[PATCH] mm, compaction: avoid isolating pinned tmpfs pages

[Xu Yu]

This makes pinned tmpfs pages bail out early in the process of page
migration, like what pinned anonymous pages do.

Signed-off-by: Xu Yu <xuyu@xxxxxxxxxxxxxxxxx>
---
 mm/compaction.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/mm/compaction.c b/mm/compaction.c
index e04f4476e68e..78c3b992a1c9 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -964,11 +964,11 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
 		}
 
 		/*
-		 * Migration will fail if an anonymous page is pinned in memory,
-		 * so avoid taking lru_lock and isolating it unnecessarily in an
-		 * admittedly racy check.
+		 * Migration will fail if an anonymous or tmpfs page is pinned
+		 * in memory, so avoid taking lru_lock and isolating it
+		 * unnecessarily in an admittedly racy check.
 		 */
-		if (!page_mapping(page) &&
+		if (!page_is_file_lru(page) &&
 		    page_count(page) > page_mapcount(page))
 			goto isolate_fail;
 
-- 
2.20.1.2432.ga663e714