cset-set(1)
===========
Alex Tsariounov <alext@novell.com>
v1.5.6, June 2011

NAME
----
cset-set - manage sets of cpus

SYNOPSIS
--------
[verse]
'cset' [cset options] 'set' [set options] [args]
'cset' set --help
'cset' set
'cset' set --recurse
'cset' set --list myset
'cset' set myset
'cset' set --recurse --list myset
'cset' set --cpu 2-5 --mem 0 --set newset
'cset' set --cpu 2-5 newset
'cset' set --cpu 1,2,5-7 another_set
'cset' set --destroy newset
'cset' set --destroy /mygroup_sets/my_set

OPTIONS
-------
-h, --help::
  prints the list of options for this command

-l, --list::
  list the named cpuset(s); if -r is used, will list recursively

-c CPUSPEC, --cpu=CPUSPEC::
  create or modify cpuset in the specified cpuset with CPUSPEC
  specification

-m MEMSPEC, --mem=MEMSPEC::
  specify which memory nodes to assign to the created or modified
  cpuset

-d, --destroy::
  destroy specified cpuset

-s CPUSET, --set=CPUSET::
  specify cpuset name to be acted on

-r, --recurse::
  do recursive listing, for use with --list

-v, --verbose::
  prints more detailed output, for the set command, using this flag
  will not chop listing to fit in 80 columns

--cpu_exclusive::
  mark this cpuset as owning its CPUs exclusively

--mem_exclusive::
  mark this cpuset as owning its MEMs exclusively

DESCRIPTION
-----------
This command is used to create, modify, and destroy cpusets.
Cpusets form a tree-like structure rooted at the root cpuset
which always includes all system CPUs and all system memory
nodes.

A cpuset is an organizational unit that defines a group of CPUs
and a group of memory nodes where a process or thread (i.e. task)
is allowed to run on.  For non-NUMA machines, the memory node is
always 0 (zero) and cannot be set to anything else.  For NUMA
machines, the memory node can be set to a similar specification
as the CPU definition and will tie those memory nodes to that
cpuset.  You will usually want the memory nodes that belong to
the CPUs defined to be in the same cpuset.

A cpuset can have exclusive right to the CPUs defined in it.
This means that only this cpuset can own these CPUs.  Similarly,
a cpuset can have exclusive right to the memory nodes defined in
it.  This means that only this cpuset can own these memory
nodes.

Cpusets can be specified by name or by path; however, care
should be taken when specifying by name if the name is not
unique.  This tool will generally not let you do destructive
things to non-unique cpuset names.

Cpusets are uniquely specified by path.  The path starts at where
the cpusets filesystem is mounted so you generally do not have to
know where that is.  For example, so specify a cpuset that is
called "two" which is a subset of "one" which in turn is a subset
of the root cpuset, use the path "/one/two" regardless of where
the cpusets filesystem is mounted.

When specifying CPUs, a so-called CPUSPEC is used.  The CPUSPEC
will accept a comma-separated list of CPUs and inclusive range
specifications.   For example, --cpu=1,3,5-7 will assign CPU1,
CPU3, CPU5, CPU6, and CPU7 to the specified cpuset.

Note that cpusets follow certain rules.  For example, children
can only include CPUs that the parents already have.  If you do
not follow those rules, the kernel cpuset subsystem will not let
you create that cpuset.  For example, if you create a cpuset that
contains CPU3, and then attempt to create a child of that cpuset
with a CPU other than 3, you will get an error, and the cpuset
will not be active.  The error is somewhat cryptic in that it is
usually a "Permission denied" error.

Memory nodes are specified with a MEMSPEC in a similar way to
the CPUSPEC.  For example, --mem=1,3-6 will assign MEM1, MEM3,
MEM4, MEM5, and MEM6  to the specified cpuset.

Note that if you attempt to create or modify a cpuset with a
memory node specification that is not valid, you may get a
cryptic error message, "No space left on device", and the
modification will not be allowed.

When you destroy a cpuset, then the tasks running in that set are
moved to the parent of that cpuset.  If this is not what you
want, then manually move those tasks to the cpuset of your choice
with the 'cset proc' command (see 'cset proc --help' for more
information).

EXAMPLES
~~~~~~~~

Create a cpuset with the default memory specification::

*+# cset set --cpu=2,4,6-8 --set=new_set+*

This command creates a cpuset called "new_set" located
off the root cpuset which holds CPUS 2,4,6,7,8 and node 0
(interleaved) memory.  Note that --set is optional, and
you can just specify the name for the new cpuset after
all arguments.

Create a cpuset that specifies both CPUs and memory nodes::

*+# cset set --cpu=3 --mem=3 /rad/set_one+*

Note that this command uses the full path method to
specify the name of the new cpuset "/rad/set_one". It
also names the new cpuset implicitly (i.e. no --set
option, although you can use that if you want to).  If
the "set_one" name is unique, you can subsequently refer
to is just by that.  Memory node 3 is assigned to this
cpuset as well as CPU 3.

The above commands will create the new cpusets, or if they
already exist, they will modify them to the new specifications.

LICENSE
-------
Cpuset is licensed under the GNU GPL V2 only. 

COPYRIGHT
---------
Copyright (c) 2008-2011 Novell Inc.

AUTHOR
------
Written by Alex Tsariounov <\alext@novell.com>.

SEE ALSO
--------
cset(1), cset-proc(1), cset-shield(1)

/usr/share/doc/packages/cpuset/html/tutorial.html

taskset(1), chrt(1)

/usr/src/linux/Documentation/cpusets.txt
