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PROC(5)			   Linux Programmer's Manual		       PROC(5)

NAME
       proc - process information pseudo-filesystem

DESCRIPTION
       The  proc filesystem is a pseudo-filesystem which provides an interface
       to kernel data structures.  It is commonly mounted at /proc.   Most  of
       it is read-only,	but some files allow kernel variables to be changed.

       The  following  list  describes many of the files and directories under
       the /proc hierarchy.

       /proc/[pid]
	      There is a numerical subdirectory	for each running process;  the
	      subdirectory is named by the process ID.	Each such subdirectory
	      contains the following pseudo-files and directories.

       /proc/[pid]/auxv	(since 2.6.0-test7)
	      This contains the	contents of the	 ELF  interpreter  information
	      passed  to the process at	exec time.  The	format is one unsigned
	      long ID plus one unsigned	long value for each entry.   The  last
	      entry contains two zeros.	 See also getauxval(3).

       /proc/[pid]/cgroup (since Linux 2.6.24)
	      This file	describes control groups to which the process/task be-
	      longs.  For each cgroup hierarchy	there is one entry  containing
	      colon-separated fields of	the form:

		  5:cpuacct,cpu,cpuset:/daemons

	      The colon-separated fields are, from left	to right:

		  1. hierarchy ID number

		  2. set of subsystems bound to	the hierarchy

		  3. control  group  in	the hierarchy to which the process be-
		     longs

	      This file	is present only	if the CONFIG_CGROUPS kernel  configu-
	      ration option is enabled.

       /proc/[pid]/clear_refs (since Linux 2.6.22)

	      This  is	a  write-only  file,  writable	only  by  owner	of the
	      process.

	      The following values may be written to the file:

	      1	(since Linux 2.6.22)
		     Reset the PG_Referenced and ACCESSED/YOUNG	bits  for  all
		     the  pages	 associated  with the process.	(Before	kernel
		     2.6.32, writing any nonzero value to this file  had  this
		     effect.)

	      2	(since Linux 2.6.32)
		     Reset  the	 PG_Referenced and ACCESSED/YOUNG bits for all
		     anonymous pages associated	with the process.

	      3	(since Linux 2.6.32)
		     Reset the PG_Referenced and ACCESSED/YOUNG	bits  for  all
		     file-mapped pages associated with the process.

	      Clearing	the  PG_Referenced  and	ACCESSED/YOUNG bits provides a
	      method to	measure	approximately how much memory a	process	is us-
	      ing.   One  first	inspects the values in the "Referenced"	fields
	      for the VMAs shown in /proc/[pid]/smaps to get an	 idea  of  the
	      memory  footprint	of the process.	 One then clears the PG_Refer-
	      enced and	ACCESSED/YOUNG bits and, after some measured time  in-
	      terval,  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.

	      A	further	value can be written to	affect a different bit:

	      4	(since Linux 3.11)
		     Clear  the	 soft-dirty  bit  for all the pages associated
		     with the process.	This  is  used	(in  conjunction  with
		     /proc/[pid]/pagemap) by the check-point restore system to
		     discover which pages of a process have been dirtied since
		     the file /proc/[pid]/clear_refs was written to.

	      Writing  any  value  to  /proc/[pid]/clear_refs other than those
	      listed above has no effect.

	      The /proc/[pid]/clear_refs file is  present  only	 if  the  CON-
	      FIG_PROC_PAGE_MONITOR kernel configuration option	is enabled.

       /proc/[pid]/cmdline
	      This  read-only  file  holds  the	 complete command line for the
	      process, unless the process is a zombie.	In  the	 latter	 case,
	      there is nothing in this file: that is, a	read on	this file will
	      return 0 characters.  The	command-line arguments appear in  this
	      file  as a set of	strings	separated by null bytes	('\0'),	with a
	      further null byte	after the last string.

       /proc/[pid]/comm	(since Linux 2.6.33)
	      This file	exposes	the process's comm value--that is, the command
	      name associated with the process.	 Different threads in the same
	      process  may  have  different  comm   values,   accessible   via
	      /proc/[pid]/task/[tid]/comm.   A	thread	may  modify  its  comm
	      value, or	that of	any of other thread in the same	 thread	 group
	      (see  the	discussion of CLONE_THREAD in clone(2)), by writing to
	      the  file	 /proc/self/task/[tid]/comm.   Strings	 longer	  than
	      TASK_COMM_LEN (16) characters are	silently truncated.

	      This  file  provides  a superset of the prctl(2) PR_SET_NAME and
	      PR_GET_NAME operations, and is employed by pthread_setname_np(3)
	      when used	to rename threads other	than the caller.

       /proc/[pid]/coredump_filter (since Linux	2.6.23)
	      See core(5).

       /proc/[pid]/cpuset (since Linux 2.6.12)
	      See cpuset(7).

       /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:

		  $ cd /proc/20/cwd; /bin/pwd

	      Note  that  the pwd command is often a shell built-in, and might
	      not work properly.  In bash(1), you may use pwd -P.

	      In a multithreaded process, the contents of this	symbolic  link
	      are  not	available  if  the  main thread	has already terminated
	      (typically by calling pthread_exit(3)).

       /proc/[pid]/environ
	      This file	contains the environment for the process.  The entries
	      are separated by null bytes ('\0'), and there may	be a null byte
	      at the end.  Thus, to print out the environment  of  process  1,
	      you would	do:

		  $ strings /proc/1/environ

       /proc/[pid]/exe
	      Under Linux 2.2 and later, this file is a	symbolic link contain-
	      ing 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 /proc/[pid]/exe  to  run
	      another  copy  of	the same executable as is being	run by process
	      [pid].  In a multithreaded process, the contents	of  this  sym-
	      bolic link are not available if the main thread has already ter-
	      minated (typically by calling pthread_exit(3)).

	      Under Linux 2.0 and earlier, /proc/[pid]/exe is a	pointer	to the
	      binary  which  was  executed, and	appears	as a symbolic link.  A
	      readlink(2) call on this file under Linux	2.0 returns  a	string
	      in the format:

		  [device]:inode

	      For  example, [0301]:1502	would be inode 1502 on device major 03
	      (IDE, MFM, etc. drives) minor 01 (first partition	on  the	 first
	      drive).

	      find(1) with the -inum option can	be used	to locate the file.

       /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.

	      For file descriptors for pipes and sockets, the entries will  be
	      symbolic links whose content is the file type with the inode.  A
	      readlink(2) call on this file returns a string in	the format:

		  type:[inode]

	      For example, socket:[2248868] will be a socket and its inode  is
	      2248868.	 For  sockets, that inode can be used to find more in-
	      formation	in one of the files under /proc/net/.

	      For file descriptors that	have  no  corresponding	 inode	(e.g.,
	      file  descriptors	 produced by epoll_create(2), eventfd(2), ino-
	      tify_init(2), signalfd(2), and timerfd(2)), the entry will be  a
	      symbolic link with contents of the form

		  anon_inode:<file-type>

	      In some cases, the file-type is surrounded by square brackets.

	      For  example, an epoll file descriptor will have a symbolic link
	      whose content is the string anon_inode:[eventpoll].

	      In a multithreaded process, the contents of this	directory  are
	      not  available  if the main thread has already terminated	(typi-
	      cally by calling pthread_exit(3)).

	      Programs that will take a	filename as a  command-line  argument,
	      but  will	 not  take input from standard input if	no argument is
	      supplied,	or that	write to a file	named as a command-line	 argu-
	      ment,  but  will	not send their output to standard output if no
	      argument is supplied, can	nevertheless be	made to	 use  standard
	      input or standard	out using /proc/[pid]/fd.  For example,	assum-
	      ing that -i is the flag designating an input file	and -o is  the
	      flag designating an output file:

		  $ foobar -i /proc/self/fd/0 -o /proc/self/fd/1 ...

	      and you have a working filter.

	      /proc/self/fd/N  is  approximately the same as /dev/fd/N in some
	      UNIX and UNIX-like systems.  Most	Linux MAKEDEV scripts symboli-
	      cally link /dev/fd to /proc/self/fd, in fact.

	      Most systems provide symbolic links /dev/stdin, /dev/stdout, and
	      /dev/stderr, which respectively link to the files	0, 1, and 2 in
	      /proc/self/fd.   Thus the	example	command	above could be written
	      as:

		  $ foobar -i /dev/stdin -o /dev/stdout	...

       /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 con-
	      tents of each file can be	read to	obtain information  about  the
	      corresponding file descriptor, for example:

		  $ cat	/proc/12015/fdinfo/4
		  pos:	  1000
		  flags:  01002002

	      The  pos field is	a decimal number showing the current file off-
	      set.  The	flags field is an octal	number that displays the  file
	      access mode and file status flags	(see open(2)).

	      The  files  in  this directory are readable only by the owner of
	      the process.

       /proc/[pid]/io (since kernel 2.6.20)
	      This file	contains I/O statistics	for the	process, for example:

		  # cat	/proc/3828/io
		  rchar: 323934931
		  wchar: 323929600
		  syscr: 632687
		  syscw: 632675
		  read_bytes: 0
		  write_bytes: 323932160
		  cancelled_write_bytes: 0

	      The fields are as	follows:

	      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 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).

	      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 rchar.

	      syscr: read syscalls
		     Attempt  to count the number of read I/O operations--that
		     is, system	calls such as read(2) and pread(2).

	      syscw: write syscalls
		     Attempt to	count the number of write I/O operations--that
		     is, system	calls such as write(2) and pwrite(2).

	      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.

	      write_bytes: bytes written
		     Attempt  to  count	the number of bytes which this process
		     caused to be sent to the storage layer.

	      cancelled_write_bytes:
		     The big inaccuracy	here is	truncate.  If a	process	writes
		     1MB  to a file and	then deletes the file, it will in fact
		     perform no	writeout.  But it will have been accounted  as
		     having  caused  1MB 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 write_bytes) will not be happening.

	      Note: In the current implementation, things are a	 bit  racy  on
	      32-bit  systems:	if  process A reads process B's	/proc/[pid]/io
	      while process B  is  updating  one  of  these  64-bit  counters,
	      process A	could see an intermediate result.

       /proc/[pid]/gid_map (since Linux	3.5)
	      See the description of /proc/[pid]/uid_map.

       /proc/[pid]/limits (since Linux 2.6.24)
	      This file	displays the soft limit, hard limit, and units of mea-
	      surement for each	of the process's resource  limits  (see	 getr-
	      limit(2)).   Up to and including Linux 2.6.35, this file is pro-
	      tected to	allow reading only by the real	UID  of	 the  process.
	      Since  Linux  2.6.36,  this file is readable by all users	on the
	      system.

       /proc/[pid]/map_files/ (since kernel 3.3)
	      This subdirectory	 contains  entries  corresponding  to  memory-
	      mapped  files (see 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:

		  $ ls -l /proc/self/map_files/
		  lr--------. 1	root root 64 Apr 16 21:31
			      3252e00000-3252e20000 -> /usr/lib64/ld-2.15.so
		  ...

	      Although	these entries are present for memory regions that were
	      mapped with the MAP_FILE flag, the way anonymous	shared	memory
	      (regions created with the	MAP_ANON | MAP_SHARED flags) is	imple-
	      mented in	Linux means that such regions also appear on this  di-
	      rectory.	 Here  is  an  example	where  the  target file	is the
	      deleted /dev/zero	one:

		  lrw-------. 1	root root 64 Apr 16 21:33
			      7fc075d2f000-7fc075e6f000	-> /dev/zero (deleted)

	      This directory appears  only  if	the  CONFIG_CHECKPOINT_RESTORE
	      kernel configuration option is enabled.

       /proc/[pid]/maps
	      A	 file containing the currently mapped memory regions and their
	      access permissions.  See mmap(2) for  some  further  information
	      about memory mappings.

