When direct reclaim is entered is 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 for 0 to be 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: Mel Gorman <mgorman@xxxxxxx> --- mm/vmscan.c | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 3421746..5f4c789 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2222,6 +2222,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, struct zoneref *z; struct zone *zone; unsigned long writeback_threshold; + bool should_abort_reclaim; get_mems_allowed(); delayacct_freepages_start(); @@ -2233,7 +2234,8 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, sc->nr_scanned = 0; if (!priority) disable_swap_token(sc->mem_cgroup); - if (shrink_zones(priority, zonelist, sc)) + should_abort_reclaim = shrink_zones(priority, zonelist, sc); + if (should_abort_reclaim) break; /* @@ -2301,6 +2303,10 @@ out: if (oom_killer_disabled) 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 */ if (scanning_global_lru(sc) && !all_unreclaimable(zonelist, sc)) return 1; -- 1.7.3.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>