path: root/mm/migrate.c
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authorDavid Rientjes <rientjes@google.com>2010-05-24 14:32:13 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-25 08:06:58 -0700
commite325c90ffc13b698fa2814102e05275b21c26bec (patch)
treedcb20cad204132e08476d3cb4da66f9a2e08b9fe /mm/migrate.c
parent1a5cb81465b66b74bf3d6ad36e5382238de6a132 (diff)
mm: default to node zonelist ordering when nodes have only lowmem
There are two types of zonelist ordering methodologies: - node order, preferring allocations on a node to stay local to and - zone order, preferring allocations come from a higher zone to avoid allocating in lowmem zones even though they may not be local. The ordering technique used by the kernel is configurable on the command line, but also has some logic to determine what the default should be. This logic currently lacks knowledge of systems where a node may only have lowmem. For such systems, it is necessary to use node order so that GFP_KERNEL allocations may be satisfied by nodes consisting of only lowmem. If zone order is used, GFP_KERNEL allocations to such nodes are actually allocated on a node with local affinity that includes ZONE_NORMAL. This change defaults to node zonelist ordering if any node lacks ZONE_NORMAL. To force zone order, append 'numa_zonelist_order=zone' to the kernel command line. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/migrate.c')
0 files changed, 0 insertions, 0 deletions

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