From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Date: Thu, 23 Sep 2004 09:03:45 +0000 Subject: Re: page fault scalability patch V8: [4/7] universally available cmpxchg on i386 Message-Id: <20040923090345.GA6146@wotan.suse.de> List-Id: References: <20040920205752.GH4242@wotan.suse.de> <200409211841.25507.vda@port.imtp.ilyichevsk.odessa.ua> <20040921154542.GB12132@wotan.suse.de> <41527885.8020402@myrealbox.com> In-Reply-To: <41527885.8020402@myrealbox.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Andy Lutomirski Cc: Andi Kleen , Christoph Lameter , akpm@osdl.org, "David S. Miller" , benh@kernel.crashing.org, wli@holomorphy.com, davem@redhat.com, raybry@sgi.com, ak@muc.de, manfred@colorfullife.com, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, vrajesh@umich.edu, hugh@veritas.com > Wouldn't alternative_input() choosing between a cmpxchg and a call be > the way to go here? Or is the overhead too high in an inline function? It would if you want the absolute micro optimization yes. Disadvantage is that you would waste some more space for nops in the !CONFIG_I386 case. I personally don't think it matters much and that Christian's original code was just fine. -Andi (last post on the thread) From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268335AbUIWJDz (ORCPT ); Thu, 23 Sep 2004 05:03:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268333AbUIWJDz (ORCPT ); Thu, 23 Sep 2004 05:03:55 -0400 Received: from cantor.suse.de ([195.135.220.2]:45994 "EHLO Cantor.suse.de") by vger.kernel.org with ESMTP id S268326AbUIWJDx (ORCPT ); Thu, 23 Sep 2004 05:03:53 -0400 Date: Thu, 23 Sep 2004 11:03:45 +0200 From: Andi Kleen To: Andy Lutomirski Cc: Andi Kleen , Christoph Lameter , akpm@osdl.org, "David S. Miller" , benh@kernel.crashing.org, wli@holomorphy.com, davem@redhat.com, raybry@sgi.com, ak@muc.de, manfred@colorfullife.com, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, vrajesh@umich.edu, hugh@veritas.com Subject: Re: page fault scalability patch V8: [4/7] universally available cmpxchg on i386 Message-ID: <20040923090345.GA6146@wotan.suse.de> References: <20040920205752.GH4242@wotan.suse.de> <200409211841.25507.vda@port.imtp.ilyichevsk.odessa.ua> <20040921154542.GB12132@wotan.suse.de> <41527885.8020402@myrealbox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <41527885.8020402@myrealbox.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > Wouldn't alternative_input() choosing between a cmpxchg and a call be > the way to go here? Or is the overhead too high in an inline function? It would if you want the absolute micro optimization yes. Disadvantage is that you would waste some more space for nops in the !CONFIG_I386 case. I personally don't think it matters much and that Christian's original code was just fine. -Andi (last post on the thread)