From mboxrd@z Thu Jan 1 00:00:00 1970 From: Junio C Hamano Subject: Re: [RFC/PATCH] Add a --nosort option to pack-objects Date: Fri, 07 Dec 2007 13:37:47 -0800 Message-ID: <7vzlwmyyms.fsf@gitster.siamese.dyndns.org> References: <1197061832-8489-1-git-send-email-mh@glandium.org> <7v4peu19kr.fsf@gitster.siamese.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: git@vger.kernel.org To: Mike Hommey X-From: git-owner@vger.kernel.org Fri Dec 07 22:39:03 2007 Return-path: Envelope-to: gcvg-git-2@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by lo.gmane.org with esmtp (Exim 4.50) id 1J0kuV-0002rJ-D2 for gcvg-git-2@gmane.org; Fri, 07 Dec 2007 22:39:03 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753803AbXLGViL (ORCPT ); Fri, 7 Dec 2007 16:38:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755062AbXLGViJ (ORCPT ); Fri, 7 Dec 2007 16:38:09 -0500 Received: from a-sasl-quonix.pobox.com ([208.72.237.25]:38323 "EHLO sasl.smtp.pobox.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755010AbXLGViI (ORCPT ); Fri, 7 Dec 2007 16:38:08 -0500 Received: from a-sasl-quonix (localhost [127.0.0.1]) by a-sasl-quonix.pobox.com (Postfix) with ESMTP id 07F861B98; Fri, 7 Dec 2007 16:38:00 -0500 (EST) Received: from pobox.com (ip68-225-240-77.oc.oc.cox.net [68.225.240.77]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by a-sasl-quonix.pobox.com (Postfix) with ESMTP id 457EF1B97; Fri, 7 Dec 2007 16:37:54 -0500 (EST) In-Reply-To: <7v4peu19kr.fsf@gitster.siamese.dyndns.org> (Junio C. Hamano's message of "Fri, 07 Dec 2007 13:25:24 -0800") User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Junio C Hamano writes: > Mike Hommey writes: > >> The --nosort option disabled the internal sorting used by pack-objects, >> and runs the sliding window along the object list litterally as given on >> stdin. > > I think this is a good way to give people an easier way to experiment. Actually, I take the half of this back. We need a pair of two good sort orders. The order of objects fed to pack-objects determines the final layout of the resulting pack, and using something like the "recency order" we currently have is to optimize the layout in the resulting pack for typical access patterns. By using your --nosort, you may be able to influence the deltification process, but the order you use will most likely not match the access pattern of the resulting pack. So it will be an easy, quick-and-dirty way to _experiment_ how the deltification sort order affects the final pack size, but I suspect that the resulting "small" pack won't be useful in the real life.