Merge tag 'blackfin-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/realm...

[firefly-linux-kernel-4.4.55.git] / mm / compaction.c

diff --git a/mm/compaction.c b/mm/compaction.c
index e0ab02d70f13434059d1f05442285e0773189a1c..b48c5259ea33dfed9e4c08c956d8e30a36480c42 100644 (file)
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -523,7 +523,10 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
                if (!isolation_suitable(cc, page))
                        goto next_pageblock;
 
-               /* Skip if free */
+               /*
+                * Skip if free. page_order cannot be used without zone->lock
+                * as nothing prevents parallel allocations or buddy merging.
+                */
                if (PageBuddy(page))
                        continue;