From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753604AbbLIXCr (ORCPT ); Wed, 9 Dec 2015 18:02:47 -0500 Received: from e36.co.us.ibm.com ([32.97.110.154]:32848 "EHLO e36.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751741AbbLIXCq (ORCPT ); Wed, 9 Dec 2015 18:02:46 -0500 X-IBM-Helo: d03dlp03.boulder.ibm.com X-IBM-MailFrom: paulmck@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org Date: Wed, 9 Dec 2015 15:02:43 -0800 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com Subject: [PATCH v2 tip/core/rcu 0/11] Expedited-grace-period changes for 4.5 Message-ID: <20151209230243.GA32518@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15120923-0021-0000-0000-00001524D6F8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello! This series contains follow-on cleanup changes to RCU's expedited grace-period functionality. The patches in this series are as follows: 1. Short-circuit synchronize_sched_expedited() if there is only one CPU. 2. Update comment to clarify the role of ->expmaskinitnext. 3. Separate concerns by moving smp_mb() from rcu_seq_snap() to rcu_exp_gp_seq_snap(). 4. Safe a few lines of code by inverting the sense of sync_rcu_exp_select_cpus() "if" statement. 5. Reduce expedited GP memory contention via per-CPU variables. 6. Get rid of (some) empty stall-warning messages by resolving stall-warning ties. 7. Add more diagnostics to expedited stall warning messages. 8. Add rcu_normal kernel parameter to suppress expediting for the benefit of aggressive real-time systems. 9-10. Allow expedited grace periods to be disabled just before init is spawned, allowing them to speed up boot without interfering with run-time real-time workloads. 11. Remove TINY_RCU bloat from pointless (to TINY_RCU) boot parameters. Changes since v1: o Add patch 11 removing TINY_RCU bloat. o Get cover letter and patches correctly associated. :-/ Thanx, Paul ------------------------------------------------------------------------ Documentation/kernel-parameters.txt | 37 ++++++++++++---- include/linux/rcupdate.h | 15 ++++++ init/main.c | 2 kernel/ksysfs.c | 26 ++++++++++- kernel/rcu/srcu.c | 2 kernel/rcu/tree.c | 79 +++++++++++++++++++++++------------- kernel/rcu/tree.h | 10 ++-- kernel/rcu/tree_plugin.h | 6 ++ kernel/rcu/tree_trace.c | 18 +++++--- kernel/rcu/update.c | 24 +++++++++- 10 files changed, 165 insertions(+), 54 deletions(-)