Provided by: util-linux_2.38-4ubuntu1_amd64 bug


       taskset - set or retrieve a process's CPU affinity


       taskset [options] mask command [argument...]

       taskset [options] -p [mask] pid


       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.


       -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.

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

       -V, --version
           Print version and exit.


       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


       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.


       Written by Robert M. Love.


       Copyright © 2004 Robert M. Love. This is free software; see the source for copying
       conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR


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

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


       For bug reports, use the issue tracker at


       The taskset command is part of the util-linux package which can be downloaded from Linux
       Kernel Archive <>.