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.

              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.

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


              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

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

              This 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 charac-
              ters.  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]/coredump_filter (since kernel 2.6.23)
              See core(5).

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


              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

              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:


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

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

              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, etc.

              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:


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


              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

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

       /proc/[pid]/fdinfo/ (since kernel 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
              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.

                     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]/limits (since kernel 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

       /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/

              kernel configuration option is enabled.

              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/
       35b1a1f000-35b1a20000 r--p 0001f000 08:02 135522  /usr/lib64/
       35b1a20000-35b1a21000 rw-p 00020000 08:02 135522  /usr/lib64/
       35b1a21000-35b1a22000 rw-p 00000000 00:00 0
       35b1c00000-35b1dac000 r-xp 00000000 08:02 135870  /usr/lib64/
       35b1dac000-35b1fac000 ---p 001ac000 08:02 135870  /usr/lib64/
       35b1fac000-35b1fb0000 r--p 001ac000 08:02 135870  /usr/lib64/
       35b1fb0000-35b1fb2000 rw-p 001b0000 08:02 135870  /usr/lib64/
       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:

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

              through gdb(1), strace(1), or similar.

              Under Linux 2.0 there is no field giving pathname.

              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

              (1)  mount  ID:  unique  identifier  of the mount (may be reused
                   after 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

              (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

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

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

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

              (11) super options: per-super block 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 (*)

       /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.

       /proc/[pid]/mountstats (since Linux 2.6.17)
              This  file exports information (statistics, configuration infor-
              mation) about the mount points  in  the  process's  name  space.
              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.

       /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 information
              about namespaces, see clone(2).

       /proc/[pid]/ns/ipc (since Linux 3.0)
              Bind mounting this file (see mount(2)) to somewhere else in  the
              filesystem  keeps  the IPC namespace of the process specified by
              pid alive even if all processes currently in the namespace  ter-

              Opening this file returns a file handle for the IPC namespace of
              the process specified by pid.  As long as this  file  descriptor
              remains  open,  the IPC namespace will remain alive, even if all
              processes in the namespace terminate.  The file  descriptor  can
              be passed to setns(2).

       /proc/[pid]/ns/net (since Linux 3.0)
              Bind  mounting this file (see mount(2)) to somewhere else in the
              filesystem keeps the network namespace of the process  specified
              by pid alive even if all processes in the namespace terminate.

              Opening this file returns a file handle for the UTS namespace of
              the  process  specified by pid.  As long as this file descriptor
              remains open, the UTS namespace will remain alive, even  if  all
              processes  in  the namespace terminate.  The file descriptor can
              be passed to setns(2).

       /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
              altogether  for  this  process.   A positive score increases the
              likelihood of this process being killed  by  the  OOM-killer;  a
              negative score decreases the likelihood.

              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 (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
              decreases (-) 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
              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
              exhausted, the allowed memory represents the  set  of  mempolicy
              nodes.   If  it  is  due to a memory limit (or swap limit) being
              reached, the allowed memory is that configured limit.   Finally,
              if  it  is  due  to  the  entire system being out of memory, the
              allowed memory represents all allocatable resources.

              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
              allowed  memory  from  being  considered  as scoring against the

              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.

              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 as exe, fd/*, etc. do.

              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.   For each of mappings there is a series of lines such
              as the following:

                  08048000-080bc000 r-xp 00000000 03:02 13130      /bin/bash
                  Size:               464 kB

              This file is present only if the CONFIG_MMU kernel configuration
              option is enabled.

              Status information about the process.  This is  used  by  ps(1).
              It is defined in /usr/src/linux/fs/proc/array.c.

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

              pid %d      (1) The process ID.

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

              state %c    (3) One character from the string "RSDZTW"  where  R
                          is  running, S is sleeping in an interruptible wait,
                          D is waiting in uninterruptible  disk  sleep,  Z  is
                          zombie,  T is traced or stopped (on a signal), and W
                          is paging.

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

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

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

              tty_nr %d   (7) 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.)

              tpgid %d    (8)  The  ID  of the foreground process group of the
                          controlling terminal of the process.

              flags %u (%lu before Linux 2.6.22)
                          (9) The kernel flags word of the process.   For  bit
                          meanings,  see  the PF_* defines in the Linux kernel
                          source file include/linux/sched.h.   Details  depend
                          on the kernel version.

              minflt %lu  (10) The number of minor faults the process has made
                          which have not required loading a memory  page  from

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

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

              cmajflt %lu (13)  The  number of major faults that the process's
                          (divide by sysconf(_SC_CLK_TCK)).

              cutime %ld  (16) 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

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

              priority %ld
                          (18) (Explanation for Linux 2.6) For processes  run-
                          ning  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  (setpriority(2))  as represented in the
                          kernel.  The kernel stores nice values as numbers in
                          the range 0 (high) to 39 (low), corresponding to the
                          user-visible nice range of -20 to 19.