	      The format of the	file is:

       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]

	      The  address  field is the address space in the process that the
	      mapping occupies.	 The perms field is a set of permissions:

		   r = read
		   w = write
		   x = execute
		   s = shared
		   p = private (copy on	write)

	      The offset field is the offset into the  file/whatever;  dev  is
	      the  device (major:minor); 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).

	      The  pathname field will usually be the file that	is backing the
	      mapping.	For ELF	files, you can easily coordinate with the off-
	      set  field  by  looking  at  the Offset field in the ELF program
	      headers (readelf -l).

	      There are	additional helpful pseudo-paths:

		   [stack]
			  The  initial	process's  (also  known	 as  the  main
			  thread's) stack.

		   [stack:_tid_] (since	Linux 3.4)
			  A  thread's  stack (where the	_tid_ is a thread ID).
			  It corresponds to the	/proc/[pid]/task/[tid]/	path.

		   [vdso] The virtual dynamically linked shared	object.

		   [heap] The process's	heap.

	      If the pathname field is blank, this is an anonymous mapping  as
	      obtained	via the	mmap(2)	function.  There is no easy way	to co-
	      ordinate this back to a process's	source,	short  of  running  it
	      through gdb(1), strace(1), or similar.

	      Under Linux 2.0, there is	no field giving	pathname.

       /proc/[pid]/mem
	      This  file can be	used to	access the pages of a process's	memory
	      through open(2), read(2),	and lseek(2).

       /proc/[pid]/mountinfo (since Linux 2.6.26)
	      This file	contains information about mount points.  It  contains
	      lines of the form:

	      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)

	      The  numbers  in parentheses are labels for the descriptions be-
	      low:

	      (1)  mount ID: unique identifier of the mount (may be reused af-
		   ter umount(2)).

	      (2)  parent  ID:	ID  of parent mount (or	of self	for the	top of
		   the mount tree).

	      (3)  major:minor:	value of st_dev	for files on  filesystem  (see
		   stat(2)).

	      (4)  root: root of the mount within the filesystem.

	      (5)  mount point:	mount point relative to	the process's root.

	      (6)  mount options: per-mount options.

	      (7)  optional   fields:	zero   or  more	 fields	 of  the  form
		   "tag[:value]".

	      (8)  separator: marks the	end of the optional fields.

	      (9)  filesystem type: name of filesystem in the form "type[.sub-
		   type]".

	      (10) mount source: filesystem-specific information or "none".

	      (11) super options: per-superblock options.

	      Parsers  should  ignore  all unrecognized	optional fields.  Cur-
	      rently the possible optional fields are:

		   shared:X	     mount is shared in	peer group X

		   master:X	     mount is slave to peer group X

		   propagate_from:X  mount is slave and	 receives  propagation
				     from peer group X (*)

		   unbindable	     mount is unbindable

	      (*)  X  is  the  closest dominant	peer group under the process's
	      root.  If	X is the immediate master of the mount,	or if there is
	      no  dominant peer	group under the	same root, then	only the "mas-
	      ter:X" field is present and not the "propagate_from:X" field.

	      For  more	 information  on  mount	 propagation  see:  Documenta-
	      tion/filesystems/sharedsubtree.txt  in  the  Linux kernel	source
	      tree.

       /proc/[pid]/mounts (since Linux 2.4.19)
	      This is a	list of	all the	filesystems currently mounted  in  the
	      process's	 mount	namespace.   The  format of this file is docu-
	      mented in	fstab(5).  Since kernel	version	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	 select(2)  to
	      mark   the   file	  descriptor  as  readable,  and  poll(2)  and
	      epoll_wait(2) mark the file as having an error  condition.   See
	      namespaces(7) for	more information.

       /proc/[pid]/mountstats (since Linux 2.6.17)
	      This  file exports information (statistics, configuration	infor-
	      mation) about the	mount points in	the process's mount namespace.
	      Lines in this file have the form:

	      device /dev/sda7 mounted on /home	with fstype ext3 [statistics]
	      (	      1	     )		  ( 2 )		    (3 ) (4)

	      The fields in each line are:

	      (1)  The	name  of the mounted device (or	"nodevice" if there is
		   no corresponding device).

	      (2)  The mount point within the filesystem tree.

	      (3)  The filesystem type.

	      (4)  Optional statistics and  configuration  information.	  Cur-
		   rently  (as	at  Linux 2.6.26), only	NFS filesystems	export
		   information via this	field.

	      This file	is readable only by the	owner of the process.

	      See namespaces(7)	for more information.

       /proc/[pid]/ns/ (since Linux 3.0)
	      This is a	subdirectory containing	one entry for  each  namespace
	      that  supports being manipulated by setns(2).  For more informa-
	      tion, see	namespaces(7).

       /proc/[pid]/numa_maps (since Linux 2.6.14)
	      See numa(7).

       /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	 oom_score value: valid	values are in the range	-16 to
	      +15, plus	the special value -17, which disables OOM-killing  al-
	      together for this	process.  A positive score increases the like-
	      lihood of	this process being killed by the OOM-killer;  a	 nega-
	      tive score decreases the likelihood.

	      The default value	for this file is 0; a new process inherits its
	      parent's	oom_adj	 setting.   A  process	must   be   privileged
	      (CAP_SYS_RESOURCE) to update this	file.

	      Since  Linux  2.6.36, use	of this	file is	deprecated in favor of
	      /proc/[pid]/oom_score_adj.

       /proc/[pid]/oom_score (since Linux 2.6.11)
	      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  de-
	      creases (-) for factors including:

	      *	whether	 the  process  creates a lot of	children using fork(2)
		(+);

	      *	whether	the process has	been running a long time, or has  used
		a lot of CPU time (-);

	      *	whether	the process has	a low nice value (i.e.,	> 0) (+);

	      *	whether	the process is privileged (-); and

	      *	whether	the process is making direct hardware access (-).

	      The  oom_score  also  reflects  the  adjustment specified	by the
	      oom_score_adj or oom_adj setting for the process.

       /proc/[pid]/oom_score_adj (since	Linux 2.6.36)
	      This file	can be used to adjust the badness  heuristic  used  to
	      select which process gets	killed in out-of-memory	conditions.

	      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.

	      There is an additional factor included  in  the  badness	score:
	      root processes are given 3% extra	memory over other tasks.

	      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
	      cpuset(7)).   If	it  is	due to a mempolicy's node(s) being ex-
	      hausted, 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 al-
	      lowed memory represents all allocatable resources.

	      The value	of 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.

	      Consequently, it is very simple for user	space  to  define  the
	      amount   of  memory  to  consider	 for  each  task.   Setting  a
	      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 al-
	      lowed memory from	being considered as scoring against the	task.

	      For    backward	 compatibility	  with	  previous    kernels,
	      /proc/[pid]/oom_adj can still be used to tune the	badness	score.
	      Its value	is scaled linearly with	oom_score_adj.

	      Writing to /proc/[pid]/oom_score_adj or /proc/[pid]/oom_adj will
	      change the other with its	scaled value.

       /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  fol-
	      lows:

		   63	  If set, the page is present in RAM.

		   62	  If set, the page is in swap space

		   61 (since Linux 3.5)
			  The page is a	file-mapped page or a shared anonymous
			  page.

		   60-56 (since	Linux 3.11)
			  Zero

		   55 (Since Linux 3.11)
			  PTE is soft-dirty (see the kernel source file	 Docu-
			  mentation/vm/soft-dirty.txt).

		   54-0	  If  the  page	is present in RAM (bit 63), then these
			  bits provide the page	frame  number,	which  can  be
			  used to index	/proc/kpageflags and /proc/kpagecount.
			  If the page is present in swap (bit 62),  then  bits
			  4-0  give  the  swap	type, and bits 54-5 encode the
			  swap offset.

	      Before Linux 3.11, bits 60-55 were used to encode	the base-2 log
	      of the page size.

	      To  employ /proc/[pid]/pagemap efficiently, use /proc/[pid]/maps
	      to determine which areas of memory are actually mapped and  seek
	      to skip over unmapped regions.

	      The  /proc/[pid]/pagemap	file  is  present  only	 if  the  CON-
	      FIG_PROC_PAGE_MONITOR kernel configuration option	is enabled.

       /proc/[pid]/personality (since Linux 2.6.28)
	      This read-only file exposes the process's	execution  domain,  as
	      set  by  personality(2).	 The value is displayed	in hexadecimal
	      notation.

       /proc/[pid]/root
	      UNIX and Linux support the idea of a  per-process	 root  of  the
	      filesystem,  set	by  the	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 exe, and fd/*.

	      In  a  multithreaded process, the	contents of this symbolic link
	      are not available	if the	main  thread  has  already  terminated
	      (typically by calling pthread_exit(3)).

       /proc/[pid]/smaps (since	Linux 2.6.14)
	      This  file  shows	 memory	 consumption for each of the process's
	      mappings.	 (The 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:

		  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
		  Swap:			 0 kB
		  KernelPageSize:	 4 kB
		  MMUPageSize:		 4 kB
		  Locked:		 0 kB

	      The first	of these lines shows the same information as  is  dis-
	      played for the mapping in	/proc/[pid]/maps.  The remaining lines
	      show the size of the mapping, the	amount of the mapping that  is
	      currently	 resident  in  RAM  ("Rss"), the process' 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.  "Anony-
	      mous" 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.

	      The "KernelPageSize" entry is the	page size used by  the	kernel
	      to back a	VMA.  This matches the size used by the	MMU in the ma-
	      jority of	cases.	However, one counter-example occurs  on	 PPC64
	      kernels whereby a	kernel using 64K as a base page	size may still
	      use 4K pages for the MMU on older	processors.   To  distinguish,
	      this  patch  reports  "MMUPageSize" as the page size used	by the
	      MMU.

	      The "Locked" indicates whether the mapping is locked  in	memory
	      or not.

	      "VmFlags"	 field represents the kernel flags associated with the
	      particular virtual memory	area in	 two  letter  encoded  manner.
	      The codes	are the	following:

		  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
		  nl  -	non-linear mapping
		  ar  -	architecture specific flag
		  dd  -	do not include area into core dump
		  sd  -	soft-dirty flag
		  mm  -	mixed map area
		  hg  -	huge page advise flag
		  nh  -	no-huge	page advise flag
		  mg  -	mergeable advise flag

	      The   /proc/[pid]/smaps	file  is  present  only	 if  the  CON-
	      FIG_PROC_PAGE_MONITOR kernel configuration option	is enabled.

       /proc/[pid]/stack (since	Linux 2.6.29)
	      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	 CONFIG_STACKTRACE  configuration  op-
	      tion.

       /proc/[pid]/stat
	      Status  information  about  the process.	This is	used by	ps(1).
	      It is defined in the kernel source file fs/proc/array.c.

	      The fields, in order, with their proper scanf(3)	format	speci-
	      fiers, are:

	      (1) pid  %d
			The process ID.

	      (2) comm	%s
			The  filename of the executable, in parentheses.  This
			is visible whether or not the  executable  is  swapped
			out.

	      (3) state	 %c
			One  of	 the  following	characters, indicating process
			state:

			R  Running

			S  Sleeping in an interruptible	wait

			D  Waiting in uninterruptible disk sleep

			Z  Zombie

			T  Stopped (on a  signal)  or  (before	Linux  2.6.33)
			   trace stopped

			t  Tracing stop	(Linux 2.6.33 onward)

			W  Paging (only	before Linux 2.6.0)

			X  Dead	(from Linux 2.6.0 onward)

			x  Dead	(Linux 2.6.33 to 3.13 only)

			K  Wakekill (Linux 2.6.33 to 3.13 only)

			W  Waking (Linux 2.6.33	to 3.13	only)

			P  Parked (Linux 3.9 to	3.13 only)

	      (4) ppid	%d
			The PID	of the parent of this process.

