From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kamezawa Hiroyuki Subject: Re: [PATCH v4 1/6] memcg: prevent changes to move_charge_at_immigrate during task attach Date: Tue, 29 Jan 2013 09:11:03 +0900 Message-ID: <51071397.2080908@jp.fujitsu.com> References: <1358862461-18046-1-git-send-email-glommer@parallels.com> <1358862461-18046-2-git-send-email-glommer@parallels.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1358862461-18046-2-git-send-email-glommer-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Glauber Costa Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Tejun Heo , Michal Hocko , Johannes Weiner (2013/01/22 22:47), Glauber Costa wrote: > Currently, we rely on the cgroup_lock() to prevent changes to > move_charge_at_immigrate during task migration. However, this is only > needed because the current strategy keeps checking this value throughout > the whole process. Since all we need is serialization, one needs only to > guarantee that whatever decision we made in the beginning of a specific > migration is respected throughout the process. > > We can achieve this by just saving it in mc. By doing this, no kind of > locking is needed. > > [ v2: change flag name to avoid confusion ] > > Signed-off-by: Glauber Costa > Acked-by: Michal Hocko Acked-by: KAMEZAWA Hiroyuki From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx140.postini.com [74.125.245.140]) by kanga.kvack.org (Postfix) with SMTP id EE5556B0027 for ; Mon, 28 Jan 2013 19:11:19 -0500 (EST) Received: from m4.gw.fujitsu.co.jp (unknown [10.0.50.74]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 781EF3EE0BB for ; Tue, 29 Jan 2013 09:11:18 +0900 (JST) Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 578F745DE53 for ; Tue, 29 Jan 2013 09:11:18 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 4376545DE4F for ; Tue, 29 Jan 2013 09:11:18 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 334FFE08002 for ; Tue, 29 Jan 2013 09:11:18 +0900 (JST) Received: from m1000.s.css.fujitsu.com (m1000.s.css.fujitsu.com [10.240.81.136]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id DF0B71DB803B for ; Tue, 29 Jan 2013 09:11:17 +0900 (JST) Message-ID: <51071397.2080908@jp.fujitsu.com> Date: Tue, 29 Jan 2013 09:11:03 +0900 From: Kamezawa Hiroyuki MIME-Version: 1.0 Subject: Re: [PATCH v4 1/6] memcg: prevent changes to move_charge_at_immigrate during task attach References: <1358862461-18046-1-git-send-email-glommer@parallels.com> <1358862461-18046-2-git-send-email-glommer@parallels.com> In-Reply-To: <1358862461-18046-2-git-send-email-glommer@parallels.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Glauber Costa Cc: cgroups@vger.kernel.org, linux-mm@kvack.org, Tejun Heo , Michal Hocko , Johannes Weiner (2013/01/22 22:47), Glauber Costa wrote: > Currently, we rely on the cgroup_lock() to prevent changes to > move_charge_at_immigrate during task migration. However, this is only > needed because the current strategy keeps checking this value throughout > the whole process. Since all we need is serialization, one needs only to > guarantee that whatever decision we made in the beginning of a specific > migration is respected throughout the process. > > We can achieve this by just saving it in mc. By doing this, no kind of > locking is needed. > > [ v2: change flag name to avoid confusion ] > > Signed-off-by: Glauber Costa > Acked-by: Michal Hocko Acked-by: KAMEZAWA Hiroyuki -- 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