.\" 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 as
-.\" published by the Free Software Foundation; either version 2 of
-.\" the License.
+.\" 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
.\" 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 manual; if not, write to the Free
-.\" Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111,
-.\" USA.
+.\" 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.
.\"
-.\" 2002-05-11 Robert Love <rml@tech9.net>
-.\" Initial version
-.\"
-.TH TASKSET "1" "Apr 2003" "schedutils" "Linux User's Manual"
+.TH TASKSET 1 "August 2014" "util-linux" "User Commands"
.SH NAME
-taskset \- retrieve or set a process's CPU affinity
+taskset \- set or retrieve a process's CPU affinity
.SH SYNOPSIS
.B taskset
-.RI [ options ]\ mask
-.IR command\ [ arg ]...
+[options]
+.IR mask\ command\ [ argument ...]
.br
.B taskset
-.RI [ options ]
+[options]
.B \-p
.RI [ mask ]\ pid
.SH DESCRIPTION
.PP
-.BR 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
+.B taskset
+is used to set or retrieve the CPU affinity of a running process given its
+\fIpid\fR, or to launch a new \fIcommand\fR 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
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,
+error is returned. The masks may be specified in hexadecimal (with or without
+a leading "0x"), or as a CPU list with the
+.B \-\-cpu\-list
+option. For example,
+.RS 4
+.TP 12
+.B 0x00000001
+is processor #0,
+.TP
+.B 0x00000003
+is processors #0 and #1,
.TP
-.BR 0x00000001
-is processor #0
+.B 0xFFFFFFFF
+is processors #0 through #31,
.TP
-.BR 0x00000003
-is processors #0 and #1
+.B 32
+is processors #1, #4, and #5,
.TP
-.BR 0xFFFFFFFF
-is all processors (#0 through #31)
+.B \-\-cpu\-list\ 0-2,6
+is processors #0, #1, #2, and #6.
+.TP
+.B \-\-cpu\-list\ 0-10:2
+is processors #0, #2, #4, #6, #8 and #10. The suffix ":N" specifies stride in
+the range, for example 0-10:3 is interpreted as 0,3,6,9 list.
+.RE
.PP
When
-.BR taskset
+.B taskset
returns, it is guaranteed that the given program has been scheduled to a legal
CPU.
.SH OPTIONS
.TP
-.BR \-p ,\ \-\-pid
-operate on an existing PID and not launch a new task
+.BR \-a ,\ \-\-all\-tasks
+Set or retrieve the CPU affinity of all the tasks (threads) for a given PID.
.TP
-.BR \-c ,\ \-\-cpu-list
-specify a numerical list of processors instead of a bitmask. The list may
-contain multiple items, separated by comma, and ranges. For example,
-.BR 0,5,7,9-11 .
+.BR \-c ,\ \-\-cpu\-list
+Interpret \fImask\fR as numerical list of processors instead of a bitmask.
+Numbers are separated by commas and may include ranges. For example:
+.BR 0,5,8-11 .
.TP
-.BR \-h ,\ \-\-help
-display usage information and exit
+.BR \-p ,\ \-\-pid
+Operate on an existing PID and do not launch a new task.
.TP
.BR \-V ,\ \-\-version
-output version information and exit
+Display version information and exit.
+.TP
+.BR \-h ,\ \-\-help
+Display help text and exit.
.SH USAGE
.TP
The default behavior is to run a new command with a given affinity mask:
.B taskset \-p
.I mask pid
.SH PERMISSIONS
+A user can change the CPU affinity of a process belonging to the same user.
A user must possess
.B CAP_SYS_NICE
-to change the CPU affinity of a process. Any user can retrieve the affinity
-mask.
-.SH AUTHOR
-Written by Robert M. Love.
-.SH COPYRIGHT
-Copyright \(co 2004 Robert M. Love
-.br
-This is free software; see the source for copying conditions. There is NO
-warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
-.SH "SEE ALSO"
+to change the CPU affinity of a process belonging to another user.
+A user can retrieve the affinity mask of any process.
+.SH SEE ALSO
.BR chrt (1),
.BR nice (1),
.BR renice (1),
-.BR sched_setaffinity (2),
-.BR sched_getaffinity (2)
+.BR sched_getaffinity (2),
+.BR sched_setaffinity (2)
.sp
See
-.BR sched_setscheduler (2)
+.BR sched (7)
for a description of the Linux scheduling scheme.
+.SH AUTHOR
+Written by Robert M. Love.
+.SH COPYRIGHT
+Copyright \(co 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.
.SH AVAILABILITY
-The taskset command is part of the util-linux-ng package and is available from
-ftp://ftp.kernel.org/pub/linux/utils/util-linux-ng/.
+The taskset command is part of the util-linux package and is available from
+https://www.kernel.org/pub/linux/utils/util-linux/.
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