TASKSET(1) Linux User's Manual TASKSET(1)
taskset - retrieve or set a processes's CPU affinity
taskset [options] [mask | list ] [pid | command [arg]...]
taskset is used to set or retrieve the CPU affinity of a running pro-
cess 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 practi-
cal for performance reasons. Therefore, forcing a specific CPU affin-
ity 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 corre-
sponding 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,
is processor #0
is processors #0 and #1
is all processors (#0 through #31)
When taskset returns, it is guaranteed that the given program has been
scheduled to a legal CPU.
operate on an existing PID and not launch a new task
specifiy a numerical list of processors instead of a bitmask.
The list may contain multiple items, separated by comma, and
ranges. For example, 0,5,7,9-11.
display usage information and exit
output version information and exit
The default behavior is to run a new command with a given affinity
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 must possess CAP_SYS_NICE to change the CPU affinity of a pro-
cess. Any user can retrieve the affinity mask.
Written by Robert M. Love.
Report bugs to <email@example.com>.
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
chrt(1), nice(1), renice(1), sched_setaffinity(2), sched_getaffinity(2)
See sched_setscheduler(2) for a description of the Linux scheduling
schedutils Apr 2003 TASKSET(1)