temporary writeback buffers. -.TP -.IR CommitLimit " %lu (since Linux 2.6.10)" -This is the total amount of memory currently available to -be allocated on the system, expressed in kilobytes. -This limit is adhered to -only if strict overcommit accounting is enabled (mode 2 in -.IR /proc/sys/vm/overcommit_memory ). -The limit is calculated according to the formula described under -.IR /proc/sys/vm/overcommit_memory . -For further details, see the kernel source file -.IR Documentation/vm/overcommit\-accounting.rst . -.TP -.IR Committed_AS " %lu" -The amount of memory presently allocated on the system. -The committed memory is a sum of all of the memory which -has been allocated by processes, even if it has not been -"used" by them as of yet. -A process which allocates 1 GB of memory (using -.BR malloc (3) -or similar), but touches only 300 MB of that memory will show up -as using only 300 MB of memory even if it has the address space -allocated for the entire 1 GB. -.IP -This 1 GB is memory which has been "committed" to by the VM -and can be used at any time by the allocating application. -With strict overcommit enabled on the system (mode 2 in -.IR /proc/sys/vm/overcommit_memory ), -allocations which would exceed the -.I CommitLimit -will not be permitted. -This is useful if one needs to guarantee that processes will not -fail due to lack of memory once that memory has been successfully allocated. -.TP -.IR VmallocTotal " %lu" -Total size of vmalloc memory area. -.TP -.IR VmallocUsed " %lu" -Amount of vmalloc area which is used. -Since Linux 4.4, -.\" commit a5ad88ce8c7fae7ddc72ee49a11a75aa837788e0 -this field is no longer calculated, and is hard coded as 0. -See -.IR /proc/vmallocinfo . -.TP -.IR VmallocChunk " %lu" -Largest contiguous block of vmalloc area which is free. -Since Linux 4.4, -.\" commit a5ad88ce8c7fae7ddc72ee49a11a75aa837788e0 -this field is no longer calculated and is hard coded as 0. -See -.IR /proc/vmallocinfo . -.TP -.IR HardwareCorrupted " %lu (since Linux 2.6.32)" -(\fBCONFIG_MEMORY_FAILURE\fP is required.) -[To be documented.] -.TP -.IR LazyFree " %lu (since Linux 4.12)" -Shows the amount of memory marked by -.BR madvise (2) -.BR MADV_FREE . -.TP -.IR AnonHugePages " %lu (since Linux 2.6.38)" -(\fBCONFIG_TRANSPARENT_HUGEPAGE\fP is required.) -Non-file backed huge pages mapped into user-space page tables. -.TP -.IR ShmemHugePages " %lu (since Linux 4.8)" -(\fBCONFIG_TRANSPARENT_HUGEPAGE\fP is required.) -Memory used by shared memory (shmem) and -.BR tmpfs (5) -allocated with huge pages. -.TP -.IR ShmemPmdMapped " %lu (since Linux 4.8)" -(\fBCONFIG_TRANSPARENT_HUGEPAGE\fP is required.) -Shared memory mapped into user space with huge pages. -.TP -.IR CmaTotal " %lu (since Linux 3.1)" -Total CMA (Contiguous Memory Allocator) pages. -(\fBCONFIG_CMA\fP is required.) -.TP -.IR CmaFree " %lu (since Linux 3.1)" -Free CMA (Contiguous Memory Allocator) pages. -(\fBCONFIG_CMA\fP is required.) -.TP -.IR HugePages_Total " %lu" -(\fBCONFIG_HUGETLB_PAGE\fP is required.) -The size of the pool of huge pages. -.TP -.IR HugePages_Free " %lu" -(\fBCONFIG_HUGETLB_PAGE\fP is required.) -The number of huge pages in the pool that are not yet allocated. -.TP -.IR HugePages_Rsvd " %lu (since Linux 2.6.17)" -(\fBCONFIG_HUGETLB_PAGE\fP is required.) -This is the number of huge pages for -which a commitment to allocate from the pool has been made, -but no allocation has yet been made. -These reserved huge pages -guarantee that an application will be able to allocate a -huge page from the pool of huge pages at fault time. -.TP -.IR HugePages_Surp " %lu (since Linux 2.6.24)" -(\fBCONFIG_HUGETLB_PAGE\fP is required.) -This is the number of huge pages in -the pool above the value in -.IR /proc/sys/vm/nr_hugepages . -The maximum number of surplus huge pages is controlled by -.IR /proc/sys/vm/nr_overcommit_hugepages . -.TP -.IR Hugepagesize " %lu" -(\fBCONFIG_HUGETLB_PAGE\fP is required.) -The size of huge pages. -.TP -.IR DirectMap4k " %lu (since Linux 2.6.27)" -Number of bytes of RAM linearly mapped by kernel in 4 kB pages. -(x86.) -.TP -.IR DirectMap4M " %lu (since Linux 2.6.27)" -Number of bytes of RAM linearly mapped by kernel in 4 MB pages. -(x86 with -.B CONFIG_X86_64 -or -.B CONFIG_X86_PAE -enabled.) -.TP -.IR DirectMap2M " %lu (since Linux 2.6.27)" -Number of bytes of RAM linearly mapped by kernel in 2 MB pages. -(x86 with neither -.B CONFIG_X86_64 -nor -.B CONFIG_X86_PAE -enabled.) -.TP -.IR DirectMap1G " %lu (since Linux 2.6.27)" -(x86 with -.B CONFIG_X86_64 -and -.B CONFIG_X86_DIRECT_GBPAGES -enabled.) -.RE -.TP -.I /proc/modules -A text list of the modules that have been loaded by the system. -See also -.BR lsmod (8). -.TP -.I /proc/mounts -Before Linux 2.4.19, this file was a list -of all the filesystems currently mounted on the system. -With the introduction of per-process mount namespaces in Linux 2.4.19 (see -.BR mount_namespaces (7)), -this file became a link to -.IR /proc/self/mounts , -which lists the mounts of the process's own mount namespace. -The format of this file is documented in -.BR fstab (5). -.TP -.I /proc/mtrr -Memory Type Range Registers. -See the Linux kernel source file -.I Documentation/x86/mtrr.rst -(or -.I Documentation/x86/mtrr.txt -.\" commit 7225e75144b9718cbbe1820d9c011c809d5773fd -before Linux 5.2, or -.I Documentation/mtrr.txt -before Linux 2.6.28) -for details. -.TP -.I /proc/net -This directory contains various files and subdirectories containing -information about the networking layer. -The files contain ASCII structures and are, -therefore, readable with -.BR cat (1). -However, the standard -.BR netstat (8) -suite provides much cleaner access to these files. -.IP -With the advent of network namespaces, -various information relating to the network stack is virtualized (see -.BR network_namespaces (7)). -Thus, since Linux 2.6.25, -.\" commit e9720acd728a46cb40daa52c99a979f7c4ff195c -.I /proc/net -is a symbolic link to the directory -.IR /proc/self/net , -which contains the same files and directories as listed below. -However, these files and directories now expose information -for the network namespace of which the process is a member. -.TP -.I /proc/net/arp -This holds an ASCII readable dump of the kernel ARP table used for -address resolutions. -It will show both dynamically learned and preprogrammed ARP entries. -The format is: -.IP -.in +4n -.EX -IP address HW type Flags HW address Mask Device -192.168.0.50 0x1 0x2 00:50:BF:25:68:F3 * eth0 -192.168.0.250 0x1 0xc 00:00:00:00:00:00 * eth0 -.EE -.in -.IP -Here "IP address" is the IPv4 address of the machine and the "HW type" -is the hardware type of the address from RFC\ 826. -The flags are the internal -flags of the ARP structure (as defined in -.IR /usr/include/linux/if_arp.h ) -and -the "HW address" is the data link layer mapping for that IP address if -it is known. -.TP -.I /proc/net/dev -The dev pseudo-file contains network device status information. -This gives -the number of received and sent packets, the number of errors and -collisions -and other basic statistics. -These are used by the -.BR ifconfig (8) -program to report device status. -The format is: -.IP -.EX -Inter\-| Receive | Transmit - face |bytes packets errs drop fifo frame compressed multicast|bytes packets errs drop fifo colls carrier compressed - lo: 2776770 11307 0 0 0 0 0 0 2776770 11307 0 0 0 0 0 0 - eth0: 1215645 2751 0 0 0 0 0 0 1782404 4324 0 0 0 427 0 0 - ppp0: 1622270 5552 1 0 0 0 0 0 354130 5669 0 0 0 0 0 0 - tap0: 7714 81 0 0 0 0 0 0 7714 81 0 0 0 0 0 0 -.EE -.\" .TP -.\" .I /proc/net/ipx -.\" No information. -.\" .TP -.\" .I /proc/net/ipx_route -.\" No information. -.TP -.I /proc/net/dev_mcast -Defined in -.IR /usr/src/linux/net/core/dev_mcast.c : -.IP -.in +4n -.EX -indx interface_name dmi_u dmi_g dmi_address -2 eth0 1 0 01005e000001 -3 eth1 1 0 01005e000001 -4 eth2 1 0 01005e000001 -.EE -.in -.TP -.I /proc/net/igmp -Internet Group Management Protocol. -Defined in -.IR /usr/src/linux/net/core/igmp.c . -.TP -.I /proc/net/rarp -This file uses the same format as the -.I arp -file and contains the current reverse mapping database used to provide -.BR rarp (8) -reverse address lookup services. -If RARP is not configured into the -kernel, -this file will not be present. -.TP -.I /proc/net/raw -Holds a dump of the RAW socket table. -Much of the information is not of -use -apart from debugging. -The "sl" value is the kernel hash slot for the -socket, -the "local_address" is the local address and protocol number pair. -\&"St" is -the internal status of the socket. -The "tx_queue" and "rx_queue" are the -outgoing and incoming data queue in terms of kernel memory usage. -The "tr", "tm\->when", and "rexmits" fields are not used by RAW. -The "uid" -field holds the effective UID of the creator of the socket. -.\" .TP -.\" .I /proc/net/route -.\" No information, but looks similar to -.\" .BR route (8). -.TP -.I /proc/net/snmp -This file holds the ASCII data needed for the IP, ICMP, TCP, and UDP -management -information bases for an SNMP agent. -.TP -.I /proc/net/tcp -Holds a dump of the TCP socket table. -Much of the information is not -of use apart from debugging. -The "sl" value is the kernel hash slot -for the socket, the "local_address" is the local address and port number pair. -The "rem_address" is the remote address and port number pair -(if connected). -\&"St" is the internal status of the socket. -The "tx_queue" and "rx_queue" are the -outgoing and incoming data queue in terms of kernel memory usage. -The "tr", "tm\->when", and "rexmits" fields hold internal information of -the kernel socket state and are useful only for debugging. -The "uid" -field holds the effective UID of the creator of the socket. -.TP -.I /proc/net/udp -Holds a dump of the UDP socket table. -Much of the information is not of -use apart from debugging. -The "sl" value is the kernel hash slot for the -socket, the "local_address" is the local address and port number pair. -The "rem_address" is the remote address and port number pair -(if connected). -"St" is the internal status of the socket. -The "tx_queue" and "rx_queue" are the outgoing and incoming data queue -in terms of kernel memory usage. -The "tr", "tm\->when", and "rexmits" fields -are not used by UDP. -The "uid" -field holds the effective UID of the creator of the socket. -The format is: -.IP -.EX -sl local_address rem_address st tx_queue rx_queue tr rexmits tm\->when uid - 1: 01642C89:0201 0C642C89:03FF 01 00000000:00000001 01:000071BA 00000000 0 - 1: 00000000:0801 00000000:0000 0A 00000000:00000000 00:00000000 6F000100 0 - 1: 00000000:0201 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 -.EE -.TP -.I /proc/net/unix -Lists the UNIX domain sockets present within the system and their -status. -The format is: -.IP -.EX -Num RefCount Protocol Flags Type St Inode Path - 0: 00000002 00000000 00000000 0001 03 42 - 1: 00000001 00000000 00010000 0001 01 1948 /dev/printer -.EE -.IP -The fields are as follows: -.RS -.TP 10 -.IR Num : -the kernel table slot number. -.TP -.IR RefCount : -the number of users of the socket. -.TP -.IR Protocol : -currently always 0. -.TP -.IR Flags : -the internal kernel flags holding the status of the socket. -.TP -.IR Type : -the socket type. -For -.B SOCK_STREAM -sockets, this is 0001; for -.B SOCK_DGRAM -sockets, it is 0002; and for -.B SOCK_SEQPACKET -sockets, it is 0005. -.TP -.IR St : -the internal state of the socket. -.TP -.IR Inode : -the inode number of the socket. -.TP -.IR Path : -the bound pathname (if any) of the socket. -Sockets in the abstract namespace are included in the list, -and are shown with a -.I Path -that commences with the character '@'. -.RE -.TP -.I /proc/net/netfilter/nfnetlink_queue -This file contains information about netfilter user-space queueing, if used. -Each line represents a queue. -Queues that have not been subscribed to -by user space are not shown. -.IP -.in +4n -.EX - 1 4207 0 2 65535 0 0 0 1 - (1) (2) (3)(4) (5) (6) (7) (8) -.EE -.in -.IP -The fields in each line are: -.RS 7 -.TP 5 -(1) -The ID of the queue. -This matches what is specified in the -.B \-\-queue\-num -or -.B \-\-queue\-balance -options to the -.BR iptables (8) -NFQUEUE target. -See -.BR iptables\-extensions (8) -for more information. -.TP -(2) -The netlink port ID subscribed to the queue. -.TP -(3) -The number of packets currently queued and waiting to be processed by -the application. -.TP -(4) -The copy mode of the queue. -It is either 1 (metadata only) or 2 -(also copy payload data to user space). -.TP -(5) -Copy range; that is, how many bytes of packet payload should be copied to -user space at most. -.TP -(6) -queue dropped. -Number of packets that had to be dropped by the kernel because -too many packets are already waiting for user space to send back the mandatory -accept/drop verdicts. -.TP -(7) -queue user dropped. -Number of packets that were dropped within the netlink -subsystem. -Such drops usually happen when the corresponding socket buffer is -full; that is, user space is not able to read messages fast enough. -.TP -(8) -sequence number. -Every queued packet is associated with a (32-bit) -monotonically increasing sequence number. -This shows the ID of the most recent packet queued. -.RE -.IP -The last number exists only for compatibility reasons and is always 1. -.TP -.I /proc/partitions -Contains the major and minor numbers of each partition as well as the number -of 1024-byte blocks and the partition name. -.TP -.I /proc/pci -This is a listing of all PCI devices found during kernel initialization -and their configuration. -.IP -This file has been deprecated in favor of a new -.I /proc -interface for PCI -.RI ( /proc/bus/pci ). -It became optional in Linux 2.2 (available with -.B CONFIG_PCI_OLD_PROC -set at kernel compilation). -It became once more nonoptionally enabled in Linux 2.4. -Next, it was deprecated in Linux 2.6 (still available with -.B CONFIG_PCI_LEGACY_PROC -set), and finally removed altogether since Linux 2.6.17. .