diff --git a/mm/compaction.c b/mm/compaction.c
index c437893..b5326b1 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -677,6 +677,13 @@
 					pfn -= pageblock_nr_pages) {
 		unsigned long isolated;
 
+		/*
+		 * This can iterate a massively long zone without finding any
+		 * suitable migration targets, so periodically check if we need
+		 * to schedule.
+		 */
+		cond_resched();
+
 		if (!pfn_valid(pfn))
 			continue;