1 files changed, 5 insertions, 4 deletions

diff --git a/mm/compaction.c b/mm/compaction.c
index 585de54dbe8c..56fa3216a6b4 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -200,7 +200,8 @@ static void reset_cached_positions(struct zone *zone)
 {
         zone->compact_cached_migrate_pfn[0] = zone->zone_start_pfn;
         zone->compact_cached_migrate_pfn[1] = zone->zone_start_pfn;
-        zone->compact_cached_free_pfn = zone_end_pfn(zone);
+        zone->compact_cached_free_pfn =
+                        round_down(zone_end_pfn(zone) - 1, pageblock_nr_pages);
 }
 
 /*
@@ -1371,11 +1372,11 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
          */
         cc->migrate_pfn = zone->compact_cached_migrate_pfn[sync];
         cc->free_pfn = zone->compact_cached_free_pfn;
-        if (cc->free_pfn < start_pfn || cc->free_pfn > end_pfn) {
-                cc->free_pfn = end_pfn & ~(pageblock_nr_pages-1);
+        if (cc->free_pfn < start_pfn || cc->free_pfn >= end_pfn) {
+                cc->free_pfn = round_down(end_pfn - 1, pageblock_nr_pages);
                 zone->compact_cached_free_pfn = cc->free_pfn;
         }
-        if (cc->migrate_pfn < start_pfn || cc->migrate_pfn > end_pfn) {
+        if (cc->migrate_pfn < start_pfn || cc->migrate_pfn >= end_pfn) {
                 cc->migrate_pfn = start_pfn;
                 zone->compact_cached_migrate_pfn[0] = cc->migrate_pfn;
                 zone->compact_cached_migrate_pfn[1] = cc->migrate_pfn;