taskset [options] -p [mask] pid
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 may be specified in hexadecimal (with or without a leading "0x"), or as a CPU list with the --cpu-list option. For example,
- is processor #0,
- is processors #0 and #1,
- is processors #0 through #31,
- is processors #1, #4, and #5,
- --cpu-list 0-2,6
- is processors #0, #1, #2, and #6.
When taskset returns, it is guaranteed that the given program has been scheduled to a legal CPU.
- -a, --all-tasks
- Set or retrieve the CPU affinity of all the tasks (threads) for a given PID.
- -c, --cpu-list
- Interpret 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, --pid
- Operate on an existing PID and do not launch a new task.
- -V, --version
- Display version information and exit.
- -h, --help
- Display help text and exit.
- 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
See sched(7) for a description of the Linux scheduling scheme.