1 files changed, 53 insertions, 24 deletions

diff --git a/mm/compaction.c b/mm/compaction.c
index d9ebebe1a2aa..74a8c825ff28 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -35,7 +35,7 @@ struct compact_control {
         unsigned long migrate_pfn;      /* isolate_migratepages search base */
         bool sync;                      /* Synchronous migration */
 
-        unsigned int order;             /* order a direct compactor needs */
+        int order;                      /* order a direct compactor needs */
         int migratetype;                /* MOVABLE, RECLAIMABLE etc */
         struct zone *zone;
 };
@@ -675,49 +675,71 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist,
 
 
 /* Compact all zones within a node */
-static int compact_node(int nid)
+static int __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc)
 {
         int zoneid;
-        pg_data_t *pgdat;
         struct zone *zone;
 
-        if (nid < 0 || nid >= nr_node_ids || !node_online(nid))
-                return -EINVAL;
-        pgdat = NODE_DATA(nid);
-
-        /* Flush pending updates to the LRU lists */
-        lru_add_drain_all();
-
         for (zoneid = 0; zoneid < MAX_NR_ZONES; zoneid++) {
-                struct compact_control cc = {
-                        .nr_freepages = 0,
-                        .nr_migratepages = 0,
-                        .order = -1,
-                        .sync = true,
-                };
 
                 zone = &pgdat->node_zones[zoneid];
                 if (!populated_zone(zone))
                         continue;
 
-                cc.zone = zone;
-                INIT_LIST_HEAD(&cc.freepages);
-                INIT_LIST_HEAD(&cc.migratepages);
-
-                compact_zone(zone, &cc);
+                cc->nr_freepages = 0;
+                cc->nr_migratepages = 0;
+                cc->zone = zone;
+                INIT_LIST_HEAD(&cc->freepages);
+                INIT_LIST_HEAD(&cc->migratepages);
+
+                if (cc->order == -1 || !compaction_deferred(zone, cc->order))
+                        compact_zone(zone, cc);
+
+                if (cc->order > 0) {
+                        int ok = zone_watermark_ok(zone, cc->order,
+                                                low_wmark_pages(zone), 0, 0);
+                        if (ok && cc->order > zone->compact_order_failed)
+                                zone->compact_order_failed = cc->order + 1;
+                        /* Currently async compaction is never deferred. */
+                        else if (!ok && cc->sync)
+                                defer_compaction(zone, cc->order);
+                }
 
-                VM_BUG_ON(!list_empty(&cc.freepages));
-                VM_BUG_ON(!list_empty(&cc.migratepages));
+                VM_BUG_ON(!list_empty(&cc->freepages));
+                VM_BUG_ON(!list_empty(&cc->migratepages));
         }
 
         return 0;
 }
 
+int compact_pgdat(pg_data_t *pgdat, int order)
+{
+        struct compact_control cc = {
+                .order = order,
+                .sync = false,
+        };
+
+        return __compact_pgdat(pgdat, &cc);
+}
+
+static int compact_node(int nid)
+{
+        struct compact_control cc = {
+                .order = -1,
+                .sync = true,
+        };
+
+        return __compact_pgdat(NODE_DATA(nid), &cc);
+}
+
 /* Compact all nodes in the system */
 static int compact_nodes(void)
 {
         int nid;
 
+        /* Flush pending updates to the LRU lists */
+        lru_add_drain_all();
+
         for_each_online_node(nid)
                 compact_node(nid);
 
@@ -750,7 +772,14 @@ ssize_t sysfs_compact_node(struct device *dev,
                         struct device_attribute *attr,
                         const char *buf, size_t count)
 {
-        compact_node(dev->id);
+        int nid = dev->id;
+
+        if (nid >= 0 && nid < nr_node_ids && node_online(nid)) {
+                /* Flush pending updates to the LRU lists */
+                lru_add_drain_all();
+
+                compact_node(nid);
+        }
 
         return count;
 }