	      (5) pgrp	%d
			The process group ID of	the process.

	      (6) session  %d
			The session ID of the process.

	      (7) tty_nr  %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.)

	      (8) tpgid	 %d
			The ID of the foreground process group of the control-
			ling terminal of the process.

	      (9) flags	 %u
			The  kernel  flags word	of the process.	 For bit mean-
			ings, see the PF_* defines in the Linux	kernel	source
			file  include/linux/sched.h.   Details	depend	on the
			kernel version.

			The format for this field was %lu before Linux 2.6.

	      (1) minflt  %lu
			The number of minor faults the process has made	 which
			have not required loading a memory page	from disk.

	      (11) cminflt  %lu
			The  number of minor faults that the process's waited-
			for children have made.

	      (12) majflt  %lu
			The number of major faults the process has made	 which
			have required loading a	memory page from disk.

	      (13) cmajflt  %lu
			The  number of major faults that the process's waited-
			for children have made.

	      (14) utime  %lu
			Amount of time that this process has been scheduled in
			user   mode,   measured	 in  clock  ticks  (divide  by
			sysconf(_SC_CLK_TCK)).	 This  includes	 guest	 time,
			guest_time  (time spent	running	a virtual CPU, see be-
			low), so that applications that	are not	aware  of  the
			guest time field do not	lose that time from their cal-
			culations.

	      (15) stime  %lu
			Amount of time that this process has been scheduled in
			kernel	mode,  measured	 in  clock  ticks  (divide  by
			sysconf(_SC_CLK_TCK)).

	      (16) cutime  %ld
			Amount of time that this process's waited-for children
			have  been  scheduled  in user mode, measured in clock
			ticks (divide  by  sysconf(_SC_CLK_TCK)).   (See  also
			times(2).)   This  includes  guest  time,  cguest_time
			(time spent running a virtual CPU, see below).

	      (17) cstime  %ld
			Amount of time that this process's waited-for children
			have  been scheduled in	kernel mode, measured in clock
			ticks (divide by sysconf(_SC_CLK_TCK)).

	      (18) priority  %ld
			(Explanation for Linux 2.6) For	 processes  running  a
			real-time   scheduling	 policy	  (policy  below;  see
			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 (setpri-
			ority(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.

			Before Linux 2.6, this was a scaled value based	on the
			scheduler weighting given to this process.

	      (19) nice	 %ld
			The  nice  value  (see setpriority(2)),	a value	in the
			range 19 (low priority)	to -20 (high priority).

	      (20) num_threads	%ld
			Number of threads in this process (since  Linux	 2.6).
			Before kernel 2.6, this	field was hard coded to	0 as a
			placeholder for	an earlier removed field.

	      (21) itrealvalue	%ld
			The time in jiffies before the next SIGALRM is sent to
			the  process  due  to an interval timer.  Since	kernel
			2.6.17,	this field is no  longer  maintained,  and  is
			hard coded as 0.

	      (22) starttime  %llu
			The  time  the	process	started	after system boot.  In
			kernels	before Linux 2.6, this value was expressed  in
			jiffies.   Since  Linux	2.6, the value is expressed in
			clock ticks (divide by sysconf(_SC_CLK_TCK)).

			The format for this field was %lu before Linux 2.6.

	      (23) vsize  %lu
			Virtual	memory size in bytes.

	      (24) rss	%ld
			Resident Set Size: number of pages the process has  in
			real  memory.	This is	just the pages which count to-
			ward text, data, or stack space.  This	does  not  in-
			clude  pages  which have not been demand-loaded	in, or
			which are swapped out.

	      (25) rsslim  %lu
			Current	soft limit in bytes on the rss of the process;
			see the	description of RLIMIT_RSS in getrlimit(2).

	      (26) startcode  %lu
			The address above which	program	text can run.

	      (27) endcode  %lu
			The address below which	program	text can run.

	      (28) startstack  %lu
			The address of the start (i.e.,	bottom)	of the stack.

	      (29) kstkesp  %lu
			The  current value of ESP (stack pointer), as found in
			the kernel stack page for the process.

	      (30) kstkeip  %lu
			The current EIP	(instruction pointer).

	      (31) signal  %lu
			The bitmap of pending signals, displayed as a  decimal
			number.	  Obsolete, because it does not	provide	infor-
			mation on real-time  signals;  use  /proc/[pid]/status
			instead.

	      (32) blocked  %lu
			The  bitmap of blocked signals,	displayed as a decimal
			number.	 Obsolete, because it does not provide	infor-
			mation	on  real-time  signals;	use /proc/[pid]/status
			instead.

	      (33) sigignore  %lu
			The bitmap of ignored signals, displayed as a  decimal
			number.	  Obsolete, because it does not	provide	infor-
			mation on real-time  signals;  use  /proc/[pid]/status
			instead.

	      (34) sigcatch  %lu
			The  bitmap  of	caught signals,	displayed as a decimal
			number.	 Obsolete, because it does not provide	infor-
			mation	on  real-time  signals;	use /proc/[pid]/status
			instead.

	      (35) wchan  %lu
			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 /proc/[pid]/wchan.

	      (36) nswap  %lu
			Number of pages	swapped	(not maintained).

	      (37) cnswap  %lu
			Cumulative nswap for child processes (not maintained).

	      (38) exit_signal	%d  (since Linux 2.1.22)
			Signal to be sent to parent when we die.

	      (39) processor  %d  (since Linux 2.2.8)
			CPU number last	executed on.

	      (40) rt_priority	%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  pol-
			icy,   or   0,	 for   non-real-time   processes  (see
			sched_setscheduler(2)).

	      (41) policy  %u  (since Linux 2.5.19)
			Scheduling policy (see sched_setscheduler(2)).	Decode
			using the SCHED_* constants in linux/sched.h.

			The format for this field was %lu before Linux 2.6.22.

	      (42) delayacct_blkio_ticks  %llu	(since Linux 2.6.18)
			Aggregated  block  I/O delays, measured	in clock ticks
			(centiseconds).

	      (43) guest_time  %lu  (since Linux 2.6.24)
			Guest time of the process (time	spent running  a  vir-
			tual  CPU  for	a guest	operating system), measured in
			clock ticks (divide by sysconf(_SC_CLK_TCK)).

	      (44) cguest_time	%ld  (since Linux 2.6.24)
			Guest time of  the  process's  children,  measured  in
			clock ticks (divide by sysconf(_SC_CLK_TCK)).

	      (45) start_data  %lu  (since Linux 3.3)
			Address	above which program initialized	and uninitial-
			ized (BSS) data	are placed.

	      (46) end_data  %lu  (since Linux 3.3)
			Address	below which program initialized	and uninitial-
			ized (BSS) data	are placed.

	      (47) start_brk  %lu  (since Linux	3.3)
			Address	 above which program heap can be expanded with
			brk(2).

	      (48) arg_start  %lu  (since Linux	3.5)
			Address	above  which  program  command-line  arguments
			(argv) are placed.

	      (49) arg_end  %lu	 (since	Linux 3.5)
			Address	 below	program	 command-line arguments	(argv)
			are placed.

	      (50) env_start  %lu  (since Linux	3.5)
			Address	above which program environment	is placed.

	      (51) env_end  %lu	 (since	Linux 3.5)
			Address	below which program environment	is placed.

	      (52) exit_code  %d  (since Linux 3.5)
			The thread's exit status in the	form reported by wait-
			pid(2).

       /proc/[pid]/statm
	      Provides information about memory	usage, measured	in pages.  The
	      columns are:

		  size	     (1) total program size
			     (same as VmSize in	/proc/[pid]/status)
		  resident   (2) resident set size
			     (same as VmRSS in /proc/[pid]/status)
		  share	     (3) shared	pages (i.e., backed by a file)
		  text	     (4) text (code)
		  lib	     (5) library (unused in Linux 2.6)
		  data	     (6) data +	stack
		  dt	     (7) dirty pages (unused in	Linux 2.6)

       /proc/[pid]/status
	      Provides	much  of  the  information  in	/proc/[pid]/stat   and
	      /proc/[pid]/statm	in a format that's easier for humans to	parse.
	      Here's an	example:

		  $ cat	/proc/$$/status
		  Name:	  bash
		  State:  S (sleeping)
		  Tgid:	  3515
		  Pid:	  3515
		  PPid:	  3452
		  TracerPid:	  0
		  Uid:	  1000	  1000	  1000	  1000
		  Gid:	  100	  100	  100	  100
		  FDSize: 256
		  Groups: 16 33	100
		  VmPeak:     9136 kB
		  VmSize:     7896 kB
		  VmLck:	 0 kB
		  VmHWM:      7572 kB
		  VmRSS:      6316 kB
		  VmData:     5224 kB
		  VmStk:	88 kB
		  VmExe:       572 kB
		  VmLib:      1708 kB
		  VmPTE:	20 kB
		  Threads:	  1
		  SigQ:	  0/3067
		  SigPnd: 0000000000000000
		  ShdPnd: 0000000000000000
		  SigBlk: 0000000000010000
		  SigIgn: 0000000000384004
		  SigCgt: 000000004b813efb
		  CapInh: 0000000000000000
		  CapPrm: 0000000000000000
		  CapEff: 0000000000000000
		  CapBnd: ffffffffffffffff
		  Cpus_allowed:	  00000001
		  Cpus_allowed_list:	  0
		  Mems_allowed:	  1
		  Mems_allowed_list:	  0
		  voluntary_ctxt_switches:	  150
		  nonvoluntary_ctxt_switches:	  545

	      The fields are as	follows:

	      *	Name: Command run by this process.

	      *	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)".

	      *	Tgid: Thread group ID (i.e., Process ID).

	      *	Pid: Thread ID (see gettid(2)).

	      *	PPid: PID of parent process.

	      *	TracerPid: PID of process tracing this process (0 if not being
		traced).

	      *	Uid,  Gid:  Real,  effective,  saved  set, and filesystem UIDs
		(GIDs).

	      *	FDSize:	Number of file descriptor slots	currently allocated.

	      *	Groups:	Supplementary group list.

	      *	VmPeak:	Peak virtual memory size.

	      *	VmSize:	Virtual	memory size.

	      *	VmLck: Locked memory size (see mlock(3)).

	      *	VmHWM: Peak resident set size ("high water mark").

	      *	VmRSS: Resident	set size.

	      *	VmData,	VmStk, VmExe: Size of data, stack, and text segments.

	      *	VmLib: Shared library code size.

	      *	VmPTE: Page table entries size (since Linux 2.6.10).

	      *	Threads: Number	of threads in process containing this thread.

	      *	SigQ: This field contains two slash-separated numbers that re-
		late  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  de-
		scription of RLIMIT_SIGPENDING in getrlimit(2)).

	      *	SigPnd,	 ShdPnd:  Number of signals pending for	thread and for
		process	as a whole (see	pthreads(7) and	signal(7)).

	      *	SigBlk,	 SigIgn,  SigCgt:  Masks  indicating   signals	 being
		blocked, ignored, and caught (see signal(7)).

	      *	CapInh,	 CapPrm,  CapEff: Masks	of capabilities	enabled	in in-
		heritable,  permitted,	and  effective	sets  (see   capabili-
		ties(7)).

	      *	CapBnd:	Capability Bounding set	(since Linux 2.6.26, see capa-
		bilities(7)).

	      *	Cpus_allowed: Mask of CPUs  on	which  this  process  may  run
		(since Linux 2.6.24, see cpuset(7)).

	      *	Cpus_allowed_list:  Same  as  previous,	 but  in "list format"
		(since Linux 2.6.26, see cpuset(7)).

	      *	Mems_allowed: Mask of memory nodes  allowed  to	 this  process
		(since Linux 2.6.24, see cpuset(7)).

	      *	Mems_allowed_list:  Same  as  previous,	 but  in "list format"
		(since Linux 2.6.26, see cpuset(7)).

