From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id 7FD9160021B for ; Mon, 28 Dec 2009 05:00:52 -0500 (EST) Received: by ywh5 with SMTP id 5so14494918ywh.11 for ; Mon, 28 Dec 2009 02:00:50 -0800 (PST) From: Minchan Kim Subject: [PATCH 2/3 -mmotm-2009-12-10-17-19] Count zero page as file_rss Date: Sat, 21 Nov 2009 12:24:19 +0900 Message-Id: In-Reply-To: References: In-Reply-To: References: Sender: owner-linux-mm@kvack.org To: Andrew Morton , LKML , linux-mm Cc: Minchan Kim , KAMEZAWA Hiroyuki List-ID: Long time ago, we counted zero page as file_rss. But after reinstanted zero page, we don't do it. It means rss of process would be smaller than old. It could chage OOM victim selection. Kame reported following as "Before starting zero-page works, I checked "questions" in lkml and found some reports that some applications start to go OOM after zero-page removal. For me, I know one of my customer's application depends on behavior of zero page (on RHEL5). So, I tried to add again it before RHEL6 because I think removal of zero-page corrupts compatibility." So how about adding zero page as file_rss again for compatibility? Signed-off-by: Minchan Kim --- mm/memory.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 3743fb5..a4ba271 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1995,6 +1995,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, int reuse = 0, ret = 0; int page_mkwrite = 0; struct page *dirty_page = NULL; + int zero_pfn = 0; old_page = vm_normal_page(vma, address, orig_pte); if (!old_page) { @@ -2117,7 +2118,8 @@ gotten: if (unlikely(anon_vma_prepare(vma))) goto oom; - if (is_zero_pfn(pte_pfn(orig_pte))) { + zero_pfn = is_zero_pfn(pte_pfn(orig_pte)); + if (zero_pfn) { new_page = alloc_zeroed_user_highpage_movable(vma, address); if (!new_page) goto oom; @@ -2147,7 +2149,7 @@ gotten: */ page_table = pte_offset_map_lock(mm, pmd, address, &ptl); if (likely(pte_same(*page_table, orig_pte))) { - if (old_page) { + if (old_page || zero_pfn) { if (!PageAnon(old_page)) { dec_mm_counter(mm, file_rss); inc_mm_counter(mm, anon_rss); @@ -2650,6 +2652,7 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, spin_lock(ptl); if (!pte_none(*page_table)) goto unlock; + inc_mm_counter(mm, file_rss); goto setpte; } -- 1.5.6.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org