Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932836Ab3DKSoS (ORCPT ); Thu, 11 Apr 2013 14:44:18 -0400 Received: from e9.ny.us.ibm.com ([32.97.182.139]:33833 "EHLO e9.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1765342Ab3DKSoP (ORCPT ); Thu, 11 Apr 2013 14:44:15 -0400 Date: Fri, 12 Apr 2013 00:13:13 +0530 From: Dipankar Sarma To: "Paul E. McKenney" Cc: Arjan van de Ven , linux-kernel@vger.kernel.org, mingo@elte.hu, laijs@cn.fujitsu.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: <20130411184313.GH22229@in.ibm.com> Reply-To: dipankar@in.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> <20130411182727.GM29861@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130411182727.GM29861@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13041118-7182-0000-0000-00000632060C Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1297 Lines: 28 On Thu, Apr 11, 2013 at 11:27:27AM -0700, Paul E. McKenney wrote: > 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. What Arjan said will also be true for Linux on Power systems. I am not sure "many architectures" would be the right way to characterize it. Thanks Dipankar -- 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/