NAME

       taskset - set or retrieve a process's CPU affinity

SYNOPSIS

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

DESCRIPTION

       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 are typically  given
       in hexadecimal.  For example,

           0x00000001  is processor #0,

           0x00000003  is processors #0 and #1,

           0xFFFFFFFF  is all processors (#0 through #31).

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

OPTIONS

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

       -c, --cpu-list numbers
              Specify  a numerical list of processors instead of a bitmask.  The 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

       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

       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.

SEE ALSO

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

       See sched_setscheduler(2) for a description of the Linux scheduling scheme.

AUTHOR

       Written by Robert M. Love.

COPYRIGHT

       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 PURPOSE.

AVAILABILITY

       The    taskset    command    is    part    of    the   util-linux   package   and   is   available   from
       ftp://ftp.kernel.org/pub/linux/utils/util-linux/.