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| author | Jonathan Corbet <corbet@lwn.net> | 2008-07-14 15:29:34 -0600 |
|---|---|---|
| committer | Jonathan Corbet <corbet@lwn.net> | 2008-07-14 15:29:34 -0600 |
| commit | 2fceef397f9880b212a74c418290ce69e7ac00eb (patch) | |
| tree | d9cc09ab992825ef7fede4a688103503e3caf655 /Documentation/cpusets.txt | |
| parent | feae1ef116ed381625d3731c5ae4f4ebcb3fa302 (diff) | |
| parent | bce7f793daec3e65ec5c5705d2457b81fe7b5725 (diff) | |
Merge commit 'v2.6.26' into bkl-removal
Diffstat (limited to 'Documentation/cpusets.txt')
| -rw-r--r-- | Documentation/cpusets.txt | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/Documentation/cpusets.txt b/Documentation/cpusets.txt index fb7b361e6ee..1f5a924d1e5 100644 --- a/Documentation/cpusets.txt +++ b/Documentation/cpusets.txt @@ -154,13 +154,15 @@ browsing and modifying the cpusets presently known to the kernel. No new system calls are added for cpusets - all support for querying and modifying cpusets is via this cpuset file system. -The /proc/<pid>/status file for each task has two added lines, +The /proc/<pid>/status file for each task has four added lines, displaying the tasks cpus_allowed (on which CPUs it may be scheduled) and mems_allowed (on which Memory Nodes it may obtain memory), -in the format seen in the following example: +in the two formats seen in the following example: Cpus_allowed: ffffffff,ffffffff,ffffffff,ffffffff + Cpus_allowed_list: 0-127 Mems_allowed: ffffffff,ffffffff + Mems_allowed_list: 0-63 Each cpuset is represented by a directory in the cgroup file system containing (on top of the standard cgroup files) the following @@ -199,7 +201,7 @@ using the sched_setaffinity, mbind and set_mempolicy system calls. The following rules apply to each cpuset: - Its CPUs and Memory Nodes must be a subset of its parents. - - It can only be marked exclusive if its parent is. + - It can't be marked exclusive unless its parent is. - If its cpu or memory is exclusive, they may not overlap any sibling. These rules, and the natural hierarchy of cpusets, enable efficient @@ -345,7 +347,7 @@ is modified to perform an inline check for this PF_SPREAD_PAGE task flag, and if set, a call to a new routine cpuset_mem_spread_node() returns the node to prefer for the allocation. -Similarly, setting 'memory_spread_cache' turns on the flag +Similarly, setting 'memory_spread_slab' turns on the flag PF_SPREAD_SLAB, and appropriately marked slab caches will allocate pages from the node returned by cpuset_mem_spread_node(). @@ -542,7 +544,10 @@ otherwise initial value -1 that indicates the cpuset has no request. 2 : search cores in a package. 3 : search cpus in a node [= system wide on non-NUMA system] ( 4 : search nodes in a chunk of node [on NUMA system] ) - ( 5~ : search system wide [on NUMA system]) + ( 5 : search system wide [on NUMA system] ) + +The system default is architecture dependent. The system default +can be changed using the relax_domain_level= boot parameter. This file is per-cpuset and affect the sched domain where the cpuset belongs to. Therefore if the flag 'sched_load_balance' of a cpuset @@ -709,7 +714,10 @@ Now you want to do something with this cpuset. In this directory you can find several files: # ls -cpus cpu_exclusive mems mem_exclusive mem_hardwall tasks +cpu_exclusive memory_migrate mems tasks +cpus memory_pressure notify_on_release +mem_exclusive memory_spread_page sched_load_balance +mem_hardwall memory_spread_slab sched_relax_domain_level Reading them will give you information about the state of this cpuset: the CPUs and Memory Nodes it can use, the processes that are using |