From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753262Ab1EBKZ1 (ORCPT ); Mon, 2 May 2011 06:25:27 -0400 Received: from e8.ny.us.ibm.com ([32.97.182.138]:56489 "EHLO e8.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750901Ab1EBKZ0 (ORCPT ); Mon, 2 May 2011 06:25:26 -0400 Date: Mon, 2 May 2011 03:25:15 -0700 From: "Paul E. McKenney" To: Josh Triplett Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, 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, patches@linaro.org, "Paul E. McKenney" Subject: Re: [PATCH tip/core/rcu 07/86] rcu: Force per-rcu_node kthreads off of the outgoing CPU Message-ID: <20110502102515.GD2297@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20110501132142.GA25494@linux.vnet.ibm.com> <1304256126-26015-7-git-send-email-paulmck@linux.vnet.ibm.com> <20110501151034.GA14829@feather> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110501151034.GA14829@feather> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, May 01, 2011 at 08:10:35AM -0700, Josh Triplett wrote: > On Sun, May 01, 2011 at 06:20:47AM -0700, Paul E. McKenney wrote: > > From: Paul E. McKenney > > > > The scheduler has had some heartburn in the past when too many real-time > > kthreads were affinitied to the outgoing CPU. So, this commit lightens > > the load by forcing the per-rcu_node and the boost kthreads off of the > > outgoing CPU. Note that RCU's per-CPU kthread remains on the outgoing > > CPU until the bitter end, as it must in order to preserve correctness. > > > > Also avoid disabling hardirqs across calls to set_cpus_allowed_ptr(), > > given that this function can block. > > This seems like two separate changes in one patch. The change to > kernel/rcutree_plugin.h seems entirely separable from the change to > kernel/rcutree.c here. > > > Signed-off-by: Paul E. McKenney > > Signed-off-by: Paul E. McKenney > > Heh, amusingly this actually seems meaningful, if you intend it as a > "role" approval. Yep, that is the intent! ;-) Thanx, Paul