From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753985Ab1A1HwX (ORCPT ); Fri, 28 Jan 2011 02:52:23 -0500 Received: from zene.cmpxchg.org ([85.214.230.12]:59016 "EHLO zene.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753472Ab1A1HwW (ORCPT ); Fri, 28 Jan 2011 02:52:22 -0500 Date: Fri, 28 Jan 2011 08:52:15 +0100 From: Johannes Weiner To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "nishimura@mxp.nes.nec.co.jp" , "balbir@linux.vnet.ibm.com" Subject: Re: [BUGFIX][PATCH 1/4] memcg: fix limit estimation at reclaim for hugepage Message-ID: <20110128075215.GA2213@cmpxchg.org> References: <20110128122229.6a4c74a2.kamezawa.hiroyu@jp.fujitsu.com> <20110128122449.e4bb0e5f.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110128122449.e4bb0e5f.kamezawa.hiroyu@jp.fujitsu.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 28, 2011 at 12:24:49PM +0900, KAMEZAWA Hiroyuki wrote: > From: KAMEZAWA Hiroyuki > > Current memory cgroup's code tends to assume page_size == PAGE_SIZE > and arrangement for THP is not enough yet. > > This is one of fixes for supporing THP. This adds > mem_cgroup_check_margin() and checks whether there are required amount of > free resource after memory reclaim. By this, THP page allocation > can know whether it really succeeded or not and avoid infinite-loop > and hangup. > > Total fixes for do_charge()/reclaim memory will follow this patch. > > Signed-off-by: KAMEZAWA Hiroyuki > --- > include/linux/res_counter.h | 11 +++++++++++ > mm/memcontrol.c | 25 ++++++++++++++++++++++++- > 2 files changed, 35 insertions(+), 1 deletion(-) > > Index: mmotm-0125/include/linux/res_counter.h > =================================================================== > --- mmotm-0125.orig/include/linux/res_counter.h > +++ mmotm-0125/include/linux/res_counter.h > @@ -182,6 +182,17 @@ static inline bool res_counter_check_und > return ret; > } > > +static inline s64 res_counter_check_margin(struct res_counter *cnt) > +{ > + s64 ret; > + unsigned long flags; > + > + spin_lock_irqsave(&cnt->lock, flags); > + ret = cnt->limit - cnt->usage; > + spin_unlock_irqrestore(&cnt->lock, flags); > + return ret; > +} This function does not check anything. You could name it res_counter_get_margin() e.g. But if you do that, I will complain that it's asymmetric to res_counter_check_under_limit(). And the result will be pretty close to my version... > @@ -1853,7 +1869,14 @@ static int __mem_cgroup_do_charge(struct > * Check the limit again to see if the reclaim reduced the > * current usage of the cgroup before giving up > */ > - if (ret || mem_cgroup_check_under_limit(mem_over_limit)) > + if (mem_cgroup_check_margin(mem_over_limit) >= csize) > + return CHARGE_RETRY; > + > + /* > + * If the charge size is a PAGE_SIZE, it's not hopeless while > + * we can reclaim a page. > + */ > + if (csize == PAGE_SIZE && ret) > return CHARGE_RETRY; That makes sense. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with ESMTP id 3B8768D0039 for ; Fri, 28 Jan 2011 02:52:22 -0500 (EST) Date: Fri, 28 Jan 2011 08:52:15 +0100 From: Johannes Weiner Subject: Re: [BUGFIX][PATCH 1/4] memcg: fix limit estimation at reclaim for hugepage Message-ID: <20110128075215.GA2213@cmpxchg.org> References: <20110128122229.6a4c74a2.kamezawa.hiroyu@jp.fujitsu.com> <20110128122449.e4bb0e5f.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110128122449.e4bb0e5f.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "nishimura@mxp.nes.nec.co.jp" , "balbir@linux.vnet.ibm.com" List-ID: On Fri, Jan 28, 2011 at 12:24:49PM +0900, KAMEZAWA Hiroyuki wrote: > From: KAMEZAWA Hiroyuki > > Current memory cgroup's code tends to assume page_size == PAGE_SIZE > and arrangement for THP is not enough yet. > > This is one of fixes for supporing THP. This adds > mem_cgroup_check_margin() and checks whether there are required amount of > free resource after memory reclaim. By this, THP page allocation > can know whether it really succeeded or not and avoid infinite-loop > and hangup. > > Total fixes for do_charge()/reclaim memory will follow this patch. > > Signed-off-by: KAMEZAWA Hiroyuki > --- > include/linux/res_counter.h | 11 +++++++++++ > mm/memcontrol.c | 25 ++++++++++++++++++++++++- > 2 files changed, 35 insertions(+), 1 deletion(-) > > Index: mmotm-0125/include/linux/res_counter.h > =================================================================== > --- mmotm-0125.orig/include/linux/res_counter.h > +++ mmotm-0125/include/linux/res_counter.h > @@ -182,6 +182,17 @@ static inline bool res_counter_check_und > return ret; > } > > +static inline s64 res_counter_check_margin(struct res_counter *cnt) > +{ > + s64 ret; > + unsigned long flags; > + > + spin_lock_irqsave(&cnt->lock, flags); > + ret = cnt->limit - cnt->usage; > + spin_unlock_irqrestore(&cnt->lock, flags); > + return ret; > +} This function does not check anything. You could name it res_counter_get_margin() e.g. But if you do that, I will complain that it's asymmetric to res_counter_check_under_limit(). And the result will be pretty close to my version... > @@ -1853,7 +1869,14 @@ static int __mem_cgroup_do_charge(struct > * Check the limit again to see if the reclaim reduced the > * current usage of the cgroup before giving up > */ > - if (ret || mem_cgroup_check_under_limit(mem_over_limit)) > + if (mem_cgroup_check_margin(mem_over_limit) >= csize) > + return CHARGE_RETRY; > + > + /* > + * If the charge size is a PAGE_SIZE, it's not hopeless while > + * we can reclaim a page. > + */ > + if (csize == PAGE_SIZE && ret) > return CHARGE_RETRY; That makes sense. -- 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/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org