From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Yakov Lerner" Subject: Re: comparing file contents in is_exact_match? Date: Tue, 18 Jul 2006 09:38:10 +0000 Message-ID: References: <20060706055729.GA12512@admingilde.org> <87fyh1ncm0.fsf@mid.deneb.enyo.de> <20060716223607.GA6023@steel.home> <87d5c4ajlu.fsf@mid.deneb.enyo.de> <1F90D448-5347-4CEB-80DE-3CC86C1CC16F@adacore.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "Git Mailing List" X-From: git-owner@vger.kernel.org Tue Jul 18 11:38:20 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 1G2m1y-0003ZS-1z for gcvg-git@gmane.org; Tue, 18 Jul 2006 11:38:18 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932105AbWGRJiM (ORCPT ); Tue, 18 Jul 2006 05:38:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932112AbWGRJiM (ORCPT ); Tue, 18 Jul 2006 05:38:12 -0400 Received: from py-out-1112.google.com ([64.233.166.180]:49186 "EHLO py-out-1112.google.com") by vger.kernel.org with ESMTP id S932105AbWGRJiK (ORCPT ); Tue, 18 Jul 2006 05:38:10 -0400 Received: by py-out-1112.google.com with SMTP id c39so1849983pyd for ; Tue, 18 Jul 2006 02:38:10 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=h4ewO8XYP/n2/Z3FrDxqkkIT3aC3oruOqZVaQYNLR71RuwqrPAuOdZk+TMUWEyZxMnwUcbdFC0lCL+kdDLkv4q7+aGAk0wR8fUNa6dzXMX3CWJqvc/CrJB0Qp0ck+MXqbhQxNFB3WBwvxmmRTSuoJf9Q1cvp477i9K3IkgamUg0= Received: by 10.35.111.14 with SMTP id o14mr5258267pym; Tue, 18 Jul 2006 02:38:10 -0700 (PDT) Received: by 10.35.14.14 with HTTP; Tue, 18 Jul 2006 02:38:10 -0700 (PDT) In-Reply-To: Content-Disposition: inline To: unlisted-recipients:; (no To-header on input) Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: Linus Torvalds wrote: > Well, the thing is, you really _do_ want to mmap as much as possible of > the pack-file as possible, if mmap() works. Juergen Ruehle wrote: > I did some > quick performance check and the NO_MMAP code path seems to be as fast > as the mmap one (even much faster in some cases). So the combination > of windows' memory management and git mmap usage doesn't seem so hot How about making this parameter (do-use-mmap vs not-use-mmap) a *runtime* parameter ? (Env. var. $GIT_MMAP or $GIT_USE_MMAP ?). What do you think ? I see two benefits: (1) much easier to benchmark two methods against each other (2) will always work on cygwin (automatic fallback to working method at runtime; say depending on filesystem) What do you say ? (Only in case when MMAP is enabled at build-time, of course) Yakov