From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752488AbZIHXhc (ORCPT ); Tue, 8 Sep 2009 19:37:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752255AbZIHXhc (ORCPT ); Tue, 8 Sep 2009 19:37:32 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.124]:49668 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752187AbZIHXhb (ORCPT ); Tue, 8 Sep 2009 19:37:31 -0400 Subject: Re: [PATCH tip/core/rcu 0/3] increase rcutorture intensity and fix a couple resulting bugs From: Steven Rostedt Reply-To: rostedt@goodmis.org To: paulmck@linux.vnet.ibm.com 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, josht@linux.vnet.ibm.com, dvhltc@us.ibm.com, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org In-Reply-To: <20090908225349.GA19524@linux.vnet.ibm.com> References: <20090908225349.GA19524@linux.vnet.ibm.com> Content-Type: text/plain Organization: Kihon Technologies Inc. Date: Tue, 08 Sep 2009 19:37:30 -0400 Message-Id: <1252453051.20985.9.camel@gandalf.stny.rr.com> Mime-Version: 1.0 X-Mailer: Evolution 2.26.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2009-09-08 at 15:53 -0700, Paul E. McKenney wrote: > This patch series increases the intensity of rcutorture testing for > TREE_PREEMPT_RCU and provides fixes for a couple resulting bugs. > > o Make rcutorture's RCU read-side critical sections occasionally > spin for a few tens of milliseconds, which greatly increases > the probability that they will be preempted and that quiescent > states will be forced. Yes, this does uncover some bugs in > TREE_PREEMPT_RCU (though TREE_RCU passes with flying colors). > > o Fix a bug where rnp->gpnum was not being updated. This > increases TREE_PREEMPT_RCU's reliability considerably, though > bugs still remain. > > o Make the initialization of multi-node trees of rcu_node > structures unconditionally acquire rnp->lock. This simplifies > the code a bit and will make it easier to allow grace-period > initialization become preemptable, should this be needed. > > Next steps include applying review comments, adding expedited grace > periods, and chasing down remaining bugs. Longer term, RCU priority > boosting. Hi Paul, These patches look decent to me. If it makes you feel comfy: Acked-by: Steven Rostedt -- Steve