From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Wong Subject: Re: svn to git, N-squared? Date: Sun, 11 Jun 2006 21:29:34 -0700 Message-ID: <20060612042934.GA12083@hand.yhbt.net> References: <9e4733910606111902l709c71ccyf45070d55112739e@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: git X-From: git-owner@vger.kernel.org Mon Jun 12 06:29:47 2006 Return-path: Envelope-to: gcvg-git@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by ciao.gmane.org with esmtp (Exim 4.43) id 1Fpe3W-0003C5-Pm for gcvg-git@gmane.org; Mon, 12 Jun 2006 06:29:39 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751272AbWFLE3g (ORCPT ); Mon, 12 Jun 2006 00:29:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751275AbWFLE3g (ORCPT ); Mon, 12 Jun 2006 00:29:36 -0400 Received: from hand.yhbt.net ([66.150.188.102]:19383 "EHLO hand.yhbt.net") by vger.kernel.org with ESMTP id S1751272AbWFLE3f (ORCPT ); Mon, 12 Jun 2006 00:29:35 -0400 Received: by hand.yhbt.net (Postfix, from userid 500) id E20C77DC005; Sun, 11 Jun 2006 21:29:34 -0700 (PDT) To: Jon Smirl Content-Disposition: inline In-Reply-To: <9e4733910606111902l709c71ccyf45070d55112739e@mail.gmail.com> User-Agent: Mutt/1.5.9i Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: Jon Smirl wrote: > I have Mozilla CVS in a SVN repository. I've been using git-svnimport > to import it. This time I am letting it run to completion; but the > import has been running for four days now and it is only up to 2004. > The import task is stable at 570MB and it is using about 50% of my > CPU. It is constantly spawning off git write-tree, read-tree, > hash-object, update-index. It is not doing excessive disk activity. SVN itself seems to get much slower as you get towards newer revisions in a repository (FSFS) with lots of history. I've been experimenting a bit with a local copy of the gcc repo from November and git-svn SUCKED at importing it (it took over a week and I cancelled it out of frustration). I started repacking too, but, and it didn't help, Much of the performance defieciency was the svn sub process. being extremely slow at updating. I also tried git-svnimport, of course, but I only had 512M on that machine and the machine became unusable due to heavy swapping. > The import seems to be getting n-squared slower. It is still making > forward progress but the progress seems to be getting slower and > slower. > > It looks like it is doing write-tree, read-tree, hash-object, > update-index once or more per change set. If these commands are > n-proportional and they are getting run n times, then this is a > n-squared process. Projecting this out, the import may take 10 days or > more to completely finish. I'm working on some improvements to git-svn to make it a bit more spiffy. -- Eric Wong