From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Shawn O. Pearce" Subject: Re: how to speed up "git log"? Date: Mon, 12 Feb 2007 01:06:41 -0500 Message-ID: <20070212060641.GC699@spearce.org> References: <200702111252.28393.bruno@clisp.org> <200702120041.27419.bruno@clisp.org> <200702120059.17676.robin.rosenberg.lists@dewire.com> <7vmz3kaugq.fsf@assigned-by-dhcp.cox.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Robin Rosenberg , Bruno Haible , Johannes Schindelin , git@vger.kernel.org To: Junio C Hamano X-From: git-owner@vger.kernel.org Mon Feb 12 07:07:03 2007 Return-path: Envelope-to: gcvg-git@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by lo.gmane.org with esmtp (Exim 4.50) id 1HGUL6-0005Ua-RU for gcvg-git@gmane.org; Mon, 12 Feb 2007 07:07:01 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933014AbXBLGGz (ORCPT ); Mon, 12 Feb 2007 01:06:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933018AbXBLGGy (ORCPT ); Mon, 12 Feb 2007 01:06:54 -0500 Received: from corvette.plexpod.net ([64.38.20.226]:35330 "EHLO corvette.plexpod.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933014AbXBLGGy (ORCPT ); Mon, 12 Feb 2007 01:06:54 -0500 Received: from cpe-74-70-48-173.nycap.res.rr.com ([74.70.48.173] helo=asimov.home.spearce.org) by corvette.plexpod.net with esmtpa (Exim 4.63) (envelope-from ) id 1HGUKq-0003M2-G8; Mon, 12 Feb 2007 01:06:44 -0500 Received: by asimov.home.spearce.org (Postfix, from userid 1000) id 59EBE20FBAE; Mon, 12 Feb 2007 01:06:41 -0500 (EST) Content-Disposition: inline In-Reply-To: <7vmz3kaugq.fsf@assigned-by-dhcp.cox.net> 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: Junio C Hamano wrote: > I doubt it -- sliding mmap() in the current git, while is a good > change overall for handling really huge repos, would most likely > perform poorer than the fixed mmap() in 1.4.4 series on > platforms with slow mmap(), most notably on MacOS X. > > It _might_ be possible that turning some sliding mmap() calls > into pread() makes it perform better on MacOS X. > > I wonder what happens it git is compiled with NO_MMAP there... So I ran three trials, v1.5.0-rc4-26-gcc46a74 with and without NO_MMAP against v1.4.4.4 on a freshly repacked git.git. v150-mmap: 3.33 real 3.12 user 0.05 sys 3.32 real 3.12 user 0.05 sys 3.34 real 3.12 user 0.05 sys v150-nommap: 3.46 real 3.13 user 0.16 sys 3.43 real 3.13 user 0.16 sys 3.46 real 3.13 user 0.16 sys v1444-mmap: 3.30 real 3.09 user 0.05 sys 3.30 real 3.09 user 0.05 sys 3.25 real 3.09 user 0.04 sys CFLAGS="-O2"; the above timings are three representative samples out of 10 runs each, all hot cache. Clearly the sliding mmap window isn't hurting us in this case by very much, and NO_MMAP really isn't helping matters at all. -- Shawn.