Provided by: util-linux_2.20.1-1ubuntu3_i386 bug

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 (C) 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/.