1 files changed, 24 insertions, 16 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 516ab623d773..671e6c94fed7 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3388,25 +3388,33 @@ static void setup_zone_migrate_reserve(struct zone *zone)
                 if (page_to_nid(page) != zone_to_nid(zone))
                         continue;
 
-                /* Blocks with reserved pages will never free, skip them. */
-                block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn);
-                if (pageblock_is_reserved(pfn, block_end_pfn))
-                        continue;
-
                 block_migratetype = get_pageblock_migratetype(page);
 
-                /* If this block is reserved, account for it */
-                if (reserve > 0 && block_migratetype == MIGRATE_RESERVE) {
-                        reserve--;
-                        continue;
-                }
+                /* Only test what is necessary when the reserves are not met */
+                if (reserve > 0) {
+                        /*
+                         * Blocks with reserved pages will never free, skip
+                         * them.
+                         */
+                        block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn);
+                        if (pageblock_is_reserved(pfn, block_end_pfn))
+                                continue;
 
-                /* Suitable for reserving if this block is movable */
-                if (reserve > 0 && block_migratetype == MIGRATE_MOVABLE) {
-                        set_pageblock_migratetype(page, MIGRATE_RESERVE);
-                        move_freepages_block(zone, page, MIGRATE_RESERVE);
-                        reserve--;
-                        continue;
+                        /* If this block is reserved, account for it */
+                        if (block_migratetype == MIGRATE_RESERVE) {
+                                reserve--;
+                                continue;
+                        }
+
+                        /* Suitable for reserving if this block is movable */
+                        if (block_migratetype == MIGRATE_MOVABLE) {
+                                set_pageblock_migratetype(page,
+                                                        MIGRATE_RESERVE);
+                                move_freepages_block(zone, page,
+                                                        MIGRATE_RESERVE);
+                                reserve--;
+                                continue;
+                        }
                 }
 
                 /*