TASKSET(1)							   User Commands							TASKSET(1)

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 affin-
       ity.  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,

	   0x00000001  is processor #0,

	   0x00000003  is processors #0 and #1,

	   0xFFFFFFFF  is processors #0 through #31,

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

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

       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
	      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

       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_getaffinity(2), sched_setaffinity(2)

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

AUTHOR

       Written by Robert M. Love.

COPYRIGHT

       Copyright  (C) 2004 Robert M. Love.  This is free software; see the source for copying conditions.  There is NO warranty; not even for MER-
       CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

AVAILABILITY

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

util-linux							    August 2014 							TASKSET(1)