Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756346Ab2HPRZz (ORCPT ); Thu, 16 Aug 2012 13:25:55 -0400 Received: from len.romanrm.net ([176.31.121.172]:44456 "EHLO len.romanrm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753562Ab2HPRZx (ORCPT ); Thu, 16 Aug 2012 13:25:53 -0400 Date: Thu, 16 Aug 2012 23:25:49 +0600 From: Roman Mamedov To: Johannes Stezenbach Cc: "Markus F.X.J. Oberhumer" , linux-kernel@vger.kernel.org, Andi Kleen , chris.mason@fusionio.com, linux-btrfs@vger.kernel.org, Nitin Gupta , Richard Purdie , richard -rw- weinberger , linux-arm-kernel@lists.infradead.org Subject: Re: [GIT PULL] Update LZO compression Message-ID: <20120816232549.4d14a6aa@natsu> In-Reply-To: <20120816150647.GA22010@sig21.net> References: <50299142.2030504@oberhumer.com> <20120814123937.GA14756@sig21.net> <502B8FE3.7080501@oberhumer.com> <20120815144539.GA8300@sig21.net> <502C92C3.7090701@oberhumer.com> <20120816150647.GA22010@sig21.net> Organization: http://version6.ru/ X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/=C.lUB/2VdSczshZJsDxK4."; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2225 Lines: 73 --Sig_/=C.lUB/2VdSczshZJsDxK4. Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Thu, 16 Aug 2012 17:06:47 +0200 Johannes Stezenbach wrote: > Well, ~2x speedup on x86 is certainly a good achievement, but there > are more ARM based devices than there are PCs, and I guess many > embedded devices use lzo compressed kernels and file systems > while I'm not convinced many PCs rely on lzo in the kernel. Keep in mind that a major user of LZO is the BTRFS filesystem, and I believ= e it is used much more often on larger machines than on ARM, in fact it had prob= lems operating on ARM at all, until quite recently. > I know everyone's either busy or on vacation, but it would > be so cool if someone could test on a more modern ARM core, > with the userspace test code I posted it should be easy to do. I have locked the Allwinner A10 CPU in my Mele A2000 to 60 MHz using cpufre= q-set, and ran your test. rnd.lzo is a 9 MB file from /dev/urandom compressed with= lzo. There doesn't seem to be a significant difference between all three variant= s. # time for i in {1..20}; do old/unlzop < rnd.lzo >/dev/null ; done real 0m11.353s user 0m3.060s sys 0m8.170s # time for i in {1..20}; do new/unlzop < rnd.lzo >/dev/null ; done real 0m11.416s user 0m3.030s sys 0m8.200s # time for i in {1..20}; do test/unlzop < rnd.lzo >/dev/null ; done real 0m11.310s user 0m3.100s sys 0m8.150s --=20 With respect, Roman ~~~~~~~~~~~~~~~~~~~~~~~~~~~ "Stallman had a printer, with code he could not see. So he began to tinker, and set the software free." --Sig_/=C.lUB/2VdSczshZJsDxK4. Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlAtLR0ACgkQTLKSvz+PZwiO5ACgiTDInffOSNH2Gi6UsYyydH53 5lwAoJB3qOltOGc3UxJgkYbOP9sfBkh9 =UjHj -----END PGP SIGNATURE----- --Sig_/=C.lUB/2VdSczshZJsDxK4.-- -- 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/