From 61469f1d51777fc3b6d8d70da8373ee77ee13349 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Tue, 4 Mar 2008 14:29:04 -0800 Subject: [PATCH] memcg: when do_swap's do_wp_page fails Don't uncharge when do_swap_page's call to do_wp_page fails: the page which was charged for is there in the pagetable, and will be correctly uncharged when that area is unmapped - it was only its COWing which failed. And while we're here, remove earlier XXX comment: yes, OR in do_wp_page's return value (maybe VM_FAULT_WRITE) with do_swap_page's there; but if it fails, mask out success bits, which might confuse some arches e.g. sparc. Signed-off-by: Hugh Dickins Cc: David Rientjes Acked-by: Balbir Singh Acked-by: KAMEZAWA Hiroyuki Cc: Hirokazu Takahashi Cc: YAMAMOTO Takashi Cc: Paul Menage Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 7f8c03ec587c..0d14d1e58a5f 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2093,12 +2093,9 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, unlock_page(page); if (write_access) { - /* XXX: We could OR the do_wp_page code with this one? */ - if (do_wp_page(mm, vma, address, - page_table, pmd, ptl, pte) & VM_FAULT_OOM) { - mem_cgroup_uncharge_page(page); - ret = VM_FAULT_OOM; - } + ret |= do_wp_page(mm, vma, address, page_table, pmd, ptl, pte); + if (ret & VM_FAULT_ERROR) + ret &= VM_FAULT_ERROR; goto out; }