\" FIXME Document /proc/sched_debug (since Linux 2.6.23) .\" See also /proc/[pid]/sched -.TP -.IR /proc/profile " (since Linux 2.4)" -This file is present only if the kernel was booted with the -.I profile=1 -command-line option. -It exposes kernel profiling information in a binary format for use by -.BR readprofile (1). -Writing (e.g., an empty string) to this file resets the profiling counters; -on some architectures, -writing a binary integer "profiling multiplier" of size -.I sizeof(int) -sets the profiling interrupt frequency. -.TP -.I /proc/scsi -A directory with the -.I scsi -mid-level pseudo-file and various SCSI low-level -driver directories, -which contain a file for each SCSI host in this system, all of -which give the status of some part of the SCSI IO subsystem. -These files contain ASCII structures and are, therefore, readable with -.BR cat (1). -.IP -You can also write to some of the files to reconfigure the subsystem or -switch certain features on or off. -.TP -.I /proc/scsi/scsi -This is a listing of all SCSI devices known to the kernel. -The listing is similar to the one seen during bootup. -scsi currently supports only the \fIadd\-single\-device\fP command which -allows root to add a hotplugged device to the list of known devices. -.IP -The command -.IP -.in +4n -.EX -echo \[aq]scsi add\-single\-device 1 0 5 0\[aq] > /proc/scsi/scsi -.EE -.in -.IP -will cause -host scsi1 to scan on SCSI channel 0 for a device on ID 5 LUN 0. -If there -is already a device known on this address or the address is invalid, an -error will be returned. -.TP -.IR /proc/scsi/ drivername -\fIdrivername\fP can currently be NCR53c7xx, aha152x, aha1542, aha1740, -aic7xxx, buslogic, eata_dma, eata_pio, fdomain, in2000, pas16, qlogic, -scsi_debug, seagate, t128, u15\-24f, ultrastore, or wd7000. -These directories show up for all drivers that registered at least one -SCSI HBA. -Every directory contains one file per registered host. -Every host-file is named after the number the host was assigned during -initialization. -.IP -Reading these files will usually show driver and host configuration, -statistics, and so on. -.IP -Writing to these files allows different things on different hosts. -For example, with the \fIlatency\fP and \fInolatency\fP commands, -root can switch on and off command latency measurement code in the -eata_dma driver. -With the \fIlockup\fP and \fIunlock\fP commands, -root can control bus lockups simulated by the scsi_debug driver. -.TP -.I /proc/self -This directory refers to the process accessing the -.I /proc -filesystem, -and is identical to the -.I /proc -directory named by the process ID of the same process. -.TP -.I /proc/slabinfo -Information about kernel caches. -See -.BR slabinfo (5) -for details. -.TP -.I /proc/stat -kernel/system statistics. -Varies with architecture. -Common -entries include: -.RS -.TP -.I cpu 10132153 290696 3084719 46828483 16683 0 25195 0 175628 0 -.TQ -.I cpu0 1393280 32966 572056 13343292 6130 0 17875 0 23933 0 -The amount of time, measured in units of -USER_HZ (1/100ths of a second on most architectures, use -.I sysconf(_SC_CLK_TCK) -to obtain the right value), -.\" 1024 on Alpha and ia64 -that the system ("cpu" line) or the specific CPU ("cpu\fIN\fR" line) -spent in various states: -.RS -.TP -.I user -(1) Time spent in user mode. -.TP -.I nice -(2) Time spent in user mode with low priority (nice). -.TP -.I system -(3) Time spent in system mode. -.TP -.I idle -(4) Time spent in the idle task. -.\" FIXME . Actually, the following info about the /proc/stat 'cpu' field -.\" does not seem to be quite right (at least in Linux 2.6.12 or Linux 3.6): -.\" the idle time in /proc/uptime does not quite match this value -This value should be USER_HZ times the -second entry in the -.I /proc/uptime -pseudo-file. -.TP -.IR iowait " (since Linux 2.5.41)" -(5) Time waiting for I/O to complete. -This value is not reliable, for the following reasons: -.\" See kernel commit 9c240d757658a3ae9968dd309e674c61f07c7f48 -.RS -.IP \[bu] 3 -The CPU will not wait for I/O to complete; -iowait is the time that a task is waiting for I/O to complete. -When a CPU goes into idle state for outstanding task I/O, -another task will be scheduled on this CPU. -.IP \[bu] -On a multi-core CPU, -the task waiting for I/O to complete is not running on any CPU, -so the iowait of each CPU is difficult to calculate. -.IP \[bu] -The value in this field may -.I decrease -in certain conditions. -.RE -.TP -.IR irq " (since Linux 2.6.0)" -.\" Precisely: Linux 2.6.0-test4 -(6) Time servicing interrupts. -.TP -.IR softirq " (since Linux 2.6.0)" -.\" Precisely: Linux 2.6.0-test4 -(7) Time servicing softirqs. -.TP -.IR steal " (since Linux 2.6.11)" -(8) Stolen time, which is the time spent in other operating systems when -running in a virtualized environment -.TP -.IR guest " (since Linux 2.6.24)" -(9) Time spent running a virtual CPU for guest -operating systems under the control of the Linux kernel. -.\" See Changelog entry for 5e84cfde51cf303d368fcb48f22059f37b3872de -.TP -.IR guest_nice " (since Linux 2.6.33)" -.\" commit ce0e7b28fb75cb003cfc8d0238613aaf1c55e797 -(10) Time spent running a niced guest (virtual CPU for guest -operating systems under the control of the Linux kernel). -.RE -.TP -\fIpage 5741 1808\fP -The number of pages the system paged in and the number that were paged -out (from disk). -.TP -\fIswap 1 0\fP -The number of swap pages that have been brought in and out. -.TP -.\" FIXME . The following is not the full picture for the 'intr' of -.\" /proc/stat on 2.6: -\fIintr 1462898\fP -This line shows counts of interrupts serviced since boot time, -for each of the possible system interrupts. -The first column is the total of all interrupts serviced -including unnumbered architecture specific interrupts; -each subsequent column is the total for that particular numbered interrupt. -Unnumbered interrupts are not shown, only summed into the total. -.TP -\fIdisk_io: (2,0):(31,30,5764,1,2) (3,0):\fP... -(major,disk_idx):(noinfo, read_io_ops, blks_read, write_io_ops, blks_written) -.br -(Linux 2.4 only) -.TP -\fIctxt 115315\fP -The number of context switches that the system underwent. -.TP -\fIbtime 769041601\fP -boot time, in seconds since the Epoch, 1970-01-01 00:00:00 +0000 (UTC). -.TP -\fIprocesses 86031\fP -Number of forks since boot. -.TP -\fIprocs_running 6\fP -Number of processes in runnable state. -(Linux 2.5.45 onward.) -.TP -\fIprocs_blocked 2\fP -Number of processes blocked waiting for I/O to complete. -(Linux 2.5.45 onward.) -.TP -.I softirq 229245889 94 60001584 13619 5175704 2471304 28 51212741 59130143 0 51240672 -.\" commit d3d64df21d3d0de675a0d3ffa7c10514f3644b30 -This line shows the number of softirq for all CPUs. -The first column is the total of all softirqs and -each subsequent column is the total for particular softirq. -(Linux 2.6.31 onward.) -.RE -.TP -.I /proc/swaps -Swap areas in use. -See also -.BR swapon (8). -.TP -.I /proc/sys -This directory (present since Linux 1.3.57) contains a number of files -and subdirectories corresponding to kernel variables. -These variables can be read and in some cases modified using -the \fI/proc\fP filesystem, and the (deprecated) -.BR sysctl (2) -system call. -.IP -String values may be terminated by either \[aq]\e0\[aq] or \[aq]\en\[aq]. -.IP -Integer and long values may be written either in decimal or in -hexadecimal notation (e.g., 0x3FFF). -When writing multiple integer or long values, these may be separated -by any of the following whitespace characters: -\[aq]\ \[aq], \[aq]\et\[aq], or \[aq]\en\[aq]. -Using other separators leads to the error -.BR EINVAL . -.TP -.IR /proc/sys/abi " (since Linux 2.4.10)" -This directory may contain files with application binary information. -.\" On some systems, it is not present. -See the Linux kernel source file -.I Documentation/sysctl/abi.rst -(or -.I Documentation/sysctl/abi.txt -before Linux 5.3) -for more information. -.TP -.I /proc/sys/debug -This directory may be empty. -.TP -.I /proc/sys/dev -This directory contains device-specific information (e.g., -.IR dev/cdrom/info ). -On -some systems, it may be empty. -.TP -.I /proc/sys/fs -This directory contains the files and subdirectories for kernel variables -related to filesystems. -.TP -.IR /proc/sys/fs/aio\-max\-nr " and " /proc/sys/fs/aio\-nr " (since Linux 2.6.4)" -.I aio\-nr -is the running total of the number of events specified by -.BR io_setup (2) -calls for all currently active AIO contexts. -If -.I aio\-nr -reaches -.IR aio\-max\-nr , -then -.BR io_setup (2) -will fail with the error -.BR EAGAIN . -Raising -.I aio\-max\-nr -does not result in the preallocation or resizing -of any kernel data structures. -.TP -.I /proc/sys/fs/binfmt_misc -Documentation for files in this directory can be found -in the Linux kernel source in the file -.I Documentation/admin\-guide/binfmt\-misc.rst -(or in -.I Documentation/binfmt_misc.txt -on older kernels). -.TP -.IR /proc/sys/fs/dentry\-state " (since Linux 2.2)" -This file contains information about the status of the -directory cache (dcache). -The file contains six numbers, -.IR nr_dentry , -.IR nr_unused , -.I age_limit -(age in seconds), -.I want_pages -(pages requested by system) and two dummy values. -.RS -.IP \[bu] 3 -.I nr_dentry -is the number of allocated dentries (dcache entries). -This field is unused in Linux 2.2. -.IP \[bu] -.I nr_unused -is the number of unused dentries. -.IP \[bu] -.I age_limit -.\" looks like this is unused in Linux 2.2 to Linux 2.6 -is the age in seconds after which dcache entries -can be reclaimed when memory is short. -.IP \[bu] -.I want_pages -.