vmscan: recalculate lru_pages on each priority

shrink_zones() need relatively long time and lru_pages can change
dramatically during shrink_zones().  So lru_pages should be recalculated
for each priority.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 13 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 5b594d62ca01..6dafa45d79e4 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1787,7 +1787,6 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
         bool all_unreclaimable;
         unsigned long total_scanned = 0;
         struct reclaim_state *reclaim_state = current->reclaim_state;
-        unsigned long lru_pages = 0;
         struct zoneref *z;
         struct zone *zone;
         enum zone_type high_zoneidx = gfp_zone(sc->gfp_mask);
@@ -1798,18 +1797,6 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 
         if (scanning_global_lru(sc))
                 count_vm_event(ALLOCSTALL);
-        /*
-         * mem_cgroup will not do shrink_slab.
-         */
-        if (scanning_global_lru(sc)) {
-                for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
-
-                        if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
-                                continue;
-
-                        lru_pages += zone_reclaimable_pages(zone);
-                }
-        }
 
         for (priority = DEF_PRIORITY; priority >= 0; priority--) {
                 sc->nr_scanned = 0;
@@ -1821,6 +1808,14 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
                  * over limit cgroups
                  */
                 if (scanning_global_lru(sc)) {
+                        unsigned long lru_pages = 0;
+                        for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
+                                if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
+                                        continue;
+
+                                lru_pages += zone_reclaimable_pages(zone);
+                        }
+
                         shrink_slab(sc->nr_scanned, sc->gfp_mask, lru_pages);
                         if (reclaim_state) {
                                 sc->nr_reclaimed += reclaim_state->reclaimed_slab;