	      *	voluntary_ctxt_switches, nonvoluntary_ctxt_switches: Number of
		voluntary   and	 involuntary  context  switches	 (since	 Linux
		2.6.23).

       /proc/[pid]/syscall (since Linux	2.6.27)
	      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 ex-
	      posed, although most system calls	use fewer registers.

	      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 file	contains just the string "run-
	      ning".

	      This file	is present only	if the kernel was configured with CON-
	      FIG_HAVE_ARCH_TRACEHOOK.

       /proc/[pid]/task	(since 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 nu-
	      merical thread ID	([tid])	of the thread (see gettid(2)).	Within
	      each of these subdirectories, there is a set of files  with  the
	      same  names  and	contents as under the /proc/[pid] directories.
	      For attributes that are shared by	all threads, the contents  for
	      each  of	the  files under the task/[tid]	subdirectories will be
	      the same as in the corresponding file in the parent  /proc/[pid]
	      directory	  (e.g.,  in  a	 multithreaded	process,  all  of  the
	      task/[tid]/cwd  files  will  have	 the   same   value   as   the
	      /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
	      task/[tid] may have different values (e.g.,  various  fields  in
	      each  of	the  task/[tid]/status files may be different for each
	      thread).

	      In a multithreaded process, the contents of the /proc/[pid]/task
	      directory	 are not available if the main thread has already ter-
	      minated (typically by calling pthread_exit(3)).

       /proc/[pid]/uid_map, /proc/[pid]/gid_map	(since Linux 3.5)
	      These files expose the mappings for user and  group  IDs	inside
	      the  user	 namespace  for	the process pid.  The description here
	      explains the details for uid_map;	gid_map	is exactly  the	 same,
	      but each instance	of "user ID" is	replaced by "group ID".

	      The  uid_map  file exposes the mapping of	user IDs from the user
	      namespace	of the process	pid  to	 the  user  namespace  of  the
	      process  that  opened  uid_map  (but see a qualification to this
	      point below).  In	other words, processes that are	 in  different
	      user namespaces will potentially see different values when read-
	      ing from a particular uid_map file, depending  on	 the  user  ID
	      mappings for the user namespaces of the reading processes.

	      Each  line  in the file specifies	a 1-to-1 mapping of a range of
	      contiguous between two user namespaces.	The  specification  in
	      each  line  takes	 the  form of three numbers delimited by white
	      space.  The first	two numbers specify the	starting  user	ID  in
	      each  user  namespace.  The third	number specifies the length of
	      the mapped range.	 In detail, the	fields are interpreted as fol-
	      lows:

	      (1) The  start of	the range of user IDs in the user namespace of
		  the process pid.

	      (2) The start of the range of user IDs to	 which	the  user  IDs
		  specified  by	 field	one map.  How field two	is interpreted
		  depends on whether the process that opened uid_map  and  the
		  process pid are in the same user namespace, as follows:

		  a) If	 the  two  processes are in different user namespaces:
		     field two is the start of a range of user IDs in the user
		     namespace of the process that opened uid_map.

		  b) If	 the  two  processes  are  in the same user namespace:
		     field two is the start of the range of user  IDs  in  the
		     parent  user  namespace of	the process pid.  (The "parent
		     user namespace" is	the user namespace of the process that
		     created  a	 user  namespace  via  a call to unshare(2) or
		     clone(2) with the CLONE_NEWUSER flag.)  This case enables
		     the  opener  of  uid_map (the common case here is opening
		     /proc/self/uid_map) to see	the mapping of user  IDs  into
		     the  user namespace of the	process	that created this user
		     namespace.

	      (3) The length of	the range of user IDs that is  mapped  between
		  the two user namespaces.

	      After the	creation of a new user namespace, the uid_map file may
	      be written to exactly once to specify the	mapping	of user	IDs in
	      the  new user namespace.	(An attempt to write more than once to
	      the file fails with the error EPERM.)

	      The lines	written	to  uid_map  must  conform  to	the  following
	      rules:

	      *	 The  three  fields  must be valid numbers, and	the last field
		 must be greater than 0.

	      *	 Lines are terminated by newline characters.

	      *	 There is an (arbitrary) limit on the number of	lines  in  the
		 file.	As at Linux 3.8, the limit is five lines.

	      *	 The  range  of	user IDs specified in each line	cannot overlap
		 with the ranges in any	other lines.  In the current implemen-
		 tation	 (Linux	 3.8), this requirement	is satisfied by	a sim-
		 plistic implementation	that imposes the  further  requirement
		 that  the  values  in	both field 1 and field 2 of successive
		 lines must be in ascending numerical order.

	      Writes that violate the above rules fail with the	error EINVAL.

	      In order for a  process  to  write  to  the  /proc/[pid]/uid_map
	      (/proc/[pid]/gid_map)  file,  the	following requirements must be
	      met:

	      *	 The process must have the CAP_SETUID (CAP_SETGID)  capability
		 in the	user namespace of the process pid.

	      *	 The  process must have	the CAP_SETUID (CAP_SETGID) capability
		 in the	parent user namespace.

	      *	 The process must be in	 either	 the  user  namespace  of  the
		 process  pid  or  inside  the	parent	user  namespace	of the
		 process pid.
       For further details, see	namespaces(7).

       /proc/[pid]/wchan (since	Linux 2.6.0)
	      The symbolic name	corresponding to the location  in  the	kernel
	      where the	process	is sleeping.

       /proc/apm
	      Advanced	power  management version and battery information when
	      CONFIG_APM is defined at kernel compilation time.

       /proc/buddyinfo
	      This file	contains information which is used for diagnosing mem-
	      ory fragmentation	issues.	 Each line starts with the identifica-
	      tion of the node and the name of the zone	which  together	 iden-
	      tify  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
	      formual:

		  (2^order) * PAGE_SIZE

	      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.

	      For example on a x86_64 system:

  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

	      In  this	example,  there	is one node containing three zones and
	      there are	11 different chunk sizes.  If the page size is 4 kilo-
	      byteis,  then  the  first	 zone  called DMA (on x86 the first 16
	      megabyte of memory) has 1	chunk of 4 kilobytes (order 0)	avail-
	      able and has 3 chunks of 4 megabytes (order 10) available.

	      If  the  memory is heavily fragmentated, the counters for	higher
	      order chunks will	be zero	and allocation of large	contiguous ar-
	      eas will fail.

	      Further  information about the zones can be found	in /proc/zone-
	      info.

       /proc/bus
	      Contains subdirectories for installed busses.

       /proc/bus/pccard
	      Subdirectory for PCMCIA devices when  CONFIG_PCMCIA  is  set  at
	      kernel compilation time.

       /proc/[pid]/timers (since Linux 3.10)
	      A	 list  of  the	POSIX  timers for this process.	 Each timer is
	      listed with a line that started with the string "ID:".  For  ex-
	      ample:

		  ID: 1
		  signal: 60/00007fff86e452a8
		  notify: signal/pid.2634
		  ClockID: 0
		  ID: 0
		  signal: 60/00007fff86e452a8
		  notify: signal/pid.2634
		  ClockID: 1

	      The lines	shown for each timer have the following	meanings:

	      ID     The ID for	this timer.  This is not the same as the timer
		     ID	returned by timer_create(2); rather, it	 is  the  same
		     kernel-internal  ID  that is available via	the si_timerid
		     field of the siginfo_t structure (see sigaction(2)).

	      signal This is the signal	number that this timer uses to deliver
		     notifications   followed	by   a	slash,	and  then  the
		     sigev_value.sival_ptr value supplied to the  signal  han-
		     dler.  Valid only for timers that notify via a signal.

	      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
		     SIGEV_THREAD_ID  notification,  or	 "pid" for timers that
		     notify by other mechanisms.  Following the	"." is the PID
		     of	 the  process  that  will be delivered a signal	if the
		     timer delivers notifications via a	signal.

	      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 CLOCK_*  constants  exposed
		     via  _time.h_.   CLOCK_PROCESS_CPUTIME_ID	timers display
		     with    a	  value	   of	 -6	in     this	field.
		     CLOCK_THREAD_CPUTIME_ID timers display with a value of -2
		     in	this field.

       /proc/bus/pccard/drivers

       /proc/bus/pci
	      Contains various bus subdirectories and pseudo-files  containing
	      information  about  PCI  busses,	installed  devices, and	device
	      drivers.	Some of	these files are	not ASCII.

       /proc/bus/pci/devices
	      Information about	PCI devices.  They  may	 be  accessed  through
	      lspci(8) and setpci(8).

       /proc/cmdline
	      Arguments	 passed	 to the	Linux kernel at	boot time.  Often done
	      via a boot manager such as lilo(8) or grub(8).

       /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 .config file that resulted when  configur-
	      ing  the	kernel	(using make xconfig, make config, or similar).
	      The file contents	are compressed;	 view  or  search  them	 using
	      zcat(1)  and  zgrep(1).  As long as no changes have been made to
	      the following file, the contents of /proc/config.gz are the same
	      as those provided	by :

		  cat /lib/modules/$(uname -r)/build/.config

	      /proc/config.gz  is  provided  only  if the kernel is configured
	      with CONFIG_IKCONFIG_PROC.

       /proc/cpuinfo
	      This is a	collection of CPU and  system  architecture  dependent
	      items,  for  each	 supported architecture	a different list.  Two
	      common entries are processor which  gives	 CPU  number  and  bo-
	      gomips;  a system	constant that is calculated during kernel ini-
	      tialization.  SMP	machines have information for each  CPU.   The
	      lscpu(1) command gathers its information from this file.

       /proc/devices
	      Text  listing  of	 major numbers and device groups.  This	can be
	      used by MAKEDEV scripts for consistency with the kernel.

       /proc/diskstats (since Linux 2.5.69)
	      This file	contains disk I/O statistics  for  each	 disk  device.
	      See  the	Linux kernel source file Documentation/iostats.txt for
	      further information.

       /proc/dma
	      This is a	list of	the registered ISA DMA (direct memory  access)
	      channels in use.

       /proc/driver
	      Empty subdirectory.

       /proc/execdomains
	      List of the execution domains (ABI personalities).

       /proc/fb
	      Frame buffer information when CONFIG_FB is defined during	kernel
	      compilation.

       /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
	      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).

	      Incidentally, this file may be used by mount(8) when no filesys-
	      tem is specified and it didn't manage to determine the  filesys-
	      tem  type.   Then	 filesystems  contained	in this	file are tried
	      (excepted	those that are marked with "nodev").

       /proc/fs
	      Contains subdirectories that in turn contain files with informa-
	      tion about (certain) mounted filesystems.

       /proc/ide
	      This  directory  exists  on systems with the IDE bus.  There are
	      directories for each IDE channel and attached device.  Files in-
	      clude:

		  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's model number
		  settings	     drive settings
		  smart_thresholds   in	hexadecimal
		  smart_values	     in	hexadecimal

	      The  hdparm(8)  utility provides access to this information in a
	      friendly format.

       /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 architec-
	      tures, 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.

       /proc/iomem
	      I/O memory map in	Linux 2.4.

       /proc/ioports
	      This is a	list of	currently registered Input-Output port regions
	      that are in use.

       /proc/kallsyms (since Linux 2.5.71)
	      This holds the kernel exported symbol definitions	 used  by  the
	      modules(X)  tools	to dynamically link and	bind loadable modules.
	      In Linux 2.5.47 and earlier, a similar file with	slightly  dif-
	      ferent syntax was	named ksyms.

       /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 (/usr/src/linux/vmlinux) binary, GDB	can be
	      used to examine the current state	of any kernel data structures.

	      The total	length of the file is  the  size  of  physical	memory
	      (RAM) plus 4KB.

       /proc/kmsg
	      This  file  can  be used instead of the 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 syslog(2) system call facility to log kernel mes-
	      sages.

