diff options
| author | Mel Gorman <mgorman@suse.de> | 2011-10-31 17:09:33 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-10-31 17:30:50 -0700 |
| commit | e0c23279c9f800c403f37511484d9014ac83adec (patch) | |
| tree | 9dcf058d3d1c691328ea5839dfe9c340e47ee3fa /mm | |
| parent | e0887c19b2daa140f20ca8104bdc5740f39dbb86 (diff) | |
vmscan: abort reclaim/compaction if compaction can proceed
If compaction can proceed, shrink_zones() stops doing any work but its
callers still call shrink_slab() which raises the priority and potentially
sleeps. This is unnecessary and wasteful so this patch aborts direct
reclaim/compaction entirely if compaction can proceed.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Johannes Weiner <jweiner@redhat.com>
Cc: Josh Boyer <jwboyer@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/vmscan.c | 32 |
1 files changed, 21 insertions, 11 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 7e0f0579738..a90c603a8d0 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2103,14 +2103,19 @@ restart: * * If a zone is deemed to be full of pinned pages then just give it a light * scan then give up on it. + * + * This function returns true if a zone is being reclaimed for a costly + * high-order allocation and compaction is either ready to begin or deferred. + * This indicates to the caller that it should retry the allocation or fail. */ -static void shrink_zones(int priority, struct zonelist *zonelist, +static bool shrink_zones(int priority, struct zonelist *zonelist, struct scan_control *sc) { struct zoneref *z; struct zone *zone; unsigned long nr_soft_reclaimed; unsigned long nr_soft_scanned; + bool should_abort_reclaim = false; for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(sc->gfp_mask), sc->nodemask) { @@ -2127,19 +2132,20 @@ static void shrink_zones(int priority, struct zonelist *zonelist, continue; /* Let kswapd poll it */ if (COMPACTION_BUILD) { /* - * If we already have plenty of memory - * free for compaction, don't free any - * more. Even though compaction is - * invoked for any non-zero order, - * only frequent costly order - * reclamation is disruptive enough to - * become a noticable problem, like - * transparent huge page allocations. + * If we already have plenty of memory free for + * compaction in this zone, don't free any more. + * Even though compaction is invoked for any + * non-zero order, only frequent costly order + * reclamation is disruptive enough to become a + * noticable problem, like transparent huge page + * allocations. */ if (sc->order > PAGE_ALLOC_COSTLY_ORDER && (compaction_suitable(zone, sc->order) || - compaction_deferred(zone))) + compaction_deferred(zone))) { + should_abort_reclaim = true; continue; + } } /* * This steals pages from memory cgroups over softlimit @@ -2158,6 +2164,8 @@ static void shrink_zones(int priority, struct zonelist *zonelist, shrink_zone(priority, zone, sc); } + + return should_abort_reclaim; } static bool zone_reclaimable(struct zone *zone) @@ -2222,7 +2230,9 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, sc->nr_scanned = 0; if (!priority) disable_swap_token(sc->mem_cgroup); - shrink_zones(priority, zonelist, sc); + if (shrink_zones(priority, zonelist, sc)) + break; + /* * Don't shrink slabs when reclaiming memory from * over limit cgroups |