From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shawn Pearce Subject: Re: [PATCH 3/5] autoconf: Preliminary check for working mmap Date: Mon, 4 Sep 2006 23:09:29 -0400 Message-ID: <20060905030929.GA29865@spearce.org> References: <200609050054.24279.jnareb@gmail.com> <200609050056.52590.jnareb@gmail.com> <7vy7szjjal.fsf@assigned-by-dhcp.cox.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: git@vger.kernel.org X-From: git-owner@vger.kernel.org Tue Sep 05 09:25:33 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 1GKVJI-0003lN-G7 for gcvg-git@gmane.org; Tue, 05 Sep 2006 09:25:28 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751494AbWIEHZZ (ORCPT ); Tue, 5 Sep 2006 03:25:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751449AbWIEHZZ (ORCPT ); Tue, 5 Sep 2006 03:25:25 -0400 Received: from corvette.plexpod.net ([64.38.20.226]:39345 "EHLO corvette.plexpod.net") by vger.kernel.org with ESMTP id S965150AbWIEE1L (ORCPT ); Tue, 5 Sep 2006 00:27:11 -0400 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 4.52) id 1GKSTw-00068f-Cp; Tue, 05 Sep 2006 00:27:09 -0400 Received: by asimov.home.spearce.org (Postfix, from userid 1000) id 41EBE212693; Mon, 4 Sep 2006 23:09:30 -0400 (EDT) To: Junio C Hamano Content-Disposition: inline In-Reply-To: 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: Jakub Narebski wrote: > Junio C Hamano wrote: > > > Jakub Narebski writes: > > > >> This patch sent earlier in other patch series and dropped, > >> as git uses private mapping, not private fixed. I think > >> that this check is better than no check at all... > > > > I think the next major change that is needed fairly soon is to > > be able to mmap parts of a large pack file (even with 32-bit > > offset). I haven't loooked into it deeply enough but it may or > > may not turn out to be beneficial if we map at fixed location so > > the requirements of "working mmap()" might change. I'd be > > happier if you held onto this part of the patch before that > > happens. > > Well, this patch perhaps not always would set NO_MMAP when it should > (some broken mmap that does private+fixed but not private), but I guess that > if it would set NO_MMAP then mmap is broken (or doesn't exist at all). > > I have noticed AC_FUNC_MMAP test, and thought why not to use it? > The simplest check if mmap exist would be to check libc for mmap function. Are there really mmap implementations that will only do private+fixed? Sick. I'm maybe only 1/3 of the way through the sliding window mmap implementation. I've got a good chunk of sha1_file.c converted but I still have to deal with the copying in pack-objects.c and the verify code in verify-pack.c. I'm hoping I can send a preliminary patch series tomorrow as I'm going to work on it more tonight and tomorrow. -- Shawn.