2 files changed, 14 insertions, 2 deletions

diff --git a/mm/mlock.c b/mm/mlock.c
index 4e1a68162285..b1eb53634005 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -79,6 +79,7 @@ void clear_page_mlock(struct page *page)
  */
 void mlock_vma_page(struct page *page)
 {
+        /* Serialize with page migration */
         BUG_ON(!PageLocked(page));
 
         if (!TestSetPageMlocked(page)) {
@@ -174,6 +175,7 @@ unsigned int munlock_vma_page(struct page *page)
         unsigned int nr_pages;
         struct zone *zone = page_zone(page);
 
+        /* For try_to_munlock() and to serialize with page migration */
         BUG_ON(!PageLocked(page));
 
         /*
diff --git a/mm/rmap.c b/mm/rmap.c
index 11cf322f8133..9c3e77396d1a 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1332,9 +1332,19 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
                 BUG_ON(!page || PageAnon(page));
 
                 if (locked_vma) {
-                        mlock_vma_page(page);   /* no-op if already mlocked */
-                        if (page == check_page)
+                        if (page == check_page) {
+                                /* we know we have check_page locked */
+                                mlock_vma_page(page);
                                 ret = SWAP_MLOCK;
+                        } else if (trylock_page(page)) {
+                                /*
+                                 * If we can lock the page, perform mlock.
+                                 * Otherwise leave the page alone, it will be
+                                 * eventually encountered again later.
+                                 */
+                                mlock_vma_page(page);
+                                unlock_page(page);
+                        }
                         continue;       /* don't unmap */
                 }