From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754049AbZHQTUj (ORCPT ); Mon, 17 Aug 2009 15:20:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753429AbZHQTUi (ORCPT ); Mon, 17 Aug 2009 15:20:38 -0400 Received: from e5.ny.us.ibm.com ([32.97.182.145]:46722 "EHLO e5.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753271AbZHQTUi (ORCPT ); Mon, 17 Aug 2009 15:20:38 -0400 Date: Mon, 17 Aug 2009 12:20:36 -0700 From: "Paul E. McKenney" To: Josh Triplett Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, dvhltc@us.ibm.com, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, hugh.dickins@tiscali.co.uk, benh@kernel.crashing.org Subject: Re: [PATCH -tip/core/rcu 1/6] Cleanups and fixes for RCU in face of heavy CPU-hotplug stress Message-ID: <20090817192036.GJ6760@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20090815165153.GA8886@linux.vnet.ibm.com> <1250533487.2709.14.camel@josh-work.beaverton.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1250533487.2709.14.camel@josh-work.beaverton.ibm.com> User-Agent: Mutt/1.5.15+20070412 (2007-04-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 17, 2009 at 11:24:47AM -0700, Josh Triplett wrote: > On Sat, 2009-08-15 at 09:51 -0700, Paul E. McKenney wrote: > > These pass tests combining rcutorture and continuous CPU-hotplug > > operations, in other words, no sleeping between successive CPU-hotplug > > operations. This set does not fix the bug involving deadlocks through > > rcutorture, kthread_stop(), and migration threads. However, this bug > > does not affect production systems, so should not stand in the way of > > applying these patches. > > Commit 63706172f332fd3f6e7458ebfb35fa6de9c21dc5, "kthreads: rework > kthread_stop()", looks like it fixes kthread_stop to work concurrently. > That may fix the issue you observed. Very cool!!! Given that Oleg is the author, it probably also works. :-) Thanx, Paul