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authorSimon Horman <horms@verge.net.au>2008-10-07 08:40:11 +1100
committerSimon Horman <horms@verge.net.au>2008-10-07 08:40:11 +1100
commita5e8546a8bff5d2047adc279df5753c44ba7b1a1 (patch)
treed9ca91f74d8279adbb1d3e942cc7ab145780ee29 /Documentation/cpusets.txt
parentcb7f6a7b716e801097b564dec3ccb58d330aef56 (diff)
parentc7004482e8dcb7c3c72666395cfa98a216a4fb70 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 into lvs-next-2.6
Diffstat (limited to 'Documentation/cpusets.txt')
-rw-r--r--Documentation/cpusets.txt18
1 files changed, 10 insertions, 8 deletions
diff --git a/Documentation/cpusets.txt b/Documentation/cpusets.txt
index 1f5a924d1e56..47e568a9370a 100644
--- a/Documentation/cpusets.txt
+++ b/Documentation/cpusets.txt
@@ -635,14 +635,16 @@ prior 'mems' setting, will not be moved.
There is an exception to the above. If hotplug functionality is used
to remove all the CPUs that are currently assigned to a cpuset,
-then the kernel will automatically update the cpus_allowed of all
-tasks attached to CPUs in that cpuset to allow all CPUs. When memory
-hotplug functionality for removing Memory Nodes is available, a
-similar exception is expected to apply there as well. In general,
-the kernel prefers to violate cpuset placement, over starving a task
-that has had all its allowed CPUs or Memory Nodes taken offline. User
-code should reconfigure cpusets to only refer to online CPUs and Memory
-Nodes when using hotplug to add or remove such resources.
+then all the tasks in that cpuset will be moved to the nearest ancestor
+with non-empty cpus. But the moving of some (or all) tasks might fail if
+cpuset is bound with another cgroup subsystem which has some restrictions
+on task attaching. In this failing case, those tasks will stay
+in the original cpuset, and the kernel will automatically update
+their cpus_allowed to allow all online CPUs. When memory hotplug
+functionality for removing Memory Nodes is available, a similar exception
+is expected to apply there as well. In general, the kernel prefers to
+violate cpuset placement, over starving a task that has had all
+its allowed CPUs or Memory Nodes taken offline.
There is a second exception to the above. GFP_ATOMIC requests are
kernel internal allocations that must be satisfied, immediately.