	      Information in this file is retrieved with the dmesg(1) program.

       /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	/proc/[pid]/pagemap).

	      The  /proc/kpagecount  file  is  present	only   if   the	  CON-
	      FIG_PROC_PAGE_MONITOR kernel configuration option	is enabled.

       /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  discus-
	      sion of /proc/[pid]/pagemap).  The bits are as follows:

		   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)
		  16 - 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)

	      For  further details on the meanings of these bits, see the ker-
	      nel source  file	Documentation/vm/pagemap.txt.	Before	kernel
	      2.6.29,  KPF_WRITEBACK,  KPF_RECLAIM,  KPF_BUDDY,	and KPF_LOCKED
	      did not report correctly.

	      The  /proc/kpageflags  file  is  present	only   if   the	  CON-
	      FIG_PROC_PAGE_MONITOR kernel configuration option	is enabled.

       /proc/ksyms (Linux 1.1.23-2.5.47)
	      See /proc/kallsyms.

       /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	uptime(1)  and
	      other  programs.	The fourth field consists of two numbers sepa-
	      rated by a slash (/).  The first of these	is the number of  cur-
	      rently runnable kernel scheduling	entities (processes, threads).
	      The value	after the slash	is the number of kernel	scheduling en-
	      tities  that  currently exist on the system.  The	fifth field is
	      the PID of the process that was most  recently  created  on  the
	      system.

       /proc/locks
	      This  file  shows	current	file locks (flock(2) and fcntl(2)) and
	      leases (fcntl(2)).

       /proc/malloc (only up to	and including Linux 2.2)
	      This file	is present only	 if  CONFIG_DEBUG_MALLOC  was  defined
	      during compilation.

       /proc/meminfo
	      This  file  reports statistics about memory usage	on the system.
	      It is used by free(1) to report the amount of free and used mem-
	      ory (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 be-
	      low,  all	 of  the fields	have been present since	at least Linux
	      2.6.0.  Some fields are displayed	only if	the kernel was config-
	      ured  with  various options; those dependencies are noted	in the
	      list.

	      MemTotal %lu
		     Total usable RAM (i.e., physical RAM minus	a few reserved
		     bits and the kernel binary	code).

	      MemFree %lu
		     The sum of	LowFree+HighFree.

	      Buffers %lu
		     Relatively	 temporary  storage  for  raw disk blocks that
		     shouldn't get tremendously	large (20MB or so).

	      Cached %lu
		     In-memory cache for files read from the  disk  (the  page
		     cache).  Doesn't include SwapCached.

	      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 be-
		     cause they	are already in	the  swap  file.   This	 saves
		     I/O.)

	      Active %lu
		     Memory  that  has been used more recently and usually not
		     reclaimed unless absolutely necessary.

	      Inactive %lu
		     Memory which has been less	recently used.	It is more el-
		     igible to be reclaimed for	other purposes.

	      Active(anon) %lu (since Linux 2.6.28)
		     [To be documented.]

	      Inactive(anon) %lu (since	Linux 2.6.28)
		     [To be documented.]

	      Active(file) %lu (since Linux 2.6.28)
		     [To be documented.]

	      Inactive(file) %lu (since	Linux 2.6.28)
		     [To be documented.]

	      Unevictable %lu (since Linux 2.6.28)
		     (From  Linux 2.6.28 to 2.6.30, CONFIG_UNEVICTABLE_LRU was
		     required.)	 [To be	documented.]

	      Mlocked %lu (since Linux 2.6.28)
		     (From Linux 2.6.28	to 2.6.30, CONFIG_UNEVICTABLE_LRU  was
		     required.)	 [To be	documented.]

	      HighTotal	%lu
		     (Starting with Linux 2.6.19, CONFIG_HIGHMEM is required.)
		     Total amount of highmem.  Highmem	is  all	 memory	 above
		     ~860MB  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.

	      HighFree %lu
		     (Starting with Linux 2.6.19, CONFIG_HIGHMEM is required.)
		     Amount of free highmem.

	      LowTotal %lu
		     (Starting with Linux 2.6.19, CONFIG_HIGHMEM 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	every-
		     thing from	Slab is	allocated.   Bad  things  happen  when
		     you're out	of lowmem.

	      LowFree %lu
		     (Starting with Linux 2.6.19, CONFIG_HIGHMEM is required.)
		     Amount of free lowmem.

	      MmapCopy %lu (since Linux	2.6.29)
		     (CONFIG_MMU is required.)	[To be documented.]

	      SwapTotal	%lu
		     Total amount of swap space	available.

	      SwapFree %lu
		     Amount of swap space that is currently unused.

	      Dirty %lu
		     Memory which is waiting to	get written back to the	disk.

	      Writeback	%lu
		     Memory which is actively being written back to the	disk.

	      AnonPages	%lu (since Linux 2.6.18)
		     Non-file backed pages mapped into user-space page tables.

	      Mapped %lu
		     Files which have been mapped into memory (with  mmap(2)),
		     such as libraries.

	      Shmem %lu	(since Linux 2.6.32)
		     [To be documented.]

	      Slab %lu
		     In-kernel data structures cache.

	      SReclaimable %lu (since Linux 2.6.19)
		     Part of Slab, that	might be reclaimed, such as caches.

	      SUnreclaim %lu (since Linux 2.6.19)
		     Part  of  Slab,  that cannot be reclaimed on memory pres-
		     sure.

	      KernelStack %lu (since Linux 2.6.32)
		     Amount of memory allocated	to kernel stacks.

	      PageTables %lu (since Linux 2.6.18)
		     Amount of memory dedicated	to the lowest  level  of  page
		     tables.

	      Quicklists %lu (since Linux 2.6.27)
		     (CONFIG_QUICKLIST is required.)  [To be documented.]

	      NFS_Unstable %lu (since Linux 2.6.18)
		     NFS  pages	 sent  to the server, but not yet committed to
		     stable storage.

	      Bounce %lu (since	Linux 2.6.18)
		     Memory used for block device "bounce buffers".

	      WritebackTmp %lu (since Linux 2.6.26)
		     Memory used by FUSE for temporary writeback buffers.

	      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 /proc/sys/vm/overcommit_memory).
		     The limit is calculated  according	 to  the  formula  de-
		     scribed  under  /proc/sys/vm/overcommit_memory.  For fur-
		     ther details,  see	 the  kernel  source  file  Documenta-
		     tion/vm/overcommit-accounting.

	      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  1GB
		     of	 memory	(using malloc(3) or similar), but touches only
		     300MB of that memory will show up as using	only 300MB  of
		     memory even if it has the address space allocated for the
		     entire 1GB.

		     This 1GB is memory	which has been "committed" to  by  the
		     VM	and can	be used	at any time by the allocating applica-
		     tion.  With strict	overcommit enabled on the system (mode
		     2	in  IR	/proc/sys/vm/overcommit_memory	), allocations
		     which would exceed	the 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.

	      VmallocTotal %lu
		     Total size	of vmalloc memory area.

	      VmallocUsed %lu
		     Amount of vmalloc area which is used.

	      VmallocChunk %lu
		     Largest contiguous	block of vmalloc area which is free.

	      HardwareCorrupted	%lu (since Linux 2.6.32)
		     (CONFIG_MEMORY_FAILURE is required.)  [To be documented.]

	      AnonHugePages %lu	(since Linux 2.6.38)
		     (CONFIG_TRANSPARENT_HUGEPAGE   is	 required.)   Non-file
		     backed huge pages mapped into user-space page tables.

	      HugePages_Total %lu
		     (CONFIG_HUGETLB_PAGE is required.)	 The size of the  pool
		     of	huge pages.

	      HugePages_Free %lu
		     (CONFIG_HUGETLB_PAGE  is  required.)   The	number of huge
		     pages in the pool that are	not yet	allocated.

	      HugePages_Rsvd %lu (since	Linux 2.6.17)
		     (CONFIG_HUGETLB_PAGE 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.

	      HugePages_Surp %lu (since	Linux 2.6.24)
		     (CONFIG_HUGETLB_PAGE is required.)	 This is the number of
		     huge   pages   in	 the   pool   above   the   value   in
		     /proc/sys/vm/nr_hugepages.	 The maximum number of surplus
		     huge  pages  is  controlled  by  /proc/sys/vm/nr_overcom-
		     mit_hugepages.

	      Hugepagesize %lu
		     (CONFIG_HUGETLB_PAGE  is  required.)   The	 size  of huge
		     pages.

       /proc/modules
	      A	text list of the modules that have been	loaded by the  system.
	      See also lsmod(8).

       /proc/mounts
	      Before  kernel  2.4.19, this file	was a list of all the filesys-
	      tems currently mounted on	the system.  With the introduction  of
	      per-process mount	namespaces in Linux 2.4.19, this file became a
	      link to /proc/self/mounts, which lists the mount points  of  the
	      process's	own mount namespace.  The format of this file is docu-
	      mented in	fstab(5).

       /proc/mtrr
	      Memory Type Range	Registers.  See	the Linux kernel  source  file
	      Documentation/mtrr.txt for details.

       /proc/net
	      various  net  pseudo-files, all of which give the	status of some
	      part of the networking layer.  These files contain ASCII	struc-
	      tures  and  are,	therefore, readable with cat(1).  However, the
	      standard netstat(8) suite	provides much cleaner access to	 these
	      files.

       /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 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

	      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
	      /usr/include/linux/if_arp.h) and the "HW address"	 is  the  data
	      link layer mapping for that IP address if	it is known.

       /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 ifconfig(8) program to report	 device	 status.   The
	      format is:

 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

       /proc/net/dev_mcast
	      Defined in /usr/src/linux/net/core/dev_mcast.c:
		   indx	interface_name	dmi_u dmi_g dmi_address
		   2	eth0		1     0	    01005e000001
		   3	eth1		1     0	    01005e000001
		   4	eth2		1     0	    01005e000001

       /proc/net/igmp
	      Internet	   Group     Management	   Protocol.	 Defined    in
	      /usr/src/linux/net/core/igmp.c.

       /proc/net/rarp
	      This file	uses the same format as	the arp	file and contains  the
	      current reverse mapping database used to provide rarp(8) reverse
	      address lookup services.	If RARP	is  not	 configured  into  the
	      kernel, this file	will not be present.

       /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  ker-
	      nel  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.

       /proc/net/snmp
	      This file	holds the ASCII	data needed for	the IP,	ICMP, TCP, and
	      UDP management information bases for an SNMP agent.

       /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 ker-
	      nel 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	inter-
	      nal status of the	socket.	 The "tx_queue"	and "rx_queue" are the
	      outgoing and incoming data queue in terms	of kernel  memory  us-
	      age.   The  "tr",	"tm->when", and	"rexmits" fields hold internal
	      information of the kernel	socket state and are only  useful  for
	      debugging.   The "uid" field holds the effective UID of the cre-
	      ator of the socket.

       /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 ker-
	      nel 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	inter-
	      nal status of the	socket.	 The "tx_queue"	and "rx_queue" are the
	      outgoing and incoming data queue in terms	of kernel  memory  us-
	      age.  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:

 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

       /proc/net/unix
	      Lists  the  UNIX	domain	sockets	 present within	the system and
	      their status.  The format	is:
	      Num RefCount Protocol Flags    Type St Path
	       0: 00000002 00000000 00000000 0001 03
	       1: 00000001 00000000 00010000 0001 01 /dev/printer

	      Here "Num" is the	kernel table slot number,  "RefCount"  is  the
	      number of	users of the socket, "Protocol"	is currently always 0,
	      "Flags" represent	the internal kernel flags holding  the	status
	      of the socket.  Currently, type is always	"1" (UNIX domain data-
	      gram sockets are not yet supported in the	kernel).  "St" is  the
	      internal state of	the socket and Path is the bound path (if any)
	      of the socket.

