proc_pid_stat(5) File Formats Manual proc_pid_stat(5)
NAME
/proc/pid/stat - status information
DESCRIPTION
/proc/pid/stat
Status information about the process. This is used by ps(1). It
is defined in the kernel source file fs/proc/array.c.
The fields, in order, with their proper scanf(3) format speci-
fiers, are listed below. Whether or not certain of these fields
display valid information is governed by a ptrace access mode
PTRACE_MODE_READ_FSCREDS | PTRACE_MODE_NOAUDIT check (refer to
ptrace(2)). If the check denies access, then the field value is
displayed as 0. The affected fields are indicated with the mark-
ing [PT].
(1) pid %d
The process ID.
(2) comm %s
The filename of the executable, in parentheses. Strings
longer than TASK_COMM_LEN (16) characters (including the
terminating null byte) are silently truncated. This is
visible whether or not the executable is swapped out.
(3) state %c
One of the following characters, indicating process state:
R Running
S Sleeping in an interruptible wait
D Waiting in uninterruptible disk sleep
Z Zombie
T Stopped (on a signal) or (before Linux 2.6.33)
trace stopped
t Tracing stop (Linux 2.6.33 onward)
W Paging (only before Linux 2.6.0)
X Dead (from Linux 2.6.0 onward)
x Dead (Linux 2.6.33 to 3.13 only)
K Wakekill (Linux 2.6.33 to 3.13 only)
W Waking (Linux 2.6.33 to 3.13 only)
P Parked (Linux 3.9 to 3.13 only)
I Idle (Linux 4.14 onward)
(4) ppid %d
The PID of the parent of this process.
(5) pgrp %d
The process group ID of the process.
(6) session %d
The session ID of the process.
(7) tty_nr %d
The controlling terminal of the process. (The minor de-
vice number is contained in the combination of bits 31 to
20 and 7 to 0; the major device number is in bits 15 to
8.)
(8) tpgid %d
The ID of the foreground process group of the controlling
terminal of the process.
(9) flags %u
The kernel flags word of the process. For bit meanings,
see the PF_* defines in the Linux kernel source file in-
clude/linux/sched.h. Details depend on the kernel ver-
sion.
The format for this field was %lu before Linux 2.6.
(10) minflt %lu
The number of minor faults the process has made which have
not required loading a memory page from disk.
(11) cminflt %lu
The number of minor faults that the process's waited-for
children have made.
(12) majflt %lu
The number of major faults the process has made which have
required loading a memory page from disk.
(13) cmajflt %lu
The number of major faults that the process's waited-for
children have made.
(14) utime %lu
Amount of time that this process has been scheduled in
user mode, measured in clock ticks (divide by
sysconf(_SC_CLK_TCK)). This includes guest time,
guest_time (time spent running a virtual CPU, see below),
so that applications that are not aware of the guest time
field do not lose that time from their calculations.
(15) stime %lu
Amount of time that this process has been scheduled in
kernel mode, measured in clock ticks (divide by
sysconf(_SC_CLK_TCK)).
(16) cutime %ld
Amount of time that this process's waited-for children
have been scheduled in user mode, measured in clock ticks
(divide by sysconf(_SC_CLK_TCK)). (See also times(2).)
This includes guest time, cguest_time (time spent running
a virtual CPU, see below).
(17) cstime %ld
Amount of time that this process's waited-for children
have been scheduled in kernel mode, measured in clock
ticks (divide by sysconf(_SC_CLK_TCK)).
(18) priority %ld
(Explanation for Linux 2.6) For processes running a real-
time scheduling policy (policy below; see sched_setsched-
uler(2)), this is the negated scheduling priority, minus
one; that is, a number in the range -2 to -100, corre-
sponding 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-vis-
ible nice range of -20 to 19.
Before Linux 2.6, this was a scaled value based on the
scheduler weighting given to this process.
(19) nice %ld
The nice value (see setpriority(2)), a value in the range
19 (low priority) to -20 (high priority).
(20) num_threads %ld
Number of threads in this process (since Linux 2.6). Be-
fore Linux 2.6, this field was hard coded to 0 as a place-
holder for an earlier removed field.
