From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Ericsson Subject: Re: git performance Date: Thu, 23 Oct 2008 09:43:35 +0200 Message-ID: <49002B27.50201@op5.se> References: <000801c93483$2fdad340$8f9079c0$@com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: Edward Ned Harvey , git@vger.kernel.org To: Jakub Narebski X-From: git-owner@vger.kernel.org Thu Oct 23 09:44:56 2008 connect(): Connection refused 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 1KsusI-0006lI-Mr for gcvg-git-2@gmane.org; Thu, 23 Oct 2008 09:44:55 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751032AbYJWHnj (ORCPT ); Thu, 23 Oct 2008 03:43:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751993AbYJWHnj (ORCPT ); Thu, 23 Oct 2008 03:43:39 -0400 Received: from mail.op5.se ([193.201.96.20]:33213 "EHLO mail.op5.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750999AbYJWHnj (ORCPT ); Thu, 23 Oct 2008 03:43:39 -0400 Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.op5.se (Postfix) with ESMTP id 0B9B71B800A6; Thu, 23 Oct 2008 09:37:24 +0200 (CEST) X-Virus-Scanned: amavisd-new at X-Spam-Flag: NO X-Spam-Score: -3.926 X-Spam-Level: X-Spam-Status: No, score=-3.926 tagged_above=-10 required=6.6 tests=[ALL_TRUSTED=-1.8, AWL=0.473, BAYES_00=-2.599] Received: from mail.op5.se ([127.0.0.1]) by localhost (mail.op5.se [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id yBoFePXdmH1c; Thu, 23 Oct 2008 09:37:22 +0200 (CEST) Received: from clix.int.op5.se (unknown [192.168.1.20]) by mail.op5.se (Postfix) with ESMTP id 035631B8006F; Thu, 23 Oct 2008 09:37:21 +0200 (CEST) User-Agent: Thunderbird 2.0.0.16 (X11/20080723) In-Reply-To: Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Jakub Narebski wrote: > "Edward Ned Harvey" writes: > >> I see things all over the Internet saying git is fast. I'm >> currently struggling with poor svn performance and poor attitude of >> svn developers, so I'd like to consider switching to git. A quick >> question first. >> >> The core of the performance problem I'm facing is the need to "walk >> the tree" for many thousand files. Every time I do "svn update" or >> "svn status" the svn client must stat every file to check for local >> modifications (a coffee cup or a beer worth of stats). In essence, >> this is unavoidable if there is no mechanism to constantly monitor >> filesystem activity during normal operations. Analogous to >> filesystem journaling. >> >> So - I didn't see anything out there saying "git is fast because it >> uses inotify" or anything like that. Perhaps git would not help me >> at all? Because git still needs to stat all the files in the tree? > > http://git.or.cz/gitwiki/GitBenchmarks > > While it should be possible to use 'assume unchanged' bit together > with inotify / icron, it is not something tha is done; IIRC Mercurial > had Linux-only InotifyPlugin... > Well, inotify() is Linux specific, so it'd be quite hard to support on another platform. Emulating it with a billion stat() calls feels rather like a disk (and I/O performance) killer. -- Andreas Ericsson andreas.ericsson@op5.se OP5 AB www.op5.se Tel: +46 8-230225 Fax: +46 8-230231