NAME

       taskset - retrieve or set a process's CPU affinity

SYNOPSIS

       taskset [options] mask command [arg]...
       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.

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

       -c, --cpu-list
              Specify  a numerical list of processors instead of a bitmask.  The numbers are separated by commas
              and may include ranges.  For example: 0,5,7,9-11.

       -h, --help
              Display usage information and exit.

       -V, --version
              Display version information 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 must possess CAP_SYS_NICE to change the CPU affinity of a process.   Any  user  can  retrieve  the
       affinity mask.

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.

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.

AVAILABILITY

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