thp: cleanup: introduce mk_huge_pmd()

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

diff --git a/mm/compaction.c b/mm/compaction.c
index 9eef55838fca5ff99580982e85ea0c0fa6dea839..694eaabaaebdc0827c93d81c97f200fc534a115e 100644 (file)
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -713,7 +713,15 @@ static void isolate_freepages(struct zone *zone,
 
                /* Found a block suitable for isolating free pages from */
                isolated = 0;
-               end_pfn = min(pfn + pageblock_nr_pages, zone_end_pfn);
+
+               /*
+                * As pfn may not start aligned, pfn+pageblock_nr_page
+                * may cross a MAX_ORDER_NR_PAGES boundary and miss
+                * a pfn_valid check. Ensure isolate_freepages_block()
+                * only scans within a pageblock
+                */
+               end_pfn = ALIGN(pfn + 1, pageblock_nr_pages);
+               end_pfn = min(end_pfn, zone_end_pfn);
                isolated = isolate_freepages_block(cc, pfn, end_pfn,
                                                   freelist, false);
                nr_freepages += isolated;