cpuset(4)cpuset(4)NAME
cpuset, miser_cpuset - cpuset configuration files
DESCRIPTION
A cpuset is defined by a cpuset configuration file and a name. The
cpuset configuration file is used to list the CPUs that are members of
the cpuset and contains any additional parameters needed to define the
cpuset. The file permissions of the configuration file define access to
the cpuset. Every time permissions need to be checked, the current
permissions of the file are used. It is therefore possible to change
access to a particular cpuset, without having to tear it down and
recreate it, simply by changing the access permissions. Read access
allows a user to retrieve information about a cpuset while execute
permission allows the user to attach a process to the cpuset.
The name of the cpuset is a three to eight character string. Queue names
having one or two characters are reserved for use by IRIX.
For information on how to use cpusets in a Trusted IRIX environment, see
the cpuset(1) man page.
EXAMPLE
The following configuration file describes an exclusive cpuset containing
8 CPUs:
#cpuset configuration file
EXCLUSIVE
MEMORY_LOCAL
MEMORY_EXCLUSIVE
CPU 16
CPU 17-19, 21, 23
CPU 25
CPU 27
This specification will create a cpuset containing 8 CPUs, and will
restrict those cpus to running threads that have been explicitly assigned
to the cpuset. Jobs running on the cpuset will use memory from nodes
containing the cpus in the cpuset. Jobs running on other cpusets or on
the global cpuset will not use memory from these nodes.
SUMMARY
Commands are newline terminated, characters following the comment
delimiter '#' are ignored, case matters, and tokens are separated by
whitespace which is ignored.
The valid tokens are:
EXCLUSIVE
Defines a cpuset to be restricted. It can occur anywhere in the
file. Anything else on the line is ignored.
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EXPLICIT
By default, if a CPU is part of a cpuset the memory on the node
where the CPU is located is also part of the cpuset. This flag
overrides the default behavior. If this directive is present, the
nodes with memory that are to be included in the cpuset must be
specified using the MEM or NODE directives.
MEMORY_LOCAL
Threads assigned to the cpuset will attempt to assign memory only
from nodes within the cpuset. Assignment of memory from outside the
cpuset will occur only if no free memory is available from within
the cpuset. No restrictions are made on memory assignment to
threads running outside the cpuset.
MEMORY_EXCLUSIVE
Threads not assigned to the cpuset will not use memory from within
the cpuset unless no memory outside the cpuset is available.
If, at the time a cpuset is created, memory is already assigned to
threads that are already running, no attempt will be made to
explicitly move this memory. If page migration is enabled, the
pages will be migrated when the system detects that most references
to the pages are non-local.
MEMORY_KERNEL_AVOID
The kernel will attempt to avoid allocating memory from nodes
contained in this cpuset. If kernel memory requests cannot be
satisfied from outside this cpuset, this option will be ignored and
allocations will occur from within the cpuset.
WARNING: It is strongly recommended that this option not be used for
most cpuset configurations. A side effect of this option is that
kernel memory allocations become concentrated on the remaining
system nodes, which may in turn degrade system performance. This
option is effective only for certain workload patterns, and could
cause severe performance penalties in other situations. It is
recommended that this option be used only when indicated by SGI
support.
Currently this option prevents only the system buffer cache from
being placed on the specified nodes. Future IRIX releases may
expand the scope of this protection to exclude other kernel memory
allocations from the specified nodes.
This option was introduced in IRIX 6.5.7.
MEMORY_MANDATORY
The kernel will limit all memory allocations to nodes that are
contained in this cpuset. If memory requests cannot be satisfied,
the allocating process will sleep until memory is available. The
process will be killed if no more memory can be allocated. See
policies below.
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POLICY_PAGE
Requires MEMORY_MANDATORY. This is the default policy if no policy
is specified. This policy will cause the kernel to page user pages
to the swap file (see swap(1M)) to free physical memory on the nodes
contained in this cpuset. If swap space is exhausted, the process
will be killed.
