From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jakub Narebski Subject: Re: Git and GCC Date: Fri, 07 Dec 2007 14:14:15 -0800 (PST) Message-ID: References: <20071206.193121.40404287.davem@davemloft.net> <20071207063848.GA13101@coredump.intra.peff.net> <9e4733910712062310s30153afibc44a5550fd9ea99@mail.gmail.com> <20071207.045329.204650714.davem@davemloft.net> <4759AC8E.3070102@develer.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Linus Torvalds , David Miller , jonsmirl@gmail.com, peff@peff.net, nico@cam.org, dberlin@dberlin.org, harvey.harrison@gmail.com, ismail@pardus.org.tr, gcc@gcc.gnu.org, git@vger.kernel.org To: Giovanni Bajo X-From: git-owner@vger.kernel.org Fri Dec 07 23:14:48 2007 Return-path: Envelope-to: gcvg-git-2@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by lo.gmane.org with esmtp (Exim 4.50) id 1J0lSz-0000hu-1e for gcvg-git-2@gmane.org; Fri, 07 Dec 2007 23:14:41 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754990AbXLGWOT (ORCPT ); Fri, 7 Dec 2007 17:14:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754709AbXLGWOT (ORCPT ); Fri, 7 Dec 2007 17:14:19 -0500 Received: from nf-out-0910.google.com ([64.233.182.185]:3402 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754377AbXLGWOS (ORCPT ); Fri, 7 Dec 2007 17:14:18 -0500 Received: by nf-out-0910.google.com with SMTP id g13so405749nfb for ; Fri, 07 Dec 2007 14:14:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:received:received:x-authentication-warning:to:cc:subject:references:in-reply-to:message-id:lines:user-agent:mime-version:content-type:from:date; bh=H0drTO6WCCPvYdkWjXxn1d65ifAkObD0YTLkladP/3w=; b=ZJ15f2y8higCFc9xzKjkYx8oYqZcsR8b0gZedcMJvo8SsbiuMdeDo/GhtlCVoYYK56+MSykqnqmtAouSogl4TfixylbwCCPDsFvz4kMpgz4nf0SkKdOR8WvGvZ/gRknc8gfRr6rdt7Oc4SUkojcFxo+0nCMa93svn98PV74UqO0= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=x-authentication-warning:to:cc:subject:references:in-reply-to:message-id:lines:user-agent:mime-version:content-type:from:date; b=tl2U2MNTBlS0XnhqgnuMSpRQWOmUsoEE/b+58dwpuypvTpAnh/vLgb79bvE9Hz4iH4Y60G4X4EM/lNl2bGmJXfq2vOsjxxJiSZChIPrNmEwM3SWYvI2QhxjX81eZBAPuHnuaM0NbFHU71umUk3fPtfzu/+zpHwD8dUvLGi/eOc0= Received: by 10.86.66.1 with SMTP id o1mr2633249fga.1197065656697; Fri, 07 Dec 2007 14:14:16 -0800 (PST) Received: from roke.D-201 ( [83.8.198.153]) by mx.google.com with ESMTPS id b17sm243604fka.2007.12.07.14.14.13 (version=TLSv1/SSLv3 cipher=OTHER); Fri, 07 Dec 2007 14:14:15 -0800 (PST) Received: from roke (localhost.localdomain [127.0.0.1]) by roke.D-201 (8.13.4/8.13.4) with ESMTP id lB7ME5oU009436; Fri, 7 Dec 2007 23:14:08 +0100 Received: (from jnareb@localhost) by roke (8.13.4/8.13.4/Submit) id lB7MDwST009433; Fri, 7 Dec 2007 23:13:58 +0100 X-Authentication-Warning: roke: jnareb set sender to jnareb@fuw.edu.pl using -f In-Reply-To: <4759AC8E.3070102@develer.com> User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.4 Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Giovanni Bajo writes: > On 12/7/2007 6:23 PM, Linus Torvalds wrote: > > >> Is SHA a significant portion of the compute during these repacks? > >> I should run oprofile... > > SHA1 is almost totally insignificant on x86. It hardly shows up. But > > we have a good optimized version there. > > zlib tends to be a lot more noticeable (especially the > > *uncompression*: it may be faster than compression, but it's done _so_ > > much more that it totally dominates). > > Have you considered alternatives, like: > http://www.oberhumer.com/opensource/ucl/ As compared to LZO, the UCL algorithms achieve a better compression ratio but *decompression* is a little bit slower. See below for some rough timings. It is uncompression speed that is more important, because it is used much more often. -- Jakub Narebski ShadeHawk on #git