From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753808AbaBEEE3 (ORCPT ); Tue, 4 Feb 2014 23:04:29 -0500 Received: from e28smtp05.in.ibm.com ([122.248.162.5]:37210 "EHLO e28smtp05.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751470AbaBEEE1 (ORCPT ); Tue, 4 Feb 2014 23:04:27 -0500 Message-ID: <52F1B773.6050901@linux.vnet.ibm.com> Date: Wed, 05 Feb 2014 09:30:51 +0530 From: Preeti U Murthy User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120717 Thunderbird/14.0 MIME-Version: 1.0 To: Arjan van de Ven CC: linux-pm@vger.kernel.org, rjw@rjwysocki.net, linux-kernel@vger.kernel.org, len.brown@intel.com, benh@kernel.crashing.org, daniel.lezcano@linaro.org, srivatsa.bhat@linux.vnet.ibm.com, paulmck@linux.vnet.ibm.com, svaidy@linux.vnet.ibm.com Subject: Re: [PATCH V3] cpuidle/governors: Fix logic in selection of idle states References: <20140204083531.24802.63370.stgit@preeti.in.ibm.com> <52F0FE9F.501@linux.intel.com> In-Reply-To: <52F0FE9F.501@linux.intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14020504-8256-0000-0000-00000B4EF6CA Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Arjan, On 02/04/2014 08:22 PM, Arjan van de Ven wrote: > On 2/4/2014 12:35 AM, Preeti U Murthy wrote: >> The cpuidle governors today are not handling scenarios where no idle >> state >> can be chosen. Such scenarios coud arise if the user has disabled all the >> idle states at runtime or the latency requirement from the cpus is >> very strict. >> >> The menu governor returns 0th index of the idle state table when no other >> idle state is suitable. This is even when the idle state corresponding >> to this >> index is disabled or the latency requirement is strict and the >> exit_latency >> of the lowest idle state is also not acceptable. Hence this patch >> fixes this logic in the menu governor by defaulting to an idle state >> index >> of -1 unless any other state is suitable. > > state 0 is defined as polling, and polling ALWAYS should be ok Hmm.. you are right. This is convincing. There is no need for this patch. Thanks Regards Preeti U Murthy >