Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755035AbZKHTrk (ORCPT ); Sun, 8 Nov 2009 14:47:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754521AbZKHTrk (ORCPT ); Sun, 8 Nov 2009 14:47:40 -0500 Received: from mail-fx0-f221.google.com ([209.85.220.221]:33018 "EHLO mail-fx0-f221.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754286AbZKHTrj convert rfc822-to-8bit (ORCPT ); Sun, 8 Nov 2009 14:47:39 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type:content-transfer-encoding; b=mxoMpoSq6kk9KabJl+MPCU2WL2JBqEcjMofPwoXeBOcpXNhIH2uutWfBebs65jsA6Z IQrJc1OssG4irJN1SYe8Mi0lD++N5JxbHZkddDaa9M8x66LRPlOJKHg32zstPp8gHs9p PMWYipDSmZO8mRXbsX3GpamPI1r1qyuKwQv2M= MIME-Version: 1.0 In-Reply-To: <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> <20091108193618.GB4186@elf.ucw.cz> From: Matteo Croce Date: Sun, 8 Nov 2009 20:47:24 +0100 Message-ID: <40101cc30911081147j77f7b81o86f2cc5a869aca1f@mail.gmail.com> Subject: Re: i686 quirk for AMD Geode To: Pavel Machek Cc: Sven-Haegar Koch , "H. Peter Anvin" , Ingo Molnar , linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2714 Lines: 59 On Sun, Nov 8, 2009 at 8:36 PM, Pavel Machek wrote: > 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 > Better to be sure that a NOPL whouldn't SIGILL your program, isn't it? -- 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/