(21) itrealvalue %ld
The time in jiffies before the next SIGALRM is sent to the
process due to an interval timer. Since Linux 2.6.17,
this field is no longer maintained, and is hard coded as
0.
(22) starttime %llu
The time the process started after system boot. Before
Linux 2.6, this value was expressed in jiffies. Since
Linux 2.6, the value is expressed in clock ticks (divide
by sysconf(_SC_CLK_TCK)).
The format for this field was %lu before Linux 2.6.
(23) vsize %lu
Virtual memory size in bytes.
(24) rss %ld
Resident Set Size: number of pages the process has in real
memory. This is just the pages which count 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 /proc/pid/statm below.
(25) rsslim %lu
Current soft limit in bytes on the rss of the process; see
the description of RLIMIT_RSS in getrlimit(2).
(26) startcode %lu [PT]
The address above which program text can run.
(27) endcode %lu [PT]
The address below which program text can run.
(28) startstack %lu [PT]
The address of the start (i.e., bottom) of the stack.
(29) kstkesp %lu [PT]
The current value of ESP (stack pointer), as found in the
kernel stack page for the process.
(30) kstkeip %lu [PT]
The current EIP (instruction pointer).
(31) signal %lu
The bitmap of pending signals, displayed as a decimal num-
ber. Obsolete, because it does not provide information on
real-time signals; use /proc/pid/status instead.
(32) blocked %lu
The bitmap of blocked signals, displayed as a decimal num-
ber. Obsolete, because it does not provide information on
real-time signals; use /proc/pid/status instead.
(33) sigignore %lu
The bitmap of ignored signals, displayed as a decimal num-
ber. Obsolete, because it does not provide information on
real-time signals; use /proc/pid/status instead.
(34) sigcatch %lu
The bitmap of caught signals, displayed as a decimal num-
ber. Obsolete, because it does not provide information on
real-time signals; use /proc/pid/status instead.
(35) wchan %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 /proc/pid/wchan.
(36) nswap %lu
Number of pages swapped (not maintained).
(37) cnswap %lu
Cumulative nswap for child processes (not maintained).
(38) exit_signal %d (since Linux 2.1.22)
Signal to be sent to parent when we die.
(39) processor %d (since Linux 2.2.8)
CPU number last executed on.
(40) rt_priority %u (since Linux 2.5.19)
Real-time scheduling priority, a number in the range 1 to
99 for processes scheduled under a real-time policy, or 0,
for non-real-time processes (see sched_setscheduler(2)).
(41) policy %u (since Linux 2.5.19)
Scheduling policy (see sched_setscheduler(2)). Decode us-
ing the SCHED_* constants in linux/sched.h.
The format for this field was %lu before Linux 2.6.22.
(42) delayacct_blkio_ticks %llu (since Linux 2.6.18)
Aggregated block I/O delays, measured in clock ticks (cen-
tiseconds).
(43) guest_time %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 sysconf(_SC_CLK_TCK)).
(44) cguest_time %ld (since Linux 2.6.24)
Guest time of the process's children, measured in clock
ticks (divide by sysconf(_SC_CLK_TCK)).
(45) start_data %lu (since Linux 3.3) [PT]
Address above which program initialized and uninitialized
(BSS) data are placed.
(46) end_data %lu (since Linux 3.3) [PT]
Address below which program initialized and uninitialized
(BSS) data are placed.
(47) start_brk %lu (since Linux 3.3) [PT]
Address above which program heap can be expanded with
brk(2).
(48) arg_start %lu (since Linux 3.5) [PT]
Address above which program command-line arguments (argv)
are placed.
(49) arg_end %lu (since Linux 3.5) [PT]
Address below program command-line arguments (argv) are
placed.
(50) env_start %lu (since Linux 3.5) [PT]
Address above which program environment is placed.
(51) env_end %lu (since Linux 3.5) [PT]
Address below which program environment is placed.
(52) exit_code %d (since Linux 3.5) [PT]
The thread's exit status in the form reported by wait-
pid(2).
SEE ALSO
proc(5), proc_pid_status(5)
Linux man-pages 6.9.1 2024-05-02 proc_pid_stat(5)
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