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

       The taskset command 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,

           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 for

SEE ALSO         top

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

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

REPORTING BUGS         top

       For bug reports, use the issue tracker at

AVAILABILITY         top

       The taskset command is part of the util-linux package which can
       be downloaded from Linux Kernel Archive
       <https://www.kernel.org/pub/linux/utils/util-linux/>. 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
       2021-08-27. (At that time, the date of the most recent commit
       that was found in the repository was 2021-08-24.) 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 2.37.85-637cc       2021-04-02                     TASKSET(1)

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