       /proc/partitions
	      Contains the major and minor numbers of each partition  as  well
	      as the number of 1024-byte blocks	and the	partition name.

       /proc/pci
	      This  is	a  listing of all PCI devices found during kernel ini-
	      tialization and their configuration.

	      This file	has been deprecated in favor of	a new /proc  interface
	      for  PCI	(/proc/bus/pci).   It  became  optional	 in  Linux 2.2
	      (available with 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  CON-
	      FIG_PCI_LEGACY_PROC  set),  and finally removed altogether since
	      Linux 2.6.17.

       /proc/profile (since Linux 2.4)
	      This file	is present only	if the kernel was booted with the pro-
	      file=1  command-line option.  It exposes kernel profiling	infor-
	      mation in	a binary format	for use	 by  readprofile(1).   Writing
	      (e.g.,  an empty string) to this file resets the profiling coun-
	      ters; on some architectures, writing a binary integer "profiling
	      multiplier"  of  size  sizeof(int)  sets the profiling interrupt
	      frequency.

       /proc/scsi
	      A	directory with the 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	cat(1).

	      You can also write to some of the	files to reconfigure the  sub-
	      system or	switch certain features	on or off.

       /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  cur-
	      rently  supports only the	add-single-device command which	allows
	      root to add a hotplugged device to the list of known devices.

	      The command

		  echo 'scsi add-single-device 1 0 5 0'	> /proc/scsi/scsi

	      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.

       /proc/scsi/[drivername]
	      [drivername]  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 reg-
	      istered 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.

	      Reading these files will usually show driver and host configura-
	      tion, statistics,	and so on.

	      Writing  to  these  files	 allows	 different things on different
	      hosts.  For example, with	the latency  and  nolatency  commands,
	      root  can	 switch	on and off command latency measurement code in
	      the eata_dma driver.  With the lockup and	unlock commands,  root
	      can control bus lockups simulated	by the scsi_debug driver.

       /proc/self
	      This  directory  refers  to  the	process	 accessing  the	 /proc
	      filesystem, and is identical to the /proc	directory named	by the
	      process ID of the	same process.

       /proc/slabinfo
	      Information  about  kernel caches.  Since	Linux 2.6.16 this file
	      is present only if the CONFIG_SLAB kernel	 configuration	option
	      is enabled.  The columns in /proc/slabinfo are:

		  cache-name
		  num-active-objs
		  total-objs
		  object-size
		  num-active-slabs
		  total-slabs
		  num-pages-per-slab

	      See slabinfo(5) for details.

       /proc/stat
	      kernel/system statistics.	 Varies	with architecture.  Common en-
	      tries include:

	      cpu  3357	0 4313 1362393
		     The  amount  of  time,  measured  in  units  of   USER_HZ
		     (1/100ths	 of   a	 second	 on  most  architectures,  use
		     sysconf(_SC_CLK_TCK) to obtain the	right value), that the
		     system spent in various states:

		     user   (1)	Time spent in user mode.

		     nice   (2)	 Time  spent  in  user	mode with low priority
			    (nice).

		     system (3)	Time spent in system mode.

		     idle   (4)	Time spent  in	the  idle  task.   This	 value
			    should  be	USER_HZ	 times the second entry	in the
			    /proc/uptime pseudo-file.

		     iowait (since Linux 2.5.41)
			    (5)	Time waiting for I/O to	complete.

		     irq (since	Linux 2.6.0-test4)
			    (6)	Time servicing interrupts.

		     softirq (since Linux 2.6.0-test4)
			    (7)	Time servicing softirqs.

		     steal (since Linux	2.6.11)
			    (8)	Stolen time, which is the time spent in	 other
			    operating  systems	when  running in a virtualized
			    environment

		     guest (since Linux	2.6.24)
			    (9)	Time spent running a virtual CPU for guest op-
			    erating  systems  under  the  control of the Linux
			    kernel.

		     guest_nice	(since Linux 2.6.33)
			    (10) Time spent running a niced guest (virtual CPU
			    for	 guest	operating systems under	the control of
			    the	Linux kernel).

	      page 5741	1808
		     The number	of pages the system paged in  and  the	number
		     that were paged out (from disk).

	      swap 1 0
		     The  number  of  swap pages that have been	brought	in and
		     out.

	      intr 1462898
		     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  in-
		     cluding unnumbered	architecture specific interrupts; each
		     subsequent	column is the total for	that  particular  num-
		     bered  interrupt.	 Unnumbered  interrupts	are not	shown,
		     only summed into the total.

	      disk_io: (2,0):(31,30,5764,1,2) (3,0):...
		     (major,disk_idx):(noinfo,	   read_io_ops,	    blks_read,
		     write_io_ops, blks_written)
		     (Linux 2.4	only)

	      ctxt 115315
		     The number	of context switches that the system underwent.

	      btime 769041601
		     boot   time,  in  seconds	since  the  Epoch,  1970-01-01
		     00:00:00 +0000 (UTC).

	      processes	86031
		     Number of forks since boot.

	      procs_running 6
		     Number of processes in runnable state.  (Linux 2.5.45 on-
		     ward.)

	      procs_blocked 2
		     Number  of	processes blocked waiting for I/O to complete.
		     (Linux 2.5.45 onward.)

       /proc/swaps
	      Swap areas in use.  See also swapon(8).

       /proc/sys
	      This directory (present since 1.3.57) contains a number of files
	      and  subdirectories  corresponding  to  kernel variables.	 These
	      variables	can be read and	sometimes  modified  using  the	 /proc
	      filesystem, and the (deprecated) sysctl(2) system	call.

       /proc/sys/abi (since Linux 2.4.10)
	      This  directory may contain files	with application binary	infor-
	      mation.	See  the   Linux   kernel   source   file   Documenta-
	      tion/sysctl/abi.txt for more information.

       /proc/sys/debug
	      This directory may be empty.

       /proc/sys/dev
	      This   directory	contains  device-specific  information	(e.g.,
	      dev/cdrom/info).	On some	systems, it may	be empty.

       /proc/sys/fs
	      This directory contains the files	and subdirectories for	kernel
	      variables	related	to filesystems.

       /proc/sys/fs/binfmt_misc
	      Documentation  for  files	 in this directory can be found	in the
	      Linux kernel sources in Documentation/binfmt_misc.txt.

       /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, nr_dentry,
	      nr_unused, age_limit (age	in  seconds),  want_pages  (pages  re-
	      quested by system) and two dummy values.

	      *	nr_dentry  is  the  number  of	allocated dentries (dcache en-
		tries).	 This field is unused in Linux 2.2.

	      *	nr_unused is the number	of unused dentries.

	      *	age_limit is the age in	seconds	after which dcache entries can
		be reclaimed when memory is short.

	      *	want_pages   is	  nonzero   when   the	 kernel	  has	called
		shrink_dcache_pages() and the dcache isn't pruned yet.

       /proc/sys/fs/dir-notify-enable
	      This file	can be used to disable or enable the dnotify interface
	      described	 in  fcntl(2) on a system-wide basis.  A value of 0 in
	      this file	disables the interface,	and a value of 1 enables it.

       /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.

       /proc/sys/fs/dquot-nr
	      This file	shows the number of allocated disk quota  entries  and
	      the number of free disk quota entries.

       /proc/sys/fs/epoll (since Linux 2.6.28)
	      This  directory contains the file	max_user_watches, which	can be
	      used to limit the	amount of kernel memory	consumed by the	 epoll
	      interface.  For further details, see epoll(7).

       /proc/sys/fs/file-max
	      This  file  defines  a  system-wide  limit on the	number of open
	      files for	all processes.	(See also setrlimit(2),	which  can  be
	      used  by	a process to set the per-process limit,	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
	      (look for	"VFS: file-max limit <number> reached"), try  increas-
	      ing this value:

		  echo 100000 >	/proc/sys/fs/file-max

	      The  kernel constant NR_OPEN imposes an upper limit on the value
	      that may be placed in file-max.

	      Privileged processes (CAP_SYS_ADMIN) can override	 the  file-max
	      limit.

       /proc/sys/fs/file-nr
	      This  (read-only)	file contains three numbers: the number	of al-
	      located file  handles  (i.e.,  the  number  of  files  presently
	      opened); the number of free file handles;	and the	maximum	number
	      of file handles (i.e., the same value as /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  in-
	      dicates  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.

       /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 3-4 times	larger than  the  value	 in  file-max,
	      since  stdin,  stdout  and network sockets also need an inode to
	      handle them.  When you regularly run out of inodes, you need  to
	      increase this value.

	      Starting	with  Linux  2.4, there	is no longer a static limit on
	      the number of inodes, and	this file is removed.

       /proc/sys/fs/inode-nr
	      This file	contains the first two values from inode-state.

       /proc/sys/fs/inode-state
	      This file	contains  seven	 numbers:  nr_inodes,  nr_free_inodes,
	      preshrink, and four dummy	values (always zero).

	      nr_inodes	 is  the  number  of  inodes the system	has allocated.
	      nr_free_inodes represents	the number of free inodes.

	      preshrink	is nonzero when	the nr_inodes >	inode-max and the sys-
	      tem  needs  to  prune the	inode list instead of allocating more;
	      since Linux 2.4, this field is a dummy value (always zero).

       /proc/sys/fs/inotify (since Linux 2.6.13)
	      This directory contains  files  max_queued_events,  max_user_in-
	      stances,	and  max_user_watches,	that  can be used to limit the
	      amount of	kernel memory consumed by the inotify interface.   For
	      further details, see inotify(7).

       /proc/sys/fs/lease-break-time
	      This file	specifies the grace period that	the kernel grants to a
	      process holding a	file lease (fcntl(2)) after it has sent	a sig-
	      nal to that process notifying it that another process is waiting
	      to open the file.	 If the	lease holder does not remove or	 down-
	      grade  the  lease	 within	this grace period, the kernel forcibly
	      breaks the lease.

       /proc/sys/fs/leases-enable
	      This file	can be used to enable  or  disable  file  leases  (fc-
	      ntl(2)) on a system-wide basis.  If this file contains the value
	      0, leases	are disabled.  A nonzero value enables leases.

       /proc/sys/fs/mqueue (since Linux	2.6.6)
	      This  directory  contains	 files	 msg_max,   msgsize_max,   and
	      queues_max,  controlling	the  resources	used  by POSIX message
	      queues.  See mq_overview(7) for details.

       /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 en-
	      abled, any UID or	GID that would exceed 65535 is	translated  to
	      the overflow value before	being written to disk.

       /proc/sys/fs/pipe-max-size (since Linux 2.6.35)
	      The  value  in  this file	defines	an upper limit for raising the
	      capacity of a pipe using the  fcntl(2)  F_SETPIPE_SZ  operation.
	      This  limit applies only to unprivileged processes.  The default
	      value for	this file is 1,048,576.	 The value  assigned  to  this
	      file  may	 be  rounded upward, to	reflect	the value actually em-
	      ployed  for  a  convenient  implementation.   To	determine  the
	      rounded-up  value,  display  the contents	of this	file after as-
	      signing a	value to it.  The minimum value	that can  be  assigned
	      to this file is the system page size.

       /proc/sys/fs/protected_hardlinks	(since Linux 3.6)
	      When  the	value in this file is 0, no restrictions are placed on
	      the creation of hard links (i.e.,	this is	the historical	behav-
	      ior 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  follow-
	      ing conditions is	true:

	      *	 The caller has	the CAP_FOWNER capability.

	      *	 The  filesystem  UID of the process creating the link matches
		 the owner (UID) of the	target file (as	described  in  creden-
		 tials(7),  a process's	filesystem UID is normally the same as
		 its effective UID).

