summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--mm/memory.c19
1 files changed, 13 insertions, 6 deletions
diff --git a/mm/memory.c b/mm/memory.c
index dd7d7fc5ed60..65962534b4ed 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1467,11 +1467,21 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
goto gotten;
/*
- * Only catch write-faults on shared writable pages, read-only
- * shared pages can get COWed by get_user_pages(.write=1, .force=1).
+ * Take out anonymous pages first, anonymous shared vmas are
+ * not dirty accountable.
*/
- if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) ==
+ if (PageAnon(old_page)) {
+ if (!TestSetPageLocked(old_page)) {
+ reuse = can_share_swap_page(old_page);
+ unlock_page(old_page);
+ }
+ } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) ==
(VM_WRITE|VM_SHARED))) {
+ /*
+ * Only catch write-faults on shared writable pages,
+ * read-only shared pages can get COWed by
+ * get_user_pages(.write=1, .force=1).
+ */
if (vma->vm_ops && vma->vm_ops->page_mkwrite) {
/*
* Notify the address space that the page is about to
@@ -1503,9 +1513,6 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
dirty_page = old_page;
get_page(dirty_page);
reuse = 1;
- } else if (PageAnon(old_page) && !TestSetPageLocked(old_page)) {
- reuse = can_share_swap_page(old_page);
- unlock_page(old_page);
}
if (reuse) {