From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754540AbaGNKKE (ORCPT ); Mon, 14 Jul 2014 06:10:04 -0400 Received: from e38.co.us.ibm.com ([32.97.110.159]:41577 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754611AbaGNKGM (ORCPT ); Mon, 14 Jul 2014 06:06:12 -0400 Date: Mon, 14 Jul 2014 03:06:04 -0700 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@kernel.org, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, niv@us.ibm.com, 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, sbw@mit.edu, linux-rt-users@vger.kernel.org Subject: [PATCH RFC tip/core/rcu 0/2] NOCB kthread economization patches Message-ID: <20140714100604.GA9905@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: 14071410-1344-0000-0000-000002D02C84 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello! This series provides a couple of patches that reduce the number of rcuo kthreads in cases where nr_cpu_ids is larger than the actual number of online CPUs. 1. Preparation patch that rationalizes RCU's creation of early-boot kthreads. 2. Instead of creation rcuo kthreads for each possible CPU, create them only for those CPUs that have come online at least once since boot. Thanx, Paul ------------------------------------------------------------------------ b/kernel/rcu/tree.c | 8 ++- b/kernel/rcu/tree.h | 5 +- b/kernel/rcu/tree_plugin.h | 105 ++++++++++++++++++++++++++++++++++++--------- 3 files changed, 95 insertions(+), 23 deletions(-)