From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934227AbZJNUkX (ORCPT ); Wed, 14 Oct 2009 16:40:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934155AbZJNUkV (ORCPT ); Wed, 14 Oct 2009 16:40:21 -0400 Received: from slow3-v.mail.gandi.net ([217.70.178.89]:33698 "EHLO slow3-v.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934087AbZJNUkS (ORCPT ); Wed, 14 Oct 2009 16:40:18 -0400 Date: Wed, 14 Oct 2009 13:28:53 -0700 From: Josh Triplett To: "Paul E. McKenney" 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, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, npiggin@suse.de, jens.axboe@oracle.com Subject: Re: [PATCH tip/core/rcu 0/6] rcu: fix synchronize_rcu_expedited(), update docs, improve perf Message-ID: <20091014202853.GD2395@feather> References: <20091014171517.GA13635@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091014171517.GA13635@linux.vnet.ibm.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 14, 2009 at 10:15:17AM -0700, Paul E. McKenney wrote: > This patchset contains a bug fix, a performance improvement, and > documentation updates: > > o Update Documentation/RCU/trace.txt to reflect recent changes > (including the removal of rcupreempt.c). > > o Fix to the severe performance problem with excessive IPIs and > lock contention in presence of very large (but legal) numbers > of RCU callbacks (reported by Nick Piggin). > > o Stopgap fix for a bug in TREE_PREEMPT_RCU's implementation of > synchronize_rcu_expedited(). This fix is correct, but no faster > than synchronize_rcu(). > > o Add exports for the updated synchronize_rcu_expedited() > implementation, which moved from a static inline in > include/linux/rcupdate.h to a separately compiled function > in kernel/rcutree_plugin.h. > > o Add the new rnp->blocked_tasks field to the rcuhier trace file > in debugfs. > > o Update the Documentation/RCU/trace.txt documentation to include > the rnp->blocked_tasks tracing. > > I believe that this is 2.6.32 material. > > Documentation/RCU/trace.txt | 22 ++- > b/Documentation/RCU/trace.txt | 232 +++++------------------------------------- > b/include/linux/rcutree.h | 6 - > b/kernel/rcutree.c | 29 ++++- > b/kernel/rcutree.h | 5 > b/kernel/rcutree_plugin.h | 20 +++ > b/kernel/rcutree_trace.c | 8 - > kernel/rcutree_plugin.h | 3 > 8 files changed, 103 insertions(+), 222 deletions(-) For all of these patches except 5/6 (commented on separately): Acked-by: Josh Triplett I agree that these need to go into 2.6.32, to accompany the switch to using hierarchical RCU exclusively. - Josh Triplett