From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755052AbYDUFyh (ORCPT ); Mon, 21 Apr 2008 01:54:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751913AbYDUFy3 (ORCPT ); Mon, 21 Apr 2008 01:54:29 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:59494 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751901AbYDUFy2 (ORCPT ); Mon, 21 Apr 2008 01:54:28 -0400 Date: Sun, 20 Apr 2008 22:53:54 -0700 From: Arjan van de Ven To: Andi Kleen Cc: Daniel Hazelton , Adrian Bunk , Alan Cox , Shawn Bohrer , Ingo Molnar , Andrew Morton , Linux Kernel Mailing List , Thomas Gleixner Subject: Re: x86: 4kstacks default Message-ID: <20080420225354.08b1d096@laptopd505.fenrus.org> In-Reply-To: <87prsk86d5.fsf@basil.nowhere.org> References: <200804181737.m3IHbabI010051@hera.kernel.org> <20080420104444.GI1595@cs181133002.pp.htv.fi> <87y778aezh.fsf@basil.nowhere.org> <200804201144.33308.dhazelton@enter.net> <480B7CB2.3080002@firstfloor.org> <20080420114845.77bf3fed@laptopd505.fenrus.org> <480BA12A.4000307@firstfloor.org> <20080420153318.553e5d2d@laptopd505.fenrus.org> <87prsk86d5.fsf@basil.nowhere.org> Organization: Intel X-Mailer: Claws Mail 3.2.0 (GTK+ 2.12.5; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 21 Apr 2008 01:16:22 +0200 Andi Kleen wrote: > Arjan van de Ven writes: > > > > it is you who keeps putting up the 50k argument. > > See the links I posted and quote in an earlier message up the thread > if you don't remember what you wrote yourself. > > I originally only hold up the fragmentation argument (or rather only > argued against it), until I was corrected by both Ingo and you in the > earlier thread and you both insisted that 50k threads were the real > reason'd'etre for 4k stacks. > > You're saying that was wrong and the fragmentation issue was really > the real reason for 4k stacks? If both you and Ingo can agree on that > I would be happy to forget the 50k threads :) I already corrected you misquoting/misunderstanding me; should I do this again? > > > What I'm talking about is in the 10k to 20k range; and that is > > actual workloads by real customers. > > On a 32bit kernel? > > My estimate is that you need around 32k for a functional blocked > thread in a network server (8k + 2*4k for poll with large fd table > and wait queues + some pinned dentries and inodes + misc other > stuff). With 20k you're 625MB into your lowmem which leaves about > 200MB left on a 3:1 system with 16GB (and ~128MB mem_map). That > might work for some time, but I expect it will fall over at some > point because there is just too much pinned lowmem and not enough > left for other stuff (like networking buffers etc.) > > 10k sounds more doable. But again do 4k more or less make > a big difference with the other thread overhead? I don't think so. no but the other ones are order 0.. -- If you want to reach me at my work email, use arjan@linux.intel.com For development, discussion and tips for power savings, visit http://www.lesswatts.org