From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965020AbYD1Rup (ORCPT ); Mon, 28 Apr 2008 13:50:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S935772AbYD1RuI (ORCPT ); Mon, 28 Apr 2008 13:50:08 -0400 Received: from main.gmane.org ([80.91.229.2]:54475 "EHLO ciao.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935514AbYD1RuD (ORCPT ); Mon, 28 Apr 2008 13:50:03 -0400 X-Injected-Via-Gmane: http://gmane.org/ To: linux-kernel@vger.kernel.org From: Bill Davidsen Subject: Re: x86: 4kstacks default Date: Mon, 28 Apr 2008 13:56:51 -0400 Message-ID: <48160FE3.6000401@tmr.com> References: <20080419142329.GA5339@elte.hu> <20080419145948.GA4528@lintop> <20080420080901.GF1595@cs181133002.pp.htv.fi> <20080420090623.7b173ef1@the-village.bc.nu> <20080420085104.GG1595@cs181133002.pp.htv.fi> <20080420103611.2c0d3519@the-village.bc.nu> <20080420104444.GI1595@cs181133002.pp.htv.fi> <87y778aezh.fsf@basil.nowhere.org> <20080420124717.GH8474@1wt.eu> <480B3FCF.1090207@firstfloor.org> <20080420133007.GB1899@cs181133002.pp.htv.fi> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@ger.gmane.org Cc: Andi Kleen , Willy Tarreau , Alan Cox , Shawn Bohrer , Ingo Molnar , Andrew Morton , Linux Kernel Mailing List , Arjan van de Ven , Thomas Gleixner X-Gmane-NNTP-Posting-Host: pool-68-236-140-141.alb.east.verizon.net User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.8) Gecko/20061105 SeaMonkey/1.0.6 In-Reply-To: <20080420133007.GB1899@cs181133002.pp.htv.fi> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Adrian Bunk wrote: > On Sun, Apr 20, 2008 at 03:06:23PM +0200, Andi Kleen wrote: >> Willy Tarreau wrote: >> ... >>> I have nothing against changing the default setting to 4k provided that >>> it is easy to get back to the save setting >> So you're saying that only advanced users who understand all their >> CONFIG options should have the safe settings? And everyone else >> the "only explodes once a week" mode? >> >> For me that is exactly the wrong way around. >> >> If someone is sure they know what they're doing they can set whatever >> crazy settings they want (given there is a quick way to check >> for the crazy settings in oops reports so that I can ignore those), but >> the default should be always safe and optimized for reliability. > > That means we'll have nearly zero testing of the "crazy setting" and > when someone tries it he'll have a high probability of running into some > problems. > > Such a "crazy setting" shouldn't be offered to users at all. > > We should either aim at 4k stacks unconditionally for all 32bit > architectures with 4k page size or don't allow any architecture > to offer 4k stacks. > I have suggested before that the solution is to allocate memory in "stack size" units (obviously must be a multiple of the hardware page size). The reason allocation fails is more often fragmentation than actual lack of memory, or so it has been reported. -- Bill Davidsen "We have more to fear from the bungling of the incompetent than from the machinations of the wicked." - from Slashdot