POLICY_KILL
Requires MEMORY_MANDATORY. The kernel will attempt to free as much
space as possible from kernel heaps, but will not page user pages to
the swap file. If all physical memory on the nodes contained in
this cpuset are exhausted, the process will be killed.
POLICY_SHARE_WARN
When creating a cpuset, if it is possible for the new cpuset to
share memory on a node with another cpuset the new cpuset will be
created but a warning message will be issued. POLICY_SHARE_WARN and
POLICY_SHARE_FAIL cannot be used together.
POLICY_SHARE_FAIL
When creating a cpuset, if it is possible for the new cpuset to
share memory on a node with another cpuset the new cpuset will fail
to be created and an error message will be issued. POLICY_SHARE_WARN
and POLICY_SHARE_FAIL cannot be used together.
CPU cpuid or cpuids
Specifies a single CPU or a list of CPUs that will be part of the
cpuset. The user can mix a single cpu line with a cpu list line.
For example:
CPU 2
CPU 3-4,5,7,9-12
MEM nodeid or nodeids
Specifies a single node's memory or a list of nodes' memory that
will be part of the cpuset. The specification of nodes follows the
same syntax as the CPU specification.
NODE nodeid or nodeids
Specifies a single node's CPUs and memory, or a list of nodes' CPUs
and memory that will be part of the cpuset. This directive is used
to specify that all node resources (CPU and memory) are to be
included in the cpuset. The specification of nodes follows the same
syntax as the CPU specification.
MEMORY_SIZE_ADVISORY size
Upon creation of a new cpuset, if the memory to be included is below
the specified size, a warning message will be issued and the cpuset
will continue to be created. The value for size, is specified as an
integer suffixed by a size factor: B indicates bytes, K indicates
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kilobytes, M indicates megabytes, G indicates gigabytes, and T to
indicate terabytes. MEMORY_SIZE_ADVISORY and MEMORY_SIZE_MANDATORY
can be used together.
MEMORY_SIZE_ADVISORY 130965K # 130.964 MegaBytes
MEMORY_SIZE_ADVISORY 8192M # 8.192 GigaBytes
MEMORY_SIZE_ADVISORY 4G # 4 GigaBytes
MEMORY_SIZE_ADVISORY 1T # 1 TeraByte
MEMORY_SIZE_MANDATORY size
Upon creation of a new cpuset, if the memory to be included is below
the specified size, an error message will be issued and the cpuset
will fail to be created. The value for size, is specified as an
integer suffixed by a size factor: B indicates bytes, K indicates
kilobytes, M indicates megabytes, G indicates gigabytes, and T to
indicate terabytes. MEMORY_SIZE_ADVISORY and MEMORY_SIZE_MANDATORY
can be used together. An example of the syntax for specifying the
size is seen in the example for MEMORY_SIZE_ADVISORY.
CPU_COUNT_ADVISORY count
Upon creation of a new cpuset, if the number of CPUs to be included
is below the specified count, a warning message will be issued and
the cpuset will continue to be created. CPU_COUNT_ADVISORY and
CPU_COUNT_MANDATORY can be used together. An example follows:
CPU_COUNT_ADVISORY 128 # If number CPUs < 128 warn
CPU_COUNT_MANDATORY count
Upon creation of a new cpuset, if the number of CPUs to be included
is below the specified count, an error message will be issued and
the cpuset will fail to be created. CPU_COUNT_ADVISORY and
CPU_COUNT_MANDATORY can be used together. An example follows:
CPU_COUNT_MANDATORY 96 # If number CPUs < 96 fail
NOTES
In a cluster environment, the cpuset configuration file should reside on
the root filesystem. If the cpuset configuration file resides on a
filesystem other than the root filesystem and you attempt to unmount the
filesystem, the vnode for the cpuset remains active and the unmount (see
mount(1M) command fails.
Make sure that your workload manager sets the configuration file to
reside on the root filesystem.
SEE ALSOcpuset(1), cpuset(5).
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IRIX Admin: Resource Administration
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