diff options
| -rw-r--r-- | mm/memory.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/mm/memory.c b/mm/memory.c index dd7d7fc5ed609..65962534b4ed0 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) { |