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| author | Christoph Lameter <clameter@sgi.com> | 2007-10-16 12:25:38 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-16 20:42:59 +0400 |
| commit | 0e1e7c7a739562a321fda07c7cd2a97a7114f8f8 (patch) | |
| tree | f2148e5b667152681625c19cf8b2a556500994ea /Documentation/cpusets.txt | |
| parent | 523b945855a1427000ffc707c610abe5947ae607 (diff) | |
| download | linux-0e1e7c7a739562a321fda07c7cd2a97a7114f8f8.tar.xz | |
Memoryless nodes: Use N_HIGH_MEMORY for cpusets
cpusets try to ensure that any node added to a cpuset's mems_allowed is
on-line and contains memory. The assumption was that online nodes contained
memory. Thus, it is possible to add memoryless nodes to a cpuset and then add
tasks to this cpuset. This results in continuous series of oom-kill and
apparent system hang.
Change cpusets to use node_states[N_HIGH_MEMORY] [a.k.a. node_memory_map] in
place of node_online_map when vetting memories. Return error if admin
attempts to write a non-empty mems_allowed node mask containing only
memoryless-nodes.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Bob Picco <bob.picco@hp.com>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@skynet.ie>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/cpusets.txt')
| -rw-r--r-- | Documentation/cpusets.txt | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/Documentation/cpusets.txt b/Documentation/cpusets.txt index f2c0a6842930..b875d231ac74 100644 --- a/Documentation/cpusets.txt +++ b/Documentation/cpusets.txt @@ -35,7 +35,8 @@ CONTENTS: ---------------------- Cpusets provide a mechanism for assigning a set of CPUs and Memory -Nodes to a set of tasks. +Nodes to a set of tasks. In this document "Memory Node" refers to +an on-line node that contains memory. Cpusets constrain the CPU and Memory placement of tasks to only the resources within a tasks current cpuset. They form a nested @@ -220,8 +221,8 @@ and name space for cpusets, with a minimum of additional kernel code. The cpus and mems files in the root (top_cpuset) cpuset are read-only. The cpus file automatically tracks the value of cpu_online_map using a CPU hotplug notifier, and the mems file -automatically tracks the value of node_online_map using the -cpuset_track_online_nodes() hook. +automatically tracks the value of node_states[N_MEMORY]--i.e., +nodes with memory--using the cpuset_track_online_nodes() hook. 1.4 What are exclusive cpusets ? |