Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754753AbZKHSKW (ORCPT ); Sun, 8 Nov 2009 13:10:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754056AbZKHSKV (ORCPT ); Sun, 8 Nov 2009 13:10:21 -0500 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:33183 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754042AbZKHSKV (ORCPT ); Sun, 8 Nov 2009 13:10:21 -0500 Date: Sun, 8 Nov 2009 19:10:17 +0100 From: Pavel Machek To: Matteo Croce Cc: "H. Peter Anvin" , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: i686 quirk for AMD Geode Message-ID: <20091108181016.GB32364@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> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <40101cc30911080940s18eb26bbg641beeaddbc25c3d@mail.gmail.com> 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: 2436 Lines: 62 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. > > Gcc 4.4 already knows about it, just sucks at optimizing: Good. So there's really no point in breaking kernel. > # CFLAGS='-march=geode' ./dry.c > gcc -c -O3 -march=geode ./dry.c -o dry1.o > gcc -DPASS2 -O3 -march=geode ./dry.c dry1.o -o dry2 > > Dhrystone Benchmark, Version C, Version 2.2 > Program compiled without 'register' attribute > Using times(), HZ=100 > > Trying 5000000 runs through Dhrystone: > Microseconds for one run through Dhrystone: 1.4 > Dhrystones per Second: 719424 ...fix gcc to genereta code at least as good as for i686 and you are done...? 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/