\" looks like this is unused in Linux 2.2 to Linux 2.6 -is nonzero when the kernel has called shrink_dcache_pages() and the -dcache isn't pruned yet. -.RE -.TP -.I /proc/sys/fs/dir\-notify\-enable -This file can be used to disable or enable the -.I dnotify -interface described in -.BR fcntl (2) -on a system-wide basis. -A value of 0 in this file disables the interface, -and a value of 1 enables it. -.TP -.I /proc/sys/fs/dquot\-max -This file shows the maximum number of cached disk quota entries. -On some (2.4) systems, it is not present. -If the number of free cached disk quota entries is very low and -you have some awesome number of simultaneous system users, -you might want to raise the limit. -.TP -.I /proc/sys/fs/dquot\-nr -This file shows the number of allocated disk quota -entries and the number of free disk quota entries. -.TP -.IR /proc/sys/fs/epoll " (since Linux 2.6.28)" -This directory contains the file -.IR max_user_watches , -which can be used to limit the amount of kernel memory consumed by the -.I epoll -interface. -For further details, see -.BR epoll (7). -.TP -.I /proc/sys/fs/file\-max -This file defines -a system-wide limit on the number of open files for all processes. -System calls that fail when encountering this limit fail with the error -.BR ENFILE . -(See also -.BR setrlimit (2), -which can be used by a process to set the per-process limit, -.BR RLIMIT_NOFILE , -on the number of files it may open.) -If you get lots -of error messages in the kernel log about running out of file handles -(open file descriptions) -(look for "VFS: file\-max limit <number> reached"), -try increasing this value: -.IP -.in +4n -.EX -echo 100000 > /proc/sys/fs/file\-max -.EE -.in -.IP -Privileged processes -.RB ( CAP_SYS_ADMIN ) -can override the -.I file\-max -limit. -.TP -.I /proc/sys/fs/file\-nr -This (read-only) file contains three numbers: -the number of allocated file handles -(i.e., the number of open file descriptions; see -.BR open (2)); -the number of free file handles; -and the maximum number of file handles (i.e., the same value as -.IR /proc/sys/fs/file\-max ). -If the number of allocated file handles is close to the -maximum, you should consider increasing the maximum. -Before Linux 2.6, -the kernel allocated file handles dynamically, -but it didn't free them again. -Instead the free file handles were kept in a list for reallocation; -the "free file handles" value indicates the size of that list. -A large number of free file handles indicates that there was -a past peak in the usage of open file handles. -Since Linux 2.6, the kernel does deallocate freed file handles, -and the "free file handles" value is always zero. -.TP -.IR /proc/sys/fs/inode\-max " (only present until Linux 2.2)" -This file contains the maximum number of in-memory inodes. -This value should be 3\[en]4 times larger -than the value in -.IR file\-max , -since \fIstdin\fP, \fIstdout\fP -and network sockets also need an inode to handle them. -When you regularly run out of inodes, you need to increase this value. -.IP -Starting with Linux 2.4, -there is no longer a static limit on the number of inodes, -and this file is removed. -.TP -.I /proc/sys/fs/inode\-nr -This file contains the first two values from -.IR inode\-state . -.TP -.I /proc/sys/fs/inode\-state -This file -contains seven numbers: -.IR nr_inodes , -.IR nr_free_inodes , -.IR preshrink , -and four dummy values (always zero). -.IP -.I nr_inodes -is the number of inodes the system has allocated. -.\" This can be slightly more than -.\" .I inode\-max -.\" because Linux allocates them one page full at a time. -.I nr_free_inodes -represents the number of free inodes. -.IP -.I preshrink -is nonzero when the -.I nr_inodes -> -.I inode\-max -and the system needs to prune the inode list instead of allocating more; -since Linux 2.4, this field is a dummy value (always zero). -.TP -.IR /proc/sys/fs/inotify " (since Linux 2.6.13)" -This directory contains files -.IR max_queued_events ", " max_user_instances ", and " max_user_watches , -that can be used to limit the amount of kernel memory consumed by the -.I inotify -interface. -For further details, see -.BR inotify (7). -.TP -.I /proc/sys/fs/lease\-break\-time -This file specifies the grace period that the kernel grants to a process -holding a file lease -.RB ( fcntl (2)) -after it has sent a signal to that process notifying it -that another process is waiting to open the file. -If the lease holder does not remove or downgrade the lease within -this grace period, the kernel forcibly breaks the lease. -.TP -.I /proc/sys/fs/leases\-enable -This file can be used to enable or disable file leases -.RB ( fcntl (2)) -on a system-wide basis. -If this file contains the value 0, leases are disabled. -A nonzero value enables leases. -.TP -.IR /proc/sys/fs/mount\-max " (since Linux 4.9)" -.\" commit d29216842a85c7970c536108e093963f02714498 -The value in this file specifies the maximum number of mounts that may exist -in a mount namespace. -The default value in this file is 100,000. -.TP -.IR /proc/sys/fs/mqueue " (since Linux 2.6.6)" -This directory contains files -.IR msg_max ", " msgsize_max ", and " queues_max , -controlling the resources used by POSIX message queues. -See -.BR mq_overview (7) -for details. -.TP -.IR /proc/sys/fs/nr_open " (since Linux 2.6.25)" -.\" commit 9cfe015aa424b3c003baba3841a60dd9b5ad319b -This file imposes a ceiling on the value to which the -.B RLIMIT_NOFILE -resource limit can be raised (see -.BR getrlimit (2)). -This ceiling is enforced for both unprivileged and privileged process. -The default value in this file is 1048576. -(Before Linux 2.6.25, the ceiling for -.B RLIMIT_NOFILE -was hard-coded to the same value.) -.TP -.IR /proc/sys/fs/overflowgid " and " /proc/sys/fs/overflowuid -These files -allow you to change the value of the fixed UID and GID. -The default is 65534. -Some filesystems support only 16-bit UIDs and GIDs, although in Linux -UIDs and GIDs are 32 bits. -When one of these filesystems is mounted -with writes enabled, any UID or GID that would exceed 65535 is translated -to the overflow value before being written to disk. -.TP -.IR /proc/sys/fs/pipe\-max\-size " (since Linux 2.6.35)" -See -.BR pipe (7). -.TP -.IR /proc/sys/fs/pipe\-user\-pages\-hard " (since Linux 4.5)" -See -.BR pipe (7). -.TP -.IR /proc/sys/fs/pipe\-user\-pages\-soft " (since Linux 4.5)" -See -.BR pipe (7). -.TP -.IR /proc/sys/fs/protected_fifos " (since Linux 4.19)" -The value in this file is/can be set to one of the following: -.RS -.TP 4 -0 -Writing to FIFOs is unrestricted. -.TP -1 -Don't allow -.B O_CREAT -.BR open (2) -on FIFOs that the caller doesn't own in world-writable sticky directories, -unless the FIFO is owned by the owner of the directory. -.TP -2 -As for the value 1, -but the restriction also applies to group-writable sticky directories. -.RE -.IP -The intent of the above protections is to avoid unintentional writes to an -attacker-controlled FIFO when a program expected to create a regular file. -.TP -.IR /proc/sys/fs/protected_hardlinks " (since Linux 3.6)" -.\" commit 800179c9b8a1e796e441674776d11cd4c05d61d7 -When the value in this file is 0, -no restrictions are placed on the creation of hard links -(i.e., this is the historical behavior before Linux 3.6). -When the value in this file is 1, -a hard link can be created to a target file -only if one of the following conditions is true: -.RS -.IP \[bu] 3 -The calling process has the -.B CAP_FOWNER -capability in its user namespace -and the file UID has a mapping in the namespace. -.IP \[bu] -The filesystem UID of the process creating the link matches -the owner (UID) of the target file -(as described in -.BR credentials (7), -a process's filesystem UID is normally the same as its effective UID). -.IP \[bu] -All of the following conditions are true: -.RS 4 -.IP \[bu] 3 -the target is a regular file; -.IP \[bu] -the target file does not have its set-user-ID mode bit enabled; -.IP \[bu] -the target file does not have both its set-group-ID and -group-executable mode bits enabled; and -.IP \[bu] -the caller has permission to read and write the target file -(either via the file's permissions mask or because it has -suitable capabilities). -.RE -.RE -.IP -The default value in this file is 0. -Setting the value to 1 -prevents a longstanding class of security issues caused by -hard-link-based time-of-check, time-of-use races, -most commonly seen in world-writable directories such as -.IR /tmp . -The common method of exploiting this flaw -is to cross privilege boundaries when following a given hard link -(i.e., a root process follows a hard link created by another user). -Additionally, on systems without separated partitions, -this stops unauthorized users from "pinning" vulnerable set-user-ID and -set-group-ID files against being upgraded by -the administrator, or linking to special files. -.TP -.IR /proc/sys/fs/protected_regular " (since Linux 4.19)" -The value in this file is/can be set to one of the following: -.RS -.TP 4 -0 -Writing to regular files is unrestricted. -.TP -1 -Don't allow -.B O_CREAT -.BR open (2) -on regular files that the caller doesn't own in -world-writable sticky directories, -unless the regular file is owned by the owner of the directory. -.TP -2 -As for the value 1, -but the restriction also applies to group-writable sticky directories. -.RE -.IP -The intent of the above protections is similar to -.IR protected_fifos , -but allows an application to -avoid writes to an attacker-controlled regular file, -where the application expected to create one. -.TP -.IR /proc/sys/fs/protected_symlinks " (since Linux 3.6)" -.\" commit 800179c9b8a1e796e441674776d11cd4c05d61d7 -When the value in this file is 0, -no restrictions are placed on following symbolic links -(i.e., this is the historical behavior before Linux 3.6). -When the value in this file is 1, symbolic links are followed only -in the following circumstances: -.RS -.IP \[bu] 3 -the filesystem UID of the process following the link matches -the owner (UID) of the symbolic link -(as described in -.BR credentials (7), -a process's filesystem UID is normally the same as its effective UID); -.IP \[bu] -the link is not in a sticky world-writable directory; or -.IP \[bu] -the symbolic link and its parent directory have the same owner (UID) -.RE -.IP -A system call that fails to follow a symbolic link -because of the above restrictions returns the error -.B EACCES -in -.IR errno . -.IP -The default value in this file is 0. -Setting the value to 1 avoids a longstanding class of security issues -based on time-of-check, time-of-use races when accessing symbolic links. -.TP -.IR /proc/sys/fs/suid_dumpable " (since Linux 2.6.13)" -.\" The following is based on text from Documentation/sysctl/kernel.txt -The value in this file is assigned to a process's "dumpable" flag -in the circumstances described in -.BR prctl (2). -In effect, -the value in this file determines whether core dump files are -produced for set-user-ID or otherwise protected/tainted binaries. -The "dumpable" setting also affects the ownership of files in a process's -.IR /proc/ pid -directory, as described above. -.IP -Three different integer values can be specified: -.RS -.TP -\fI0\ (default)\fP -.\" In kernel source: SUID_DUMP_DISABLE -This provides the traditional (pre-Linux 2.6.13) behavior. -A core dump will not be produced for a process which has -changed credentials (by calling -.BR seteuid (2), -.BR setgid (2), -or similar, or by executing a set-user-ID or set-group-ID program) -or whose binary does not have read permission enabled. -.TP -\fI1\ ("debug")\fP -.\" In kernel source: SUID_DUMP_USER -All processes dump core when possible. -(Reasons why a process might nevertheless not dump core are described in -.BR core (5).) -The core dump is owned by the filesystem user ID of the dumping process -and no security is applied. -This is intended for system debugging situations only: -this mode is insecure because it allows unprivileged users to -examine the memory contents of privileged processes. -.TP -\fI2\ ("suidsafe")\fP -.\" In kernel source: SUID_DUMP_ROOT -Any binary which normally would not be dumped (see "0" above) -is dumped readable by root only. -This allows the user to remove the core dump file but not to read it. -For security reasons core dumps in this mode will not overwrite one -another or other files. -This mode is appropriate when administrators are -attempting to debug problems in a normal environment. -.IP -Additionally, since Linux 3.6, -.\" 9520628e8ceb69fa9a4aee6b57f22675d9e1b709 -.I /proc/sys/kernel/core_pattern -must either be an absolute pathname -or a pipe command, as detailed in -.BR core (5). -Warnings will be written to the kernel log if -.I core_pattern -does not follow these rules, and no core dump will be produced. -.