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-rw-r--r--Documentation/cpusets.txt20
1 files changed, 14 insertions, 6 deletions
diff --git a/Documentation/cpusets.txt b/Documentation/cpusets.txt
index fb7b361e6eea..1f5a924d1e56 100644
--- a/Documentation/cpusets.txt
+++ b/Documentation/cpusets.txt
@@ -154,13 +154,15 @@ browsing and modifying the cpusets presently known to the kernel. No
154new system calls are added for cpusets - all support for querying and 154new system calls are added for cpusets - all support for querying and
155modifying cpusets is via this cpuset file system. 155modifying cpusets is via this cpuset file system.
156 156
157The /proc/<pid>/status file for each task has two added lines, 157The /proc/<pid>/status file for each task has four added lines,
158displaying the tasks cpus_allowed (on which CPUs it may be scheduled) 158displaying the tasks cpus_allowed (on which CPUs it may be scheduled)
159and mems_allowed (on which Memory Nodes it may obtain memory), 159and mems_allowed (on which Memory Nodes it may obtain memory),
160in the format seen in the following example: 160in the two formats seen in the following example:
161 161
162 Cpus_allowed: ffffffff,ffffffff,ffffffff,ffffffff 162 Cpus_allowed: ffffffff,ffffffff,ffffffff,ffffffff
163 Cpus_allowed_list: 0-127
163 Mems_allowed: ffffffff,ffffffff 164 Mems_allowed: ffffffff,ffffffff
165 Mems_allowed_list: 0-63
164 166
165Each cpuset is represented by a directory in the cgroup file system 167Each cpuset is represented by a directory in the cgroup file system
166containing (on top of the standard cgroup files) the following 168containing (on top of the standard cgroup files) the following
@@ -199,7 +201,7 @@ using the sched_setaffinity, mbind and set_mempolicy system calls.
199The following rules apply to each cpuset: 201The following rules apply to each cpuset:
200 202
201 - Its CPUs and Memory Nodes must be a subset of its parents. 203 - Its CPUs and Memory Nodes must be a subset of its parents.
202 - It can only be marked exclusive if its parent is. 204 - It can't be marked exclusive unless its parent is.
203 - If its cpu or memory is exclusive, they may not overlap any sibling. 205 - If its cpu or memory is exclusive, they may not overlap any sibling.
204 206
205These rules, and the natural hierarchy of cpusets, enable efficient 207These 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
345flag, and if set, a call to a new routine cpuset_mem_spread_node() 347flag, and if set, a call to a new routine cpuset_mem_spread_node()
346returns the node to prefer for the allocation. 348returns the node to prefer for the allocation.
347 349
348Similarly, setting 'memory_spread_cache' turns on the flag 350Similarly, setting 'memory_spread_slab' turns on the flag
349PF_SPREAD_SLAB, and appropriately marked slab caches will allocate 351PF_SPREAD_SLAB, and appropriately marked slab caches will allocate
350pages from the node returned by cpuset_mem_spread_node(). 352pages from the node returned by cpuset_mem_spread_node().
351 353
@@ -542,7 +544,10 @@ otherwise initial value -1 that indicates the cpuset has no request.
542 2 : search cores in a package. 544 2 : search cores in a package.
543 3 : search cpus in a node [= system wide on non-NUMA system] 545 3 : search cpus in a node [= system wide on non-NUMA system]
544 ( 4 : search nodes in a chunk of node [on NUMA system] ) 546 ( 4 : search nodes in a chunk of node [on NUMA system] )
545 ( 5~ : search system wide [on NUMA system]) 547 ( 5 : search system wide [on NUMA system] )
548
549The system default is architecture dependent. The system default
550can be changed using the relax_domain_level= boot parameter.
546 551
547This file is per-cpuset and affect the sched domain where the cpuset 552This file is per-cpuset and affect the sched domain where the cpuset
548belongs to. Therefore if the flag 'sched_load_balance' of a cpuset 553belongs to. Therefore if the flag 'sched_load_balance' of a cpuset
@@ -709,7 +714,10 @@ Now you want to do something with this cpuset.
709 714
710In this directory you can find several files: 715In this directory you can find several files:
711# ls 716# ls
712cpus cpu_exclusive mems mem_exclusive mem_hardwall tasks 717cpu_exclusive memory_migrate mems tasks
718cpus memory_pressure notify_on_release
719mem_exclusive memory_spread_page sched_load_balance
720mem_hardwall memory_spread_slab sched_relax_domain_level
713 721
714Reading them will give you information about the state of this cpuset: 722Reading them will give you information about the state of this cpuset:
715the CPUs and Memory Nodes it can use, the processes that are using 723the CPUs and Memory Nodes it can use, the processes that are using