From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758514Ab2FHE1v (ORCPT ); Fri, 8 Jun 2012 00:27:51 -0400 Received: from e1.ny.us.ibm.com ([32.97.182.141]:51966 "EHLO e1.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753230Ab2FHE1g (ORCPT ); Fri, 8 Jun 2012 00:27:36 -0400 Date: Thu, 7 Jun 2012 21:26:32 -0700 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@elte.hu, 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, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, darren@dvhart.com, fweisbec@gmail.com, patches@linaro.org Subject: [PATCH tip/core/rcu 0/7] RCU_FAST_NO_HZ changes for 3.6 Message-ID: <20120608042632.GA1250@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-Content-Scanned: Fidelis XPS MAILER x-cbid: 12060804-6078-0000-0000-00000BDD24AA Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello! This patch series provides more adjustments to the (relatively) new large-system-safe implementation for RCU_FAST_NO_HZ: 1. Remove RCU_FAST_NO_HZ dependency on stop_machine() nature of CPU hotplug. 2. Make RCU_FAST_NO_HZ tracing distinguish between short and long idle intervals. 3. Move RCU_FAST_NO_HZ per-CPU state variables to the rcu_dynticks per-CPU structure. 4. Precompute RCU_FAST_NO_HZ timer offsets so that the timers will actually be paid attention to. This fixes the slow-boot problem that hit a few people. 5. Convert ftrace_dump() calls in idle entry and idle exit from DUMP_ALL to DUMP_ORIG. 6. Fix erroneous TINY_PREEMPT_RCU assumption that rcu_preempt_needs_cpu() is a quiescent state (it is not). 7. Round RCU_FAST_NO_HZ lazy timeout to nearest second to conserve power on systems with synchronized scheduler-clock interrupts. I am considering pushing #1-#4 into 3.5 for the slow-boot regression. If you object, please let me know. Thanx, Paul b/include/linux/rcupdate.h | 2 b/include/linux/rcutiny.h | 6 + b/include/linux/rcutree.h | 2 b/include/trace/events/rcu.h | 1 b/kernel/rcutiny_plugin.h | 2 b/kernel/rcutree.c | 2 b/kernel/rcutree.h | 14 +++ b/kernel/rcutree_plugin.h | 8 +- b/kernel/time/tick-sched.c | 7 + kernel/rcutree.c | 4 - kernel/rcutree_plugin.h | 167 ++++++++++++++++++++++--------------------- 11 files changed, 124 insertions(+), 91 deletions(-)