Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1751381AbdGQTso (ORCPT <rfc822;w@1wt.eu>);
        Mon, 17 Jul 2017 15:48:44 -0400
Received: from mga04.intel.com ([192.55.52.120]:37271 "EHLO mga04.intel.com"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1751316AbdGQTsn (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Mon, 17 Jul 2017 15:48:43 -0400
X-ExtLoop1: 1
X-IronPort-AV: E=Sophos;i="5.40,375,1496127600"; 
   d="scan'208";a="112344190"
Subject: Re: [RFC PATCH v1 00/11] Create fast idle path for short idle periods
To: Peter Zijlstra <peterz@infradead.org>, Andi Kleen <ak@linux.intel.com>
References: <20170713083649.febfflfl5hafkko5@hirez.programming.kicks-ass.net>
 <16e12e23-6b28-f174-7c4b-4d719225cd3b@linux.intel.com>
 <20170713145311.z4zxlyd2dospeoqg@hirez.programming.kicks-ass.net>
 <4a577bd6-20b1-abb6-2153-f9870f0a721e@linux.intel.com>
 <20170713182820.sn3fjitnd3mca27p@hirez.programming.kicks-ass.net>
 <31170ac6-9db1-f0b8-4841-f1661c8ed6e1@linux.intel.com>
 <20170714153818.pjauqxebxyhs6ljp@hirez.programming.kicks-ass.net>
 <20170714155356.GH3441@tassilo.jf.intel.com>
 <20170714160648.tg2u6eo2id6gmnjz@hirez.programming.kicks-ass.net>
 <20170714162619.GJ3441@tassilo.jf.intel.com>
 <20170717192309.ubn5muvc3u7htuaw@hirez.programming.kicks-ass.net>
Cc: "Li, Aubrey" <aubrey.li@linux.intel.com>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Christoph Lameter <cl@linux.com>, Aubrey Li <aubrey.li@intel.com>,
        tglx@linutronix.de, len.brown@intel.com, rjw@rjwysocki.net,
        tim.c.chen@linux.intel.com, paulmck@linux.vnet.ibm.com,
        yang.zhang.wz@gmail.com, x86@kernel.org, linux-kernel@vger.kernel.org,
        daniel.lezcano@linaro.org
From: Arjan van de Ven <arjan@linux.intel.com>
Message-ID: <dd8f283b-a869-dbdb-f77e-659eb2c878ce@linux.intel.com>
Date: Mon, 17 Jul 2017 12:48:38 -0700
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101
 Thunderbird/45.8.0
MIME-Version: 1.0
In-Reply-To: <20170717192309.ubn5muvc3u7htuaw@hirez.programming.kicks-ass.net>
Content-Type: text/plain; charset=windows-1252; format=flowed
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 423
Lines: 10

On 7/17/2017 12:23 PM, Peter Zijlstra wrote:
> Of course, this all assumes a Gaussian distribution to begin with, if we
> get bimodal (or worse) distributions we can still get it wrong. To fix
> that, we'd need to do something better than what we currently have.
>

fwiw some time ago I made a chart for predicted vs actual so you can sort
of judge the distribution of things visually

http://git.fenrus.org/tmp/linux2.png