From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shawn Pearce Subject: Re: 1.3.0 creating bigger packs than 1.2.3 Date: Thu, 20 Apr 2006 22:32:22 -0400 Message-ID: <20060421023222.GA1117@spearce.org> References: <20060420150315.GB31198@spearce.org> <20060420164351.GB31738@spearce.org> <20060420175554.GH31738@spearce.org> <7v8xq0yteb.fsf@assigned-by-dhcp.cox.net> <7vfyk8vscl.fsf@assigned-by-dhcp.cox.net> <20060421012029.GB819@spearce.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Nicolas Pitre , git@vger.kernel.org X-From: git-owner@vger.kernel.org Fri Apr 21 04:33:19 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 1FWlSI-0004ts-Qy for gcvg-git@gmane.org; Fri, 21 Apr 2006 04:33:11 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932214AbWDUCco (ORCPT ); Thu, 20 Apr 2006 22:32:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932209AbWDUCcf (ORCPT ); Thu, 20 Apr 2006 22:32:35 -0400 Received: from corvette.plexpod.net ([64.38.20.226]:2204 "EHLO corvette.plexpod.net") by vger.kernel.org with ESMTP id S932134AbWDUCc2 (ORCPT ); Thu, 20 Apr 2006 22:32:28 -0400 Received: from cpe-72-226-60-173.nycap.res.rr.com ([72.226.60.173] helo=asimov.home.spearce.org) by corvette.plexpod.net with esmtpa (Exim 4.52) id 1FWlRN-00053J-Cg; Thu, 20 Apr 2006 22:32:13 -0400 Received: by asimov.home.spearce.org (Postfix, from userid 1000) id E711A20FBB4; Thu, 20 Apr 2006 22:32:22 -0400 (EDT) To: Junio C Hamano Content-Disposition: inline In-Reply-To: <20060421012029.GB819@spearce.org> User-Agent: Mutt/1.5.11 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - corvette.plexpod.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [0 0] / [47 12] X-AntiAbuse: Sender Address Domain - spearce.org X-Source: X-Source-Args: X-Source-Dir: Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: I just tried the patch below on a couple-month-old Linux 2.6 repository from Linus (last commit: Feb 14 2006). It did not decrease the pack file size by much despite the higher delta: 'next' Total 189435, written 189435 (delta 142093), reused 44057 (delta 0) 'next'+patch Total 189435, written 189435 (delta 142712), reused 43954 (delta 0) 'next' 104464297 bytes 'next'+patch 104092920 bytes (99.6% of 'next') 'next' 328.98 real 206.02 user 93.60 sys 'next'+patch 363.06 real 218.98 user 94.72 sys So it looks like the patch is taking longer to run, and by about 10%. An expensive price to pay for what amounts to only a 0.4% reduction in pack size on the kernel. Shawn Pearce wrote: > Based on Linus' comment I changed your patch to just the following. > It still produced the 46M pack file, so the first hunk apears to > not have had much of an affect with this data. > > From a running time perspective it appears as though this patch is > making things slightly better, not worse. I ran it a few times > for each case always using the 46M pack as input for > "git-repack -a -d -f". > > 'next' 137.13 real 95.82 user 25.24 sys > 'next'+patch 131.62 real 89.35 user 28.56 sys > > but even if the running time was an extra 6 seconds I'd still rather > spend 4% more running time to use 1/2 the storage space. > > > diff --git a/pack-objects.c b/pack-objects.c > index 09f4f2c..f7d6217 100644 > --- a/pack-objects.c > +++ b/pack-objects.c > @@ -1052,7 +1052,7 @@ static int try_delta(struct unpacked *cu > if (cur_entry->delta) > max_size = cur_entry->delta_size-1; > if (sizediff >= max_size) > - return -1; > + return 0; > delta_buf = diff_delta(old->data, oldsize, > cur->data, size, &delta_size, max_size); > if (!delta_buf) -- Shawn.