From mboxrd@z Thu Jan 1 00:00:00 1970 From: "C. Scott Ananian" Subject: Re: WARNING! Object DB conversion (was Re: [PATCH] write-tree performance problems) Date: Wed, 20 Apr 2005 10:35:02 -0400 (EDT) Message-ID: References: <200504191250.10286.mason@suse.com> <200504191708.23536.mason@suse.com> <200504192049.21947.mason@suse.com> <42660708.60109@zytor.com> <2cfc4032050420050655265d3a@mail.gmail.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: jon@zeta.org.au, Git Mailing List X-From: git-owner@vger.kernel.org Wed Apr 20 16:32:41 2005 Return-path: Received: from vger.kernel.org ([12.107.209.244]) by ciao.gmane.org with esmtp (Exim 4.43) id 1DOGEW-0006ci-A5 for gcvg-git@gmane.org; Wed, 20 Apr 2005 16:31:17 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261624AbVDTOf2 (ORCPT ); Wed, 20 Apr 2005 10:35:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261650AbVDTOf2 (ORCPT ); Wed, 20 Apr 2005 10:35:28 -0400 Received: from sincerity-forever.csail.mit.edu ([128.30.67.31]:36489 "EHLO sincerity-forever.csail.mit.edu") by vger.kernel.org with ESMTP id S261624AbVDTOfY (ORCPT ); Wed, 20 Apr 2005 10:35:24 -0400 Received: from catfish.lcs.mit.edu ([128.30.67.25] helo=cag.csail.mit.edu) by sincerity-forever.csail.mit.edu with esmtp (Exim 3.36 #1 (Debian)) id 1DOGIK-0008Sp-00; Wed, 20 Apr 2005 10:35:12 -0400 To: Linus Torvalds In-Reply-To: Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org On Wed, 20 Apr 2005, Linus Torvalds wrote: > - _keep_ the same compression format, but notice that we already have an > object by looking at the uncompressed one. With a chunked file, you can also skip writing certain *subtrees* of the file as soon as you notice it's already present on disk. I can code this up if you are interested. Of course, the paranoid folks will give up any performance benefit you obtain if they keep their "yes the SHA1 matches, but is the file *really* the same" code. But maybe they're willing to be slow -- and they can do an uncompress rather than a compress in order to do the comparison, which will give *some* performance improvement. --scott LCPANGS Serbian MKSEARCH security KUCLUB LCPANES Saddam Hussein Secretary Delta Force AMLASH ESMERALDITE TPAJAX plutonium ESGAIN Ft. Meade India ( http://cscott.net/ )