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authorRafael J. Wysocki <rjw@sisk.pl>2009-06-16 15:32:41 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-16 19:47:40 -0700
commit7f33d49a2ed546e01f7b1d0607661810f2421859 (patch)
tree8b05ac7ec2cd123efb266ecaa1bf0bd1487158f8 /mm/page_alloc.c
parent75927af8bcb940dad4fe281713d526cb520869ff (diff)
downloadconfigs-7f33d49a2ed546e01f7b1d0607661810f2421859.tar.gz
mm, PM/Freezer: Disable OOM killer when tasks are frozen
Currently, the following scenario appears to be possible in theory: * Tasks are frozen for hibernation or suspend. * Free pages are almost exhausted. * Certain piece of code in the suspend code path attempts to allocate some memory using GFP_KERNEL and allocation order less than or equal to PAGE_ALLOC_COSTLY_ORDER. * __alloc_pages_internal() cannot find a free page so it invokes the OOM killer. * The OOM killer attempts to kill a task, but the task is frozen, so it doesn't die immediately. * __alloc_pages_internal() jumps to 'restart', unsuccessfully tries to find a free page and invokes the OOM killer. * No progress can be made. Although it is now hard to trigger during hibernation due to the memory shrinking carried out by the hibernation code, it is theoretically possible to trigger during suspend after the memory shrinking has been removed from that code path. Moreover, since memory allocations are going to be used for the hibernation memory shrinking, it will be even more likely to happen during hibernation. To prevent it from happening, introduce the oom_killer_disabled switch that will cause __alloc_pages_internal() to fail in the situations in which the OOM killer would have been called and make the freezer set this switch after tasks have been successfully frozen. [akpm@linux-foundation.org: be nicer to the namespace] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Fengguang Wu <fengguang.wu@gmail.com> Cc: David Rientjes <rientjes@google.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page_alloc.c')
-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 61290ea721c..5b09488d0f5 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -178,6 +178,8 @@ static void set_pageblock_migratetype(struct page *page, int migratetype)
PB_migrate, PB_migrate_end);
}
+bool oom_killer_disabled __read_mostly;
+
#ifdef CONFIG_DEBUG_VM
static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
{
@@ -1769,6 +1771,8 @@ rebalance:
*/
if (!did_some_progress) {
if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
+ if (oom_killer_disabled)
+ goto nopage;
page = __alloc_pages_may_oom(gfp_mask, order,
zonelist, high_zoneidx,
nodemask, preferred_zone,