From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx176.postini.com [74.125.245.176]) by kanga.kvack.org (Postfix) with SMTP id 490516B004F for ; Wed, 25 Jan 2012 17:48:39 -0500 (EST) Received: by qadc11 with SMTP id c11so1337227qad.14 for ; Wed, 25 Jan 2012 14:48:38 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20120124134750.de5f31ee.kamezawa.hiroyu@jp.fujitsu.com> References: <20120113173001.ee5260ca.kamezawa.hiroyu@jp.fujitsu.com> <20120113174019.8dff3fc1.kamezawa.hiroyu@jp.fujitsu.com> <20120124134750.de5f31ee.kamezawa.hiroyu@jp.fujitsu.com> Date: Wed, 25 Jan 2012 14:48:38 -0800 Message-ID: Subject: Re: [RFC] [PATCH 3/7 v2] memcg: remove PCG_MOVE_LOCK flag from pc->flags From: Ying Han Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org List-ID: To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "hugh.dickins@tiscali.co.uk" , "hannes@cmpxchg.org" , Michal Hocko , cgroups@vger.kernel.org, "bsingharora@gmail.com" On Mon, Jan 23, 2012 at 8:47 PM, KAMEZAWA Hiroyuki wrote: > On Mon, 23 Jan 2012 14:02:48 -0800 > Ying Han wrote: > >> On Fri, Jan 13, 2012 at 12:40 AM, KAMEZAWA Hiroyuki >> wrote: >> > >> > From 1008e84d94245b1e7c4d237802ff68ff00757736 Mon Sep 17 00:00:00 2001 >> > From: KAMEZAWA Hiroyuki >> > Date: Thu, 12 Jan 2012 15:53:24 +0900 >> > Subject: [PATCH 3/7] memcg: remove PCG_MOVE_LOCK flag from pc->flags. >> > >> > PCG_MOVE_LOCK bit is used for bit spinlock for avoiding race between >> > memcg's account moving and page state statistics updates. >> > >> > Considering page-statistics update, very hot path, this lock is >> > taken only when someone is moving account (or PageTransHuge()) >> > And, now, all moving-account between memcgroups (by task-move) >> > are serialized. >> >> This might be a side question, can you clarify the serialization here? >> Does it mean that we only allow one task-move at a time system-wide? >> > > current implementation has that limit by mutex. ah, thanks. that is the cgroup_mutex lock which serializes mem_cgroup_move_charge() from move task. --Ying > > Thanks, > -Kame > -- 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 internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org