.\" Copyright (C) 1994, 1995, Daniel Quinlan <quinlan@yggdrasil.com>
.\" Copyright (C) 2002-2008, 2017, Michael Kerrisk <mtk.manpages@gmail.com>
.\" Copyright (C) 2023, Alejandro Colomar <alx@kernel.org>
.\"
.\" SPDX-License-Identifier: GPL-3.0-or-later
.\"
.TH proc_pid_stat 5 2024-05-02 "Linux man-pages (unreleased)"
.SH NAME
/proc/pid/stat \- status information
.SH DESCRIPTION
.TP
.IR /proc/ pid /stat
Status information about the process.
This is used by
.BR ps (1).
It is defined in the kernel source file
.IR fs/proc/array.c "."
.IP
The fields, in order, with their proper
.BR scanf (3)
format specifiers, are listed below.
Whether or not certain of these fields display valid information is governed by
a ptrace access mode
.BR PTRACE_MODE_READ_FSCREDS " | " PTRACE_MODE_NOAUDIT
check (refer to
.BR ptrace (2)).
If the check denies access, then the field value is displayed as 0.
The affected fields are indicated with the marking [PT].
.RS
.TP
(1) \fIpid\fP \ %d
.br
The process ID.
.TP
(2) \fIcomm\fP \ %s
The filename of the executable, in parentheses.
Strings longer than
.B TASK_COMM_LEN
(16) characters (including the terminating null byte) are silently truncated.
This is visible whether or not the executable is swapped out.
.TP
(3) \fIstate\fP \ %c
One of the following characters, indicating process state:
.RS
.TP
R
Running
.TP
S
Sleeping in an interruptible wait
.TP
D
Waiting in uninterruptible
disk sleep
.TP
Z
Zombie
.TP
T
Stopped (on a signal) or (before Linux 2.6.33) trace stopped
.TP
t
.\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29
Tracing stop (Linux 2.6.33 onward)
.TP
W
Paging (only before Linux 2.6.0)
.TP
X
Dead (from Linux 2.6.0 onward)
.TP
x
.\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29
Dead (Linux 2.6.33 to
.\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457
3.13 only)
.TP
K
.\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29
Wakekill (Linux 2.6.33 to
.\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457
3.13 only)
.TP
W
.\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29
Waking (Linux 2.6.33 to
.\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457
3.13 only)
.TP
P
.\" commit f2530dc71cf0822f90bb63ea4600caaef33a66bb
Parked (Linux 3.9 to
.\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457
3.13 only)
.TP
I
.\" commit 06eb61844d841d0032a9950ce7f8e783ee49c0d0
Idle (Linux 4.14 onward)
.RE
.TP
(4) \fIppid\fP \ %d
The PID of the parent of this process.
.TP
(5) \fIpgrp\fP \ %d
The process group ID of the process.
.TP
(6) \fIsession\fP \ %d
The session ID of the process.
.TP
(7) \fItty_nr\fP \ %d
The controlling terminal of the process.
(The minor device number is contained in the combination of bits
31 to 20 and 7 to 0;
the major device number is in bits 15 to 8.)
.TP
(8) \fItpgid\fP \ %d
.\" This field and following, up to and including wchan added 0.99.1
The ID of the foreground process group of the controlling
terminal of the process.
.TP
(9) \fIflags\fP \ %u
The kernel flags word of the process.
For bit meanings,
see the PF_* defines in the Linux kernel source file
.IR include/linux/sched.h .
Details depend on the kernel version.
.IP
The format for this field was %lu before Linux 2.6.
.TP
(10) \fIminflt\fP \ %lu
The number of minor faults the process has made which have not
required loading a memory page from disk.
.TP
(11) \fIcminflt\fP \ %lu
The number of minor faults that the process's
waited-for children have made.
.TP
(12) \fImajflt\fP \ %lu
The number of major faults the process has made which have
required loading a memory page from disk.
.TP
(13) \fIcmajflt\fP \ %lu
The number of major faults that the process's
waited-for children have made.
.TP
(14) \fIutime\fP \ %lu
Amount of time that this process has been scheduled in user mode,
measured in clock ticks (divide by
.IR sysconf(_SC_CLK_TCK) ).
This includes guest time, \fIguest_time\fP
(time spent running a virtual CPU, see below),
so that applications that are not aware of the guest time field
do not lose that time from their calculations.
