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authorDavid Rientjes <rientjes@google.com>2007-10-17 02:25:55 -0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-17 11:42:45 -0400
commit098d7f128a4e53cb64930628915ac767785e0e60 (patch)
treeed3cab1daecab7f2a64b27deed190df3ec218789 /include/linux/mmzone.h
parente815af95f94914993bbad279c71cf5fef9f4eaac (diff)
oom: add per-zone locking
OOM killer synchronization should be done with zone granularity so that memory policy and cpuset allocations may have their corresponding zones locked and allow parallel kills for other OOM conditions that may exist elsewhere in the system. DMA allocations can be targeted at the zone level, which would not be possible if locking was done in nodes or globally. Synchronization shall be done with a variation of "trylocks." The goal is to put the current task to sleep and restart the failed allocation attempt later if the trylock fails. Otherwise, the OOM killer is invoked. Each zone in the zonelist that __alloc_pages() was called with is checked for the newly-introduced ZONE_OOM_LOCKED flag. If any zone has this flag present, the "trylock" to serialize the OOM killer fails and returns zero. Otherwise, all the zones have ZONE_OOM_LOCKED set and the try_set_zone_oom() function returns non-zero. Cc: Andrea Arcangeli <andrea@suse.de> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: 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 'include/linux/mmzone.h')
-rw-r--r--include/linux/mmzone.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index bad9486ee0cc..9011505e740d 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -344,6 +344,7 @@ struct zone {
344typedef enum { 344typedef enum {
345 ZONE_ALL_UNRECLAIMABLE, /* all pages pinned */ 345 ZONE_ALL_UNRECLAIMABLE, /* all pages pinned */
346 ZONE_RECLAIM_LOCKED, /* prevents concurrent reclaim */ 346 ZONE_RECLAIM_LOCKED, /* prevents concurrent reclaim */
347 ZONE_OOM_LOCKED, /* zone is in OOM killer zonelist */
347} zone_flags_t; 348} zone_flags_t;
348 349
349static inline void zone_set_flag(struct zone *zone, zone_flags_t flag) 350static inline void zone_set_flag(struct zone *zone, zone_flags_t flag)
@@ -363,6 +364,10 @@ static inline int zone_is_reclaim_locked(const struct zone *zone)
363{ 364{
364 return test_bit(ZONE_RECLAIM_LOCKED, &zone->flags); 365 return test_bit(ZONE_RECLAIM_LOCKED, &zone->flags);
365} 366}
367static inline int zone_is_oom_locked(const struct zone *zone)
368{
369 return test_bit(ZONE_OOM_LOCKED, &zone->flags);
370}
366 371
367/* 372/*
368 * The "priority" of VM scanning is how much of the queues we will scan in one 373 * The "priority" of VM scanning is how much of the queues we will scan in one