From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755589AbaCKVws (ORCPT ); Tue, 11 Mar 2014 17:52:48 -0400 Received: from mail-pa0-f47.google.com ([209.85.220.47]:43097 "EHLO mail-pa0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755238AbaCKVwo (ORCPT ); Tue, 11 Mar 2014 17:52:44 -0400 Message-ID: <531F85AC.3000404@linaro.org> Date: Tue, 11 Mar 2014 22:52:44 +0100 From: Daniel Lezcano User-Agent: Mozilla/5.0 (X11; Linux i686; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 MIME-Version: 1.0 To: Len Brown CC: "Rafael J. Wysocki" , Linux PM list , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] cpuidle: add 'failed' statistic References: <1394165650-6927-1-git-send-email-daniel.lezcano@linaro.org> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/11/2014 03:00 AM, Len Brown wrote: > Exactly what use-case do you have in mind for this attribute? Nothing more than balance the c-state usage with the selection efficiency of this state. The current statistics do not give a lot of clues of what is happening. > "failed" is a strong word. > Some validation guy is going to send me e-mail when it is non-zero... > I don't like that use-case. > > But even if re-named, I don't see see how it will be useful. > When I want to see how C-state predictions are doing, I use ftrace, > which can show me the actual expected and actual times, not just a count > of how man times predicted was < actual. Mmh, where do you retrieve the target_residency from userspace ? This information is not exported from ftrace neither sysfs. > I would rather see some good tracepoints go upstream. Ok, which tracepoints you would like to see ? target residency=%lu, expected residency=%lu, measured residency=%lu ?? Thanks -- Daniel -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog