Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764182AbZAOLIu (ORCPT ); Thu, 15 Jan 2009 06:08:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758351AbZAOLIl (ORCPT ); Thu, 15 Jan 2009 06:08:41 -0500 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:56881 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756660AbZAOLIk (ORCPT ); Thu, 15 Jan 2009 06:08:40 -0500 From: KOSAKI Motohiro To: KAMEZAWA Hiroyuki Subject: [PATCH] mark_page_accessed() in do_swap_page() move latter than memcg charge Cc: kosaki.motohiro@jp.fujitsu.com, balbir@linux.vnet.ibm.com, Daisuke Nishimura , linux-mm@kvack.org, linux-kernel@vger.kernel.org, lizf@cn.fujitsu.com, menage@google.com, Hugh Dickins In-Reply-To: <20090109134736.a995fc49.kamezawa.hiroyu@jp.fujitsu.com> References: <20090109043257.GB9737@balbir.in.ibm.com> <20090109134736.a995fc49.kamezawa.hiroyu@jp.fujitsu.com> Message-Id: <20090115200545.EBE6.KOSAKI.MOTOHIRO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.42 [ja] Date: Thu, 15 Jan 2009 20:08:36 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2063 Lines: 79 sorry for late responce. > > In this case we've hit a case where the page is valid and the pc is > > not. This does fix the problem, but won't this impact us getting > > correct reclaim stats and thus indirectly impact the working of > > pressure? > > > - If retruns NULL, only global LRU's status is updated. > > Because this page is not belongs to any memcg, we cannot update > any counters. But yes, your point is a concern. > > Maybe moving acitvate_page() to > == > do_swap_page() > { > > - activate_page() > mem_cgroup_try_charge().. > .... > mem_cgroup_commit_charge().... > .... > + activate_page() > } > == > is necessary. How do you think, kosaki ? OK. it makes sense. and my test found no bug. == mark_page_accessed() update reclaim_stat statics. but currently, memcg charge is called after mark_page_accessed(). then, mark_page_accessed() don't update memcg statics correctly. fixing here. Signed-off-by: KOSAKI Motohiro Cc: KAMEZAWA Hiroyuki Cc: Daisuke Nishimura Cc: Balbir Singh --- mm/memory.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) Index: b/mm/memory.c =================================================================== --- a/mm/memory.c +++ b/mm/memory.c @@ -2426,8 +2426,6 @@ static int do_swap_page(struct mm_struct count_vm_event(PGMAJFAULT); } - mark_page_accessed(page); - lock_page(page); delayacct_clear_flag(DELAYACCT_PF_SWAPIN); @@ -2480,6 +2478,8 @@ static int do_swap_page(struct mm_struct try_to_free_swap(page); unlock_page(page); + mark_page_accessed(page); + if (write_access) { ret |= do_wp_page(mm, vma, address, page_table, pmd, ptl, pte); if (ret & VM_FAULT_ERROR) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/