From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <48BBAFDD.1000902@openvz.org> Date: Mon, 01 Sep 2008 13:03:25 +0400 From: Pavel Emelyanov MIME-Version: 1.0 Subject: Re: [RFC][PATCH] Remove cgroup member from struct page References: <20080831174756.GA25790@balbir.in.ibm.com> In-Reply-To: <20080831174756.GA25790@balbir.in.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Balbir Singh Cc: Andrew Morton , hugh@veritas.com, kamezawa.hiroyu@jp.fujitsu.com, menage@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: Balbir Singh wrote: > This is a rewrite of a patch I had written long back to remove struct page > (I shared the patches with Kamezawa, but never posted them anywhere else). > I spent the weekend, cleaning them up for 2.6.27-rc5-mmotm (29 Aug 2008). > > I've tested the patches on an x86_64 box, I've run a simple test running > under the memory control group and the same test running concurrently under > two different groups (and creating pressure within their groups). I've also > compiled the patch with CGROUP_MEM_RES_CTLR turned off. > > Advantages of the patch > > 1. It removes the extra pointer in struct page > > Disadvantages > > 1. It adds an additional lock structure to struct page_cgroup > 2. Radix tree lookup is not an O(1) operation, once the page is known > getting to the page_cgroup (pc) is a little more expensive now. And besides, we also have a global lock, that protects even lookup from this structure. Won't this affect us too much on bug-smp nodes? > This is an initial RFC for comments > > TODOs > > 1. Test the page migration changes > 2. Test the performance impact of the patch/approach > > Comments/Reviews? > > Signed-off-by: Balbir Singh -- 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