From 2344d7e44b870f9df67e505ee4e633217de752ba Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Wed, 6 Aug 2014 16:06:15 -0700 Subject: mm: vmscan: remove all_unreclaimable() Direct reclaim currently calls shrink_zones() to reclaim all members of a zonelist, and if that wasn't successful it does another pass through the same zonelist to check overall reclaimability. Just check reclaimability in shrink_zones() directly and propagate the result through the return value. Then remove all_unreclaimable(). Signed-off-by: Johannes Weiner Cc: Mel Gorman Cc: Rik van Riel Acked-by: Michal Hocko Cc: Vlastimil Babka Acked-by: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmscan.c | 49 ++++++++++++++++++++++++------------------------- 1 file changed, 24 insertions(+), 25 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 6f43df4..74a9e0a 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2244,9 +2244,10 @@ static inline bool should_continue_reclaim(struct zone *zone, } } -static void shrink_zone(struct zone *zone, struct scan_control *sc) +static bool shrink_zone(struct zone *zone, struct scan_control *sc) { unsigned long nr_reclaimed, nr_scanned; + bool reclaimable = false; do { struct mem_cgroup *root = sc->target_mem_cgroup; @@ -2290,8 +2291,13 @@ static void shrink_zone(struct zone *zone, struct scan_control *sc) sc->nr_scanned - nr_scanned, sc->nr_reclaimed - nr_reclaimed); + if (sc->nr_reclaimed - nr_reclaimed) + reclaimable = true; + } while (should_continue_reclaim(zone, sc->nr_reclaimed - nr_reclaimed, sc->nr_scanned - nr_scanned, sc)); + + return reclaimable; } /* Returns true if compaction should go ahead for a high-order request */ @@ -2340,8 +2346,10 @@ static inline bool compaction_ready(struct zone *zone, int order) * * If a zone is deemed to be full of pinned pages then just give it a light * scan then give up on it. + * + * Returns true if a zone was reclaimable. */ -static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc) +static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc) { struct zoneref *z; struct zone *zone; @@ -2354,6 +2362,7 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc) .gfp_mask = sc->gfp_mask, }; enum zone_type requested_highidx = gfp_zone(sc->gfp_mask); + bool reclaimable = false; /* * If the number of buffer_heads in the machine exceeds the maximum @@ -2414,10 +2423,17 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc) &nr_soft_scanned); sc->nr_reclaimed += nr_soft_reclaimed; sc->nr_scanned += nr_soft_scanned; + if (nr_soft_reclaimed) + reclaimable = true; /* need some check for avoid more shrink_zone() */ } - shrink_zone(zone, sc); + if (shrink_zone(zone, sc)) + reclaimable = true; + + if (global_reclaim(sc) && + !reclaimable && zone_reclaimable(zone)) + reclaimable = true; } /* @@ -2439,26 +2455,8 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc) * promoted it to __GFP_HIGHMEM. */ sc->gfp_mask = orig_mask; -} - -/* All zones in zonelist are unreclaimable? */ -static bool all_unreclaimable(struct zonelist *zonelist, - struct scan_control *sc) -{ - struct zoneref *z; - struct zone *zone; - for_each_zone_zonelist_nodemask(zone, z, zonelist, - gfp_zone(sc->gfp_mask), sc->nodemask) { - if (!populated_zone(zone)) - continue; - if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) - continue; - if (zone_reclaimable(zone)) - return false; - } - - return true; + return reclaimable; } /* @@ -2482,6 +2480,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, { unsigned long total_scanned = 0; unsigned long writeback_threshold; + bool zones_reclaimable; delayacct_freepages_start(); @@ -2492,7 +2491,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, vmpressure_prio(sc->gfp_mask, sc->target_mem_cgroup, sc->priority); sc->nr_scanned = 0; - shrink_zones(zonelist, sc); + zones_reclaimable = shrink_zones(zonelist, sc); total_scanned += sc->nr_scanned; if (sc->nr_reclaimed >= sc->nr_to_reclaim) @@ -2532,8 +2531,8 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, if (sc->compaction_ready) return 1; - /* top priority shrink_zones still had more to do? don't OOM, then */ - if (global_reclaim(sc) && !all_unreclaimable(zonelist, sc)) + /* Any of the zones still reclaimable? Don't OOM. */ + if (zones_reclaimable) return 1; return 0; -- cgit v1.1