\" 54b501992dd2a839e94e76aa392c392b55080ce8 -.RE -.IP -For details of the effect of a process's "dumpable" setting -on ptrace access mode checking, see -.BR ptrace (2). -.TP -.I /proc/sys/fs/super\-max -This file -controls the maximum number of superblocks, and -thus the maximum number of mounted filesystems the kernel -can have. -You need increase only -.I super\-max -if you need to mount more filesystems than the current value in -.I super\-max -allows you to. -.TP -.I /proc/sys/fs/super\-nr -This file -contains the number of filesystems currently mounted. -.TP -.I /proc/sys/kernel -This directory contains files controlling a range of kernel parameters, -as described below. -.TP -.I /proc/sys/kernel/acct -This file -contains three numbers: -.IR highwater , -.IR lowwater , -and -.IR frequency . -If BSD-style process accounting is enabled, these values control -its behavior. -If free space on filesystem where the log lives goes below -.I lowwater -percent, accounting suspends. -If free space gets above -.I highwater -percent, accounting resumes. -.I frequency -determines -how often the kernel checks the amount of free space (value is in -seconds). -Default values are 4, 2, and 30. -That is, suspend accounting if 2% or less space is free; resume it -if 4% or more space is free; consider information about amount of free space -valid for 30 seconds. -.TP -.IR /proc/sys/kernel/auto_msgmni " (Linux 2.6.27 to Linux 3.18)" -.\" commit 9eefe520c814f6f62c5d36a2ddcd3fb99dfdb30e (introduces feature) -.\" commit 0050ee059f7fc86b1df2527aaa14ed5dc72f9973 (rendered redundant) -From Linux 2.6.27 to Linux 3.18, -this file was used to control recomputing of the value in -.I /proc/sys/kernel/msgmni -upon the addition or removal of memory or upon IPC namespace creation/removal. -Echoing "1" into this file enabled -.I msgmni -automatic recomputing (and triggered a recomputation of -.I msgmni -based on the current amount of available memory and number of IPC namespaces). -Echoing "0" disabled automatic recomputing. -(Automatic recomputing was also disabled if a value was explicitly assigned to -.IR /proc/sys/kernel/msgmni .) -The default value in -.I auto_msgmni -was 1. -.IP -Since Linux 3.19, the content of this file has no effect (because -.I msgmni -.\" FIXME Must document the 3.19 'msgmni' changes. -defaults to near the maximum value possible), -and reads from this file always return the value "0". -.TP -.IR /proc/sys/kernel/cap_last_cap " (since Linux 3.2)" -See -.BR capabilities (7). -.TP -.IR /proc/sys/kernel/cap\-bound " (from Linux 2.2 to Linux 2.6.24)" -This file holds the value of the kernel -.I "capability bounding set" -(expressed as a signed decimal number). -This set is ANDed against the capabilities permitted to a process -during -.BR execve (2). -Starting with Linux 2.6.25, -the system-wide capability bounding set disappeared, -and was replaced by a per-thread bounding set; see -.BR capabilities (7). -.TP -.I /proc/sys/kernel/core_pattern -See -.BR core (5). -.TP -.I /proc/sys/kernel/core_pipe_limit -See -.BR core (5). -.TP -.I /proc/sys/kernel/core_uses_pid -See -.BR core (5). -.TP -.I /proc/sys/kernel/ctrl\-alt\-del -This file -controls the handling of Ctrl-Alt-Del from the keyboard. -When the value in this file is 0, Ctrl-Alt-Del is trapped and -sent to the -.BR init (1) -program to handle a graceful restart. -When the value is greater than zero, Linux's reaction to a Vulcan -Nerve Pinch (tm) will be an immediate reboot, without even -syncing its dirty buffers. -Note: when a program (like dosemu) has the keyboard in "raw" -mode, the Ctrl-Alt-Del is intercepted by the program before it -ever reaches the kernel tty layer, and it's up to the program -to decide what to do with it. -.TP -.IR /proc/sys/kernel/dmesg_restrict " (since Linux 2.6.37)" -The value in this file determines who can see kernel syslog contents. -A value of 0 in this file imposes no restrictions. -If the value is 1, only privileged users can read the kernel syslog. -(See -.BR syslog (2) -for more details.) -Since Linux 3.4, -.\" commit 620f6e8e855d6d447688a5f67a4e176944a084e8 -only users with the -.B CAP_SYS_ADMIN -capability may change the value in this file. -.TP -.IR /proc/sys/kernel/domainname " and " /proc/sys/kernel/hostname -can be used to set the NIS/YP domainname and the -hostname of your box in exactly the same way as the commands -.BR domainname (1) -and -.BR hostname (1), -that is: -.IP -.in +4n -.EX -.RB "#" " echo \[aq]darkstar\[aq] > /proc/sys/kernel/hostname" -.RB "#" " echo \[aq]mydomain\[aq] > /proc/sys/kernel/domainname" -.EE -.in -.IP -has the same effect as -.IP -.in +4n -.EX -.RB "#" " hostname \[aq]darkstar\[aq]" -.RB "#" " domainname \[aq]mydomain\[aq]" -.EE -.in -.IP -Note, however, that the classic darkstar.frop.org has the -hostname "darkstar" and DNS (Internet Domain Name Server) -domainname "frop.org", not to be confused with the NIS (Network -Information Service) or YP (Yellow Pages) domainname. -These two -domain names are in general different. -For a detailed discussion -see the -.BR hostname (1) -man page. -.TP -.I /proc/sys/kernel/hotplug -This file -contains the pathname for the hotplug policy agent. -The default value in this file is -.IR /sbin/hotplug . -.TP -.\" Removed in commit 87f504e5c78b910b0c1d6ffb89bc95e492322c84 (tglx/history.git) -.IR /proc/sys/kernel/htab\-reclaim " (before Linux 2.4.9.2)" -(PowerPC only) If this file is set to a nonzero value, -the PowerPC htab -.\" removed in commit 1b483a6a7b2998e9c98ad985d7494b9b725bd228, before Linux 2.6.28 -(see kernel file -.IR Documentation/powerpc/ppc_htab.txt ) -is pruned -each time the system hits the idle loop. -.TP -.I /proc/sys/kernel/keys/* -This directory contains various files that define parameters and limits -for the key-management facility. -These files are described in -.BR keyrings (7). -.TP -.IR /proc/sys/kernel/kptr_restrict " (since Linux 2.6.38)" -.\" 455cd5ab305c90ffc422dd2e0fb634730942b257 -The value in this file determines whether kernel addresses are exposed via -.I /proc -files and other interfaces. -A value of 0 in this file imposes no restrictions. -If the value is 1, kernel pointers printed using the -.I %pK -format specifier will be replaced with zeros unless the user has the -.B CAP_SYSLOG -capability. -If the value is 2, kernel pointers printed using the -.I %pK -format specifier will be replaced with zeros regardless -of the user's capabilities. -The initial default value for this file was 1, -but the default was changed -.\" commit 411f05f123cbd7f8aa1edcae86970755a6e2a9d9 -to 0 in Linux 2.6.39. -Since Linux 3.4, -.\" commit 620f6e8e855d6d447688a5f67a4e176944a084e8 -only users with the -.B CAP_SYS_ADMIN -capability can change the value in this file. -.TP -.I /proc/sys/kernel/l2cr -(PowerPC only) This file -contains a flag that controls the L2 cache of G3 processor -boards. -If 0, the cache is disabled. -Enabled if nonzero. -.TP -.I /proc/sys/kernel/modprobe -This file contains the pathname for the kernel module loader. -The default value is -.IR /sbin/modprobe . -The file is present only if the kernel is built with the -.B CONFIG_MODULES -.RB ( CONFIG_KMOD -in Linux 2.6.26 and earlier) -option enabled. -It is described by the Linux kernel source file -.I Documentation/kmod.txt -(present only in Linux 2.4 and earlier). -.TP -.IR /proc/sys/kernel/modules_disabled " (since Linux 2.6.31)" -.\" 3d43321b7015387cfebbe26436d0e9d299162ea1 -.\" From Documentation/sysctl/kernel.txt -A toggle value indicating if modules are allowed to be loaded -in an otherwise modular kernel. -This toggle defaults to off (0), but can be set true (1). -Once true, modules can be neither loaded nor unloaded, -and the toggle cannot be set back to false. -The file is present only if the kernel is built with the -.B CONFIG_MODULES -option enabled. -.TP -.IR /proc/sys/kernel/msgmax " (since Linux 2.2)" -This file defines -a system-wide limit specifying the maximum number of bytes in -a single message written on a System V message queue. -.TP -.IR /proc/sys/kernel/msgmni " (since Linux 2.4)" -This file defines the system-wide limit on the number of -message queue identifiers. -See also -.IR /proc/sys/kernel/auto_msgmni . -.TP -.IR /proc/sys/kernel/msgmnb " (since Linux 2.2)" -This file defines a system-wide parameter used to initialize the -.I msg_qbytes -setting for subsequently created message queues. -The -.I msg_qbytes -setting specifies the maximum number of bytes that may be written to the -message queue. -.TP -.IR /proc/sys/kernel/ngroups_max " (since Linux 2.6.4)" -This is a read-only file that displays the upper limit on the -number of a process's group memberships. -.TP -.IR /proc/sys/kernel/ns_last_pid " (since Linux 3.3)" -See -.BR pid_namespaces (7). -.TP -.IR /proc/sys/kernel/ostype " and " /proc/sys/kernel/osrelease -These files -give substrings of -.IR /proc/version . -.TP -.IR /proc/sys/kernel/overflowgid " and " /proc/sys/kernel/overflowuid -These files duplicate the files -.I /proc/sys/fs/overflowgid -and -.IR /proc/sys/fs/overflowuid . -.TP -.I /proc/sys/kernel/panic -This file gives read/write access to the kernel variable -.IR panic_timeout . -If this is zero, the kernel will loop on a panic; if nonzero, -it indicates that the kernel should autoreboot after this number -of seconds. -When you use the -software watchdog device driver, the recommended setting is 60. -.TP -.IR /proc/sys/kernel/panic_on_oops " (since Linux 2.5.68)" -This file controls the kernel's behavior when an oops -or BUG is encountered. -If this file contains 0, then the system -tries to continue operation. -If it contains 1, then the system -delays a few seconds (to give klogd time to record the oops output) -and then panics. -If the -.I /proc/sys/kernel/panic -file is also nonzero, then the machine will be rebooted. -.TP -.IR /proc/sys/kernel/pid_max " (since Linux 2.5.34)" -This file specifies the value at which PIDs wrap around -(i.e., the value in this file is one greater than the maximum PID). -PIDs greater than this value are not allocated; -thus, the value in this file also acts as a system-wide limit -on the total number of processes and threads. -The default value for this file, 32768, -results in the same range of PIDs as on earlier kernels. -On 32-bit platforms, 32768 is the maximum value for -.IR pid_max . -On 64-bit systems, -.I pid_max -can be set to any value up to 2\[ha]22 -.RB ( PID_MAX_LIMIT , -approximately 4 million). -.\" Prior to Linux 2.6.10, pid_max could also be raised above 32768 on 32-bit -.\" platforms, but this broke /proc/[pid] -.\" See http://marc.theaimsgroup.com/?l=linux-kernel&m=109513010926152&w=2 -.TP -.IR /proc/sys/kernel/powersave\-nap " (PowerPC only)" -This file contains a flag. -If set, Linux-PPC will use the "nap" mode of -powersaving, -otherwise the "doze" mode will be used. -.TP -.I /proc/sys/kernel/printk -See -.BR syslog (2). -.TP -.IR /proc/sys/kernel/pty " (since Linux 2.6.4)" -This directory contains two files relating to the number of UNIX 98 -pseudoterminals (see -.BR pts (4)) -on the system. -.TP -.I /proc/sys/kernel/pty/max -This file defines the maximum number of pseudoterminals. -.\" FIXME Document /proc/sys/kernel/pty/reserve -.\" New in Linux 3.3 -.\" commit e9aba5158a80098447ff207a452a3418ae7ee386 -.TP -.I /proc/sys/kernel/pty/nr -This read-only file -indicates how many pseudoterminals are currently in use. -.TP -.I /proc/sys/kernel/random -This directory -contains various parameters controlling the operation of the file -.IR /dev/random . -See -.BR random (4) -for further information. -.TP -.IR /proc/sys/kernel/random/uuid " (since Linux 2.4)" -Each read from this read-only file returns a randomly generated 128-bit UUID, -as a string in the standard UUID format. -.TP -.IR /proc/sys/kernel/randomize_va_space " (since Linux 2.6.12)" -.\" Some further details can be found in Documentation/sysctl/kernel.txt -Select the address space layout randomization (ASLR) policy for the system -(on architectures that support ASLR). -Three values are supported for this file: -.RS -.TP -.B 0 -Turn ASLR off. -This is the default for architectures that don't support ASLR, -and when the kernel is booted with the -.I norandmaps -parameter. -.TP -.B 1 -Make the addresses of -.BR mmap (2) -allocations, the stack, and the VDSO page randomized. -Among other things, this means that shared libraries will be -loaded at randomized addresses. -The text segment of PIE-linked binaries will also be loaded -at a randomized address. -This value is the default if the kernel was configured with -.BR CONFIG_COMPAT_BRK . -.TP -.B 2 -(Since Linux 2.6.25) -.