1TASKSET(1) User Commands TASKSET(1)
2
6 taskset - set or retrieve a process's CPU affinity
7
9 taskset [options] mask command [argument...]
10 taskset [options] -p [mask] pid
12
14 The taskset command is used to set or retrieve the CPU affinity of a
15 running process given its pid, or to launch a new command with a given
16 CPU affinity. CPU affinity is a scheduler property that "bonds" a
17 process to a given set of CPUs on the system. The Linux scheduler will
18 honor the given CPU affinity and the process will not run on any other
19 CPUs. Note that the Linux scheduler also supports natural CPU affinity:
20 the scheduler attempts to keep processes on the same CPU as long as
21 practical for performance reasons. Therefore, forcing a specific CPU
22 affinity is useful only in certain applications.
23 The CPU affinity is represented as a bitmask, with the lowest order bit
25 corresponding to the first logical CPU and the highest order bit
26 corresponding to the last logical CPU. Not all CPUs may exist on a
27 given system but a mask may specify more CPUs than are present. A
28 retrieved mask will reflect only the bits that correspond to CPUs
29 physically on the system. If an invalid mask is given (i.e., one that
30 corresponds to no valid CPUs on the current system) an error is
31 returned. The masks may be specified in hexadecimal (with or without a
32 leading "0x"), or as a CPU list with the --cpu-list option. For
33 example,
34 0x00000001
36 is processor #0,
37 0x00000003
39 is processors #0 and #1,
40 0xFFFFFFFF
42 is processors #0 through #31,
43 32
45 is processors #1, #4, and #5,
46 --cpu-list 0-2,6
48 is processors #0, #1, #2, and #6.
49 --cpu-list 0-10:2
51 is processors #0, #2, #4, #6, #8 and #10. The suffix ":N" specifies
52 stride in the range, for example 0-10:3 is interpreted as 0,3,6,9
53 list.
54 When taskset returns, it is guaranteed that the given program has been
56 scheduled to a legal CPU.
57
59 -a, --all-tasks
60 Set or retrieve the CPU affinity of all the tasks (threads) for a
61 given PID.
62 -c, --cpu-list
64 Interpret mask as numerical list of processors instead of a
65 bitmask. Numbers are separated by commas and may include ranges.
66 For example: 0,5,8-11.
67 -p, --pid
69 Operate on an existing PID and do not launch a new task.
70 -h, --help
72 Display help text and exit.
73 -V, --version
75 Print version and exit.
76
78 The default behavior is to run a new command with a given affinity
79 mask:
80 taskset mask command [arguments]
81 You can also retrieve the CPU affinity of an existing task:
83 taskset -p pid
84 Or set it:
86 taskset -p mask pid
87
89 A user can change the CPU affinity of a process belonging to the same
90 user. A user must possess CAP_SYS_NICE to change the CPU affinity of a
91 process belonging to another user. A user can retrieve the affinity
92 mask of any process.
93
95 Written by Robert M. Love.
96
98 Copyright © 2004 Robert M. Love. This is free software; see the source
99 for copying conditions. There is NO warranty; not even for
100 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
101
103 chrt(1), nice(1), renice(1), sched_getaffinity(2), sched_setaffinity(2)
104 See sched(7) for a description of the Linux scheduling scheme.
106
108 For bug reports, use the issue tracker at
109 https://github.com/util-linux/util-linux/issues.
110
112 The taskset command is part of the util-linux package which can be
113 downloaded from Linux Kernel Archive
114 <https://www.kernel.org/pub/linux/utils/util-linux/>.
115util-linux 2.38.1 2022-05-11 TASKSET(1)