Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933525Ab3DSVB4 (ORCPT ); Fri, 19 Apr 2013 17:01:56 -0400 Received: from mail-pa0-f52.google.com ([209.85.220.52]:37521 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932474Ab3DSVBy (ORCPT ); Fri, 19 Apr 2013 17:01:54 -0400 From: Kevin Hilman To: "Paul E. McKenney" 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, josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, edumazet@google.com, darren@dvhart.com, fweisbec@gmail.com, sbw@mit.edu, Borislav Petkov , Arjan van de Ven , Christoph Lameter Subject: Re: [PATCH documentation 1/2] nohz1: Add documentation. References: <20130411160524.GA30384@linux.vnet.ibm.com> <1365696359-30958-1-git-send-email-paulmck@linux.vnet.ibm.com> Date: Fri, 19 Apr 2013 14:01:49 -0700 In-Reply-To: <1365696359-30958-1-git-send-email-paulmck@linux.vnet.ibm.com> (Paul E. McKenney's message of "Thu, 11 Apr 2013 09:05:58 -0700") Message-ID: <877gjyxmiq.fsf@linaro.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 859 Lines: 28 "Paul E. McKenney" writes: > +KNOWN ISSUES [...] > +o Unless all CPUs are idle, at least one CPU must keep the > + scheduling-clock interrupt going in order to support accurate > + timekeeping. At least with the implementation I'm using (Frederic's 3.9-nohz1 branch), at least one CPU is forced to stay out of dyntick-idle *always*, even if all CPUs are idle. IMO, this is important to list as a known issue since this will have its own power implications when the system is mostly idle. Otherwise, document looks great. Reviewed-by: Kevin Hilman Kevin -- 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/