Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753759Ab0KMWa4 (ORCPT ); Sat, 13 Nov 2010 17:30:56 -0500 Received: from mail-fx0-f46.google.com ([209.85.161.46]:61599 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753301Ab0KMWaz (ORCPT ); Sat, 13 Nov 2010 17:30:55 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=aL/zKPN1kXemLO+QjU1PAWyO0HSdOpNX7K9swWyze/fDb6yUiwrdbEPXVAHsaAlhyd R0DNnp7tIXw0iW5oHd4e/nOSW0LvVrS9q6Yh9PHpe9tLwJ/GnkPf8HNO1vXtoimth0hy Vdfygl313iyiFniVzcSBVbLo2eWYZi5oZxtqw= Date: Sat, 13 Nov 2010 23:30:49 +0100 From: Frederic Weisbecker To: "Paul E. McKenney" Cc: Peter Zijlstra , Lai Jiangshan , Joe Korty , 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 Subject: Re: [PATCH] a local-timer-free version of RCU Message-ID: <20101113223046.GB5445@nowhere> References: <20101104232148.GA28037@linux.vnet.ibm.com> <20101105210059.GA27317@tsunami.ccur.com> <4CD912E9.1080907@cn.fujitsu.com> <20101110155419.GC5750@nowhere> <1289410271.2084.25.camel@laptop> <20101111041920.GD3134@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101111041920.GD3134@linux.vnet.ibm.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1152 Lines: 40 On Wed, Nov 10, 2010 at 08:19:20PM -0800, Paul E. McKenney wrote: > On Wed, Nov 10, 2010 at 06:31:11PM +0100, Peter Zijlstra wrote: > > 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(); > > } > > I am still holding out for a dyntick-hpc version of RCU that does not > need the tick. ;-) So you don't think it would be an appropriate solution? Keeping the tick for short periods of time while we need it only, that looks quite a good way to try. Hmm? -- 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/