Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751575AbcDRBz1 (ORCPT ); Sun, 17 Apr 2016 21:55:27 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:50672 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751175AbcDRBz0 (ORCPT ); Sun, 17 Apr 2016 21:55:26 -0400 Date: Mon, 18 Apr 2016 02:55:21 +0100 From: Al Viro To: kernel test robot Cc: lkp@01.org, LKML Subject: Re: [lkp] [parallel lookups machinery, part 2] 96352435af: kernel BUG at mm/slab.c:2599! Message-ID: <20160418015521.GZ25498@ZenIV.linux.org.uk> References: <87k2jvg1yc.fsf@yhuang-dev.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87k2jvg1yc.fsf@yhuang-dev.intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 615 Lines: 12 On Mon, Apr 18, 2016 at 09:06:35AM +0800, kernel test robot wrote: > FYI, we noticed the below changes on > > https://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git testing.lookups > commit 96352435afd792d713ec91e2d5693bdcf40a6b03 ("parallel lookups machinery, part 2") Very odd. All stores in that commit are to ->d_parent->d_inode->i_dir_seq of in-lookup dentries. And if ->d_parent in those gets buggered, we were really deep in trouble. Could you try to reproduce that without __d_move() or __d_add() parts and see which one ends up triggering that crap? Note that we don't *use* ->i_dir_seq yet...