From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Francis Moreau" Subject: Re: [PATCH 0/17] Sliding window mmap for packfiles. Date: Sun, 24 Dec 2006 10:36:16 +0100 Message-ID: <38b2ab8a0612240136r559376d4s14af3123f762a45d@mail.gmail.com> References: <20061223073317.GA9837@spearce.org> <38b2ab8a0612240056k152344ael891e9b0b9f8cbc47@mail.gmail.com> <20061224090508.GF7443@spearce.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "Junio C Hamano" , git@vger.kernel.org X-From: git-owner@vger.kernel.org Sun Dec 24 10:36:22 2006 Return-path: Envelope-to: gcvg-git@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by dough.gmane.org with esmtp (Exim 4.50) id 1GyPmH-0001fH-As for gcvg-git@gmane.org; Sun, 24 Dec 2006 10:36:21 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754232AbWLXJgS (ORCPT ); Sun, 24 Dec 2006 04:36:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754221AbWLXJgR (ORCPT ); Sun, 24 Dec 2006 04:36:17 -0500 Received: from wx-out-0506.google.com ([66.249.82.231]:40487 "EHLO wx-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754232AbWLXJgQ (ORCPT ); Sun, 24 Dec 2006 04:36:16 -0500 Received: by wx-out-0506.google.com with SMTP id h27so3252556wxd for ; Sun, 24 Dec 2006 01:36:16 -0800 (PST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=sPXCXp+DQnCocHz5Gs71qsx3lmHxcw//9lUN5N1P51QpP7XSBYfYGlMgkJEY76tE18X8nv5+9dMmAznXDWBsntCG5NNK7oRIZ/VXeyQcLvXVRwBczKFWdVsJu9pKDxb0EqqYpoNJpRmGExf249mNmq5Kh0WenZdwrcBPgMXjhig= Received: by 10.90.104.14 with SMTP id b14mr10183024agc.1166952976038; Sun, 24 Dec 2006 01:36:16 -0800 (PST) Received: by 10.90.106.16 with HTTP; Sun, 24 Dec 2006 01:36:16 -0800 (PST) To: "Shawn Pearce" In-Reply-To: <20061224090508.GF7443@spearce.org> Content-Disposition: inline Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: On 12/24/06, Shawn Pearce wrote: > Francis Moreau wrote: > > On 12/23/06, Shawn O. Pearce wrote: > > >This 17 patch series implements my much discussed, but never produced > > [snip] > > > > > >This series also permits accessing packfiles up to 4 GiB in size, > > >even on systems which permit only 2 GiB of virtual memory within > > >a single process (e.g. Windows and some older UNIXes). Of course > > > > Just out of curiosity, do you mean that there are some OS running on > > 32 bits machines which allow 4GiB size of virtual memory within a > > single process ? If so, could you give an example of such OS ? > > No. What I meant was the Git packfile/index format currently > supports up to 4 GiB of data in a single packfile. But *no* > OS using 32 bit virtual address space would permit us to access > that packfile prior to this series as we would have *no* memory > left for a stack, let alone for parsing commits, etc., as *all* > of the address space would have been dedicated to the packfile. > ok. > However with this series even a 32 bit OS which only permits > processes to have at most 2 GiB of address space (2 GiB split > between kernel space and userspace) can access packfiles up > to 4 GiB in size. That seems to be the split most OSes wind > up using, if they didn't push it out to 3.2 GiB like Linux > and Solaris have done. > Does it still needed for 64 bit OS ? if not, can the overhead (if there is a significant one) implied by your rework be avoid for such cases ? > This series is a good change because Git can now really make > full use of the space allowed by a single packfile. :-) > Yes I agree with you. -- Francis