From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D13DC46467 for ; Sun, 27 Nov 2022 06:39:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229530AbiK0Ggt (ORCPT ); Sun, 27 Nov 2022 01:36:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229496AbiK0Ggq (ORCPT ); Sun, 27 Nov 2022 01:36:46 -0500 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6781BDF8F; Sat, 26 Nov 2022 22:36:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1669531004; x=1701067004; h=message-id:subject:from:to:cc:date:in-reply-to: references:mime-version:content-transfer-encoding; bh=j18kDwi3QaatD8jlibnN39tgtT/ATwnSdJDJnE/5veU=; b=naZw9Ge8a2oXQNfAxNoMJmaU0FD9BdKCnUilaErWD8gzDPdZz+hXn6Wg SnWsOAAB5fntDdqALlfT+xlEqcrqZBjC1imb+FdrYBqFHt6ou1sF5Bjr+ sJ8UAxpJWfjGdHS7Mx/XjaLIDxFBOUziqg7hl6rohCpcS4jIDghM7W7Co qud3Wggktk5enO+FDhn7lHVneXlcvDz70oZ05q4e2YOY0rPPn5BtHy/2Q Blhr01Af8CSMosqL66pO26tFU4m1wI9xlp0BfzpzBjd4Wc/Obq2CtdxQv 7uvtg3xgC0vTMO6QfBVknNgR1tYn0Gxkv4jo56Xiywi9GPMrHI8nvrbrQ Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10543"; a="316473420" X-IronPort-AV: E=Sophos;i="5.96,197,1665471600"; d="scan'208";a="316473420" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Nov 2022 22:36:43 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10543"; a="593550769" X-IronPort-AV: E=Sophos;i="5.96,197,1665471600"; d="scan'208";a="593550769" Received: from liyi4-mobl1.ccr.corp.intel.com ([10.254.214.186]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Nov 2022 22:36:41 -0800 Message-ID: <876f3b51660b0e3e328c8f9d1ac3d4e14d749b0e.camel@intel.com> Subject: Re: [RFC PATCH v4 0/2] cpuidle: teo: Introduce util-awareness From: Zhang Rui To: Doug Smythies Cc: daniel.lezcano@linaro.org, lukasz.luba@arm.com, Dietmar.Eggemann@arm.com, yu.chen.surf@gmail.com, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, 'Kajetan Puchalski' , rafael@kernel.org Date: Sun, 27 Nov 2022 14:36:39 +0800 In-Reply-To: <003d01d901e2$025853c0$0708fb40$@telus.net> References: <20221102152808.2978590-1-kajetan.puchalski@arm.com> <00a801d8ffba$6cd72a70$46857f50$@telus.net> <044424e924967a1c93649812b6e1670c8c37fce4.camel@intel.com> <003d01d901e2$025853c0$0708fb40$@telus.net> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5-0ubuntu1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 2022-11-26 at 13:56 -0800, Doug Smythies wrote: > On 2022.11.26 08:26 Rui wrote: > > On Wed, 2022-11-23 at 20:08 -0800, Doug Smythies wrote: > > > On 2022.11.21 04:23 Kajetan Puchalski wrote: > > > > On Wed, Nov 02, 2022 at 03:28:06PM +0000, Kajetan Puchalski > > > > wrote: > > > > > > > > [...] > > > > > > > > > v3 -> v4: > > > > > - remove the chunk of code skipping metrics updates when the > > > > > CPU > > > > > was utilized > > > > > - include new test results and more benchmarks in the cover > > > > > letter > > > > > > > > [...] > > > > > > > > It's been some time so I just wanted to bump this, what do you > > > > think > > > > about this v4? Doug has already tested it, resuls for his > > > > machine > > > > are > > > > attached to the v3 thread. > > > > > > Hi All, > > > > > > I continued to test this and included the proposed ladder idle > > > governor in my continued testing. > > > (Which is why I added Rui as an addressee) > > > > Hi, Doug, > > Hi Rui, > > > Really appreciated your testing data on this. > > I have some dumb questions and I need your help so that I can > > better > > understand some of the graphs. :) > > > > > However, I ran out of time. Here is what I have: > > > > > > Kernel: 6.1-rc3 and with patch sets > > > Processor: Intel(R) Core(TM) i5-10600K CPU @ 4.10GHz > > > CPU scaling driver: intel_cpufreq > > > HWP disabled. > > > Unless otherwsie stated, performance CPU scaling govenor. > > > > > > Legend: > > > teo: the current teo idle governor > > > util-v4: the RFC utilization teo patch set version 4. > > > menu: the menu idle governor > > > ladder-old: the current ladder idle governor > > > ladder: the RFC ladder patchset. > > > > > > Workflow: shell-intensive serialized workloads. > > > Variable: PIDs per second. > > > Note: Single threaded. > > > Master reference: forced CPU affinity to 1 CPU. > > This is the 1cpu on the graph. > > > > Performance Results: > > > http://smythies.com/~doug/linux/idle/teo-util/graphs/pids-perf.png > > > Schedutil Results: > > > http://smythies.com/~doug/linux/idle/teo-util/graphs/pids-su.png > > > > what does 1cpu mean? > > For shell-intensive serialized workflow or: > > Dountil the list of tasks is finished: > Start the next task in the list of stuff to do (with a new PID). > Wait for it to finish > Enduntil > > We know it represents a challenge for CPU frequency scaling drivers, > schedulers, and therefore idle drivers. > > We also know that the best performance is achieved by overriding > the scheduler and forcing CPU affinity. I use this "best" case as the > master reference, using the label 1cpu on the graph. > Got it. > > > Workflow: sleeping ebizzy 128 threads. > > > Variable: interval (uSecs). > > > Performance Results: > > > http://smythies.com/~doug/linux/idle/teo-util/graphs/ebizzy-128-perf.png > > > Performance power and idle data: > > > http://smythies.com/~doug/linux/idle/teo-util/ebizzy/perf/ > > > > for the "Idle state 0/1/2/3 was too deep" graphs, may I know how > > you > > assert that an idle state is too deep/shallow? > > I get those stats directly from the kernel driver statistics. For > example: > > $ grep . /sys/devices/system/cpu/cpu4/cpuidle/state*/above > /sys/devices/system/cpu/cpu4/cpuidle/state0/above:0 > /sys/devices/system/cpu/cpu4/cpuidle/state1/above:38085 > /sys/devices/system/cpu/cpu4/cpuidle/state2/above:7668 > /sys/devices/system/cpu/cpu4/cpuidle/state3/above:6823 > > $ grep . /sys/devices/system/cpu/cpu4/cpuidle/state*/below > /sys/devices/system/cpu/cpu4/cpuidle/state0/below:72059 > /sys/devices/system/cpu/cpu4/cpuidle/state1/below:246573 > /sys/devices/system/cpu/cpu4/cpuidle/state2/below:7817 > /sys/devices/system/cpu/cpu4/cpuidle/state3/below:0 > > I keep track of the changes per sample interval and graph > the sum for all CPUs as a percentage of the usage of > that idle state. > > Because I can never remember what "above" and "below" > actually mean, I use the terms "was too shallow" > and "was too deep". I just checked the code. My understanding is that "above" means the previous idle state residency is too short, and a shallower state would have been a better match. "below" means the previous idle state residency is too long, and a deeper state would have been a better match. So probably "above" means "should be shallower" or "was too deep", and "below" means "should be deeper" or "was to shallow"? thanks, rui