- cpuset.cpus (mandatory)
-
specifies the CPUs that tasks in this control group are permitted to access. This is a comma-separated list in ASCII format, with dashes ("-
") to represent ranges. For example,
0-2,16
represents CPUs 0, 1, 2, and 16.
- cpuset.mems (mandatory)
-
specifies the memory nodes that tasks in this control group are permitted to access. This is a comma-separated list in ASCII format, with dashes ("-
") to represent ranges. For example,
0-2,16
represents memory nodes 0, 1, 2, and 16.
- cpuset.memory_migrate
-
contains a flag (0
or 1
) that specifies whether a page in memory should migrate to a new node if the values in cpuset.mems
change. By default, memory migration is disabled (0
) and pages stay on the node to which they were originally allocated, even if this node is no longer one of the nodes now specified in cpuset.mems
. If enabled (1
), the system will migrate pages to memory nodes within the new parameters specified by cpuset.mems
, maintaining their relative placement if possible — for example, pages on the second node on the list originally specified by cpuset.mems
will be allocated to the second node on the list now specified by cpuset.mems
, if this place is available.
- cpuset.cpu_exclusive
-
contains a flag (0
or 1
) that specifies whether cpusets other than this one and its parents and children can share the CPUs specified for this cpuset. By default (0
), CPUs are not allocated exclusively to one cpuset.
- cpuset.mem_exclusive
-
contains a flag (0
or 1
) that specifies whether other cpusets can share the memory nodes specified for this cpuset. By default (0
), memory nodes are not allocated exclusively to one cpuset. Reserving memory nodes for the exclusive use of a cpuset (1
) is functionally the same as enabling a memory hardwall with cpuset.mem_hardwall
.
- cpuset.mem_hardwall
-
contains a flag (0
or 1
) that specifies whether kernel allocations of memory page and buffer data should be restricted to the memory nodes specified for this cpuset. By default (0
), page and buffer data is shared across processes belonging to multiple users. With a hardwall enabled (1
), each tasks's user allocation can be kept separate.
- cpuset.memory_pressure
-
a read-only file that contains a running average of the memory pressure created by the processes in this cpuset. The value in this pseudofile is automatically updated when cpuset.memory_pressure_enabled
is enabled, otherwise, the pseudofile contains the value 0
.
- cpuset.memory_pressure_enabled
-
contains a flag (0
or 1
) that specifies whether the system should compute the memory pressure created by the processes in this control group. Computed values are output to cpuset.memory_pressure
and represent the rate at which processes attempt to free in-use memory, reported as an integer value of attempts to reclaim memory per second, multiplied by 1000.
- cpuset.memory_spread_page
-
contains a flag (0
or 1
) that specifies whether file system buffers should be spread evenly across the memory nodes allocated to this cpuset. By default (0
), no attempt is made to spread memory pages for these buffers evenly, and buffers are placed on the same node on which the process that created them is running.
- cpuset.memory_spread_slab
-
contains a flag (0
or 1
) that specifies whether kernel slab caches for file input/output operations should be spread evenly across the cpuset. By default (0
), no attempt is made to spread kernel slab caches evenly, and slab caches are placed on the same node on which the process that created them is running.
- cpuset.sched_load_balance
-
contains a flag (0
or 1
) that specifies whether the kernel will balance loads across the CPUs in this cpuset. By default (1
), the kernel balances loads by moving processes from overloaded CPUs to less heavily used CPUs.
Note, however, that setting this flag in a control group has no effect if load balancing is enabled in any parent control group, as load balancing is already being carried out at a higher level. Therefore, to disable load balancing in a control group, disable load balancing also in each of its parents in the hierarchy. In this case, you should also consider whether load balancing should be enabled for any siblings of the control group in question.
- cpuset.sched_relax_domain_level
-
contains an integer between -1
and a small positive value, which represents the width of the range of CPUs across which the kernel should attempt to balance loads. This value is meaningless if cpuset.sched_load_balance
is disabled.
The precise effect of this value varies according to system architecture, but the following values are typical:
Values of cpuset.sched_relax_domain_level
Value |
Effect |
-1 |
Use the system default value for load balancing |
0 |
Do not perform immediate load balancing; balance loads only periodically |
1 |
Immediately balance loads across threads on the same core |
2 |
Immediately balance loads across cores in the same package |
3 |
Immediately balance loads across CPUs on the same node or blade |
4 |
Immediately balance loads across several CPUs on architectures with non-uniform memory access (NUMA) |
5 |
Immediately balance loads across all CPUs on architectures with NUMA |