Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758427Ab3DKS2E (ORCPT ); Thu, 11 Apr 2013 14:28:04 -0400 Received: from e31.co.us.ibm.com ([32.97.110.149]:42763 "EHLO e31.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750973Ab3DKS2A (ORCPT ); Thu, 11 Apr 2013 14:28:00 -0400 Date: Thu, 11 Apr 2013 11:27:27 -0700 From: "Paul E. McKenney" To: Arjan van de Ven 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 , Kevin Hilman , Christoph Lameter , arnd@arndb.de, Robin.Randhawa@arm.com, linux-rt-users@vger.kernel.org Subject: Re: [PATCH documentation 1/2] nohz1: Add documentation. Message-ID: <20130411182727.GM29861@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20130411160524.GA30384@linux.vnet.ibm.com> <1365696359-30958-1-git-send-email-paulmck@linux.vnet.ibm.com> <5166EF74.4030106@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5166EF74.4030106@linux.intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13041118-7282-0000-0000-0000160A1E34 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1063 Lines: 23 On Thu, Apr 11, 2013 at 10:14:28AM -0700, Arjan van de Ven wrote: > >+2. Many architectures will place dyntick-idle CPUs into deep sleep > >+ states, which further degrades from-idle transition latencies. > >+ > I think this part should just be deleted. > On x86, the deeper idle states are even used with non-tickless system (the break even times are > quite a bit less than even 1 msec). > I can't imagine that ARM is worse on this, at which point the statement above is highly dubious Interesting point, and I freely admit that I don't have full knowledge of the energy-consumption characteristics of all the architectures that Linux supports. Adding a few of the ARM guys on CC for their take, plus linux-rt-users. If there are no objections, I will delete point 2 above as Arjan suggests. Thanx, Paul -- 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/