diff --git a/mm/compaction.c b/mm/compaction.c
index 017a1a1963cb..329973a1ae45 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -787,6 +787,15 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
 		cc->nr_migratepages++;
 		nr_isolated++;
 
+		/*
+		 * Record where we could have freed pages by migration and not
+		 * yet flushed them to buddy allocator.
+		 * - this is the lowest page that was isolated and likely be
+		 * then freed by migration.
+		 */
+		if (!cc->last_migrated_pfn)
+			cc->last_migrated_pfn = low_pfn;
+
 		/* Avoid isolating too much */
 		if (cc->nr_migratepages == COMPACT_CLUSTER_MAX) {
 			++low_pfn;
@@ -1075,7 +1084,6 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
 	unsigned long block_start_pfn;
 	unsigned long block_end_pfn;
 	unsigned long low_pfn;
-	unsigned long isolate_start_pfn;
 	struct page *page;
 	const isolate_mode_t isolate_mode =
 		(sysctl_compact_unevictable_allowed ? ISOLATE_UNEVICTABLE : 0) |
@@ -1130,7 +1138,6 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
 			continue;
 
 		/* Perform the isolation */
-		isolate_start_pfn = low_pfn;
 		low_pfn = isolate_migratepages_block(cc, low_pfn,
 						block_end_pfn, isolate_mode);
 
@@ -1139,15 +1146,6 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
 			return ISOLATE_ABORT;
 		}
 
-		/*
-		 * Record where we could have freed pages by migration and not
-		 * yet flushed them to buddy allocator.
-		 * - this is the lowest page that could have been isolated and
-		 * then freed by migration.
-		 */
-		if (cc->nr_migratepages && !cc->last_migrated_pfn)
-			cc->last_migrated_pfn = isolate_start_pfn;
-
 		/*
 		 * Either we isolated something and proceed with migration. Or
 		 * we failed and compact_zone should decide if we should