From mboxrd@z Thu Jan 1 00:00:00 1970 From: Junio C Hamano Subject: Re: best practices against long git rebase times? Date: Mon, 07 Dec 2015 14:56:33 -0800 Message-ID: References: <20151204150546.GA17210@inner.h.apk.li> <20151204153103.GP18913@serenity.lan> <20151206164345.GH22288@inner.h.apk.li> <20151207210212.GF30203@sigill.intra.peff.net> Mime-Version: 1.0 Content-Type: text/plain Cc: Andreas Krey , John Keeping , Git Mailing List To: Jeff King X-From: git-owner@vger.kernel.org Mon Dec 07 23:56:41 2015 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1a64i0-0003uM-NQ for gcvg-git-2@plane.gmane.org; Mon, 07 Dec 2015 23:56:41 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756637AbbLGW4g (ORCPT ); Mon, 7 Dec 2015 17:56:36 -0500 Received: from pb-smtp0.int.icgroup.com ([208.72.237.35]:62216 "EHLO sasl.smtp.pobox.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756204AbbLGW4f (ORCPT ); Mon, 7 Dec 2015 17:56:35 -0500 Received: from sasl.smtp.pobox.com (unknown [127.0.0.1]) by pb-smtp0.pobox.com (Postfix) with ESMTP id C317E32380; Mon, 7 Dec 2015 17:56:34 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; s=sasl; bh=14QY3Eu65gQqGGn/SisWNhSilEw=; b=tYQrxq 20pyZ3e2GP57N5pXrofT5ukpaiuftPJUj9F0N3B0rEB+86L/x6Sz7Z09A8PopLGm wL1S0GJ+I5dnVW34Icu83VnCz78390eT/wOfc8PZ0Z8DcrR9mFwpM2REA9Du+zau aPfUBBW+35xPOEio5UD9RtHgNtc6O++rEvWT4= DomainKey-Signature: a=rsa-sha1; c=nofws; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; q=dns; s=sasl; b=APiAP6tmMalFSiE4LKm5lAQnCUaz4pTD 6L9cZVUoZzbbbGhONNMs3oX79ZiRqV/C9RgN+YPU10gvJCz0wpemR9NCKcfJ5Mm1 Lw4N1PxKuX+AZIju6eTeuE9hReogblMxVHcVPFgHi7HSHlyotrCOHXc8vTGU0E63 zhEZ4kLf31Y= Received: from pb-smtp0.int.icgroup.com (unknown [127.0.0.1]) by pb-smtp0.pobox.com (Postfix) with ESMTP id BA8223237F; Mon, 7 Dec 2015 17:56:34 -0500 (EST) Received: from pobox.com (unknown [216.239.45.64]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by pb-smtp0.pobox.com (Postfix) with ESMTPSA id 419973237D; Mon, 7 Dec 2015 17:56:34 -0500 (EST) In-Reply-To: <20151207210212.GF30203@sigill.intra.peff.net> (Jeff King's message of "Mon, 7 Dec 2015 16:02:12 -0500") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) X-Pobox-Relay-ID: C3769BDE-9D35-11E5-B7A8-6BD26AB36C07-77302942!pb-smtp0.pobox.com Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Jeff King writes: > You're computing the patch against the parent for each of those 3000 > commits (to get a hash of it to compare against the single hash on the > other side). Twelve minutes sounds long, but if you have a really > gigantic tree, it might not be unreasonable. > > You can also try compiling with "make XDL_FAST_HASH=" (i.e., setting > that option to the empty string). Last year I found there were some > pretty suboptimal corner cases, and you may be hitting one (we should > probably turn that option off by default; I got stuck on trying to find > a hash that would perform faster and never followed up[1]. > > I doubt that is your problem, but it's possible). > > -Peff > > [1] http://thread.gmane.org/gmane.comp.version-control.git/261638 I vaguely recall having discussed caching the patch-ids somewhere so that this does not have to be done every time. Would such an extension help here, I wonder?