From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751834Ab3GBFLe (ORCPT ); Tue, 2 Jul 2013 01:11:34 -0400 Received: from moutng.kundenserver.de ([212.227.17.9]:50616 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750994Ab3GBFLd (ORCPT ); Tue, 2 Jul 2013 01:11:33 -0400 Message-ID: <1372741852.7363.110.camel@marge.simpson.net> Subject: Re: [PATCH RFC nohz_full v2 2/7] nohz_full: Add rcu_dyntick data for scalable detection of all-idle state From: Mike Galbraith To: paulmck@linux.vnet.ibm.com Cc: Josh Triplett , 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, dhowells@redhat.com, edumazet@google.com, darren@dvhart.com, fweisbec@gmail.com, sbw@mit.edu Date: Tue, 02 Jul 2013 07:10:52 +0200 In-Reply-To: <20130701191656.GR3773@linux.vnet.ibm.com> References: <20130628200949.GA17458@linux.vnet.ibm.com> <1372450222-19420-1-git-send-email-paulmck@linux.vnet.ibm.com> <1372450222-19420-2-git-send-email-paulmck@linux.vnet.ibm.com> <20130701153150.GB2923@leaf> <20130701155220.GL3773@linux.vnet.ibm.com> <20130701181601.GA7964@jtriplet-mobl1> <20130701182326.GQ3773@linux.vnet.ibm.com> <20130701183412.GA18804@jtriplet-mobl1> <20130701191656.GR3773@linux.vnet.ibm.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 X-Provags-ID: V02:K0:+Ivh9WrW0Y5kO3NZkSOh9UT+EYHWNEdZdf7rHOWDyY3 j7aiZxFAA7LEuoosmQ+V486mBO91JbaZRYNISzeWufXouY64oi 0SUT93+YXa4tSxmFc7aUSQ7NQLThjLGocQQEHaZzP7S28qfUP/ Msg4L5UW3mVnse3mEPPZDplHeQ29yaqD7zNkSt3lJ5rO3IBK2W Zre5bbjARXI7RlE/LQvLGIbqm4XyV77dsf9eH5YoByywlwpH2t ZOcO5w4W1cuanRas7vjQSFy5+mJ1cgryw+z06pO5p/ufJbsv1y lTU6GFXn4DNGz2Mtz2XfyqBNBFfU++pG8B5fleoL+fP6PDrLQk TxPH3kX4CjT2oi60HUuv7YFYh1tcQpXPJy0fayUuUxaE73tCab 5JO+RGRDYZ15Q== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2013-07-01 at 12:16 -0700, Paul E. McKenney wrote: > On Mon, Jul 01, 2013 at 11:34:13AM -0700, Josh Triplett wrote: > > > > This also naturally raises the question "How can we let userspace get > > > > accurate time without forcing a timer tick?". > > > > > > We don't. ;-) > > > > We don't currently, hence my question about how we can. :) > > Per-CPU atomic clocks? Great idea, who needs timekeeping code. http://www.euronews.com/2013/04/02/swiss-sets-sights-on-miniscule-atomic-clock/ -Mike