\" commit c1d171a002942ea2d93b4fbd0c9583c56fce0772 -Also support heap randomization. -This value is the default if the kernel was not configured with -.BR CONFIG_COMPAT_BRK . -.RE -.TP -.I /proc/sys/kernel/real\-root\-dev -This file is documented in the Linux kernel source file -.I Documentation/admin\-guide/initrd.rst -.\" commit 9d85025b0418163fae079c9ba8f8445212de8568 -(or -.I Documentation/initrd.txt -before Linux 4.10). -.TP -.IR /proc/sys/kernel/reboot\-cmd " (Sparc only)" -This file seems to be a way to give an argument to the SPARC -ROM/Flash boot loader. -Maybe to tell it what to do after -rebooting? -.TP -.I /proc/sys/kernel/rtsig\-max -(Up to and including Linux 2.6.7; see -.BR setrlimit (2)) -This file can be used to tune the maximum number -of POSIX real-time (queued) signals that can be outstanding -in the system. -.TP -.I /proc/sys/kernel/rtsig\-nr -(Up to and including Linux 2.6.7.) -This file shows the number of POSIX real-time signals currently queued. -.TP -.IR /proc/ pid /sched_autogroup_enabled " (since Linux 2.6.38)" -.\" commit 5091faa449ee0b7d73bc296a93bca9540fc51d0a -See -.BR sched (7). -.TP -.IR /proc/sys/kernel/sched_child_runs_first " (since Linux 2.6.23)" -If this file contains the value zero, then, after a -.BR fork (2), -the parent is first scheduled on the CPU. -If the file contains a nonzero value, -then the child is scheduled first on the CPU. -(Of course, on a multiprocessor system, -the parent and the child might both immediately be scheduled on a CPU.) -.TP -.IR /proc/sys/kernel/sched_rr_timeslice_ms " (since Linux 3.9)" -See -.BR sched_rr_get_interval (2). -.TP -.IR /proc/sys/kernel/sched_rt_period_us " (since Linux 2.6.25)" -See -.BR sched (7). -.TP -.IR /proc/sys/kernel/sched_rt_runtime_us " (since Linux 2.6.25)" -See -.BR sched (7). -.TP -.IR /proc/sys/kernel/seccomp " (since Linux 4.14)" -.\" commit 8e5f1ad116df6b0de65eac458d5e7c318d1c05af -This directory provides additional seccomp information and -configuration. -See -.BR seccomp (2) -for further details. -.TP -.IR /proc/sys/kernel/sem " (since Linux 2.4)" -This file contains 4 numbers defining limits for System V IPC semaphores. -These fields are, in order: -.RS -.TP -SEMMSL -The maximum semaphores per semaphore set. -.TP -SEMMNS -A system-wide limit on the number of semaphores in all semaphore sets. -.TP -SEMOPM -The maximum number of operations that may be specified in a -.BR semop (2) -call. -.TP -SEMMNI -A system-wide limit on the maximum number of semaphore identifiers. -.RE -.TP -.I /proc/sys/kernel/sg\-big\-buff -This file -shows the size of the generic SCSI device (sg) buffer. -You can't tune it just yet, but you could change it at -compile time by editing -.I include/scsi/sg.h -and changing -the value of -.BR SG_BIG_BUFF . -However, there shouldn't be any reason to change this value. -.TP -.IR /proc/sys/kernel/shm_rmid_forced " (since Linux 3.1)" -.\" commit b34a6b1da371ed8af1221459a18c67970f7e3d53 -.\" See also Documentation/sysctl/kernel.txt -If this file is set to 1, all System V shared memory segments will -be marked for destruction as soon as the number of attached processes -falls to zero; -in other words, it is no longer possible to create shared memory segments -that exist independently of any attached process. -.IP -The effect is as though a -.BR shmctl (2) -.B IPC_RMID -is performed on all existing segments as well as all segments -created in the future (until this file is reset to 0). -Note that existing segments that are attached to no process will be -immediately destroyed when this file is set to 1. -Setting this option will also destroy segments that were created, -but never attached, -upon termination of the process that created the segment with -.BR shmget (2). -.IP -Setting this file to 1 provides a way of ensuring that -all System V shared memory segments are counted against the -resource usage and resource limits (see the description of -.B RLIMIT_AS -in -.BR getrlimit (2)) -of at least one process. -.IP -Because setting this file to 1 produces behavior that is nonstandard -and could also break existing applications, -the default value in this file is 0. -Set this file to 1 only if you have a good understanding -of the semantics of the applications using -System V shared memory on your system. -.TP -.IR /proc/sys/kernel/shmall " (since Linux 2.2)" -This file -contains the system-wide limit on the total number of pages of -System V shared memory. -.TP -.IR /proc/sys/kernel/shmmax " (since Linux 2.2)" -This file -can be used to query and set the run-time limit -on the maximum (System V IPC) shared memory segment size that can be -created. -Shared memory segments up to 1 GB are now supported in the -kernel. -This value defaults to -.BR SHMMAX . -.TP -.IR /proc/sys/kernel/shmmni " (since Linux 2.4)" -This file -specifies the system-wide maximum number of System V shared memory -segments that can be created. -.TP -.IR /proc/sys/kernel/sysctl_writes_strict " (since Linux 3.16)" -.\" commit f88083005ab319abba5d0b2e4e997558245493c8 -.\" commit 2ca9bb456ada8bcbdc8f77f8fc78207653bbaa92 -.\" commit f4aacea2f5d1a5f7e3154e967d70cf3f711bcd61 -.\" commit 24fe831c17ab8149413874f2fd4e5c8a41fcd294 -The value in this file determines how the file offset affects -the behavior of updating entries in files under -.IR /proc/sys . -The file has three possible values: -.RS -.TP 4 -\-1 -This provides legacy handling, with no printk warnings. -Each -.BR write (2) -must fully contain the value to be written, -and multiple writes on the same file descriptor -will overwrite the entire value, regardless of the file position. -.TP -0 -(default) This provides the same behavior as for \-1, -but printk warnings are written for processes that -perform writes when the file offset is not 0. -.TP -1 -Respect the file offset when writing strings into -.I /proc/sys -files. -Multiple writes will -.I append -to the value buffer. -Anything written beyond the maximum length -of the value buffer will be ignored. -Writes to numeric -.I /proc/sys -entries must always be at file offset 0 and the value must be -fully contained in the buffer provided to -.BR write (2). -.\" FIXME . -.\" With /proc/sys/kernel/sysctl_writes_strict==1, writes at an -.\" offset other than 0 do not generate an error. Instead, the -.\" write() succeeds, but the file is left unmodified. -.\" This is surprising. The behavior may change in the future. -.\" See thread.gmane.org/gmane.linux.man/9197 -.\" From: Michael Kerrisk (man-pages <mtk.manpages@...> -.\" Subject: sysctl_writes_strict documentation + an oddity? -.\" Newsgroups: gmane.linux.man, gmane.linux.kernel -.\" Date: 2015-05-09 08:54:11 GMT -.RE -.TP -.I /proc/sys/kernel/sysrq -This file controls the functions allowed to be invoked by the SysRq key. -By default, -the file contains 1 meaning that every possible SysRq request is allowed -(in older kernel versions, SysRq was disabled by default, -and you were required to specifically enable it at run-time, -but this is not the case any more). -Possible values in this file are: -.RS -.TP 5 -0 -Disable sysrq completely -.TP -1 -Enable all functions of sysrq -.TP -> 1 -Bit mask of allowed sysrq functions, as follows: -.PD 0 -.RS -.TP 5 -\ \ 2 -Enable control of console logging level -.TP -\ \ 4 -Enable control of keyboard (SAK, unraw) -.TP -\ \ 8 -Enable debugging dumps of processes etc. -.TP -\ 16 -Enable sync command -.TP -\ 32 -Enable remount read-only -.TP -\ 64 -Enable signaling of processes (term, kill, oom-kill) -.TP -128 -Allow reboot/poweroff -.TP -256 -Allow nicing of all real-time tasks -.RE -.PD -.RE -.IP -This file is present only if the -.B CONFIG_MAGIC_SYSRQ -kernel configuration option is enabled. -For further details see the Linux kernel source file -.I Documentation/admin\-guide/sysrq.rst -.\" commit 9d85025b0418163fae079c9ba8f8445212de8568 -(or -.I Documentation/sysrq.txt -before Linux 4.10). -.TP -.I /proc/sys/kernel/version -This file contains a string such as: -.IP -.in +4n -.EX -#5 Wed Feb 25 21:49:24 MET 1998 -.EE -.in -.IP -The "#5" means that -this is the fifth kernel built from this source base and the -date following it indicates the time the kernel was built. -.TP -.IR /proc/sys/kernel/threads\-max " (since Linux 2.3.11)" -.\" The following is based on Documentation/sysctl/kernel.txt -This file specifies the system-wide limit on the number of -threads (tasks) that can be created on the system. -.IP -Since Linux 4.1, -.\" commit 230633d109e35b0a24277498e773edeb79b4a331 -the value that can be written to -.I threads\-max -is bounded. -The minimum value that can be written is 20. -The maximum value that can be written is given by the -constant -.B FUTEX_TID_MASK -(0x3fffffff). -If a value outside of this range is written to -.IR threads\-max , -the error -.B EINVAL -occurs. -.IP -The value written is checked against the available RAM pages. -If the thread structures would occupy too much (more than 1/8th) -of the available RAM pages, -.I threads\-max -is reduced accordingly. -.TP -.IR /proc/sys/kernel/yama/ptrace_scope " (since Linux 3.5)" -See -.BR ptrace (2). -.TP -.IR /proc/sys/kernel/zero\-paged " (PowerPC only)" -This file -contains a flag. -When enabled (nonzero), Linux-PPC will pre-zero pages in -the idle loop, possibly speeding up get_free_pages. -.TP -.I /proc/sys/net -This directory contains networking stuff. -Explanations for some of the files under this directory can be found in -.BR tcp (7) -and -.BR ip (7). -.TP -.I /proc/sys/net/core/bpf_jit_enable -See -.BR bpf (2). -.TP -.I /proc/sys/net/core/somaxconn -This file defines a ceiling value for the -.I backlog -argument of -.BR listen (2); -see the -.BR listen (2) -manual page for details. -.TP -.I /proc/sys/proc -This directory may be empty. -.TP -.I /proc/sys/sunrpc -This directory supports Sun remote procedure call for network filesystem -(NFS). -On some systems, it is not present. -.TP -.IR /proc/sys/user " (since Linux 4.9)" -See -.BR namespaces (7). -.TP -.I /proc/sys/vm -This directory contains files for memory management tuning, buffer, and -cache management. -.TP -.IR /proc/sys/vm/admin_reserve_kbytes " (since Linux 3.10)" -.\" commit 4eeab4f5580d11bffedc697684b91b0bca0d5009 -This file defines the amount of free memory (in KiB) on the system that -should be reserved for users with the capability -.BR CAP_SYS_ADMIN . -.IP -The default value in this file is the minimum of [3% of free pages, 8MiB] -expressed as KiB. -The default is intended to provide enough for the superuser -to log in and kill a process, if necessary, -under the default overcommit 'guess' mode (i.e., 0 in -.IR /proc/sys/vm/overcommit_memory ). -.IP -Systems running in "overcommit never" mode (i.e., 2 in -.IR /proc/sys/vm/overcommit_memory ) -should increase the value in this file to account -for the full virtual memory size of the programs used to recover (e.g., -.BR login (1) -.BR ssh (1), -and -.BR top (1)) -Otherwise, the superuser may not be able to log in to recover the system. -For example, on x86-64 a suitable value is 131072 (128MiB reserved). -.IP -Changing the value in this file takes effect whenever -an application requests memory. -.TP -.IR /proc/sys/vm/compact_memory " (since Linux 2.6.35)" -When 1 is written to this file, all zones are compacted such that free -memory is available in contiguous blocks where possible. -The effect of this action can be seen by examining -.IR /proc/buddyinfo . -.IP -Present only if the kernel was configured with -.BR CONFIG_COMPACTION . -.TP -.IR /proc/sys/vm/drop_caches " (since Linux 2.6.16)" -Writing to this file causes the kernel to drop clean caches, dentries, and -inodes from memory, causing that memory to become free. -This can be useful for memory management testing and -performing reproducible filesystem benchmarks. -Because writing to this file causes the benefits of caching to be lost, -it can degrade overall system performance. -.IP -To free pagecache, use: -.IP -.in +4n -.EX -echo 1 > /proc/sys/vm/drop_caches -.EE -.in -.IP -To free dentries and inodes, use: -.IP -.in +4n -.EX -echo 2 > /proc/sys/vm/drop_caches -.EE -.in -.IP -To free pagecache, dentries, and inodes, use: -.IP -.in +4n -.EX -echo 3 > /proc/sys/vm/drop_caches -.EE -.in -.IP -Because writing to this file is a nondestructive operation and dirty objects -are not freeable, the -user should run -.BR sync (1) -first. -.TP -.IR /proc/sys/vm/sysctl_hugetlb_shm_group " (since Linux 2.6.7)" -This writable file contains a group ID that is allowed -to allocate memory using huge pages. -If a process has a filesystem group ID or any supplementary group ID that -matches this group ID, -then it can make huge-page allocations without holding the -.B CAP_IPC_LOCK -capability; see -.BR memfd_create (2), -.BR mmap (2), -and -.BR shmget (2). -.TP -.IR /proc/sys/vm/legacy_va_layout " (since Linux 2.6.9)" -.