taskset(1) — Linux manual page


TASKSET(1)                    User Commands                   TASKSET(1)

NAME         top

       taskset - set or retrieve a process's CPU affinity

SYNOPSIS         top

       taskset [options] mask command [argument...]
       taskset [options] -p [mask] pid

DESCRIPTION         top

       taskset is used to set or retrieve the CPU affinity of a running
       process given its pid, or to launch a new command with a given
       CPU affinity.  CPU affinity is a scheduler property that "bonds"
       a process to a given set of CPUs on the system.  The Linux
       scheduler will honor the given CPU affinity and the process will
       not run on any other CPUs.  Note that the Linux scheduler also
       supports natural CPU affinity: the scheduler attempts to keep
       processes on the same CPU as long as practical for performance
       reasons.  Therefore, forcing a specific CPU affinity is useful
       only in certain applications.

       The CPU affinity is represented as a bitmask, with the lowest
       order bit corresponding to the first logical CPU and the highest
       order bit corresponding to the last logical CPU.  Not all CPUs
       may exist on a given system but a mask may specify more CPUs than
       are present.  A retrieved mask will reflect only the bits that
       correspond to CPUs physically on the system.  If an invalid mask
       is given (i.e., one that corresponds to no valid CPUs on the
       current system) an error is returned.  The masks may be specified
       in hexadecimal (with or without a leading "0x"), or as a CPU list
       with the --cpu-list option.  For example,

                  is processor #0,

                  is processors #0 and #1,

                  is processors #0 through #31,

           32     is processors #1, #4, and #5,

           --cpu-list 0-2,6
                  is processors #0, #1, #2, and #6.

           --cpu-list 0-10:2
                  is processors #0, #2, #4, #6, #8 and #10. The suffix
                  ":N" specifies stride in the range, for example 0-10:3
                  is interpreted as 0,3,6,9 list.

       When taskset returns, it is guaranteed that the given program has
       been scheduled to a legal CPU.

OPTIONS         top

       -a, --all-tasks
              Set or retrieve the CPU affinity of all the tasks
              (threads) for a given PID.

       -c, --cpu-list
              Interpret mask as numerical list of processors instead of
              a bitmask.  Numbers are separated by commas and may
              include ranges.  For example: 0,5,8-11.

       -p, --pid
              Operate on an existing PID and do not launch a new task.

       -V, --version
              Display version information and exit.

       -h, --help
              Display help text and exit.

USAGE         top

       The default behavior is to run a new command with a given
       affinity mask:
              taskset mask command [arguments]

       You can also retrieve the CPU affinity of an existing task:
              taskset -p pid

       Or set it:
              taskset -p mask pid

PERMISSIONS         top

       A user can change the CPU affinity of a process belonging to the
       same user.  A user must possess CAP_SYS_NICE to change the CPU
       affinity of a process belonging to another user.  A user can
       retrieve the affinity mask of any process.

AUTHORS         top

       Written by Robert M. Love.

COPYRIGHT         top

       Copyright © 2004 Robert M. Love.  This is free software; see the
       source for copying conditions.  There is NO warranty; not even

SEE ALSO         top

       chrt(1), nice(1), renice(1), sched_getaffinity(2),

       See sched(7) for a description of the Linux scheduling scheme.

AVAILABILITY         top

       The taskset command is part of the util-linux package and is
       available from

COLOPHON         top

       This page is part of the util-linux (a random collection of Linux
       utilities) project.  Information about the project can be found
       at ⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩.  If you
       have a bug report for this manual page, send it to
       util-linux@vger.kernel.org.  This page was obtained from the
       project's upstream Git repository
       ⟨git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git⟩ on
       2021-03-21.  (At that time, the date of the most recent commit
       that was found in the repository was 2021-03-19.)  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

util-linux                     August 2014                    TASKSET(1)

Pages that refer to this page: chrt(1)uclampset(1)sched_setaffinity(2)cpuset(7)sched(7)migratepages(8)