Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753602Ab0KJRbT (ORCPT ); Wed, 10 Nov 2010 12:31:19 -0500 Received: from casper.infradead.org ([85.118.1.10]:42866 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753152Ab0KJRbS convert rfc822-to-8bit (ORCPT ); Wed, 10 Nov 2010 12:31:18 -0500 Subject: Re: [PATCH] a local-timer-free version of RCU From: Peter Zijlstra To: Frederic Weisbecker Cc: Lai Jiangshan , Joe Korty , "Paul E. McKenney" , mathieu.desnoyers@efficios.com, dhowells@redhat.com, loic.minier@linaro.org, dhaval.giani@gmail.com, tglx@linutronix.de, linux-kernel@vger.kernel.org, josh@joshtriplett.org, houston.jim@comcast.net In-Reply-To: <20101110155419.GC5750@nowhere> References: <20101104232148.GA28037@linux.vnet.ibm.com> <20101105210059.GA27317@tsunami.ccur.com> <4CD912E9.1080907@cn.fujitsu.com> <20101110155419.GC5750@nowhere> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Wed, 10 Nov 2010 18:31:11 +0100 Message-ID: <1289410271.2084.25.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 666 Lines: 30 On Wed, 2010-11-10 at 16:54 +0100, Frederic Weisbecker wrote: > run the sched tick and if there was nothing to do > for some time and we are in userspace, deactivate it. Not for some time, immediately, have the tick track if it was useful, if it was not, have it stop itself, like: tick() { int stop = 1; if (nr_running > 1) stop = 0; if(rcu_needs_cpu()) stop = 0; ... if (stop) enter_nohz_mode(); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/