From mboxrd@z Thu Jan 1 00:00:00 1970 From: Junio C Hamano Subject: Re: git bisect and the merge from hell Date: Fri, 03 Feb 2006 12:34:58 -0800 Message-ID: <7virrwdvv1.fsf@assigned-by-dhcp.cox.net> References: <200602031947.k13JlaDr003720@agluck-lia64.sc.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: git@vger.kernel.org X-From: git-owner@vger.kernel.org Fri Feb 03 21:35:17 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 1F57e6-0008QJ-Th for gcvg-git@gmane.org; Fri, 03 Feb 2006 21:35:07 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751472AbWBCUfB (ORCPT ); Fri, 3 Feb 2006 15:35:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751479AbWBCUfB (ORCPT ); Fri, 3 Feb 2006 15:35:01 -0500 Received: from fed1rmmtao03.cox.net ([68.230.241.36]:55442 "EHLO fed1rmmtao03.cox.net") by vger.kernel.org with ESMTP id S1751472AbWBCUfA (ORCPT ); Fri, 3 Feb 2006 15:35:00 -0500 Received: from assigned-by-dhcp.cox.net ([68.4.9.127]) by fed1rmmtao03.cox.net (InterMail vM.6.01.05.02 201-2131-123-102-20050715) with ESMTP id <20060203203343.JBBV20875.fed1rmmtao03.cox.net@assigned-by-dhcp.cox.net>; Fri, 3 Feb 2006 15:33:43 -0500 To: "Luck, Tony" In-Reply-To: <200602031947.k13JlaDr003720@agluck-lia64.sc.intel.com> (Tony Luck's message of "Fri, 3 Feb 2006 11:47:36 -0800") User-Agent: Gnus/5.110004 (No Gnus v0.4) Emacs/21.4 (gnu/linux) Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: "Luck, Tony" writes: > Sometime between -rc1 and -rc2 the ia64 kernel picked up a bug > that prevents booting a UP kernel on my workstation (I recycled > the serial cable to hook up a new machine, so I don't have the > OOPS). > > So I thought I'd use git bisect to narrow it down. A few iterations > in it picked the merge from hell, and two iterations after that it > appears to have wandered into the weeds and picked something from > before -rc1. > > $ git describe 3c5c363826e435cf4d54d917202567e5b57cae5f > v2.6.15-g3c5c3638 > > Is this normal? I haven't looked at your ancestry graph yet (I am at work writing this message during my lunch break), but if one of the branches merged between rc1 and rc2 were forked from the mainline at a commit before rc1, that is an expected behaviour. Suppose: .o---o---o--- ... ---o---o. / \ / \ ---o---o---*---o--- ... ---o---o---*---o---o---* rc1 octopus rc2 And you said "rc1 was OK but rc2 is BAD". Now, the bug may well be somewhere between rc1 and Len's octopus on the lower development track. But the problem may have been introduced by some of the commits on the upper development track that bypassed rc1. They are not descendant of rc1, and describe would say they come after v2.6.15. The side branch merged during that timeperiod that forked before rc1 may not be the one merged by Len's octopus but may be merged by some other merge, but the story is the same.