Messages in this thread Patch in this message | | | From | KOSAKI Motohiro <> | Subject | [PATCH 7/8] Use TASK_KILLABLE instead TASK_UNINTERRUPTIBLE | Date | Mon, 14 Dec 2009 21:32:18 +0900 (JST) |
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When fork bomb invoke OOM Killer, almost task might start to reclaim and sleep on shrink_zone_begin(). if we use TASK_UNINTERRUPTIBLE, OOM killer can't kill such task. it mean we never recover from fork bomb.
This patch fixes it.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> --- mm/vmscan.c | 20 +++++++++++++------- 1 files changed, 13 insertions(+), 7 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c index bf229d3..e537361 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1618,7 +1618,10 @@ static int shrink_zone_begin(struct zone *zone, struct scan_control *sc) * we would just make things slower. */ for (;;) { - prepare_to_wait_exclusive(wq, &wait, TASK_UNINTERRUPTIBLE); + prepare_to_wait_exclusive(wq, &wait, TASK_KILLABLE); + + if (fatal_signal_pending(current)) + goto stop_reclaim; if (atomic_read(&zone->concurrent_reclaimers) <= max_zone_concurrent_reclaimers) @@ -1631,18 +1634,21 @@ static int shrink_zone_begin(struct zone *zone, struct scan_control *sc) * break out of the loop and go back to the allocator. */ if (zone_watermark_ok(zone, sc->order, low_wmark_pages(zone), - 0, 0)) { - wake_up_all(wq); - finish_wait(wq, &wait); - sc->nr_reclaimed += sc->nr_to_reclaim; - return -ERESTARTSYS; - } + 0, 0)) + goto found_lots_memory; } finish_wait(wq, &wait); out: atomic_inc(&zone->concurrent_reclaimers); return 0; + + found_lots_memory: + wake_up_all(wq); + stop_reclaim: + finish_wait(wq, &wait); + sc->nr_reclaimed += sc->nr_to_reclaim; + return -ERESTARTSYS; } static void shrink_zone_end(struct zone *zone, struct scan_control *sc) -- 1.6.5.2
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