.TP
(15) \fIstime\fP \ %lu
Amount of time that this process has been scheduled in kernel mode,
measured in clock ticks (divide by
.IR sysconf(_SC_CLK_TCK) ).
.TP
(16) \fIcutime\fP \ %ld
Amount of time that this process's
waited-for children have been scheduled in user mode,
measured in clock ticks (divide by
.IR sysconf(_SC_CLK_TCK) ).
(See also
.BR times (2).)
This includes guest time, \fIcguest_time\fP
(time spent running a virtual CPU, see below).
.TP
(17) \fIcstime\fP \ %ld
Amount of time that this process's
waited-for children have been scheduled in kernel mode,
measured in clock ticks (divide by
.IR sysconf(_SC_CLK_TCK) ).
.TP
(18) \fIpriority\fP \ %ld
(Explanation for Linux 2.6)
For processes running a real-time scheduling policy
.RI ( policy
below; see
.BR sched_setscheduler (2)),
this is the negated scheduling priority, minus one;
that is, a number in the range \-2 to \-100,
corresponding to real-time priorities 1 to 99.
For processes running under a non-real-time scheduling policy,
this is the raw nice value
.RB ( setpriority (2))
as represented in the kernel.
The kernel stores nice values as numbers
in the range 0 (high) to 39 (low),
corresponding to the user-visible nice range of \-20 to 19.
.IP
Before Linux 2.6, this was a scaled value based on
the scheduler weighting given to this process.
.\" And back in Linux 1.2 days things were different again.
.TP
(19) \fInice\fP \ %ld
The nice value (see
.BR setpriority (2)),
a value in the range 19 (low priority) to \-20 (high priority).
.\" Back in Linux 1.2 days things were different.
.\" .TP
.\" \fIcounter\fP %ld
.\" The current maximum size in jiffies of the process's next timeslice,
.\" or what is currently left of its current timeslice, if it is the
.\" currently running process.
.\" .TP
.\" \fItimeout\fP %u
.\" The time in jiffies of the process's next timeout.
.\" timeout was removed sometime around 2.1/2.2
.TP
(20) \fInum_threads\fP \ %ld
Number of threads in this process (since Linux 2.6).
Before Linux 2.6, this field was hard coded to 0 as a placeholder
for an earlier removed field.
.TP
(21) \fIitrealvalue\fP \ %ld
The time in jiffies before the next
.B SIGALRM
is sent to the process due to an interval timer.
Since Linux 2.6.17, this field is no longer maintained,
and is hard coded as 0.
.TP
(22) \fIstarttime\fP \ %llu
The time the process started after system boot.
Before Linux 2.6, this value was expressed in jiffies.
Since Linux 2.6, the value is expressed in clock ticks (divide by
.IR sysconf(_SC_CLK_TCK) ).
.IP
The format for this field was %lu before Linux 2.6.
.TP
(23) \fIvsize\fP \ %lu
Virtual memory size in bytes.
.TP
(24) \fIrss\fP \ %ld
Resident Set Size: number of pages the process has in real memory.
This is just the pages which
count toward text, data, or stack space.
This does not include pages
which have not been demand-loaded in, or which are swapped out.
This value is inaccurate; see
.IR /proc/ pid /statm
below.
.TP
(25) \fIrsslim\fP \ %lu
Current soft limit in bytes on the rss of the process;
see the description of
.B RLIMIT_RSS
in
.BR getrlimit (2).
.TP
(26) \fIstartcode\fP \ %lu \ [PT]
The address above which program text can run.
.TP
(27) \fIendcode\fP \ %lu \ [PT]
The address below which program text can run.
.TP
(28) \fIstartstack\fP \ %lu \ [PT]
The address of the start (i.e., bottom) of the stack.
.TP
(29) \fIkstkesp\fP \ %lu \ [PT]
The current value of ESP (stack pointer), as found in the
kernel stack page for the process.
.TP
(30) \fIkstkeip\fP \ %lu \ [PT]
The current EIP (instruction pointer).
.TP
(31) \fIsignal\fP \ %lu
The bitmap of pending signals, displayed as a decimal number.
Obsolete, because it does not provide information on real-time signals; use
.IR /proc/ pid /status
instead.
.TP
(32) \fIblocked\fP \ %lu
The bitmap of blocked signals, displayed as a decimal number.
