From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luke Lu Subject: Re: Git and GCC Date: Fri, 7 Dec 2007 15:04:25 -0800 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 (Apple Message framework v752.3) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Content-Transfer-Encoding: 7bit Cc: Giovanni Bajo , 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: Jakub Narebski X-From: git-owner@vger.kernel.org Sat Dec 08 00:05:02 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 1J0mFe-000158-Ae for gcvg-git-2@gmane.org; Sat, 08 Dec 2007 00:04:58 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753717AbXLGXEg (ORCPT ); Fri, 7 Dec 2007 18:04:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755418AbXLGXEg (ORCPT ); Fri, 7 Dec 2007 18:04:36 -0500 Received: from rv-out-0910.google.com ([209.85.198.191]:48224 "EHLO rv-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751008AbXLGXEf (ORCPT ); Fri, 7 Dec 2007 18:04:35 -0500 Received: by rv-out-0910.google.com with SMTP id k20so855438rvb for ; Fri, 07 Dec 2007 15:04:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:in-reply-to:references:mime-version:content-type:message-id:cc:content-transfer-encoding:from:subject:date:to:x-mailer:sender; bh=PttN1c2LuE8eeg/7cV5oN9mW7c9Ug9e9o7Djt1y/LZ8=; b=SEmMhmz3foEUflOqRv0VJhJxXeWn3gdiHuOWze0iWDiS0kcMbPeOrnv8O0EB0BUZvaWUfGu3RChYvHDLP/9D5EOTj/4rDWstp1Gs7UmJytdHeqjc5O8kInx6r0KMnWz6ZG9XXM2hSRLwBcuSbspOBfh35JMZNn+YhdBl3K2F1cQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=in-reply-to:references:mime-version:content-type:message-id:cc:content-transfer-encoding:from:subject:date:to:x-mailer:sender; b=bYuLTElrg/JhTAGGivb0Eao7bCY3zWntdrZm3kpvBf531aSbfAmlfFkSou0lt3+Ssh/1NheCTGEV0NjCDRq2LPXVk60w+wVlcLmp1ASIlcIFnPF8i0lepjQiaWt9e3Pj8gCQob3gVtessVH2S1IdYq9tc3tylAwOQ1hLNl7HKbM= Received: by 10.141.83.15 with SMTP id k15mr3008082rvl.1197068674863; Fri, 07 Dec 2007 15:04:34 -0800 (PST) Received: from ?192.168.15.20? ( [98.207.63.2]) by mx.google.com with ESMTPS id b21sm424227rvf.2007.12.07.15.04.31 (version=SSLv3 cipher=OTHER); Fri, 07 Dec 2007 15:04:32 -0800 (PST) In-Reply-To: X-Mailer: Apple Mail (2.752.3) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Dec 7, 2007, at 2:14 PM, Jakub Narebski wrote: > 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. So why didn't we consider lzo then? It's much faster than zlib. __Luke