taskset — set or retrieve a process's CPU affinity
taskset [options] mask
command [ argument... ]
taskset [options]
−p [mask] pid
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,
0x00000001is processor #0,
0x00000003is processors #0 and #1,
0xFFFFFFFFis all processors (#0 through #31).
When taskset returns, it is guaranteed that the given program has been scheduled to a legal CPU.
−a,
−−all−tasksSet or retrieve the CPU affinity of all the tasks (threads) for a given PID.
−c,
−−cpu−listInterpret 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,
−−pidOperate on an existing PID and do not launch a new task.
−V,
−−versionDisplay version information and exit.
−h,
−−helpDisplay help text and exit.
taskset mask command[arguments]
taskset
−p pid
taskset −p mask pid
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.
chrt(1), nice(1), renice(1), sched_setaffinity(2), sched_getaffinity(2)
See sched_setscheduler(2) for a description of the Linux scheduling scheme.
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.
The taskset command is part of the util-linux package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux/.
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taskset(1) manpage Copyright (C) 2004 Robert Love This is free documentation; you can redistribute it and/or modify it under the terms of the GNU General Public License, version 2, as published by the Free Software Foundation. The GNU General Public License's references to "object code" and "executables" are to be interpreted as the output of any document formatting or typesetting system, including intermediate and printed output. This manual is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |