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authorMel Gorman <mel@csn.ul.ie>2007-07-31 00:37:30 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-31 15:39:36 -0700
commita8bbf72ab9b3072ece630d97689145b1a2f01221 (patch)
tree4d55318fff1aecd3c5d2c1e877847bcb2347dd2e /mm
parent252e48389ed30d7c77385fb92fca765a680de408 (diff)
downloadlinux-linaro-a8bbf72ab9b3072ece630d97689145b1a2f01221.tar.gz
Do not trigger OOM-killer for high-order allocation failures
out_of_memory() may be called when an allocation is failing and the direct reclaim is not making any progress. This does not take into account the requested order of the allocation. If the request if for an order larger than PAGE_ALLOC_COSTLY_ORDER, it is reasonable to fail the allocation because the kernel makes no guarantees about those allocations succeeding. This false OOM situation can occur if a user is trying to grow the hugepage pool in a script like; #!/bin/bash REQUIRED=$1 echo 1 > /proc/sys/vm/hugepages_treat_as_movable echo $REQUIRED > /proc/sys/vm/nr_hugepages ACTUAL=`cat /proc/sys/vm/nr_hugepages` while [ $REQUIRED -ne $ACTUAL ]; do echo Huge page pool at $ACTUAL growing to $REQUIRED echo $REQUIRED > /proc/sys/vm/nr_hugepages ACTUAL=`cat /proc/sys/vm/nr_hugepages` sleep 1 done This is a reasonable scenario when ZONE_MOVABLE is in use but triggers OOM easily on 2.6.23-rc1. This patch will fail an allocation for an order above PAGE_ALLOC_COSTLY_ORDER instead of killing processes and retrying. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Andy Whitcroft <apw@shadowen.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/page_alloc.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0bd4d82ddff..3da85b81dab 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1350,6 +1350,10 @@ nofail_alloc:
if (page)
goto got_pg;
+ /* The OOM killer will not help higher order allocs so fail */
+ if (order > PAGE_ALLOC_COSTLY_ORDER)
+ goto nopage;
+
out_of_memory(zonelist, gfp_mask, order);
goto restart;
}