From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964872AbbELVtx (ORCPT ); Tue, 12 May 2015 17:49:53 -0400 Received: from e32.co.us.ibm.com ([32.97.110.150]:41163 "EHLO e32.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964849AbbELVtv (ORCPT ); Tue, 12 May 2015 17:49:51 -0400 Date: Tue, 12 May 2015 14:49:45 -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, 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 tip/core/rcu 0/9] CPU-hotplug updates for 4.2 Message-ID: <20150512214945.GA813@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: 15051221-0005-0000-0000-00000ABED242 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello! The following series improves RCU's handling of CPU hotplug. It also contains a couple of ARM placeholder patches in case someone gets caught out by tighter diagnostics. 1. Eliminate a HOTPLUG_CPU #ifdef in favor of IS_ENABLED() 2. Adjust rcu_read_unlock_special()'s acquisition of the task's lock to start allowing for the fact that blocked tasks are no longer migrated to the root rcu_node structure. If the warning does not trigger, a later patch will eliminate the loop. 3. Rmove dead code from force_qs_rnp(). 4. Remove redundant offline check. 5. Correctly initialize ->rcu_qs_ctr_snap at online time to get the code out of its current "working by accident" state. 6. Move smpboot_unpark_threads() handling into a notifier for uniformity. 7. [Placeholder for ARM64] Use common code for ARM64 CPU-offline notification. 8. [Placeholder for ARM] Use common code for ARM CPU-offline notification. 9. Remove extraneous __cpuinit, courtesy of Paul Gortmaker. Thanx, Paul ------------------------------------------------------------------------ b/arch/arm/kernel/smp.c | 6 +---- b/arch/arm64/kernel/smp.c | 6 +---- b/kernel/cpu.c | 4 +-- b/kernel/rcu/tree.c | 47 ++++++++++++++------------------------------- b/kernel/rcu/tree_plugin.h | 9 +++++--- 5 files changed, 27 insertions(+), 45 deletions(-)