From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756547AbYDISUc (ORCPT ); Wed, 9 Apr 2008 14:20:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753464AbYDISUZ (ORCPT ); Wed, 9 Apr 2008 14:20:25 -0400 Received: from one.firstfloor.org ([213.235.205.2]:46837 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753441AbYDISUY (ORCPT ); Wed, 9 Apr 2008 14:20:24 -0400 Date: Wed, 9 Apr 2008 20:24:54 +0200 From: Andi Kleen To: Alexey Dobriyan Cc: Mathieu Desnoyers , akpm@linux-foundation.org, Ingo Molnar , linux-kernel@vger.kernel.org, Andi Kleen , Rusty Russell , Jason Baron , Adrian Bunk , Christoph Hellwig , akpm@osdl.org Subject: Re: [patch 09/17] Add all cpus option to stop machine run Message-ID: <20080409182454.GF30885@one.firstfloor.org> References: <20080409150829.855195878@polymtl.ca> <20080409152049.513274847@polymtl.ca> <20080409181010.GA4924@martell.zuzino.mipt.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080409181010.GA4924@martell.zuzino.mipt.ru> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 09, 2008 at 10:10:10PM +0400, Alexey Dobriyan wrote: > I continue to think that all this so-called "immediate" infrastructure > is an absolute overkill and declared D-cache line savings will _never_ > matter You are quite wrong on that. > and will never be measured on real life workloads. Right now you > claim 1 (one) cacheline saving in schedule() which can be trivially That is just an example. Once the infrastructure is in a lot more flags would move it into it. I think eventually most sysctls should be immediate values for once. > Also, my gut feeling of a guy who is also on receiveing end of bugreports > at SWsoft that line with .text games was crossed by SMP alternatives and You already lost -- Linux regularly rewrites itself. Ok not quite yet but self modifying code is already wide spread and happens commonly (e.g. with alternatives and some other cases) > > And bugs when CPU executed bullshit and silently rebooted. So far nobody has seen that and the probably of it actually happening is rather remote too. > And so on. > > Alexey, more and more liking OpenBSD > where such games won't even > hit mailing lists Maybe that is why Linux scales to large systems and OpenBSD doesn't ... -Andi