Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754329AbZKHTgZ (ORCPT ); Sun, 8 Nov 2009 14:36:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753856AbZKHTgY (ORCPT ); Sun, 8 Nov 2009 14:36:24 -0500 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:45301 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753909AbZKHTgX (ORCPT ); Sun, 8 Nov 2009 14:36:23 -0500 Date: Sun, 8 Nov 2009 20:36:19 +0100 From: Pavel Machek To: Sven-Haegar Koch Cc: Matteo Croce , "H. Peter Anvin" , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: i686 quirk for AMD Geode Message-ID: <20091108193618.GB4186@elf.ucw.cz> References: <40101cc30910021912r17b3a08bue1b9412e4fa47d89@mail.gmail.com> <20091003072127.GC21407@elte.hu> <40101cc30911060659k7b3b6428ob1340e476bdbac5b@mail.gmail.com> <4AF4526B.4060101@zytor.com> <40101cc30911061418w357b74d8i3bf9a9537de052d4@mail.gmail.com> <20091108173708.GF1372@ucw.cz> <40101cc30911080940s18eb26bbg641beeaddbc25c3d@mail.gmail.com> <20091108181016.GB32364@elf.ucw.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2459 Lines: 55 On Sun 2009-11-08 20:29:55, Sven-Haegar Koch wrote: > On Sun, 8 Nov 2009, Pavel Machek wrote: > > > On Sun 2009-11-08 18:40:06, Matteo Croce wrote: > > > On Sun, Nov 8, 2009 at 6:37 PM, Pavel Machek wrote: > > > > On Fri 2009-11-06 23:18:06, Matteo Croce wrote: > > > >> On Fri, Nov 6, 2009 at 5:44 PM, H. Peter Anvin wrote: > > > >> > On 11/06/2009 06:59 AM, Matteo Croce wrote: > > > >> >> indeed it has MMX, MMXEXT and CMOV, just lacks the long NOP instruction (NOPL). > > > >> > > > > >> > MMX and MMXEXT are hardly hallmarks of i686, which leaves only cmov. > > > >> > I'm somewhat wondering about the general value of this patch; is i686 > > > >> > code really that much faster on Geode that it's worth it? > > > >> > > > > >> > ? ? ? ?-hpa > > > >> > > > > >> > -- > > > >> > H. Peter Anvin, Intel Open Source Technology Center > > > >> > I work for Intel. ?I don't speak on their behalf. > > > >> > > > > >> > > > > >> > > > >> yes, I did some test like gzip, bzip2, lame etc and they give more or less > > > >> the same results of dhrystone > > > >> > > > >> root@alix:/usr/src# CFLAGS='-march=i586' ./dry.c > > > >> Microseconds for one run through Dhrystone: ? ? ? ?1.4 > > > >> Dhrystones per Second: ? ? ? ? ? ? ? ? ? ? ? ? ?740741 > > > > ... > > > >> root@alix:/usr/src# CFLAGS='-march=i686' ./dry.c > > > >> Trying 5000000 runs through Dhrystone: > > > >> Microseconds for one run through Dhrystone: ? ? ? ?1.2 > > > >> Dhrystones per Second: ? ? ? ? ? ? ? ? ? ? ? ? ?841751 > > > > > > > > Teach gcc that geodelx exists? No need to break kernel for that... and > > > > you probably can gain even bigger gains. > > But no standard distribution will be made available in a geode special > version - not enough machines in the marekt. So I think it is better to > be able to use the i686 specific things they already support, like > libc6-686 from debian for example. So hack your distribution to use libc6-686 if you know that it is safe... (that is no NOPL usage there). Still no need to break /proc/cpuinfo. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/