From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 857BE6B021C for ; Fri, 23 Apr 2010 22:26:19 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp ([10.0.50.71]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o3O2QGeG028858 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Sat, 24 Apr 2010 11:26:17 +0900 Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id A750945DE4F for ; Sat, 24 Apr 2010 11:26:16 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 8687345DE4D for ; Sat, 24 Apr 2010 11:26:16 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 6C2C71DB804B for ; Sat, 24 Apr 2010 11:26:16 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.249.87.103]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 2265A1DB8045 for ; Sat, 24 Apr 2010 11:26:16 +0900 (JST) Date: Sat, 24 Apr 2010 11:22:17 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH -mmotm 1/5] memcg: disable irq at page cgroup lock Message-Id: <20100424112217.e2efb61b.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <1272056226.1821.41.camel@laptop> References: <1268609202-15581-2-git-send-email-arighi@develer.com> <20100318133527.420b2f25.kamezawa.hiroyu@jp.fujitsu.com> <20100318162855.GG18054@balbir.in.ibm.com> <20100319102332.f1d81c8d.kamezawa.hiroyu@jp.fujitsu.com> <20100319024039.GH18054@balbir.in.ibm.com> <20100319120049.3dbf8440.kamezawa.hiroyu@jp.fujitsu.com> <20100414140523.GC13535@redhat.com> <20100415114022.ef01b704.nishimura@mxp.nes.nec.co.jp> <20100415152104.62593f37.nishimura@mxp.nes.nec.co.jp> <20100415155432.cf1861d9.kamezawa.hiroyu@jp.fujitsu.com> <1272056226.1821.41.camel@laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Peter Zijlstra Cc: Greg Thelen , Daisuke Nishimura , Vivek Goyal , balbir@linux.vnet.ibm.com, Andrea Righi , Trond Myklebust , Suleiman Souhlal , "Kirill A. Shutemov" , Andrew Morton , containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Fri, 23 Apr 2010 22:57:06 +0200 Peter Zijlstra wrote: > On Fri, 2010-04-23 at 13:17 -0700, Greg Thelen wrote: > > +static void mem_cgroup_begin_page_cgroup_reassignment(void) > > +{ > > + VM_BUG_ON(mem_cgroup_account_move_ongoing); > > + mem_cgroup_account_move_ongoing = true; > > + synchronize_rcu(); > > +} > > btw, you know synchronize_rcu() is _really_ slow? > IIUC, this is called once per an event when task is moved and we have to move accouting information...and once per an event when we call rmdir() to destroy cgroup. So, this is not frequenctly called. (hooks to migration in this patch is removable.) 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/ . Don't email: email@kvack.org