From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Nguyen Thai Ngoc Duy" Subject: Re: git performance Date: Thu, 23 Oct 2008 20:04:07 +0700 Message-ID: References: <000801c93483$2fdad340$8f9079c0$@com> <49002B27.50201@op5.se> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: "Jakub Narebski" , "Edward Ned Harvey" , git@vger.kernel.org To: "Andreas Ericsson" X-From: git-owner@vger.kernel.org Thu Oct 23 15:06:18 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 1KszsT-0003TZ-El for gcvg-git-2@gmane.org; Thu, 23 Oct 2008 15:05:49 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752902AbYJWNEM (ORCPT ); Thu, 23 Oct 2008 09:04:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752711AbYJWNEM (ORCPT ); Thu, 23 Oct 2008 09:04:12 -0400 Received: from mail-gx0-f16.google.com ([209.85.217.16]:53996 "EHLO mail-gx0-f16.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751275AbYJWNEL (ORCPT ); Thu, 23 Oct 2008 09:04:11 -0400 Received: by gxk9 with SMTP id 9so1273537gxk.13 for ; Thu, 23 Oct 2008 06:04:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:cc:in-reply-to:mime-version:content-type :content-transfer-encoding:content-disposition:references; bh=skGrw7fomRLGF04Kg9N1Rd/4Gl87KZtxw982lRvchZo=; b=uHZVm38CzuGyAAToSLeGdO0EscxGaqEAvKxUIMnfJ1kDlJtlfxAzlrdu0UpjkeOfxL N1QcQbwbzxdUvPpjAkAerBc91tP25/Id46caNjA5GT93KRjKI/Bsu7S8UoBnbpbI4VgY Aa6UM+YujlBCz6P4EctFZ8z376Tq/IjRD5noI= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=A5pylGf7jnLzNax3EdwRMjj1+KK0dwauWgmJR4y5wu4p5AmgGEwAnlGiOoFAf6VnKn hJ53njEUD/IPmDsP/+qruzXT36r/sul/SNQQxq7O7oNyxTKI040YmCLHy1aTNRyGK36N B+cIDz/GsIK+SvweHpbMp9Mf8sAvMdzrHv4J8= Received: by 10.86.95.8 with SMTP id s8mr1143094fgb.33.1224767047338; Thu, 23 Oct 2008 06:04:07 -0700 (PDT) Received: by 10.86.95.9 with HTTP; Thu, 23 Oct 2008 06:04:07 -0700 (PDT) In-Reply-To: <49002B27.50201@op5.se> Content-Disposition: inline Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On 10/23/08, Andreas Ericsson wrote: > 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. There is "filemon" on Windows, which monitors file access. I don't know how it impacts performance though. A quick search revealed kqueue for FreeBSD/Mac OSX. -- Duy