	      *	 All of	the following conditions are true:

		  o  the target	is a regular file;

		  o  the target	file does not have its set-user-ID  permission
		     bit enabled;

		  o  the  target  file does not	have both its set-group-ID and
		     group-executable permission bits enabled; and

		  o  the caller	has permission to read and  write  the	target
		     file  (either  via	the file's permissions mask or because
		     it	has suitable capabilities).

	      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 /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 "pin-
	      ning" vulnerable set-user-ID and set-group-ID files against  be-
	      ing upgraded by the administrator, or linking to special files.

       /proc/sys/fs/protected_symlinks (since Linux 3.6)
	      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:

	      *	 the filesystem	UID of the process following the link  matches
		 the owner (UID) of the	symbolic link (as described in creden-
		 tials(7), a process's filesystem UID is normally the same  as
		 its effective UID);

	      *	 the link is not in a sticky world-writable directory; or

	      *	 the  symbolic	link  and  its	parent directory have the same
		 owner (UID)

	      A	system call that fails to follow a symbolic  link  because  of
	      the above	restrictions returns the error EACCES in errno.

	      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.

       /proc/sys/fs/suid_dumpable (since Linux 2.6.13)
	      The  value  in  this file	determines whether core	dump files are
	      produced for set-user-ID or  otherwise  protected/tainted	 bina-
	      ries.  Three different integer values can	be specified:

	      0	(default)
		     This  provides  the traditional (pre-Linux	2.6.13)	behav-
		     ior.  A core dump will not	 be  produced  for  a  process
		     which  has	 changed  credentials  (by calling seteuid(2),
		     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.

	      1	("debug")
		     All processes dump	core when possible.  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.	 Ptrace	is unchecked.

	      2	("suidsafe")
		     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 ap-
		     propriate when administrators  are	 attempting  to	 debug
		     problems in a normal environment.

		     Additionally, since Linux 3.6, /proc/sys/kernel/core_pat-
		     tern must either be an absolute pathname or a  pipe  com-
		     mand,  as	detailed in core(5).  Warnings will be written
		     to	the kernel log if core_pattern does not	 follow	 these
		     rules, and	no core	dump will be produced.

       /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	 super-max  if	you need to mount more
	      filesystems than the current value in super-max allows you to.

       /proc/sys/fs/super-nr
	      This file	contains the number of filesystems currently mounted.

       /proc/sys/kernel
	      This directory contains files controlling	a range	of kernel  pa-
	      rameters,	as described below.

       /proc/sys/kernel/acct
	      This  file contains three	numbers: highwater, lowwater, and fre-
	      quency.  If BSD-style process accounting is enabled, these  val-
	      ues control its behavior.	 If free space on filesystem where the
	      log lives	goes below lowwater percent, accounting	suspends.   If
	      free  space  gets	 above	highwater percent, accounting resumes.
	      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.

       /proc/sys/kernel/cap_last_cap (since Linux 3.2)
	      See capabilities(7).

       /proc/sys/kernel/cap-bound (from	Linux 2.2 to 2.6.24)
	      This file	holds the value	of the kernel capability bounding  set
	      (expressed  as  a	 signed	 decimal  number).   This set is ANDed
	      against the capabilities	permitted  to  a  process  during  ex-
	      ecve(2).	Starting with Linux 2.6.25, the	system-wide capability
	      bounding set disappeared,	 and  was  replaced  by	 a  per-thread
	      bounding set; see	capabilities(7).

       /proc/sys/kernel/core_pattern
	      See core(5).

       /proc/sys/kernel/core_uses_pid
	      See core(5).

       /proc/sys/kernel/ctrl-alt-del
	      This  file  controls  the	handling of Ctrl-Alt-Del from the key-
	      board.  When the value  in  this	file  is  0,  Ctrl-Alt-Del  is
	      trapped  and  sent  to  the init(8) 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, with-
	      out even syncing its dirty buffers.  Note: when a	program	 (like
	      dosemu)  has the keyboard	in "raw" mode, the ctrl-alt-del	is in-
	      tercepted	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.

       /proc/sys/kernel/dmesg_restrict (since Linux 2.6.37)
	      The value	in this	file determines	who can	see kernel syslog con-
	      tents.  A	value of 0 in this file	imposes	no  restrictions.   If
	      the  value  is 1,	only privileged	users can read the kernel sys-
	      log.  (See syslog(2) for more details.)  Since Linux  3.4,  only
	      users  with the CAP_SYS_ADMIN capability may change the value in
	      this file.

       /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 domainname(1)
	      and hostname(1), that is:

		  # echo 'darkstar' > /proc/sys/kernel/hostname
		  # echo 'mydomain' > /proc/sys/kernel/domainname

	      has the same effect as

		  # hostname 'darkstar'
		  # domainname 'mydomain'

	      Note, however, that the classic darkstar.frop.org	has the	 host-
	      name "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 hostname(1) man page.

       /proc/sys/kernel/hotplug
	      This  file  contains the path for	the hotplug policy agent.  The
	      default value in this file is /sbin/hotplug.

       /proc/sys/kernel/htab-reclaim
	      (PowerPC only) If	this file is set to a nonzero value, the  Pow-
	      erPC  htab  (see kernel file Documentation/powerpc/ppc_htab.txt)
	      is pruned	each time the system hits the idle loop.

       /proc/sys/kernel/kptr_restrict (since Linux 2.6.38)
	      The value	in this	file determines	whether	kernel	addresses  are
	      exposed  via  /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 %pK format specifier will be replaced
	      with zeros unless	the user has the  CAP_SYSLOG  capability.   If
	      the  value  is  2,  kernel pointers printed using	the %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 to 0 in Linux	2.6.39.	  Since	 Linux
	      3.4, only	users with the CAP_SYS_ADMIN capability	can change the
	      value in this file.

       /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.  En-
	      abled if nonzero.

       /proc/sys/kernel/modprobe
	      This file	contains the path for the kernel module	 loader.   The
	      default  value  is  /sbin/modprobe.  The file is present only if
	      the kernel is built  with	 the  CONFIG_MODULES  (CONFIG_KMOD  in
	      Linux  2.6.26  and  earlier) option enabled.  It is described by
	      the Linux	kernel	source	file  Documentation/kmod.txt  (present
	      only in kernel 2.4 and earlier).

       /proc/sys/kernel/modules_disabled (since	Linux 2.6.31)
	      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 CON-
	      FIG_MODULES option enabled.

       /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 mes-
	      sage queue.

       /proc/sys/kernel/msgmni (since Linux 2.4)
	      This file	defines	the system-wide	limit on the number of message
	      queue identifiers.

       /proc/sys/kernel/msgmnb (since Linux 2.2)
	      This file	defines	a system-wide parameter	used to	initialize the
	      msg_qbytes setting for subsequently created message queues.  The
	      msg_qbytes  setting  specifies  the maximum number of bytes that
	      may be written to	the message queue.

       /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.

       /proc/sys/kernel/ostype and /proc/sys/kernel/osrelease
	      These files give substrings of /proc/version.

       /proc/sys/kernel/overflowgid and	/proc/sys/kernel/overflowuid
	      These  files  duplicate  the  files /proc/sys/fs/overflowgid and
	      /proc/sys/fs/overflowuid.

       /proc/sys/kernel/panic
	      This  file  gives	 read/write  access  to	 the  kernel  variable
	      panic_timeout.   If  this	 is  zero,  the	 kernel	will loop on a
	      panic; if	nonzero, it indicates that the kernel  should  autore-
	      boot  after  this	 number	of seconds.  When you use the software
	      watchdog device driver, the recommended setting is 60.

       /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 /proc/sys/kernel/panic file	is  also  non-
	      zero, then the machine will be rebooted.

       /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  num-
	      ber  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 pid_max.  On
	      64-bit systems, pid_max can be set  to  any  value  up  to  2^22
	      (PID_MAX_LIMIT, approximately 4 million).

       /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.

       /proc/sys/kernel/printk
	      See syslog(2).

       /proc/sys/kernel/pty (since Linux 2.6.4)
	      This directory contains two files	relating to the	number of UNIX
	      98 pseudoterminals (see pts(4)) on the system.

       /proc/sys/kernel/pty/max
	      This file	defines	the maximum number of pseudoterminals.

       /proc/sys/kernel/pty/nr
	      This  read-only file indicates how many pseudoterminals are cur-
	      rently in	use.

       /proc/sys/kernel/random
	      This directory contains various parameters controlling the oper-
	      ation of the file	/dev/random.  See random(4) for	further	infor-
	      mation.

       /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.

       /proc/sys/kernel/real-root-dev
	      This file	is documented in the Linux kernel source file Documen-
	      tation/initrd.txt.

       /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 re-
	      booting?

       /proc/sys/kernel/rtsig-max
	      (Only in kernels up to and including  2.6.7;  see	 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.

       /proc/sys/kernel/rtsig-nr
	      (Only in kernels up to and including 2.6.7.)   This  file	 shows
	      the number POSIX real-time signals currently queued.

       /proc/sys/kernel/sched_rr_timeslice_ms (since Linux 3.9)
	      See sched_rr_get_interval(2).

       /proc/sys/kernel/sched_rt_period_us (Since Linux	2.6.25)
	      See sched(7).

       /proc/sys/kernel/sched_rt_runtime_us (Since Linux 2.6.25)
	      See sched(7).

       /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:

	      SEMMSL  The maximum semaphores per semaphore set.

	      SEMMNS  A	system-wide limit on the number	of semaphores  in  all
		      semaphore	sets.

	      SEMOPM  The  maximum  number of operations that may be specified
		      in a semop(2) call.

	      SEMMNI  A	system-wide limit on the maximum number	 of  semaphore
		      identifiers.

       /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	 include/scsi/sg.h  and	 changing the value of
	      SG_BIG_BUFF.  However, there shouldn't be	any reason  to	change
	      this value.

       /proc/sys/kernel/shm_rmid_forced	(since Linux 3.1)
	      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	possi-
	      ble to create shared memory segments that	exist independently of
	      any attached process.

	      The effect is as though a	shmctl(2) 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 de-
	      stroy segments that were created,	but never attached, upon  ter-
	      mination of the process that created the segment with shmget(2).

	      Setting  this file to 1 provides a way of	ensuring that all Sys-
	      tem V shared memory segments are counted	against	 the  resource
	      usage  and  resource limits (see the description of RLIMIT_AS in
	      getrlimit(2)) of at least	one process.

	      Because setting this file	to 1 produces behavior	that  is  non-
	      standard and could also break existing applications, the default
	      value in this file is 0.	Only set this file to 1	if you have  a
	      good  understanding  of  the semantics of	the applications using
	      System V shared memory on	your system.

       /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.

       /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 1GB are now supported in
	      the kernel.  This	value defaults to SHMMAX.

       /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.

       /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 specifi-
	      cally enable it at run-time, but this is not the case any	more).
	      Possible values in this file are:

		 0 - disable sysrq completely
		 1 - enable all	functions of sysrq
		>1 - bit mask of allowed sysrq functions, as follows:
			2 - enable control of console logging level
			4 - enable control of keyboard (SAK, unraw)
			8 - enable debugging dumps of processes	etc.
		       16 - enable sync	command
		       32 - enable remount read-only
		       64 - enable signaling of	processes  (term,  kill,  oom-
	      kill)
		      128 - allow reboot/poweroff
		      256 - allow nicing of all	real-time tasks

	      This  file is present only if the	CONFIG_MAGIC_SYSRQ kernel con-
	      figuration option	is enabled.  For further details see the Linux
	      kernel source file Documentation/sysrq.txt.

       /proc/sys/kernel/version
	      This file	contains a string like:

		  #5 Wed Feb 25	21:49:24 MET 1998

	      The  "#5"	 means	that  this is the fifth	kernel built from this
	      source base and the date behind it indicates the time the	kernel
	      was built.

