1 files changed, 37 insertions, 21 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 349797ba4bac..089e943c4d38 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1527,7 +1527,6 @@ int zone_reclaim_mode __read_mostly;
 #define RECLAIM_ZONE (1<<0)     /* Run shrink_cache on the zone */
 #define RECLAIM_WRITE (1<<1)    /* Writeout pages during reclaim */
 #define RECLAIM_SWAP (1<<2)     /* Swap pages out during reclaim */
-#define RECLAIM_SLAB (1<<3)     /* Do a global slab shrink if the zone is out of memory */
 
 /*
  * Priority for ZONE_RECLAIM. This determines the fraction of pages
@@ -1543,6 +1542,12 @@ int zone_reclaim_mode __read_mostly;
 int sysctl_min_unmapped_ratio = 1;
 
 /*
+ * If the number of slab pages in a zone grows beyond this percentage then
+ * slab reclaim needs to occur.
+ */
+int sysctl_min_slab_ratio = 5;
+
+/*
  * Try to free up some pages from this zone through reclaim.
  */
 static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
@@ -1573,29 +1578,37 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
         reclaim_state.reclaimed_slab = 0;
         p->reclaim_state = &reclaim_state;
 
-        /*
-         * Free memory by calling shrink zone with increasing priorities
-         * until we have enough memory freed.
-         */
-        priority = ZONE_RECLAIM_PRIORITY;
-        do {
-                nr_reclaimed += shrink_zone(priority, zone, &sc);
-                priority--;
-        } while (priority >= 0 && nr_reclaimed < nr_pages);
+        if (zone_page_state(zone, NR_FILE_PAGES) -
+                zone_page_state(zone, NR_FILE_MAPPED) >
+                zone->min_unmapped_pages) {
+                /*
+                 * Free memory by calling shrink zone with increasing
+                 * priorities until we have enough memory freed.
+                 */
+                priority = ZONE_RECLAIM_PRIORITY;
+                do {
+                        nr_reclaimed += shrink_zone(priority, zone, &sc);
+                        priority--;
+                } while (priority >= 0 && nr_reclaimed < nr_pages);
+        }
 
-        if (nr_reclaimed < nr_pages && (zone_reclaim_mode & RECLAIM_SLAB)) {
+        if (zone_page_state(zone, NR_SLAB_RECLAIMABLE) > zone->min_slab_pages) {
                 /*
                  * shrink_slab() does not currently allow us to determine how
-                 * many pages were freed in this zone. So we just shake the slab
-                 * a bit and then go off node for this particular allocation
-                 * despite possibly having freed enough memory to allocate in
-                 * this zone.  If we freed local memory then the next
-                 * allocations will be local again.
+                 * many pages were freed in this zone. So we take the current
+                 * number of slab pages and shake the slab until it is reduced
+                 * by the same nr_pages that we used for reclaiming unmapped
+                 * pages.
                  *
-                 * shrink_slab will free memory on all zones and may take
-                 * a long time.
+                 * Note that shrink_slab will free memory on all zones and may
+                 * take a long time.
                  */
-                shrink_slab(sc.nr_scanned, gfp_mask, order);
+                unsigned long limit = zone_page_state(zone,
+                                NR_SLAB_RECLAIMABLE) - nr_pages;
+
+                while (shrink_slab(sc.nr_scanned, gfp_mask, order) &&
+                        zone_page_state(zone, NR_SLAB_RECLAIMABLE) > limit)
+                        ;
         }
 
         p->reclaim_state = NULL;
@@ -1609,7 +1622,8 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
         int node_id;
 
         /*
-         * Zone reclaim reclaims unmapped file backed pages.
+         * Zone reclaim reclaims unmapped file backed pages and
+         * slab pages if we are over the defined limits.
          *
          * A small portion of unmapped file backed pages is needed for
          * file I/O otherwise pages read by file I/O will be immediately
@@ -1618,7 +1632,9 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
          * unmapped file backed pages.
          */
         if (zone_page_state(zone, NR_FILE_PAGES) -
-            zone_page_state(zone, NR_FILE_MAPPED) <= zone->min_unmapped_pages)
+            zone_page_state(zone, NR_FILE_MAPPED) <= zone->min_unmapped_pages
+            && zone_page_state(zone, NR_SLAB_RECLAIMABLE)
+                        <= zone->min_slab_pages)
                 return 0;
 
         /*