From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 27 Aug 2008 08:41:57 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [RFC][PATCH 3/14] memcg: atomic_flags Message-Id: <20080827084157.b435fa2c.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <48B3C3B2.3090205@linux.vnet.ibm.com> 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> <48B3C3B2.3090205@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: balbir@linux.vnet.ibm.com Cc: linux-mm@kvack.org, nishimura@mxp.nes.nec.co.jp List-ID: On Tue, 26 Aug 2008 14:19:54 +0530 Balbir Singh wrote: > 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 Sorry I missed it. will write reply. Thanks, -Kame > -- > 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