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

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

              num_threads %ld
                          (20) 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.

              itrealvalue %ld
                          (21) 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.

              starttime %llu (was %lu before Linux 2.6)
                          (22) 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

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

              rss %ld     (24)  Resident Set Size: number of pages the process
              endcode %lu (27) The address below which program text can run.

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

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

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

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

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

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

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

              wchan %lu   (35)  This  is the "channel" in which the process is
                          waiting.  It is the address of a  system  call,  and
                          can be looked up in a namelist if you need a textual
                          name.  (If you have an  up-to-date  /etc/psdatabase,
                          then try ps -l to see the WCHAN field in action.)

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

              cnswap %lu  (37) Cumulative nswap for child processes (not main-

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

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

              rt_priority %u (since Linux 2.5.19; was %lu before Linux 2.6.22)
                          (40) Real-time scheduling priority, a number in  the
                          range  1 to 99 for processes scheduled under a real-
                          time policy, or 0, for non-real-time processes  (see
                          virtual CPU for a guest operating system),  measured
                          in clock ticks (divide by sysconf(_SC_CLK_TCK)).

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

              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)

              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

              * 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

              * Uid, Gid: Real, effective,  saved  set,  and  filesystem  UIDs

              * 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
                relate to queued signals for the real user ID of this process.
                The  first  of these is the number of currently queued signals
                for this real user ID, and the second is the resource limit on
                the  number  of  queued  signals  for  this  process  (see the
                description of 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)).

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

       /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
              numerical  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] direc-
              tories.  For attributes that are shared by all threads, the con-
              tents  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

              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)).

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

              Contains subdirectories for installed busses.

              Subdirectory  for  PCMCIA  devices  when CONFIG_PCMCIA is set at
              kernel compilation time.


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

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

              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
              bogomips;  a  system  constant  that is calculated during kernel
              initialization.  SMP machines have  information  for  each  CPU.
              The lscpu(1) command gathers its information from this file.

              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.

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

              Empty subdirectory.

              List of the execution domains (ABI personalities).

              Frame buffer information when CONFIG_FB is defined during kernel

              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").

              Empty subdirectory.
                  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.

              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.

              I/O memory map in Linux 2.4.

              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.

              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.

              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-

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

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

              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.

              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
              below,  all of the fields have been present since at least Linux
              2.6.0.  Some fileds are displayed only if the kernel was config-
              ured  with  various options; those dependencies are noted in the

              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
                     because they are already in the swap  file.   This  saves

              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
                     eligible to be reclaimed for other purposes.

              Active(anon) %lu (since Linux 2.6.28)
                     [To be documented.]
                     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 mmaped, such as libraries.

              Shmem %lu (since Linux 2.6.32)
                     [To be documented.]
                     Amount of memory allocated to kernel stacks.

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

              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)
                     Based  on  the  overcommit ratio ('vm.overcommit_ratio'),
                     this is the total amount of  memory  currently  available
                     to  be allocated on the system.  This limit is adhered to
                     only if strict overcommit accounting is enabled  (mode  2
                     in  /proc/sys/vm/overcommit_ratio).   The  CommitLimit is
                     calculated using the following formula:

                         CommitLimit = (overcommit_ratio  *  Physical  RAM)  +

                     For example, on a system with 1GB of physical RAM and 7GB
                     of swap with  a  overcommit_ratio  of  30,  this  formula
                     yields a CommitLimit of 7.3GB.  For more details, see the
                     memory overcommit documentation in the kernel source file

              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  "commit-
                     ted"  to  by  the  VM  and can be used at any time by the
                     allocating application.  With strict  overcommit  enabled
                     on  the  system  (mode 2 /proc/sys/vm/overcommit_memory),
                     allocations which would exceed the CommitLimit  (detailed
                     above)  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

              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-

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

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

              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).

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

              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

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

              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

              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

              Internet    Group    Management    Protocol.      Defined     in

              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.

              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

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

              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.  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
              usage.  The "tr", "tm->when", and "rexmits" fields are not  used
              by  UDP.  The "uid" field holds the effective UID of the creator
              of the socket.  The format is:

 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

              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.

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

              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

              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.

              [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, etc.

              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.

              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.

              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:


              See slabinfo(5) for details.

              kernel/system statistics.   Varies  with  architecture.   Common
              entries include:

              cpu  3357 0 4313 1362393
                     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

                     guest (since Linux 2.6.24)
                            (9)  Time  spent  running  a virtual CPU for guest
                            operating systems under the control of  the  Linux

                     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

              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;
                     each subsequent column is  the  total  for  a  particular

              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).

              Swap areas in use.  See also swapon(8).

