1 files changed, 16 insertions, 6 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 1219ceb8a9b2..777af57fd8c8 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -544,6 +544,16 @@ redo:
                  */
                 lru = LRU_UNEVICTABLE;
                 add_page_to_unevictable_list(page);
+                /*
+                 * When racing with an mlock clearing (page is
+                 * unlocked), make sure that if the other thread does
+                 * not observe our setting of PG_lru and fails
+                 * isolation, we see PG_mlocked cleared below and move
+                 * the page back to the evictable list.
+                 *
+                 * The other side is TestClearPageMlocked().
+                 */
+                smp_mb();
         }
 
         /*
@@ -1088,7 +1098,7 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
         int lumpy_reclaim = 0;
 
         while (unlikely(too_many_isolated(zone, file, sc))) {
-                congestion_wait(WRITE, HZ/10);
+                congestion_wait(BLK_RW_ASYNC, HZ/10);
 
                 /* We are about to die and free our memory. Return now. */
                 if (fatal_signal_pending(current))
@@ -1356,7 +1366,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
                          * IO, plus JVM can create lots of anon VM_EXEC pages,
                          * so we ignore them here.
                          */
-                        if ((vm_flags & VM_EXEC) && !PageAnon(page)) {
+                        if ((vm_flags & VM_EXEC) && page_is_file_cache(page)) {
                                 list_add(&page->lru, &l_active);
                                 continue;
                         }
@@ -1709,10 +1719,10 @@ static void shrink_zones(int priority, struct zonelist *zonelist,
  *
  * If the caller is !__GFP_FS then the probability of a failure is reasonably
  * high - the zone may be full of dirty or under-writeback pages, which this
- * caller can't do much about.  We kick pdflush and take explicit naps in the
- * hope that some of these pages can be written.  But if the allocating task
- * holds filesystem locks which prevent writeout this might not work, and the
- * allocation attempt will fail.
+ * caller can't do much about.  We kick the writeback threads and take explicit
+ * naps in the hope that some of these pages can be written.  But if the
+ * allocating task holds filesystem locks which prevent writeout this might not
+ * work, and the allocation attempt will fail.
  *
  * returns:     0, if no pages reclaimed
  *              else, the number of pages reclaimed