\" The following is from Documentation/filesystems/proc.txt -If nonzero, this disables the new 32-bit memory-mapping layout; -the kernel will use the legacy (2.4) layout for all processes. -.TP -.IR /proc/sys/vm/memory_failure_early_kill " (since Linux 2.6.32)" -.\" The following is based on the text in Documentation/sysctl/vm.txt -Control how to kill processes when an uncorrected memory error -(typically a 2-bit error in a memory module) -that cannot be handled by the kernel -is detected in the background by hardware. -In some cases (like the page still having a valid copy on disk), -the kernel will handle the failure -transparently without affecting any applications. -But if there is no other up-to-date copy of the data, -it will kill processes to prevent any data corruptions from propagating. -.IP -The file has one of the following values: -.RS -.TP -.B 1 -Kill all processes that have the corrupted-and-not-reloadable page mapped -as soon as the corruption is detected. -Note that this is not supported for a few types of pages, -such as kernel internally -allocated data or the swap cache, but works for the majority of user pages. -.TP -.B 0 -Unmap the corrupted page from all processes and kill a process -only if it tries to access the page. -.RE -.IP -The kill is performed using a -.B SIGBUS -signal with -.I si_code -set to -.BR BUS_MCEERR_AO . -Processes can handle this if they want to; see -.BR sigaction (2) -for more details. -.IP -This feature is active only on architectures/platforms with advanced machine -check handling and depends on the hardware capabilities. -.IP -Applications can override the -.I memory_failure_early_kill -setting individually with the -.BR prctl (2) -.B PR_MCE_KILL -operation. -.IP -Present only if the kernel was configured with -.BR CONFIG_MEMORY_FAILURE . -.TP -.IR /proc/sys/vm/memory_failure_recovery " (since Linux 2.6.32)" -.\" The following is based on the text in Documentation/sysctl/vm.txt -Enable memory failure recovery (when supported by the platform). -.RS -.TP -.B 1 -Attempt recovery. -.TP -.B 0 -Always panic on a memory failure. -.RE -.IP -Present only if the kernel was configured with -.BR CONFIG_MEMORY_FAILURE . -.TP -.IR /proc/sys/vm/oom_dump_tasks " (since Linux 2.6.25)" -.\" The following is from Documentation/sysctl/vm.txt -Enables a system-wide task dump (excluding kernel threads) to be -produced when the kernel performs an OOM-killing. -The dump includes the following information -for each task (thread, process): -thread ID, real user ID, thread group ID (process ID), -virtual memory size, resident set size, -the CPU that the task is scheduled on, -oom_adj score (see the description of -.IR /proc/ pid /oom_adj ), -and command name. -This is helpful to determine why the OOM-killer was invoked -and to identify the rogue task that caused it. -.IP -If this contains the value zero, this information is suppressed. -On very large systems with thousands of tasks, -it may not be feasible to dump the memory state information for each one. -Such systems should not be forced to incur a performance penalty in -OOM situations when the information may not be desired. -.IP -If this is set to nonzero, this information is shown whenever the -OOM-killer actually kills a memory-hogging task. -.IP -The default value is 0. -.TP -.IR /proc/sys/vm/oom_kill_allocating_task " (since Linux 2.6.24)" -.\" The following is from Documentation/sysctl/vm.txt -This enables or disables killing the OOM-triggering task in -out-of-memory situations. -.IP -If this is set to zero, the OOM-killer will scan through the entire -tasklist and select a task based on heuristics to kill. -This normally selects a rogue memory-hogging task that -frees up a large amount of memory when killed. -.IP -If this is set to nonzero, the OOM-killer simply kills the task that -triggered the out-of-memory condition. -This avoids a possibly expensive tasklist scan. -.IP -If -.I /proc/sys/vm/panic_on_oom -is nonzero, it takes precedence over whatever value is used in -.IR /proc/sys/vm/oom_kill_allocating_task . -.IP -The default value is 0. -.TP -.IR /proc/sys/vm/overcommit_kbytes " (since Linux 3.14)" -.\" commit 49f0ce5f92321cdcf741e35f385669a421013cb7 -This writable file provides an alternative to -.I /proc/sys/vm/overcommit_ratio -for controlling the -.I CommitLimit -when -.I /proc/sys/vm/overcommit_memory -has the value 2. -It allows the amount of memory overcommitting to be specified as -an absolute value (in kB), -rather than as a percentage, as is done with -.IR overcommit_ratio . -This allows for finer-grained control of -.I CommitLimit -on systems with extremely large memory sizes. -.IP -Only one of -.I overcommit_kbytes -or -.I overcommit_ratio -can have an effect: -if -.I overcommit_kbytes -has a nonzero value, then it is used to calculate -.IR CommitLimit , -otherwise -.I overcommit_ratio -is used. -Writing a value to either of these files causes the -value in the other file to be set to zero. -.TP -.I /proc/sys/vm/overcommit_memory -This file contains the kernel virtual memory accounting mode. -Values are: -.RS -.IP -0: heuristic overcommit (this is the default) -.br -1: always overcommit, never check -.br -2: always check, never overcommit -.RE -.IP -In mode 0, calls of -.BR mmap (2) -with -.B MAP_NORESERVE -are not checked, and the default check is very weak, -leading to the risk of getting a process "OOM-killed". -.IP -In mode 1, the kernel pretends there is always enough memory, -until memory actually runs out. -One use case for this mode is scientific computing applications -that employ large sparse arrays. -Before Linux 2.6.0, any nonzero value implies mode 1. -.IP -In mode 2 (available since Linux 2.6), the total virtual address space -that can be allocated -.RI ( CommitLimit -in -.IR /proc/meminfo ) -is calculated as -.IP -.in +4n -.EX -CommitLimit = (total_RAM \- total_huge_TLB) * - overcommit_ratio / 100 + total_swap -.EE -.in -.IP -where: -.RS -.IP \[bu] 3 -.I total_RAM -is the total amount of RAM on the system; -.IP \[bu] -.I total_huge_TLB -is the amount of memory set aside for huge pages; -.IP \[bu] -.I overcommit_ratio -is the value in -.IR /proc/sys/vm/overcommit_ratio ; -and -.IP \[bu] -.I total_swap -is the amount of swap space. -.RE -.IP -For example, on a system with 16 GB of physical RAM, 16 GB -of swap, no space dedicated to huge pages, and an -.I overcommit_ratio -of 50, this formula yields a -.I CommitLimit -of 24 GB. -.IP -Since Linux 3.14, if the value in -.I /proc/sys/vm/overcommit_kbytes -is nonzero, then -.I CommitLimit -is instead calculated as: -.IP -.in +4n -.EX -CommitLimit = overcommit_kbytes + total_swap -.EE -.in -.IP -See also the description of -.I /proc/sys/vm/admin_reserve_kbytes -and -.IR /proc/sys/vm/user_reserve_kbytes . -.TP -.IR /proc/sys/vm/overcommit_ratio " (since Linux 2.6.0)" -This writable file defines a percentage by which memory -can be overcommitted. -The default value in the file is 50. -See the description of -.IR /proc/sys/vm/overcommit_memory . -.TP -.IR /proc/sys/vm/panic_on_oom " (since Linux 2.6.18)" -.\" The following is adapted from Documentation/sysctl/vm.txt -This enables or disables a kernel panic in -an out-of-memory situation. -.IP -If this file is set to the value 0, -the kernel's OOM-killer will kill some rogue process. -Usually, the OOM-killer is able to kill a rogue process and the -system will survive. -.IP -If this file is set to the value 1, -then the kernel normally panics when out-of-memory happens. -However, if a process limits allocations to certain nodes -using memory policies -.RB ( mbind (2) -.BR MPOL_BIND ) -or cpusets -.RB ( cpuset (7)) -and those nodes reach memory exhaustion status, -one process may be killed by the OOM-killer. -No panic occurs in this case: -because other nodes' memory may be free, -this means the system as a whole may not have reached -an out-of-memory situation yet. -.IP -If this file is set to the value 2, -the kernel always panics when an out-of-memory condition occurs. -.IP -The default value is 0. -1 and 2 are for failover of clustering. -Select either according to your policy of failover. -.TP -.I /proc/sys/vm/swappiness -.\" The following is from Documentation/sysctl/vm.txt -The value in this file controls how aggressively the kernel will swap -memory pages. -Higher values increase aggressiveness, lower values -decrease aggressiveness. -The default value is 60. -.TP -.IR /proc/sys/vm/user_reserve_kbytes " (since Linux 3.10)" -.\" commit c9b1d0981fcce3d9976d7b7a56e4e0503bc610dd -Specifies an amount of memory (in KiB) to reserve for user processes. -This is intended to prevent a user from starting a single memory hogging -process, such that they cannot recover (kill the hog). -The value in this file has an effect only when -.I /proc/sys/vm/overcommit_memory -is set to 2 ("overcommit never" mode). -In this case, the system reserves an amount of memory that is the minimum -of [3% of current process size, -.IR user_reserve_kbytes ]. -.IP -The default value in this file is the minimum of [3% of free pages, 128MiB] -expressed as KiB. -.IP -If the value in this file is set to zero, -then a user will be allowed to allocate all free memory with a single process -(minus the amount reserved by -.IR /proc/sys/vm/admin_reserve_kbytes ). -Any subsequent attempts to execute a command will result in -"fork: Cannot allocate memory". -.IP -Changing the value in this file takes effect whenever -an application requests memory. -.TP -.IR /proc/sys/vm/unprivileged_userfaultfd " (since Linux 5.2)" -.\" cefdca0a86be517bc390fc4541e3674b8e7803b0 -This (writable) file exposes a flag that controls whether -unprivileged processes are allowed to employ -.BR userfaultfd (2). -If this file has the value 1, then unprivileged processes may use -.BR userfaultfd (2). -If this file has the value 0, then only processes that have the -.B CAP_SYS_PTRACE -capability may employ -.BR userfaultfd (2). -The default value in this file is 1. -.TP -.IR /proc/sysrq\-trigger " (since Linux 2.4.21)" -Writing a character to this file triggers the same SysRq function as -typing ALT-SysRq-<character> (see the description of -.IR /proc/sys/kernel/sysrq ). -This file is normally writable only by -.IR root . -For further details see the Linux kernel source file -.I Documentation/admin\-guide/sysrq.rst -.\" commit 9d85025b0418163fae079c9ba8f8445212de8568 -(or -.I Documentation/sysrq.txt -before Linux 4.10). -.TP -.I /proc/sysvipc -Subdirectory containing the pseudo-files -.IR msg ", " sem " and " shm "." -These files list the System V Interprocess Communication (IPC) objects -(respectively: message queues, semaphores, and shared memory) -that currently exist on the system, -providing similar information to that available via -.BR ipcs (1). -These files have headers and are formatted (one IPC object per line) -for easy understanding. -.BR sysvipc (7) -provides further background on the information shown by these files. -.TP -.IR /proc/thread\-self " (since Linux 3.17)" -.\" commit 0097875bd41528922fb3bb5f348c53f17e00e2fd -This directory refers to the thread accessing the -.I /proc -filesystem, -and is identical to the -.IR /proc/self/task/ tid -directory named by the process thread ID -.RI ( tid ) -of the same thread. -.TP -.IR /proc/timer_list " (since Linux 2.6.21)" -.\" commit 289f480af87e45f7a6de6ba9b4c061c2e259fe98 -This read-only file exposes a list of all currently pending -(high-resolution) timers, -all clock-event sources, and their parameters in a human-readable form. -.TP -.IR /proc/timer_stats " (from Linux 2.6.21 until Linux 4.10)" -.\" commit 82f67cd9fca8c8762c15ba7ed0d5747588c1e221 -.