Merge branch 'v3.10/topic/misc' into linux-linaro-lsk

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

diff --git a/mm/rmap.c b/mm/rmap.c
index 6280da86b5d6761ed8a245c3fadb6e42015216c5..fbf0040a73424b56b35ebaeb66db64135d255630 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -600,7 +600,11 @@ pte_t *__page_check_address(struct page *page, struct mm_struct *mm,
        spinlock_t *ptl;
 
        if (unlikely(PageHuge(page))) {
+               /* when pud is not present, pte will be NULL */
                pte = huge_pte_offset(mm, address);
+               if (!pte)
+                       return NULL;
+
                ptl = &mm->page_table_lock;
                goto check;
        }
@@ -1386,9 +1390,19 @@ 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 */
                }