Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757118Ab1DAOiw (ORCPT ); Fri, 1 Apr 2011 10:38:52 -0400 Received: from mga09.intel.com ([134.134.136.24]:59954 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755489Ab1DAOiv (ORCPT ); Fri, 1 Apr 2011 10:38:51 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.63,282,1299484800"; d="scan'208";a="727951161" Message-ID: <4D95E35F.2080707@linux.intel.com> Date: Fri, 01 Apr 2011 07:38:23 -0700 From: Arjan van de Ven User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.15) Gecko/20110303 Thunderbird/3.1.9 MIME-Version: 1.0 To: dipankar@in.ibm.com CC: Len Brown , Peter Zijlstra , Vaidyanathan Srinivasan , Trinabh Gupta , Stephen Rothwell , suresh.b.siddha@intel.com, benh@kernel.crashing.org, venki@google.com, ak@linux.intel.com, linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com Subject: Re: cpuidle asymmetry (was Re: [RFC PATCH V4 5/5] cpuidle: cpuidle driver for apm) References: <20110322123336.28725.29810.stgit@tringupt.in.ibm.com> <20110323121458.ec7cdaf9.sfr@canb.auug.org.au> <4D89CA7D.8080108@linux.vnet.ibm.com> <4D8B550D.5000409@linux.vnet.ibm.com> <20110325180156.GC19214@dirshya.in.ibm.com> <1301577536.4859.249.camel@twins> <20110401081522.GA22339@in.ibm.com> In-Reply-To: <20110401081522.GA22339@in.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1067 Lines: 25 On 4/1/2011 1:15 AM, Dipankar Sarma wrote: > On Fri, Apr 01, 2011 at 12:09:25AM -0400, Len Brown wrote: >>>> Moorestown is already an example of an asymmetric system, >>>> since its deepest c-state is available on cpu0, but not on cpu1. >>>> So it needs different tables for each cpu. >>> wtf are these hardware guys smoking and how the heck are we supposed to >>> schedule on such a machine? Prefer to keep cpu1 busy while idling cpu0? >> they are smoking micro-amps:-) >> >> S0i3 on cpu0 can be entered only after cpu1 is already off-line, >> among other system hardware dependencies... >> >> So it makes no sense to export S0i3 as a c-state on cpu1. >> >> When cpu1 is online, the scheduler treats it as a normal SMP. > Isn't S0i3 a "system" state, as opposed to cpu state ? it's misnamed. it's a C state to the OS. -- 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/