\" Date: Fri Feb 16 01:28:13 2007 -0800 -.\" Text largely derived from Documentation/timers/timer_stats.txt -.\" removed in commit dfb4357da6ddbdf57d583ba64361c9d792b0e0b1 -.\" Date: Wed Feb 8 11:26:59 2017 -0800 -This is a debugging facility to make timer (ab)use in a Linux -system visible to kernel and user-space developers. -It can be used by kernel and user-space developers to verify that -their code does not make undue use of timers. -The goal is to avoid unnecessary wakeups, -thereby optimizing power consumption. -.IP -If enabled in the kernel -.RB ( CONFIG_TIMER_STATS ), -but not used, -it has almost zero run-time overhead and a relatively small -data-structure overhead. -Even if collection is enabled at run time, overhead is low: -all the locking is per-CPU and lookup is hashed. -.IP -The -.I /proc/timer_stats -file is used both to control sampling facility and to read out the -sampled information. -.IP -The -.I timer_stats -functionality is inactive on bootup. -A sampling period can be started using the following command: -.IP -.in +4n -.EX -# echo 1 > /proc/timer_stats -.EE -.in -.IP -The following command stops a sampling period: -.IP -.in +4n -.EX -# echo 0 > /proc/timer_stats -.EE -.in -.IP -The statistics can be retrieved by: -.IP -.in +4n -.EX -$ cat /proc/timer_stats -.EE -.in -.IP -While sampling is enabled, each readout from -.I /proc/timer_stats -will see -newly updated statistics. -Once sampling is disabled, the sampled information -is kept until a new sample period is started. -This allows multiple readouts. -.IP -Sample output from -.IR /proc/timer_stats : -.IP -.in +4n -.EX -.RB $ " cat /proc/timer_stats" -Timer Stats Version: v0.3 -Sample period: 1.764 s -Collection: active - 255, 0 swapper/3 hrtimer_start_range_ns (tick_sched_timer) - 71, 0 swapper/1 hrtimer_start_range_ns (tick_sched_timer) - 58, 0 swapper/0 hrtimer_start_range_ns (tick_sched_timer) - 4, 1694 gnome\-shell mod_delayed_work_on (delayed_work_timer_fn) - 17, 7 rcu_sched rcu_gp_kthread (process_timeout) -\&... - 1, 4911 kworker/u16:0 mod_delayed_work_on (delayed_work_timer_fn) - 1D, 2522 kworker/0:0 queue_delayed_work_on (delayed_work_timer_fn) -1029 total events, 583.333 events/sec -.EE -.in -.IP -The output columns are: -.RS -.IP [1] 5 -a count of the number of events, -optionally (since Linux 2.6.23) followed by the letter \[aq]D\[aq] -.\" commit c5c061b8f9726bc2c25e19dec227933a13d1e6b7 deferrable timers -if this is a deferrable timer; -.IP [2] -the PID of the process that initialized the timer; -.IP [3] -the name of the process that initialized the timer; -.IP [4] -the function where the timer was initialized; and -(in parentheses) -the callback function that is associated with the timer. -.RE -.IP -During the Linux 4.11 development cycle, -this file was removed because of security concerns, -as it exposes information across namespaces. -Furthermore, it is possible to obtain -the same information via in-kernel tracing facilities such as ftrace. -.TP -.I /proc/tty -Subdirectory containing the pseudo-files and subdirectories for -tty drivers and line disciplines. -.TP -.I /proc/uptime -This file contains two numbers (values in seconds): the uptime of the -system (including time spent in suspend) and the amount of time spent -in the idle process. -.TP -.I /proc/version -This string identifies the kernel version that is currently running. -It includes the contents of -.IR /proc/sys/kernel/ostype , -.IR /proc/sys/kernel/osrelease , -and -.IR /proc/sys/kernel/version . -For example: -.IP -.in +4n -.EX -Linux version 1.0.9 (quinlan@phaze) #1 Sat May 14 01:51:54 EDT 1994 -.EE -.in .\" FIXME 2.6.13 seems to have /proc/vmcore implemented; document this .\" See Documentation/kdump/kdump.txt .\" commit 666bfddbe8b8fd4fd44617d6c55193d5ac7edb29 .\" Needs CONFIG_VMCORE .\" -.TP -.IR /proc/vmstat " (since Linux 2.6.0)" -This file displays various virtual memory statistics. -Each line of this file contains a single name-value pair, -delimited by white space. -Some lines are present only if the kernel was configured with -suitable options. -(In some cases, the options required for particular files have changed -across kernel versions, so they are not listed here. -Details can be found by consulting the kernel source code.) -The following fields may be present: -.\" FIXME We need explanations for each of the following fields... -.RS -.TP -.IR nr_free_pages " (since Linux 2.6.31)" -.\" commit d23ad42324cc4378132e51f2fc5c9ba6cbe75182 -.TP -.IR nr_alloc_batch " (since Linux 3.12)" -.\" commit 81c0a2bb515fd4daae8cab64352877480792b515 -.TP -.IR nr_inactive_anon " (since Linux 2.6.28)" -.\" commit 4f98a2fee8acdb4ac84545df98cccecfd130f8db -.TP -.IR nr_active_anon " (since Linux 2.6.28)" -.\" commit 4f98a2fee8acdb4ac84545df98cccecfd130f8db -.TP -.IR nr_inactive_file " (since Linux 2.6.28)" -.\" commit 4f98a2fee8acdb4ac84545df98cccecfd130f8db -.TP -.IR nr_active_file " (since Linux 2.6.28)" -.\" commit 4f98a2fee8acdb4ac84545df98cccecfd130f8db -.TP -.IR nr_unevictable " (since Linux 2.6.28)" -.\" commit 7b854121eb3e5ba0241882ff939e2c485228c9c5 -.TP -.IR nr_mlock " (since Linux 2.6.28)" -.\" commit 5344b7e648980cc2ca613ec03a56a8222ff48820 -.TP -.IR nr_anon_pages " (since Linux 2.6.18)" -.\" commit f3dbd34460ff54962d3e3244b6bcb7f5295356e6 -.TP -.IR nr_mapped " (since Linux 2.6.0)" -.TP -.IR nr_file_pages " (since Linux 2.6.18)" -.\" commit 347ce434d57da80fd5809c0c836f206a50999c26 -.TP -.IR nr_dirty " (since Linux 2.6.0)" -.TP -.IR nr_writeback " (since Linux 2.6.0)" -.TP -.IR nr_slab_reclaimable " (since Linux 2.6.19)" -.\" commit 972d1a7b140569084439a81265a0f15b74e924e0 -.\" Linux 2.6.0 had nr_slab -.TP -.IR nr_slab_unreclaimable " (since Linux 2.6.19)" -.\" commit 972d1a7b140569084439a81265a0f15b74e924e0 -.TP -.IR nr_page_table_pages " (since Linux 2.6.0)" -.TP -.IR nr_kernel_stack " (since Linux 2.6.32)" -.\" commit c6a7f5728a1db45d30df55a01adc130b4ab0327c -Amount of memory allocated to kernel stacks. -.TP -.IR nr_unstable " (since Linux 2.6.0)" -.TP -.IR nr_bounce " (since Linux 2.6.12)" -.\" commit edfbe2b0038723e5699ab22695ccd62b5542a5c1 -.TP -.IR nr_vmscan_write " (since Linux 2.6.19)" -.\" commit e129b5c23c2b471d47f1c5d2b8b193fc2034af43 -.TP -.IR nr_vmscan_immediate_reclaim " (since Linux 3.2)" -.\" commit 49ea7eb65e7c5060807fb9312b1ad4c3eab82e2c -.TP -.IR nr_writeback_temp " (since Linux 2.6.26)" -.\" commit fc3ba692a4d19019387c5acaea63131f9eab05dd -.TP -.IR nr_isolated_anon " (since Linux 2.6.32)" -.\" commit a731286de62294b63d8ceb3c5914ac52cc17e690 -.TP -.IR nr_isolated_file " (since Linux 2.6.32)" -.\" commit a731286de62294b63d8ceb3c5914ac52cc17e690 -.TP -.IR nr_shmem " (since Linux 2.6.32)" -.\" commit 4b02108ac1b3354a22b0d83c684797692efdc395 -Pages used by shmem and -.BR tmpfs (5). -.TP -.IR nr_dirtied " (since Linux 2.6.37)" -.\" commit ea941f0e2a8c02ae876cd73deb4e1557248f258c -.TP -.IR nr_written " (since Linux 2.6.37)" -.\" commit ea941f0e2a8c02ae876cd73deb4e1557248f258c -.TP -.IR nr_pages_scanned " (since Linux 3.17)" -.\" commit 0d5d823ab4e608ec7b52ac4410de4cb74bbe0edd -.TP -.IR numa_hit " (since Linux 2.6.18)" -.\" commit ca889e6c45e0b112cb2ca9d35afc66297519b5d5 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_NUMA . -.TP -.IR numa_miss " (since Linux 2.6.18)" -.\" commit ca889e6c45e0b112cb2ca9d35afc66297519b5d5 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_NUMA . -.TP -.IR numa_foreign " (since Linux 2.6.18)" -.\" commit ca889e6c45e0b112cb2ca9d35afc66297519b5d5 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_NUMA . -.TP -.IR numa_interleave " (since Linux 2.6.18)" -.\" commit ca889e6c45e0b112cb2ca9d35afc66297519b5d5 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_NUMA . -.TP -.IR numa_local " (since Linux 2.6.18)" -.\" commit ca889e6c45e0b112cb2ca9d35afc66297519b5d5 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_NUMA . -.TP -.IR numa_other " (since Linux 2.6.18)" -.\" commit ca889e6c45e0b112cb2ca9d35afc66297519b5d5 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_NUMA . -.TP -.IR workingset_refault " (since Linux 3.15)" -.\" commit a528910e12ec7ee203095eb1711468a66b9b60b0 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR workingset_activate " (since Linux 3.15)" -.\" commit a528910e12ec7ee203095eb1711468a66b9b60b0 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR workingset_nodereclaim " (since Linux 3.15)" -.\" commit 449dd6984d0e47643c04c807f609dd56d48d5bcc -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR nr_anon_transparent_hugepages " (since Linux 2.6.38)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR nr_free_cma " (since Linux 3.7)" -.\" commit d1ce749a0db12202b711d1aba1d29e823034648d -Number of free CMA (Contiguous Memory Allocator) pages. -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR nr_dirty_threshold " (since Linux 2.6.37)" -.\" commit 79da826aee6a10902ef411bc65864bd02102fa83 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR nr_dirty_background_threshold " (since Linux 2.6.37)" -.\" commit 79da826aee6a10902ef411bc65864bd02102fa83 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgpgin " (since Linux 2.6.0)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgpgout " (since Linux 2.6.0)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pswpin " (since Linux 2.6.0)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pswpout " (since Linux 2.6.0)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgalloc_dma " (since Linux 2.6.5)" -.\" Linux 2.6.0 had pgalloc -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgalloc_dma32 " (since Linux 2.6.16)" -.\" commit 9328b8faae922e52073785ed6c1eaa8565648a0e -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgalloc_normal " (since Linux 2.6.5)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgalloc_high " (since Linux 2.6.5)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_HIGHMEM . -.TP -.IR pgalloc_movable " (since Linux 2.6.23)" -.\" commit 2a1e274acf0b1c192face19a4be7c12d4503eaaf -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgfree " (since Linux 2.6.0)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgactivate " (since Linux 2.6.0)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgdeactivate " (since Linux 2.6.0)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgfault " (since Linux 2.6.0)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgmajfault " (since Linux 2.6.0)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgrefill_dma " (since Linux 2.6.5)" -.\" Linux 2.6.0 had pgrefill -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgrefill_dma32 " (since Linux 2.6.16)" -.\" commit 9328b8faae922e52073785ed6c1eaa8565648a0e -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgrefill_normal " (since Linux 2.6.5)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgrefill_high " (since Linux 2.6.5)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_HIGHMEM . -.TP -.IR pgrefill_movable " (since Linux 2.6.23)" -.\" commit 2a1e274acf0b1c192face19a4be7c12d4503eaaf -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.\" Formerly there were -.\" pgsteal_high -.\" pgsteal_normal -.\" pgsteal_dma32 -.\" pgsteal_dma -.\" These were split out into pgsteal_kswapd* and pgsteal_direct* -.\" in commit 904249aa68010c8e223263c922fcbb840a3f42e4 -.TP -.IR pgsteal_kswapd_dma " (since Linux 3.4)" -.\" commit 904249aa68010c8e223263c922fcbb840a3f42e4 -.\" Linux 2.6.0 had pgsteal -.\" Present only if the kernel was configured with -.\" .\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgsteal_kswapd_dma32 " (since Linux 3.4)" -.\" commit 904249aa68010c8e223263c922fcbb840a3f42e4 -.\" commit 9328b8faae922e52073785ed6c1eaa8565648a0e -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgsteal_kswapd_normal " (since Linux 3.4)" -.\" commit 904249aa68010c8e223263c922fcbb840a3f42e4 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgsteal_kswapd_high " (since Linux 3.4)" -.\" commit 904249aa68010c8e223263c922fcbb840a3f42e4 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_HIGHMEM . -.TP -.IR pgsteal_kswapd_movable " (since Linux 3.4)" -.\" commit 904249aa68010c8e223263c922fcbb840a3f42e4 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.I pgsteal_direct_dma -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgsteal_direct_dma32 " (since Linux 3.4)" -.