From mboxrd@z Thu Jan 1 00:00:00 1970 From: Junio C Hamano Subject: Re: Fix object re-hashing Date: Sun, 12 Feb 2006 10:32:56 -0800 Message-ID: <7vaccwbf6v.fsf@assigned-by-dhcp.cox.net> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: git@vger.kernel.org X-From: git-owner@vger.kernel.org Sun Feb 12 19:33:08 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 1F8M1v-00059R-0v for gcvg-git@gmane.org; Sun, 12 Feb 2006 19:33:03 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750798AbWBLSdA (ORCPT ); Sun, 12 Feb 2006 13:33:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750809AbWBLSdA (ORCPT ); Sun, 12 Feb 2006 13:33:00 -0500 Received: from fed1rmmtao01.cox.net ([68.230.241.38]:25548 "EHLO fed1rmmtao01.cox.net") by vger.kernel.org with ESMTP id S1750798AbWBLSc7 (ORCPT ); Sun, 12 Feb 2006 13:32:59 -0500 Received: from assigned-by-dhcp.cox.net ([68.4.9.127]) by fed1rmmtao01.cox.net (InterMail vM.6.01.05.02 201-2131-123-102-20050715) with ESMTP id <20060212183148.HTY15695.fed1rmmtao01.cox.net@assigned-by-dhcp.cox.net>; Sun, 12 Feb 2006 13:31:48 -0500 To: Linus Torvalds In-Reply-To: (Linus Torvalds's message of "Sun, 12 Feb 2006 10:10:02 -0800 (PST)") 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: Linus Torvalds writes: > On Sun, 12 Feb 2006, Linus Torvalds wrote: >> >> I actually didn't see any of this trigger in real life, so maybe my >> analysis is wrong. Junio? Johannes? > > Btw, if it does trigger, the behaviour would be that a subsequent object > lookup will fail, because the last old slot would be NULL, and a few > entries following it (likely just a couple - never mind that the event > triggering in the first place is probably fairly rare) wouldn't have > gotten re-hashed down. > > As a result, we'd allocate a new object, and have _two_ "struct object"s > that describe the same real object. I don't know what would get upset, but > git-fsck-index certainly would be (one of them would likely be marked > unreachable, because lookup wouldn't find it, but you might have other > issues too). This "fix" makes the symptom that me fire two (maybe three) Grrrrr messages earlier this morning disappear. I haven't had my caffeine nor nicotine yet after my short sleep, so I need to take some time understanding your explanation first, but I am reasonably sure this must be it (not that I do not trust you, not at all -- it is that I do not trust *me* applying a patch without understanding when I have a bug reproducible). Thanks.