From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754912AbYDUHpz (ORCPT ); Mon, 21 Apr 2008 03:45:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751610AbYDUHpm (ORCPT ); Mon, 21 Apr 2008 03:45:42 -0400 Received: from one.firstfloor.org ([213.235.205.2]:46584 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754195AbYDUHpd (ORCPT ); Mon, 21 Apr 2008 03:45:33 -0400 Date: Mon, 21 Apr 2008 09:51:02 +0200 From: Andi Kleen To: Daniel Hazelton Cc: Andi Kleen , Arjan van de Ven , Adrian Bunk , Alan Cox , Shawn Bohrer , Ingo Molnar , Andrew Morton , Linux Kernel Mailing List , Thomas Gleixner Subject: Re: x86: 4kstacks default Message-ID: <20080421075102.GB14446@one.firstfloor.org> References: <200804181737.m3IHbabI010051@hera.kernel.org> <200804201643.35830.dhazelton@enter.net> <480BB85A.6020508@firstfloor.org> <200804202145.45146.dhazelton@enter.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200804202145.45146.dhazelton@enter.net> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Never said it worked on a 32bit system. I was pointing out that there can be > workloads that do reach Ah your point was that people might do this on 64bit systems? They could indeed. It would not be very efficient but it should work in theory at least with enough memory. Of course they don't need 4k stacks for it. They can also try it on 32bit and it will work to some extent too, just not scale very far. And 4k stack more or less won't make much difference for that because the stack is only a small part of the lowmem needed for a blocked thread with open sockets. But this thread clearly was about 32bit systems only. > that 50K thread-count that you seem to be > calling "stupid". Note I didn't come up with that number, it was quoted to me earlier (but one of its authors has distanced itself from it now, so it seems to becoming more and more irrelevant indeed now) Stupid in this case just refers to the general observation that it is quite inefficient to do one thread per request on servers who are expected to process lots of long running connections. Perhaps I could have put that better I will give you that. Please assume I always meant "inefficient" when I wrote "stupid". > talking about. If I had been running 4K stacks on that machine I probably > would have survived the mis-configuration without the reboot it took to make Now that is a very doubtful claim. You realize that a functional network server thread needs a lot more lowmem than just the stack? -Andi