From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d28relay02.in.ibm.com (d28relay02.in.ibm.com [9.184.220.59]) by e28esmtp03.in.ibm.com (8.13.1/8.13.1) with ESMTP id m7Q8ntDR022180 for ; Tue, 26 Aug 2008 14:19:55 +0530 Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay02.in.ibm.com (8.13.8/8.13.8/NCO v9.0) with ESMTP id m7Q8ntrQ1806486 for ; Tue, 26 Aug 2008 14:19:55 +0530 Received: from d28av05.in.ibm.com (loopback [127.0.0.1]) by d28av05.in.ibm.com (8.13.1/8.13.3) with ESMTP id m7Q8ntP0024648 for ; Tue, 26 Aug 2008 14:19:55 +0530 Message-ID: <48B3C3B2.3090205@linux.vnet.ibm.com> Date: Tue, 26 Aug 2008 14:19:54 +0530 From: Balbir Singh Reply-To: balbir@linux.vnet.ibm.com MIME-Version: 1.0 Subject: Re: [RFC][PATCH 3/14] memcg: atomic_flags References: <48B38CDB.1070102@linux.vnet.ibm.com> <20080822202720.b7977aab.kamezawa.hiroyu@jp.fujitsu.com> <20080822203228.98adf408.kamezawa.hiroyu@jp.fujitsu.com> <27319629.1219740371105.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <27319629.1219740371105.kamezawa.hiroyu@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: kamezawa.hiroyu@jp.fujitsu.com Cc: linux-mm@kvack.org, nishimura@mxp.nes.nec.co.jp List-ID: kamezawa.hiroyu@jp.fujitsu.com wrote: > ----- Original Message ----- >> KAMEZAWA Hiroyuki wrote: >>> This patch makes page_cgroup->flags to be atomic_ops and define >>> functions (and macros) to access it. >>> >>> This patch itself makes memcg slow but this patch's final purpose is >>> to remove lock_page_cgroup() and allowing fast access to page_cgroup. >>> >> That is a cause of worry, do the patches that follow help performance? > By applying patchs for this and RCU and removing lock_page_cgroup(), I saw sma > ll performance benefit. > >> How do we >> benefit from faster access to page_cgroup() if the memcg controller becomes s > lower? > No slow-down on my box but. But the cpu which I'm testing on is a bit old. > I'd like to try newer CPU. > As you know, I don't like slow-down very much ;) I see, yes, I do know that you like to make things faster. BTW, you did not comment on my comments below about the naming convention and using the __ variants -- Balbir -- 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