Obsolete, because it does not provide information on real-time signals; use
.IR /proc/ pid /status
instead.
.TP
(33) \fIsigignore\fP \ %lu
The bitmap of ignored signals, displayed as a decimal number.
Obsolete, because it does not provide information on real-time signals; use
.IR /proc/ pid /status
instead.
.TP
(34) \fIsigcatch\fP \ %lu
The bitmap of caught signals, displayed as a decimal number.
Obsolete, because it does not provide information on real-time signals; use
.IR /proc/ pid /status
instead.
.TP
(35) \fIwchan\fP \ %lu \ [PT]
This is the "channel" in which the process is waiting.
It is the address of a location in the kernel where the process is sleeping.
The corresponding symbolic name can be found in
.IR /proc/ pid /wchan .
.TP
(36) \fInswap\fP \ %lu
.\" nswap was added in Linux 2.0
Number of pages swapped (not maintained).
.TP
(37) \fIcnswap\fP \ %lu
.\" cnswap was added in Linux 2.0
Cumulative \fInswap\fP for child processes (not maintained).
.TP
(38) \fIexit_signal\fP \ %d \ (since Linux 2.1.22)
Signal to be sent to parent when we die.
.TP
(39) \fIprocessor\fP \ %d \ (since Linux 2.2.8)
CPU number last executed on.
.TP
(40) \fIrt_priority\fP \ %u \ (since Linux 2.5.19)
Real-time scheduling priority, a number in the range 1 to 99 for
processes scheduled under a real-time policy,
or 0, for non-real-time processes (see
.BR sched_setscheduler (2)).
.TP
(41) \fIpolicy\fP \ %u \ (since Linux 2.5.19)
Scheduling policy (see
.BR sched_setscheduler (2)).
Decode using the SCHED_* constants in
.IR linux/sched.h .
.IP
The format for this field was %lu before Linux 2.6.22.
.TP
(42) \fIdelayacct_blkio_ticks\fP \ %llu \ (since Linux 2.6.18)
Aggregated block I/O delays, measured in clock ticks (centiseconds).
.TP
(43) \fIguest_time\fP \ %lu \ (since Linux 2.6.24)
Guest time of the process (time spent running a virtual CPU
for a guest operating system), measured in clock ticks (divide by
.IR sysconf(_SC_CLK_TCK) ).
.TP
(44) \fIcguest_time\fP \ %ld \ (since Linux 2.6.24)
Guest time of the process's children, measured in clock ticks (divide by
.IR sysconf(_SC_CLK_TCK) ).
.TP
(45) \fIstart_data\fP \ %lu \ (since Linux 3.3) \ [PT]
.\" commit b3f7f573a20081910e34e99cbc91831f4f02f1ff
Address above which program initialized and
uninitialized (BSS) data are placed.
.TP
(46) \fIend_data\fP \ %lu \ (since Linux 3.3) \ [PT]
.\" commit b3f7f573a20081910e34e99cbc91831f4f02f1ff
Address below which program initialized and
uninitialized (BSS) data are placed.
.TP
(47) \fIstart_brk\fP \ %lu \ (since Linux 3.3) \ [PT]
.\" commit b3f7f573a20081910e34e99cbc91831f4f02f1ff
Address above which program heap can be expanded with
.BR brk (2).
.TP
(48) \fIarg_start\fP \ %lu \ (since Linux 3.5) \ [PT]
.\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3
Address above which program command-line arguments
.RI ( argv )
are placed.
.TP
(49) \fIarg_end\fP \ %lu \ (since Linux 3.5) \ [PT]
.\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3
Address below program command-line arguments
.RI ( argv )
are placed.
.TP
(50) \fIenv_start\fP \ %lu \ (since Linux 3.5) \ [PT]
.\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3
Address above which program environment is placed.
.TP
(51) \fIenv_end\fP \ %lu \ (since Linux 3.5) \ [PT]
.\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3
Address below which program environment is placed.
.TP
(52) \fIexit_code\fP \ %d \ (since Linux 3.5) \ [PT]
.\" commit 5b172087f99189416d5f47fd7ab5e6fb762a9ba3
The thread's exit status in the form reported by
.BR waitpid (2).
.RE
.SH SEE ALSO
.BR proc (5),
.BR proc_pid_status (5)