From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753298AbYIJLDT (ORCPT ); Wed, 10 Sep 2008 07:03:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751145AbYIJLDH (ORCPT ); Wed, 10 Sep 2008 07:03:07 -0400 Received: from smtp118.mail.mud.yahoo.com ([209.191.84.167]:45315 "HELO smtp118.mail.mud.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751125AbYIJLDH (ORCPT ); Wed, 10 Sep 2008 07:03:07 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:X-YMail-OSG:X-Yahoo-Newman-Property:From:To:Subject:Date:User-Agent:Cc:References:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding:Content-Disposition:Message-Id; b=EMwEEiXsCPO0iLf65smjX6u6An1txl4RPkbAz0QntcMXSAVFtJeS5j7764Y2thj68FdIyqONEPcUkHZ9r/GzGpLp1N9c9PxQfnkVdedc85G3oNdNKxcg0BowWv3DJDQd8RsjFl5hxcb3rZUdiQggwXDY9c4PODN/0Mhwf3vjHEE= ; X-YMail-OSG: Im7C8bAVM1mrpOI83d.KxmIYTVIsawoobTqEzC9x4ePvNbemVMOMvQS1SVGt8PWh5.0..Bonvs95ST7zL_xL2Uq8ugEk8NYH0ebikU2JsyAS9QaJCZw37fKRGdyrWS7S.kGLS4dxlYT1Il5ibSgoNoSy X-Yahoo-Newman-Property: ymail-3 From: Nick Piggin To: KAMEZAWA Hiroyuki Subject: Re: [Approach #2] [RFC][PATCH] Remove cgroup member from struct page Date: Thu, 11 Sep 2008 07:02:44 +1000 User-Agent: KMail/1.9.5 Cc: balbir@linux.vnet.ibm.com, Andrew Morton , hugh@veritas.com, menage@google.com, xemul@openvz.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <48C66AF8.5070505@linux.vnet.ibm.com> <200809110644.39334.nickpiggin@yahoo.com.au> <20080910200304.fd078007.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20080910200304.fd078007.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200809110702.45003.nickpiggin@yahoo.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 10 September 2008 21:03, KAMEZAWA Hiroyuki wrote: > On Thu, 11 Sep 2008 06:44:37 +1000 > > Nick Piggin wrote: > > On Wednesday 10 September 2008 11:49, KAMEZAWA Hiroyuki wrote: > > > On Tue, 9 Sep 2008 18:20:48 -0700 > > > > > > Balbir Singh wrote: > > > > * KAMEZAWA Hiroyuki [2008-09-09 > > > > 21:30:12]: OK, here is approach #2, it works for me and gives me > > > > really good performance (surpassing even the current memory > > > > controller). I am seeing almost a 7% increase > > > > > > This number is from pre-allcation, maybe. > > > We really do alloc-at-boot all page_cgroup ? This seems a big change. > > > > It seems really nice to me -- we get the best of both worlds, less > > overhead for those who don't enable the memory controller, and even > > better performance for those who do. > > No trobles for me for allocating-all-at-boot policy. > My small concern is > - wasting page_cgroup for hugepage area. > - memory hotplug In those cases you still waste the struct page area too. I realise that isn't a good way to justify even more wastage. But I guess it is relatively low. At least, I would think the users would be more happy to get a 7% performance increase for small pages! :) > > Are you expecting many users to want to turn this on and off at runtime? > > I wouldn't expect so, but I don't know enough about them. > > There is no runtime switch. only at boot. Fine