Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754503AbZKIUQF (ORCPT ); Mon, 9 Nov 2009 15:16:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754412AbZKIUQE (ORCPT ); Mon, 9 Nov 2009 15:16:04 -0500 Received: from caffeine.csclub.uwaterloo.ca ([129.97.134.17]:38441 "EHLO caffeine.csclub.uwaterloo.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754388AbZKIUQD (ORCPT ); Mon, 9 Nov 2009 15:16:03 -0500 Date: Mon, 9 Nov 2009 20:16:08 +0000 To: Matteo Croce Cc: "H. Peter Anvin" , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: i686 quirk for AMD Geode Message-ID: <20091109201608.GD15159@caffeine.csclub.uwaterloo.ca> References: <40101cc30910021912r17b3a08bue1b9412e4fa47d89@mail.gmail.com> <20091003072127.GC21407@elte.hu> <40101cc30911060659k7b3b6428ob1340e476bdbac5b@mail.gmail.com> <4AF4526B.4060101@zytor.com> <40101cc30911081042n93e268bs66b9436a0174a19a@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <40101cc30911081042n93e268bs66b9436a0174a19a@mail.gmail.com> User-Agent: Mutt/1.5.18 (2008-05-17) From: lsorense@csclub.uwaterloo.ca (Lennart Sorensen) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2354 Lines: 63 On Sun, Nov 08, 2009 at 07:42:48PM +0100, Matteo Croce wrote: > There is a small advantage, but considering that GCC isn't much geode aware yet > there is stil room for improvement IMHO: Perhaps gcc considers geode to mean geode GX[m12] not geode LX (which is newer and the one in question here). The Geode GX line prefers i486 code to i586 code (which appears to be what -march=geode is for). I am using i486 at the moment when I build for this one. The Geode LX is what is being discussed which is in fact mostly a K6 as far as I understand things. It seems to like i686 code, other than apparently those NOP instructions. I wonder if the K6 has those noop instructions and if not, perhaps gcc 4.4's -march=k6-3 would be the right choice. I have always suspected the LX was really a K6-3 based design (the cache sizes are a bit different, but clock speeds and instruction sets seem to match). The Geode NX (which no one has mentioned yet) is an Athlon derived chip. > root@alix:/usr/src/dist# ll > totale 257M > -rwxr-xr-x 1 1000 src 93K 8 nov 2009 bzip2-i586 > -rwxr-xr-x 1 1000 src 93K 8 nov 2009 bzip2-i686 > -rwxr-xr-x 1 1000 src 60K 8 nov 2009 gzip-i586 > -rwxr-xr-x 1 1000 src 60K 8 nov 2009 gzip-i686 > -rw-r--r-- 1 1000 src 256M 8 nov 2009 linux-2.6.31.5.tar > -rwxr-xr-x 1 1000 src 90K 8 nov 2009 lzma-i586 > -rwxr-xr-x 1 1000 src 94K 8 nov 2009 lzma-i686 > root@alix:/usr/src/dist# time cat linux-2.6.31.5.tar >/dev/null > > real 0m10.168s > user 0m0.030s > sys 0m1.390s > root@alix:/usr/src/dist# time ./gzip-i586 -9 < linux-2.6.31.5.tar >/dev/null > > real 5m22.331s > user 5m10.820s > sys 0m11.170s > root@alix:/usr/src/dist# time ./gzip-i686 -9 < linux-2.6.31.5.tar >/dev/null > > real 5m3.737s > user 4m51.880s > sys 0m11.510s > root@alix:/usr/src/dist# time ./bzip2-i586 -9 < linux-2.6.31.5.tar >/dev/null > > real 9m16.539s > user 9m4.410s > sys 0m11.760s > root@alix:/usr/src/dist# time ./bzip2-i686 -9 < linux-2.6.31.5.tar >/dev/null > > real 8m48.682s > user 8m34.950s > sys 0m13.260s -- Len Sorensen -- 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/