       /proc/sys/kernel/threads-max (since Linux 2.3.11)
	      This  file  specifies  the  system-wide  limit  on the number of
	      threads (tasks) that can be created on the system.

       /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.

       /proc/sys/net
	      This directory contains networking stuff.	 Explanations for some
	      of  the  files  under  this directory can	be found in tcp(7) and
	      ip(7).

       /proc/sys/net/core/somaxconn
	      This file	defines	a ceiling value	for the	 backlog  argument  of
	      listen(2); see the listen(2) manual page for details.

       /proc/sys/proc
	      This directory may be empty.

       /proc/sys/sunrpc
	      This  directory  supports	 Sun remote procedure call for network
	      filesystem (NFS).	 On some systems, it is	not present.

       /proc/sys/vm
	      This directory contains files for	memory management tuning, buf-
	      fer and cache management.

       /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 per-
	      forming reproducible filesystem benchmarks.  Because writing  to
	      this  file causes	the benefits of	caching	to be lost, it can de-
	      grade overall system performance.

	      To free pagecache, use:

		  echo 1 > /proc/sys/vm/drop_caches

	      To free dentries and inodes, use:

		  echo 2 > /proc/sys/vm/drop_caches

	      To free pagecache, dentries and inodes, use:

		  echo 3 > /proc/sys/vm/drop_caches

	      Because writing to this file is a	nondestructive	operation  and
	      dirty  objects  are  not	freeable,  the user should run sync(1)
	      first.

       /proc/sys/vm/legacy_va_layout (since Linux 2.6.9)
	      If nonzero, this disables	the new	32-bit memory-mapping  layout;
	      the kernel will use the legacy (2.4) layout for all processes.

       /proc/sys/vm/memory_failure_early_kill (since Linux 2.6.32)
	      Control  how  to kill processes when an uncorrected memory error
	      (typically a 2-bit error in a memory module) that	cannot be han-
	      dled  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 affect-
	      ing any applications.  But if there is no	other up-to-date  copy
	      of  the data, it will kill processes to prevent any data corrup-
	      tions from propagating.

	      The file has one of the following	values:

	      1:  Kill all processes that have	the  corrupted-and-not-reload-
		  able	page  mapped  as  soon	as the corruption is detected.
		  Note this is not supported for a few types  of  pages,  like
		  kernel  internally  allocated	 data  or  the swap cache, but
		  works	for the	majority of user pages.

	      0:  Only unmap the corrupted page	from all  processes  and  kill
		  only a process that tries to access it.

	      The  kill	is performed using a SIGBUS signal with	si_code	set to
	      BUS_MCEERR_AO.  Processes	can handle this	if they	want  to;  see
	      sigaction(2) for more details.

	      This  feature is active only on architectures/platforms with ad-
	      vanced machine check handling and	depends	on the hardware	 capa-
	      bilities.

	      Applications  can	override the memory_failure_early_kill setting
	      individually with	the prctl(2) PR_MCE_KILL operation.

	      Only present if  the  kernel  was	 configured  with  CONFIG_MEM-
	      ORY_FAILURE.

       /proc/sys/vm/memory_failure_recovery (since Linux 2.6.32)
	      Enable memory failure recovery (when supported by	the platform)

	      1:  Attempt recovery.

	      0:  Always panic on a memory failure.

	      Only  present  if	 the  kernel  was  configured with CONFIG_MEM-
	      ORY_FAILURE.

       /proc/sys/vm/oom_dump_tasks (since Linux	2.6.25)
	      Enables a	system-wide task dump (excluding kernel	threads) to be
	      produced	when the kernel	performs an OOM-killing.  The dump in-
	      cludes  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
	      /proc/[pid]/oom_adj), and	command	name.  This is helpful to  de-
	      termine why the OOM-killer was invoked and to identify the rogue
	      task that	caused it.

	      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.

	      If this is set to	nonzero, this information  is  shown  whenever
	      the OOM-killer actually kills a memory-hogging task.

	      The default value	is 0.

       /proc/sys/vm/oom_kill_allocating_task (since Linux 2.6.24)
	      This enables or disables killing the OOM-triggering task in out-
	      of-memory	situations.

	      If this is set to	zero, the OOM-killer will scan through the en-
	      tire  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.

	      If  this is set to nonzero, the OOM-killer simply	kills the task
	      that triggered the out-of-memory condition.  This	avoids a  pos-
	      sibly expensive tasklist scan.

	      If  /proc/sys/vm/panic_on_oom  is	 nonzero,  it takes precedence
	      over whatever value is  used  in	/proc/sys/vm/oom_kill_allocat-
	      ing_task.

	      The default value	is 0.

       /proc/sys/vm/overcommit_kbytes (since Linux 3.14)
	      This writable file provides an alternative to /proc/sys/vm/over-
	      commit_ratio    for    controlling    the	   CommitLimit	  when
	      /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
	      overcommit_ratio.	 This allows for finer-grained control of Com-
	      mitLimit on systems with extremely large memory sizes.

	      Only  one	 of  overcommit_kbytes or overcommit_ratio can have an
	      effect: if overcommit_kbytes has a nonzero  value,  then	it  is
	      used  to	calculate  CommitLimit,	 otherwise overcommit_ratio is
	      used.  Writing a value to	either of these	files causes the value
	      in the other file	to be set to zero.

       /proc/sys/vm/overcommit_memory
	      This  file  contains  the	kernel virtual memory accounting mode.
	      Values are:

		     0:	heuristic overcommit (this is the default)
		     1:	always overcommit, never check
		     2:	always check, never overcommit

	      In mode 0, calls of mmap(2) with MAP_NORESERVE are not  checked,
	      and  the default check is	very weak, leading to the risk of get-
	      ting a process "OOM-killed".  Under Linux	2.4, any nonzero value
	      implies mode 1.

	      In mode 2	(available since Linux 2.6), the total virtual address
	      space that can be	allocated (CommitLimit	in  /proc/meminfo)  is
	      calculated as

		  CommitLimit =	(total_RAM - total_huge_TLB) *
				overcommit_ratio / 100 + total_swap

	      where:

		   *  total_RAM	is the total amount of RAM on the system;

		   *  total_huge_TLB  is  the  amount  of memory set aside for
		      huge pages;

		   *  overcommit_ratio is the value  in	 /proc/sys/vm/overcom-
		      mit_ratio; and

		   *  total_swap is the	amount of swap space.

	      For  example,  on	 a  system  with 16GB of physical RAM, 16GB of
	      swap, no space dedicated to huge pages, and an  overcommit_ratio
	      of 50, this formula yields a CommitLimit of 24GB.

	      Since Linux 3.14,	if the value in	/proc/sys/vm/overcommit_kbytes
	      is nonzero, then CommitLimit is instead calculated as:

		  CommitLimit =	overcommit_kbytes + total_swap

       /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 /proc/sys/vm/overcommit_memory.

       /proc/sys/vm/panic_on_oom (since	Linux 2.6.18)
	      This enables or disables a kernel	panic in an out-of-memory sit-
	      uation.

	      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.

	      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 (mbind(2)
	      MPOL_BIND) or cpusets (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.

	      If this file is set to the value 2,  the	kernel	always	panics
	      when an out-of-memory condition occurs.

	      The default value	is 0.  1 and 2 are for failover	of clustering.
	      Select either according to your policy of	failover.

       /proc/sys/vm/swappiness
	      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.

       /proc/sysrq-trigger (since Linux	2.4.21)
	      Writing a	character to this file triggers	the same  SysRq	 func-
	      tion  as	typing	ALT-SysRq-<character>  (see the	description of
	      /proc/sys/kernel/sysrq).	This file is normally writable only by
	      root.  For further details see the Linux kernel source file Doc-
	      umentation/sysrq.txt.

       /proc/sysvipc
	      Subdirectory containing  the  pseudo-files  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	 ipcs(1).   These  files  have
	      headers and are formatted	(one IPC object	per line) for easy un-
	      derstanding.  svipc(7) provides further background on the	infor-
	      mation shown by these files.

       /proc/timer_list	(since Linux 2.6.21)
	      This  read-only  file  exposes  a	 list of all currently pending
	      (high-resolution)	timers,	all clock-event	sources, and their pa-
	      rameters in a human-readable form.

       /proc/timer_stats (since	Linux 2.6.21)
	      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.

	      If  enabled in the kernel	(CONFIG_TIMER_STATS), but not used, it
	      has almost zero runtime overhead and a  relatively  small	 data-
	      structure	 overhead.   Even if collection	is enabled at runtime,
	      overhead is low: all  the	 locking  is  per-CPU  and  lookup  is
	      hashed.

	      The  /proc/timer_stats file is used both to control sampling fa-
	      cility and to read out the sampled information.

	      The timer_stats functionality is inactive	on bootup.  A sampling
	      period can be started using the following	command:

		  # echo 1 > /proc/timer_stats

	      The following command stops a sampling period:

		  # echo 0 > /proc/timer_stats

	      The statistics can be retrieved by:

		  $ cat	/proc/timer_stats

	      While  sampling  is enabled, each	readout	from /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.

	      Sample output from /proc/timer_stats:

   $ 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

	      The output columns are:

	      *	 a count of the	number	of  events,  optionally	 (since	 Linux
		 2.6.23)  followed  by	the letter 'D' if this is a deferrable
		 timer;

	      *	 the PID of the	process	that initialized the timer;

	      *	 the name of the process that initialized the timer;

	      *	 the function where the	timer was initialized; and

	      *	 (in parentheses) the callback	function  that	is  associated
		 with the timer.

       /proc/tty
	      Subdirectory  containing the pseudo-files	and subdirectories for
	      tty drivers and line disciplines.

       /proc/uptime
	      This file	contains two numbers: the uptime of the	 system	 (sec-
	      onds), and the amount of time spent in idle process (seconds).

       /proc/version
	      This string identifies the kernel	version	that is	currently run-
	      ning.  It	 includes  the	contents  of  /proc/sys/kernel/ostype,
	      /proc/sys/kernel/osrelease  and  /proc/sys/kernel/version.   For
	      example:
	    Linux version 1.0.9	(quinlan@phaze)	#1 Sat May 14 01:51:54 EDT 1994

       /proc/vmstat (since Linux 2.6)
	      This file	displays various virtual memory	statistics.

       /proc/zoneinfo (since Linux 2.6.13)
	      This file	display	information about memory zones.	 This is  use-
	      ful for analyzing	virtual	memory behavior.

NOTES
       Many strings (i.e., the environment and command line) are in the	inter-
       nal format, with	subfields terminated by	null bytes ('\0'), so you  may
       find  that  things are more readable if you use od -c or	tr "\000" "\n"
       to read them.  Alternatively, echo `cat _file_` works well.

       This manual page	is incomplete, possibly	inaccurate, and	is the kind of
       thing that needs	to be updated very often.

SEE ALSO
       cat(1), dmesg(1), find(1), free(1), ps(1), tr(1), uptime(1), chroot(2),
       mmap(2),	readlink(2), syslog(2),	slabinfo(5),  hier(7),	namespaces(7),
       time(7),	 arp(8),  hdparm(8), ifconfig(8), init(8), lsmod(8), lspci(8),
       mount(8), netstat(8), procinfo(8), route(8), sysctl(8)

       The Linux kernel	source files: Documentation/filesystems/proc.txt Docu-
       mentation/sysctl/fs.txt,	  Documentation/sysctl/kernel.txt,  Documenta-
       tion/sysctl/net.txt, and	Documentation/sysctl/vm.txt.

COLOPHON
       This page is part of release 3.74 of the	Linux  man-pages  project.   A
       description  of	the project, information about reporting bugs, and the
       latest	 version    of	  this	  page,	   can	   be	  found	    at
       http://www.kernel.org/doc/man-pages/.

Linux				  2014-09-21			       PROC(5)

NAME | DESCRIPTION | NOTES | SEE ALSO | COLOPHON

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