Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758941Ab3FDGBB (ORCPT ); Tue, 4 Jun 2013 02:01:01 -0400 Received: from ozlabs.org ([203.10.76.45]:40410 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755133Ab3FDGAz (ORCPT ); Tue, 4 Jun 2013 02:00:55 -0400 From: Rusty Russell To: Ben Greear , Joe Lawrence Cc: Linux Kernel Mailing List , stable@vger.kernel.org Subject: Re: Please add to stable: module: don't unlink the module until we've removed all exposure. In-Reply-To: <51ACC60B.8090504@candelatech.com> References: <51A8E884.1080009@candelatech.com> <87ehclumhr.fsf@rustcorp.com.au> <51ACBD6A.1030304@candelatech.com> <51ACC60B.8090504@candelatech.com> User-Agent: Notmuch/0.15.2+81~gd2c8818 (http://notmuchmail.org) Emacs/23.4.1 (i686-pc-linux-gnu) Date: Tue, 04 Jun 2013 15:26:28 +0930 Message-ID: <87d2s2to4z.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1490 Lines: 31 Ben Greear writes: >> It at least works around the problem for me as well. But, a more rare >> migration/[0-3] (I think) related lockup still exists in 3.9.4 for me, >> so I will also try applying that other kobject patch and continue testing >> today... > > Well, that other kobject patch is already in 3.9.4, so I think it's still > a good idea to include the > "module: don't unlink the module until we've removed all exposure." > patch in stable. I have a decent test case to reproduce the crash, so if someone > wants me to test other patches instead, then I will do so. OK, I cannot reproduce on 3.9.4. I #if 0'd out the WARNs in sysfs and kobject, and did this (which reliably broke on 3.8): # M=`modinfo -F filename e1000` # for i in `seq 10000`; do insmod $M; rmmod e1000; done >/dev/null 2>&1 & for i in `seq 10000`; do insmod $M; rmmod e1000; done > /dev/null 2>&1 & for i in `seq 10000`; do insmod $M; rmmod e1000; done > /dev/null 2>&1 & for i in `seq 10000`; do insmod $M; rmmod e1000; done >/dev/null 2>&1 & # This was under kvm, 4-way SMP, init=/bin/bash. Do you have a backtrace of the 3.9.4 crash? You can add "CFLAGS_module.o = -O0" to get a clearer backtrace if you want... Thanks, Rusty. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/