              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.

              This directory may be empty.

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

              This  directory contains the files and subdirectories for kernel
              variables related to filesystems.

              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
              requested by system) and two dummy values.

              * nr_dentry  is  the  number  of  allocated   dentries   (dcache
                entries).  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.

              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.

              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

              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

              This (read-only) file contains  three  numbers:  the  number  of
              allocated  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
              indicates that there was a past peak in the usage of  open  file
              handles.  Since Linux 2.6, the kernel does deallocate freed file
              handles, and the "free file handles" value is always zero.

       /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.

              This file contains the first two values from 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-
              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.

              This  file  can  be  used  to  enable  or  disable  file  leases
              (fcntl(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
              enabled, 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
              employed  for  a  convenient  implementation.   To determine the
              rounded-up value,  display  the  contents  of  this  file  after
              assigning 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-
              iour before Linux 3.6).  When the value in this  file  is  1,  a
              hard  link  can  be  created to a target file only if one of the
              following conditions is true:

              *  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;

              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
              being upgraded by  the  administrator,  or  linking  to  special

       /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 behaviour
              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 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.

              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.

              This file contains the number of filesystems currently mounted.

              This directory contains files  controlling  a  range  of  kernel
              parameters, as described below.

              This  file contains three numbers: highwater, lowwater, and fre-
              quency.  If BSD-style process accounting is enabled these values
              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.  fre-
              quency 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
              execve(2).  Starting with Linux 2.6.25, the system-wide capabil-
              ity bounding set disappeared, and was replaced by  a  per-thread
              bounding set; see capabilities(7).

              See core(5).

              See core(5).

              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
              intercepted by the program before it ever reaches the kernel tty
              layer, and it's up to the program to decide what to do with it.

       /proc/sys/kernel/dmesg_restrict (since Linux 2.6.37)
              The value in this file determines who can see kernel syslog con-
                  # echo 'mydomain' > /proc/sys/kernel/domainname

              has the same effect as

                  # hostname 'darkstar'
                  # domainname 'mydomain'

              Note, however, that the classic has the  host-
              name "darkstar" and DNS (Internet Domain Name Server) domainname
              "", 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.

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

              (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.

              (PowerPC only) This file contains a flag that  controls  the  L2
              cache  of  G3  processor  boards.   If 0, the cache is disabled.
              Enabled if nonzero.

              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.

              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/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

              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 autoreboot
              after this number of seconds.  When you use the software  watch-
              dog 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 nonzero
              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).
              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.

              The  four values in this file are console_loglevel, default_mes-
              sage_loglevel,    minimum_console_level,    and     default_con-
              sole_loglevel.   These  values  influence printk() behavior when
              printing or logging error messages.  See syslog(2) for more info
              on  the  different  loglevels.   Messages with a higher priority
              than console_loglevel will be printed to the console.   Messages
              without  an  explicit  priority  will  be  printed with priority
              default_message_level.  minimum_console_loglevel is the  minimum
              (highest)   value   to   which   console_loglevel  can  be  set.
              default_console_loglevel  is  the   default   value   for   con-

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

              This file is documented in the Linux kernel source file Documen-

       /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

              (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.

              (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/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

              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.

              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.

              This  file contains the system-wide limit on the total number of
              pages of System V shared memory.

              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.

              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 signalling of processes (term, kill, oom-
                      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.

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

              This  file  defines  a ceiling value for the backlog argument of
              listen(2); see the listen(2) manual page for details.

              This directory may be empty.

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

              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
              degrade 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(8)

       /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
                  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
              advanced  machine  check  handling  and  depends on the hardware

              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-

       /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-

       /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
              includes  the  following  information  for  each  task  (thread,
              process): thread ID, real user ID, thread group ID (process ID),
              virtual memory size, resident set size, the CPU that the task is
              scheduled  on,   oom_adj   score   (see   the   description   of
              /proc/[pid]/oom_adj),  and  command  name.   This  is helpful to
              determine why the OOM-killer was invoked  and  to  identify  the
              rogue task that caused it.

              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
              entire tasklist and select a task based on heuristics  to  kill.

              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 on the system is limited to (SS +
              RAM*(r/100)), where SS is the size of the swap space, and RAM is
              the  size  of  the physical memory, and r is the contents of the
              file /proc/sys/vm/overcommit_ratio.

              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-

              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.

              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-

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

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

              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
            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.

       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.

       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), time(7), arp(8),
       hdparm(8),  ifconfig(8),  init(8),  lsmod(8),  lspci(8), mount(8), net-
       stat(8), procinfo(8), route(8), sysctl(8)

       The Linux kernel source files:  Documentation/filesystems/proc.txt  and

       This  page  is  part of release 3.54 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at

Linux                             2013-09-04                           PROC(5)
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