From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id CB2106B024D for ; Tue, 27 Jul 2010 22:39:12 -0400 (EDT) Date: Tue, 27 Jul 2010 22:39:04 -0400 From: Vivek Goyal Subject: Re: [RFC][PATCH 4/7][memcg] memcg use ID in page_cgroup Message-ID: <20100728023904.GE12642@redhat.com> References: <20100727165155.8b458b7f.kamezawa.hiroyu@jp.fujitsu.com> <20100727165629.6f98145c.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100727165629.6f98145c.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "nishimura@mxp.nes.nec.co.jp" , "balbir@linux.vnet.ibm.com" , gthelen@google.com, m-ikeda@ds.jp.nec.com, "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" List-ID: On Tue, Jul 27, 2010 at 04:56:29PM +0900, KAMEZAWA Hiroyuki wrote: > From: KAMEZAWA Hiroyuki > > Now, addresses of memory cgroup can be calculated by their ID without complex. > This patch relplaces pc->mem_cgroup from a pointer to a unsigned short. > On 64bit architecture, this offers us more 6bytes room per page_cgroup. > Use 2bytes for blkio-cgroup's page tracking. More 4bytes will be used for > some light-weight concurrent access. > > We may able to move this id onto flags field but ...go step by step. > > Signed-off-by: KAMEZAWA Hiroyuki > --- > include/linux/page_cgroup.h | 3 ++- > mm/memcontrol.c | 40 +++++++++++++++++++++++++--------------- > mm/page_cgroup.c | 2 +- > 3 files changed, 28 insertions(+), 17 deletions(-) > > Index: mmotm-0719/include/linux/page_cgroup.h > =================================================================== > --- mmotm-0719.orig/include/linux/page_cgroup.h > +++ mmotm-0719/include/linux/page_cgroup.h > @@ -12,7 +12,8 @@ > */ > struct page_cgroup { > unsigned long flags; > - struct mem_cgroup *mem_cgroup; > + unsigned short mem_cgroup; /* ID of assigned memory cgroup */ > + unsigned short blk_cgroup; /* Not Used..but will be. */ So later I shall have to use virtually indexed arrays in blkio controller? Or you are just using virtually indexed arrays for lookup speed and I can continue to use css_lookup() and not worry about using virtually indexed arrays. So the idea is that when a page is allocated, also store the blk_group id and once that page is submitted for writeback, we should be able to associate it to right blkio group? Vivek -- 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