From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Lezcano Subject: Re: [PATCH] cpuidle: add 'failed' statistic Date: Tue, 11 Mar 2014 22:52:44 +0100 Message-ID: <531F85AC.3000404@linaro.org> References: <1394165650-6927-1-git-send-email-daniel.lezcano@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-pa0-f45.google.com ([209.85.220.45]:59029 "EHLO mail-pa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752081AbaCKVwo (ORCPT ); Tue, 11 Mar 2014 17:52:44 -0400 Received: by mail-pa0-f45.google.com with SMTP id kl14so145786pab.4 for ; Tue, 11 Mar 2014 14:52:44 -0700 (PDT) In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Len Brown Cc: "Rafael J. Wysocki" , Linux PM 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=20 efficiency of this state. The current statistics do not give a lot of=20 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 co= unt > of how man times predicted was < actual. Mmh, where do you retrieve the target_residency from userspace ? This=20 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=3D%lu, expected residency=3D%lu, measured residency=3D= %lu ?? Thanks -- Daniel --=20 Linaro.org =E2=94=82 Open source software fo= r ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog