cset - manage cpusets functions in the Linux kernel
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Note
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In general, you need to have root permissions to run cset. The tool mounts the cpusets filesystem and manipulates it. Non-root users do not have permission for these actions. |
Cpuset is a Python application to make using the cpusets facilities in the Linux kernel easier. The actual included command is called cset and it allows manipulation of cpusets on the system and provides higher level functions such as implementation and control of a basic cpu shielding setup.
The concept of shielded cpus is that a certain number of cpus are partitioned off on the system and only processes that are of interest are run on these cpus (i.e., inside the shield).
For a simple shielded configuration, one typically uses three cpusets: the root set, a system set and a user set. Cset includes a super command that implements this strategy and lets you easily manage it. See cset-shield(1) for more details.
Shielding can be more complex of course where concepts such as priority cpusets and intersecting cpuset can be used. You can use cset to help manage this type of shielding as well. You will need to use the cset-set(1) and cset-proc(1) subcommands directly to do that.
The cset subcommand cset-set(1) allows you to create and destroy arbitrary cpusets on the system and assign arbitrary cpus and memory nodes to them. The cpusets so created have to follow the Linux kernel cpuset rules. See the cset-set(1) subcommand for more details.
The cset subcommand cset-proc(1) allows you to manage processes running on various cpusets created on the system. You can exec new processes in specific cpusets and move tasks around existing cpusets. See the cset-proc(1) subcommand for more details.
The following generic option flags are available. Additional options are available per-command, and documented in the command-specific documentation.
Prints the cpuset suite version that the cset program came from, as well as version of other components used, such as Python and the kernel.
Prints the synopsis and a list of all commands.
Creates a log file for the current run. All manner of useful information is stored in this file. This is usually used to debug cpuset when things don't go as planned.
Although not strictly an "option", this is a very helpful way to execute help with cpuset. The command prints out a lengthy summary of how the specified subcommand works.
The cpuset commands are divided into groups, according to the primary purpose of those commands. Following is a short description of each command. A more detailed description is available in individual command manpages. Those manpages are named cset-<command>(1). The first command, help, is especially useful as it prints out a long summary of what a particular command does.
print the detailed command usage
display version information
display copyright information
supercommand to set up and manage basic shielding (see cset-shield(1))
create, modify and destroy cpusets (see cset-set(1))
create and manage processes within cpusets (see cset-proc(1))
Cpuset is licensed under the GNU GPL V2 only.
Copyright (c) 2008 Novell Inc.
Written by Alex Tsariounov <alext@novell.com>.
Some substrate code and ideas were taken from the excellent Stacked GIT (stgit) v0.13 (see http://gna.org/projects/stgit and http://www.procode.org/stgit). Stacked GIT is under GPL V2 or later.
cset-set(1), cset-proc(1), cset-shield(1), taskset(1), chrt(1)
/usr/src/linux/Documentation/cpusets.txt