Commit 7335084d authored by Mel Gorman's avatar Mel Gorman Committed by Linus Torvalds

mm: vmscan: do not OOM if aborting reclaim to start compaction

During direct reclaim it is possible that reclaim will be aborted so that
compaction can be attempted to satisfy a high-order allocation.  If this
decision is made before any pages are reclaimed, it is possible that 0 is
returned to the page allocator potentially triggering an OOM.  This has
not been observed but it is a possibility so this patch addresses it.
Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
Reviewed-by: default avatarRik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andy Isaacson <adi@hexapodia.org>
Cc: Nai Xia <nai.xia@gmail.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 50134731
...@@ -2263,6 +2263,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, ...@@ -2263,6 +2263,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
struct zoneref *z; struct zoneref *z;
struct zone *zone; struct zone *zone;
unsigned long writeback_threshold; unsigned long writeback_threshold;
bool should_abort_reclaim;
get_mems_allowed(); get_mems_allowed();
delayacct_freepages_start(); delayacct_freepages_start();
...@@ -2274,7 +2275,8 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, ...@@ -2274,7 +2275,8 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
sc->nr_scanned = 0; sc->nr_scanned = 0;
if (!priority) if (!priority)
disable_swap_token(sc->target_mem_cgroup); disable_swap_token(sc->target_mem_cgroup);
if (shrink_zones(priority, zonelist, sc)) should_abort_reclaim = shrink_zones(priority, zonelist, sc);
if (should_abort_reclaim)
break; break;
/* /*
...@@ -2342,6 +2344,10 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, ...@@ -2342,6 +2344,10 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
if (oom_killer_disabled) if (oom_killer_disabled)
return 0; return 0;
/* Aborting reclaim to try compaction? don't OOM, then */
if (should_abort_reclaim)
return 1;
/* top priority shrink_zones still had more to do? don't OOM, then */ /* top priority shrink_zones still had more to do? don't OOM, then */
if (global_reclaim(sc) && !all_unreclaimable(zonelist, sc)) if (global_reclaim(sc) && !all_unreclaimable(zonelist, sc))
return 1; return 1;
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment