From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934045Ab2FHJE0 (ORCPT ); Fri, 8 Jun 2012 05:04:26 -0400 Received: from mail-bk0-f46.google.com ([209.85.214.46]:33025 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933075Ab2FHJEX (ORCPT ); Fri, 8 Jun 2012 05:04:23 -0400 Date: Fri, 8 Jun 2012 11:04:17 +0200 From: Ingo Molnar 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@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: Re: [PATCH tip/core/rcu 0/7] RCU_FAST_NO_HZ changes for 3.6 Message-ID: <20120608090417.GA10841@gmail.com> References: <20120608042632.GA1250@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120608042632.GA1250@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Paul E. McKenney wrote: > 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. Sure, that's sensible - could get this to me ASAP so that we can send it to Linus before -rc2? #3 and #4 are pretty large so we want them upstream ASAP. Thanks, Ingo