1 files changed, 62 insertions, 46 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index f7c4f37c3b18..5feef4d4650e 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1431,13 +1431,14 @@ int try_to_free_pages(struct zone **zones, gfp_t gfp_mask)
         int ret = 0;
         int total_scanned = 0, total_reclaimed = 0;
         struct reclaim_state *reclaim_state = current->reclaim_state;
-        struct scan_control sc;
         unsigned long lru_pages = 0;
         int i;
-
-        sc.gfp_mask = gfp_mask;
-        sc.may_writepage = !laptop_mode;
-        sc.may_swap = 1;
+        struct scan_control sc = {
+                .gfp_mask = gfp_mask,
+                .may_writepage = !laptop_mode,
+                .swap_cluster_max = SWAP_CLUSTER_MAX,
+                .may_swap = 1,
+        };
 
         inc_page_state(allocstall);
 
@@ -1455,7 +1456,6 @@ int try_to_free_pages(struct zone **zones, gfp_t gfp_mask)
                 sc.nr_mapped = read_page_state(nr_mapped);
                 sc.nr_scanned = 0;
                 sc.nr_reclaimed = 0;
-                sc.swap_cluster_max = SWAP_CLUSTER_MAX;
                 if (!priority)
                         disable_swap_token();
                 shrink_caches(priority, zones, &sc);
@@ -1478,7 +1478,8 @@ int try_to_free_pages(struct zone **zones, gfp_t gfp_mask)
                  * that's undesirable in laptop mode, where we *want* lumpy
                  * writeout.  So in laptop mode, write out the whole world.
                  */
-                if (total_scanned > sc.swap_cluster_max + sc.swap_cluster_max/2) {
+                if (total_scanned > sc.swap_cluster_max +
+                                        sc.swap_cluster_max / 2) {
                         wakeup_pdflush(laptop_mode ? 0 : total_scanned);
                         sc.may_writepage = 1;
                 }
@@ -1532,14 +1533,16 @@ static int balance_pgdat(pg_data_t *pgdat, int nr_pages, int order)
         int i;
         int total_scanned, total_reclaimed;
         struct reclaim_state *reclaim_state = current->reclaim_state;
-        struct scan_control sc;
+        struct scan_control sc = {
+                .gfp_mask = GFP_KERNEL,
+                .may_swap = 1,
+                .swap_cluster_max = nr_pages ? nr_pages : SWAP_CLUSTER_MAX,
+        };
 
 loop_again:
         total_scanned = 0;
         total_reclaimed = 0;
-        sc.gfp_mask = GFP_KERNEL;
-        sc.may_writepage = !laptop_mode;
-        sc.may_swap = 1;
+        sc.may_writepage = !laptop_mode,
         sc.nr_mapped = read_page_state(nr_mapped);
 
         inc_page_state(pageoutrun);
@@ -1621,7 +1624,6 @@ scan:
                                 zone->prev_priority = priority;
                         sc.nr_scanned = 0;
                         sc.nr_reclaimed = 0;
-                        sc.swap_cluster_max = nr_pages? nr_pages : SWAP_CLUSTER_MAX;
                         shrink_zone(priority, zone, &sc);
                         reclaim_state->reclaimed_slab = 0;
                         nr_slab = shrink_slab(sc.nr_scanned, GFP_KERNEL,
@@ -1869,46 +1871,21 @@ int zone_reclaim_interval __read_mostly = 30*HZ;
 /*
  * Try to free up some pages from this zone through reclaim.
  */
-int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
+static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
 {
-        int nr_pages;
+        const int nr_pages = 1 << order;
         struct task_struct *p = current;
         struct reclaim_state reclaim_state;
-        struct scan_control sc;
-        cpumask_t mask;
-        int node_id;
         int priority;
-
-        if (time_before(jiffies,
-                zone->last_unsuccessful_zone_reclaim + zone_reclaim_interval))
-                        return 0;
-
-        if (!(gfp_mask & __GFP_WAIT) ||
-                zone->all_unreclaimable ||
-                atomic_read(&zone->reclaim_in_progress) > 0 ||
-                (p->flags & PF_MEMALLOC))
-                        return 0;
-
-        node_id = zone->zone_pgdat->node_id;
-        mask = node_to_cpumask(node_id);
-        if (!cpus_empty(mask) && node_id != numa_node_id())
-                return 0;
-
-        sc.may_writepage = !!(zone_reclaim_mode & RECLAIM_WRITE);
-        sc.may_swap = !!(zone_reclaim_mode & RECLAIM_SWAP);
-        sc.nr_scanned = 0;
-        sc.nr_reclaimed = 0;
-        sc.nr_mapped = read_page_state(nr_mapped);
-        sc.gfp_mask = gfp_mask;
+        struct scan_control sc = {
+                .may_writepage = !!(zone_reclaim_mode & RECLAIM_WRITE),
+                .may_swap = !!(zone_reclaim_mode & RECLAIM_SWAP),
+                .nr_mapped = read_page_state(nr_mapped),
+                .swap_cluster_max = max(nr_pages, SWAP_CLUSTER_MAX),
+                .gfp_mask = gfp_mask,
+        };
 
         disable_swap_token();
-
-        nr_pages = 1 << order;
-        if (nr_pages > SWAP_CLUSTER_MAX)
-                sc.swap_cluster_max = nr_pages;
-        else
-                sc.swap_cluster_max = SWAP_CLUSTER_MAX;
-
         cond_resched();
         /*
          * We need to be able to allocate from the reserves for RECLAIM_SWAP
@@ -1949,5 +1926,44 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
 
         return sc.nr_reclaimed >= nr_pages;
 }
+
+int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
+{
+        cpumask_t mask;
+        int node_id;
+
+        /*
+         * Do not reclaim if there was a recent unsuccessful attempt at zone
+         * reclaim.  In that case we let allocations go off node for the
+         * zone_reclaim_interval.  Otherwise we would scan for each off-node
+         * page allocation.
+         */
+        if (time_before(jiffies,
+                zone->last_unsuccessful_zone_reclaim + zone_reclaim_interval))
+                        return 0;
+
+        /*
+         * Avoid concurrent zone reclaims, do not reclaim in a zone that does
+         * not have reclaimable pages and if we should not delay the allocation
+         * then do not scan.
+         */
+        if (!(gfp_mask & __GFP_WAIT) ||
+                zone->all_unreclaimable ||
+                atomic_read(&zone->reclaim_in_progress) > 0 ||
+                (current->flags & PF_MEMALLOC))
+                        return 0;
+
+        /*
+         * Only run zone reclaim on the local zone or on zones that do not
+         * have associated processors. This will favor the local processor
+         * over remote processors and spread off node memory allocations
+         * as wide as possible.
+         */
+        node_id = zone->zone_pgdat->node_id;
+        mask = node_to_cpumask(node_id);
+        if (!cpus_empty(mask) && node_id != numa_node_id())
+                return 0;
+        return __zone_reclaim(zone, gfp_mask, order);
+}
 #endif