1 files changed, 34 insertions, 2 deletions

diff --git a/mm/compaction.c b/mm/compaction.c
index 206847d35978..613c59e928cb 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1318,6 +1318,17 @@ static enum compact_result __compact_finished(struct zone *zone,
         if (is_via_compact_memory(cc->order))
                 return COMPACT_CONTINUE;
 
+        if (cc->finishing_block) {
+                /*
+                 * We have finished the pageblock, but better check again that
+                 * we really succeeded.
+                 */
+                if (IS_ALIGNED(cc->migrate_pfn, pageblock_nr_pages))
+                        cc->finishing_block = false;
+                else
+                        return COMPACT_CONTINUE;
+        }
+
         /* Direct compactor: Is a suitable page free? */
         for (order = cc->order; order < MAX_ORDER; order++) {
                 struct free_area *area = &zone->free_area[order];
@@ -1338,8 +1349,29 @@ static enum compact_result __compact_finished(struct zone *zone,
                  * other migratetype buddy lists.
                  */
                 if (find_suitable_fallback(area, order, migratetype,
-                                                true, &can_steal) != -1)
-                        return COMPACT_SUCCESS;
+                                                true, &can_steal) != -1) {
+
+                        /* movable pages are OK in any pageblock */
+                        if (migratetype == MIGRATE_MOVABLE)
+                                return COMPACT_SUCCESS;
+
+                        /*
+                         * We are stealing for a non-movable allocation. Make
+                         * sure we finish compacting the current pageblock
+                         * first so it is as free as possible and we won't
+                         * have to steal another one soon. This only applies
+                         * to sync compaction, as async compaction operates
+                         * on pageblocks of the same migratetype.
+                         */
+                        if (cc->mode == MIGRATE_ASYNC ||
+                                        IS_ALIGNED(cc->migrate_pfn,
+                                                        pageblock_nr_pages)) {
+                                return COMPACT_SUCCESS;
+                        }
+
+                        cc->finishing_block = true;
+                        return COMPACT_CONTINUE;
+                }
         }
 
         return COMPACT_NO_SUITABLE_PAGE;