Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932859AbaLAXIY (ORCPT ); Mon, 1 Dec 2014 18:08:24 -0500 Received: from e32.co.us.ibm.com ([32.97.110.150]:42288 "EHLO e32.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932676AbaLAXIT (ORCPT ); Mon, 1 Dec 2014 18:08:19 -0500 Date: Mon, 1 Dec 2014 15:08:13 -0800 From: "Paul E. McKenney" To: =?iso-8859-1?Q?D=E2niel?= Fraga Cc: Linus Torvalds , Linux Kernel Mailing List Subject: Re: frequent lockups in 3.18rc4 Message-ID: <20141201230813.GE25340@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20141126225745.GA30346@redhat.com> <20141127225637.GA24019@redhat.com> <547b8a45.6e608c0a.20f9.1002@mx.google.com> <547bbe36.48548c0a.105c.779c@mx.google.com> <20141201191431.GA17385@linux.vnet.ibm.com> <547ccf74.a5198c0a.25de.26d9@mx.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <547ccf74.a5198c0a.25de.26d9@mx.google.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14120123-0005-0000-0000-000006C6564F Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 01, 2014 at 06:28:31PM -0200, D?niel Fraga wrote: > On Mon, 1 Dec 2014 11:14:31 -0800 > "Paul E. McKenney" wrote: > > > If it would help to have !CONFIG_TREE_PREEMPT_RCU with CONFIG_PREEMPT=y, > > please let me know and I will create a patch that forces this. > > (Not mainline material, but if it helps with debug...) > > Hi Paul. Please, I'd like the patch, because without > preemption, I'm unable to trigger this bug. Well, this turned out to be way simpler than I expected. Passes light rcutorture testing. Sometimes you get lucky... Thanx, Paul diff --git a/init/Kconfig b/init/Kconfig index 903505e66d1d..2cf71fcd514f 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -469,7 +469,7 @@ choice config TREE_RCU bool "Tree-based hierarchical RCU" - depends on !PREEMPT && SMP + depends on SMP select IRQ_WORK help This option selects the RCU implementation that is -- 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/