\" commit 904249aa68010c8e223263c922fcbb840a3f42e4 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgsteal_direct_normal " (since Linux 3.4)" -.\" commit 904249aa68010c8e223263c922fcbb840a3f42e4 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgsteal_direct_high " (since Linux 3.4)" -.\" commit 904249aa68010c8e223263c922fcbb840a3f42e4 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_HIGHMEM . -.TP -.IR pgsteal_direct_movable " (since Linux 2.6.23)" -.\" commit 2a1e274acf0b1c192face19a4be7c12d4503eaaf -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.I pgscan_kswapd_dma -.\" Linux 2.6.0 had pgscan -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgscan_kswapd_dma32 " (since Linux 2.6.16)" -.\" commit 9328b8faae922e52073785ed6c1eaa8565648a0e -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgscan_kswapd_normal " (since Linux 2.6.5)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.I pgscan_kswapd_high -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_HIGHMEM . -.TP -.IR pgscan_kswapd_movable " (since Linux 2.6.23)" -.\" commit 2a1e274acf0b1c192face19a4be7c12d4503eaaf -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.I pgscan_direct_dma -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgscan_direct_dma32 " (since Linux 2.6.16)" -.\" commit 9328b8faae922e52073785ed6c1eaa8565648a0e -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.I pgscan_direct_normal -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.I pgscan_direct_high -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_HIGHMEM . -.TP -.IR pgscan_direct_movable " (since Linux 2.6.23)" -.\" commit 2a1e274acf0b1c192face19a4be7c12d4503eaaf -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgscan_direct_throttle " (since Linux 3.6)" -.\" commit 68243e76ee343d63c6cf76978588a885951e2818 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR zone_reclaim_failed " (since linux 2.6.31)" -.\" commit 24cf72518c79cdcda486ed26074ff8151291cf65 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_NUMA . -.TP -.IR pginodesteal " (since linux 2.6.0)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR slabs_scanned " (since linux 2.6.5)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR kswapd_inodesteal " (since linux 2.6.0)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR kswapd_low_wmark_hit_quickly " (since Linux 2.6.33)" -.\" commit bb3ab596832b920c703d1aea1ce76d69c0f71fb7 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR kswapd_high_wmark_hit_quickly " (since Linux 2.6.33)" -.\" commit bb3ab596832b920c703d1aea1ce76d69c0f71fb7 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pageoutrun " (since Linux 2.6.0)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR allocstall " (since Linux 2.6.0)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR pgrotated " (since Linux 2.6.0)" -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR drop_pagecache " (since Linux 3.15)" -.\" commit 5509a5d27b971a90b940e148ca9ca53312e4fa7a -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR drop_slab " (since Linux 3.15)" -.\" commit 5509a5d27b971a90b940e148ca9ca53312e4fa7a -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR numa_pte_updates " (since Linux 3.8)" -.\" commit 03c5a6e16322c997bf8f264851bfa3f532ad515f -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_NUMA_BALANCING . -.TP -.IR numa_huge_pte_updates " (since Linux 3.13)" -.\" commit 72403b4a0fbdf433c1fe0127e49864658f6f6468 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_NUMA_BALANCING . -.TP -.IR numa_hint_faults " (since Linux 3.8)" -.\" commit 03c5a6e16322c997bf8f264851bfa3f532ad515f -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_NUMA_BALANCING . -.TP -.IR numa_hint_faults_local " (since Linux 3.8)" -.\" commit 03c5a6e16322c997bf8f264851bfa3f532ad515f -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_NUMA_BALANCING . -.TP -.IR numa_pages_migrated " (since Linux 3.8)" -.\" commit 03c5a6e16322c997bf8f264851bfa3f532ad515f -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_NUMA_BALANCING -.\" and -.\" .BR CONFIG_NUMA_BALANCING . -.TP -.IR pgmigrate_success " (since Linux 3.8)" -.\" commit 5647bc293ab15f66a7b1cda850c5e9d162a6c7c2 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_MIGRATION . -.TP -.IR pgmigrate_fail " (since Linux 3.8)" -.\" commit 5647bc293ab15f66a7b1cda850c5e9d162a6c7c2 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_MIGRATION . -.TP -.IR compact_migrate_scanned " (since Linux 3.8)" -.\" commit 397487db696cae0b026a474a5cd66f4e372995e6 -.\" Linux 3.8 dropped compact_blocks_moved, compact_pages_moved, and -.\" compact_pagemigrate_failed -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_COMPACTION . -.TP -.IR compact_free_scanned " (since Linux 3.8)" -.\" commit 397487db696cae0b026a474a5cd66f4e372995e6 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_COMPACTION . -.TP -.IR compact_isolated " (since Linux 3.8)" -.\" commit 397487db696cae0b026a474a5cd66f4e372995e6 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_COMPACTION . -.TP -.IR compact_stall " (since Linux 2.6.35)" -.\" commit 56de7263fcf3eb10c8dcdf8d59a9cec831795f3f -See the kernel source file -.IR Documentation/admin\-guide/mm/transhuge.rst . -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_COMPACTION . -.TP -.IR compact_fail " (since Linux 2.6.35)" -.\" commit 56de7263fcf3eb10c8dcdf8d59a9cec831795f3f -See the kernel source file -.IR Documentation/admin\-guide/mm/transhuge.rst . -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_COMPACTION . -.TP -.IR compact_success " (since Linux 2.6.35)" -.\" commit 56de7263fcf3eb10c8dcdf8d59a9cec831795f3f -See the kernel source file -.IR Documentation/admin\-guide/mm/transhuge.rst . -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_COMPACTION . -.TP -.IR htlb_buddy_alloc_success " (since Linux 2.6.26)" -.\" commit 3b1163006332302117b1b2acf226d4014ff46525 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_HUGETLB_PAGE . -.TP -.IR htlb_buddy_alloc_fail " (since Linux 2.6.26)" -.\" commit 3b1163006332302117b1b2acf226d4014ff46525 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_HUGETLB_PAGE . -.TP -.IR unevictable_pgs_culled " (since Linux 2.6.28)" -.\" commit bbfd28eee9fbd73e780b19beb3dc562befbb94fa -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR unevictable_pgs_scanned " (since Linux 2.6.28)" -.\" commit bbfd28eee9fbd73e780b19beb3dc562befbb94fa -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR unevictable_pgs_rescued " (since Linux 2.6.28)" -.\" commit bbfd28eee9fbd73e780b19beb3dc562befbb94fa -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR unevictable_pgs_mlocked " (since Linux 2.6.28)" -.\" commit 5344b7e648980cc2ca613ec03a56a8222ff48820 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR unevictable_pgs_munlocked " (since Linux 2.6.28)" -.\" commit 5344b7e648980cc2ca613ec03a56a8222ff48820 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR unevictable_pgs_cleared " (since Linux 2.6.28)" -.\" commit 5344b7e648980cc2ca613ec03a56a8222ff48820 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.TP -.IR unevictable_pgs_stranded " (since Linux 2.6.28)" -.\" commit 5344b7e648980cc2ca613ec03a56a8222ff48820 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS . -.\" Linux 3.7 removed unevictable_pgs_mlockfreed -.TP -.IR thp_fault_alloc " (since Linux 2.6.39)" -.\" commit 81ab4201fb7d91d6b0cd9ad5b4b16776e4bed145 -See the kernel source file -.IR Documentation/admin\-guide/mm/transhuge.rst . -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_TRANSPARENT_HUGEPAGE . -.TP -.IR thp_fault_fallback " (since Linux 2.6.39)" -.\" commit 81ab4201fb7d91d6b0cd9ad5b4b16776e4bed145 -See the kernel source file -.IR Documentation/admin\-guide/mm/transhuge.rst . -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_TRANSPARENT_HUGEPAGE . -.TP -.IR thp_collapse_alloc " (since Linux 2.6.39)" -.\" commit 81ab4201fb7d91d6b0cd9ad5b4b16776e4bed145 -See the kernel source file -.IR Documentation/admin\-guide/mm/transhuge.rst . -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_TRANSPARENT_HUGEPAGE . -.TP -.IR thp_collapse_alloc_failed " (since Linux 2.6.39)" -.\" commit 81ab4201fb7d91d6b0cd9ad5b4b16776e4bed145 -See the kernel source file -.IR Documentation/admin\-guide/mm/transhuge.rst . -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_TRANSPARENT_HUGEPAGE . -.TP -.IR thp_split " (since Linux 2.6.39)" -.\" commit 81ab4201fb7d91d6b0cd9ad5b4b16776e4bed145 -See the kernel source file -.IR Documentation/admin\-guide/mm/transhuge.rst . -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_TRANSPARENT_HUGEPAGE . -.TP -.IR thp_zero_page_alloc " (since Linux 3.8)" -.\" commit d8a8e1f0da3d29d7268b3300c96a059d63901b76 -See the kernel source file -.IR Documentation/admin\-guide/mm/transhuge.rst . -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_TRANSPARENT_HUGEPAGE . -.TP -.IR thp_zero_page_alloc_failed " (since Linux 3.8)" -.\" commit d8a8e1f0da3d29d7268b3300c96a059d63901b76 -See the kernel source file -.IR Documentation/admin\-guide/mm/transhuge.rst . -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_TRANSPARENT_HUGEPAGE . -.TP -.IR balloon_inflate " (since Linux 3.18)" -.\" commit 09316c09dde33aae14f34489d9e3d243ec0d5938 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_MEMORY_BALLOON . -.TP -.IR balloon_deflate " (since Linux 3.18)" -.\" commit 09316c09dde33aae14f34489d9e3d243ec0d5938 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS -.\" and -.\" .BR CONFIG_MEMORY_BALLOON . -.TP -.IR balloon_migrate " (since Linux 3.18)" -.\" commit 09316c09dde33aae14f34489d9e3d243ec0d5938 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_VM_EVENT_COUNTERS , -.\" .BR CONFIG_MEMORY_BALLOON , -.\" and -.\" .BR CONFIG_BALLOON_COMPACTION . -.TP -.IR nr_tlb_remote_flush " (since Linux 3.12)" -.\" commit 9824cf9753ecbe8f5b47aa9b2f218207defea211 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_DEBUG_TLBFLUSH -.\" and -.\" .BR CONFIG_SMP . -.TP -.IR nr_tlb_remote_flush_received " (since Linux 3.12)" -.\" commit 9824cf9753ecbe8f5b47aa9b2f218207defea211 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_DEBUG_TLBFLUSH -.\" and -.\" .BR CONFIG_SMP . -.TP -.IR nr_tlb_local_flush_all " (since Linux 3.12)" -.\" commit 9824cf9753ecbe8f5b47aa9b2f218207defea211 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_DEBUG_TLBFLUSH . -.TP -.IR nr_tlb_local_flush_one " (since Linux 3.12)" -.\" commit 9824cf9753ecbe8f5b47aa9b2f218207defea211 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_DEBUG_TLBFLUSH . -.TP -.IR vmacache_find_calls " (since Linux 3.16)" -.\" commit 4f115147ff802267d0aa41e361c5aa5bd933d896 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_DEBUG_VM_VMACACHE . -.TP -.IR vmacache_find_hits " (since Linux 3.16)" -.\" commit 4f115147ff802267d0aa41e361c5aa5bd933d896 -.\" Present only if the kernel was configured with -.\" .BR CONFIG_DEBUG_VM_VMACACHE . -.TP -.IR vmacache_full_flushes " (since Linux 3.19)" -.\" commit f5f302e21257ebb0c074bbafc37606c26d28cc3d -.\" Present only if the kernel was configured with -.\" .BR CONFIG_DEBUG_VM_VMACACHE . -.RE -.TP -.IR /proc/zoneinfo " (since Linux 2.6.13)" -This file displays information about memory zones. -This is useful for analyzing virtual memory behavior. -.\" FIXME more should be said about /proc/zoneinfo .SH NOTES Many files contain strings (e.g., the environment and command line) that are in the internal format, with subfields terminated by null bytes (\[aq]\e0\[aq]). When inspecting such files, you may find that the results are more readable if you use a command of the following form to display them: -.PP +.P .in +4n .EX .RB "$" " cat \fIfile\fP | tr \[aq]\e000\[aq] \[aq]\en\[aq]" .EE .in -.PP -This manual page is incomplete, possibly inaccurate, and is the kind -of thing that needs to be updated very often. .\" .SH ACKNOWLEDGEMENTS .\" The material on /proc/sys/fs and /proc/sys/kernel is closely based on .\" kernel source documentation files written by Rik van Riel. @@ -6955,7 +249,7 @@ of thing that needs to be updated very often. .BR procinfo (8), .BR route (8), .BR sysctl (8) -.PP +.P The Linux kernel source files: .IR Documentation/filesystems/proc.rst , .IR Documentation/admin\-guide/sysctl/fs.rst , |