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 X-Spam-Level: X-Spam-Status: No, score=-1.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C6D18C43441 for ; Mon, 12 Nov 2018 03:49:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 886AB21582 for ; Mon, 12 Nov 2018 03:49:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=telus.net header.i=@telus.net header.b="T+Fp2sL0" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 886AB21582 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=telus.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730505AbeKLNkP (ORCPT ); Mon, 12 Nov 2018 08:40:15 -0500 Received: from cmta16.telus.net ([209.171.16.89]:47579 "EHLO cmta16.telus.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726777AbeKLNkP (ORCPT ); Mon, 12 Nov 2018 08:40:15 -0500 Received: from dougxps ([173.180.45.4]) by cmsmtp with SMTP id M3DYgXa60PTKIM3DZg8LmV; Sun, 11 Nov 2018 20:48:59 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=telus.net; s=neo; t=1541994539; bh=Yfo/AnEADA7m5Pdb7biAcHpkR2MrBe+e9fa+7ftBwxo=; h=From:To:Cc:References:In-Reply-To:Subject:Date; b=T+Fp2sL0bEW0UN4au7bgAbtNPUb9UTHTmRPyROrgoHwOUYLx3o5FpwPrRwSIMvM0q iKbkURpgiho8P+H/dHrv/DjyaByILcInapY6Kx4WiUpvDD19X5ZCsJ87fDsTpYse1V RplT1fat5fAQPUcyVXspm370zGN4ojTy2ny9bNj+mMqsfCloMHqAe+dQlJ591Hxl0W D0UH7DloSHDmhcn5h/sbwhKZe8joHvdlJNM6U+JHhP8HAdIh1YQJ62LxipNtOlaF+x ES90CBOvQc7I4ery/FO4CCIUPPgCuFm+0Es/YEHBSfsxaw3kmHb9vEA7moenTsG9vI jm9zDLr8dBUdg== X-Authority-Analysis: v=2.3 cv=ScEmicZu c=1 sm=1 tr=0 a=zJWegnE7BH9C0Gl4FFgQyA==:117 a=zJWegnE7BH9C0Gl4FFgQyA==:17 a=Pyq9K9CWowscuQLKlpiwfMBGOR0=:19 a=kj9zAlcOel0A:10 a=FGbulvE0AAAA:8 a=pTBt3e4HGWyJHFOnYdkA:9 a=qDq-Y2p-iwLrt0KP:21 a=CFiCtkeVyVkWwzcQ:21 a=CjuIK1q_8ugA:10 a=5JIPC4SmUL4A:10 a=eM4ghy-HDjkA:10 a=svzTaB3SJmTkU8mK-ULk:22 From: "Doug Smythies" To: "'Rafael J. Wysocki'" Cc: "'Srinivas Pandruvada'" , "'Peter Zijlstra'" , "'LKML'" , "'Frederic Weisbecker'" , "'Mel Gorman'" , "'Daniel Lezcano'" , "'Linux PM'" , "'Giovanni Gherdovich'" , "'Doug Smythies'" References: JLIjge0NMDhAwJLIogChPj KR9ogVaVz6DhgKRFdgxgYz LaclgNKRzDhAwLb6UgqZPJ In-Reply-To: LaclgNKRzDhAwLb6UgqZPJ Subject: RE: [RFC/RFT][PATCH v3] cpuidle: New timer events oriented governor for tickless systems Date: Sun, 11 Nov 2018 19:48:51 -0800 Message-ID: <005901d47a3a$a49420d0$edbc6270$@net> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook 12.0 Content-Language: en-ca Thread-Index: AdR0W8vD4oREAbGoTFqO9uyL0vrNhgCWrS2wAJOvwLAATRB1MA== X-CMAE-Envelope: MS4wfFbb8D/YiXqnEBVQDCVJfHFiqS/hyUwCyloqNlm7Qppb9xho2B1Y3lQDmOspUGzEFbLETq+EsxhbiPZ3k5l4R/eRQ/oGROUjm5wP168GlvyhRnPSAdqS 0Xk3MwZjGYmdn2ArQnj3ry2Ps4g24YsBK4x1E2kVAel3+bUoVRJ1A8Eygp6F4LE5Dr/iwIZuwUM189s+zLCKh6pXlfxZ8SM3SDGE1K2CQBDF+Hpzq6w4lGDs 488NYgMTNy7WDfirhIxd+p82/TdA8fTsYgVK+oK9/+dLLcA1vFC4I6DuHcrk59/11kMfkIHzOx1oJTHTk9YlhSOwNoe8URxalCwBsSQWpPhyPQR87vbJl+4y Jh9Zx0dG5QJXDSsRhhsW2UU5RwVXTBjmMDo7EYCZNeJcC1l2wE4eSCyOWPgbzWQ1m5E47+/C+dBv8P23SFhD1sALLH+edMX/ANnG2xjPEQn6ylq+SrH3R7DJ ssmEJ/CvHhPmUEM7 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018.11.10 13:48 Doug Smythies wrote: > On 2018.11.07 09:04 Doug Smythies wrote: > >> The Phoronix dbench test was run under the option to run all >> the tests, instead of just one number of clients. This was done >> with a reference/baseline kernel of 4.20-rc1, and also with this >> TEO version 3 patch. The tests were also repeated with trace >> enabled for 5000 seconds. Idle information and processor >> package power were sampled once per minute in all test runs. >> >> The results are: >> http://fast.smythies.com/linux-pm/k420/k420-dbench-teo3.htm >> http://fast.smythies.com/linux-pm/k420/histo_compare.htm > > Another observation from the data, and for the reference/ > baseline 4.20-rc1 kernel, idle state 0 histogram plots > is that there are several (280) long idle durations. > > For unknown reasons, these are consistently dominated by > CPU 5 on my system (264 of the 280, in this case). > > No other test that I have tried shows this issue, > But other tests also tend to set the need_resched > flag whereas the dbench test doesn't. > > Older kernels also have the issue. I tried: 4.19, 4.18 > 4.17, 4.16+"V9" idle re-work patch set of the time. > There is no use going back further, because "V9" was > to address excessively long durations in shallow idle states. > > I have not made progress towards determining the root issue. For whatever reason, sometimes a softirq_entry occurs and it is a considerably longer than usual time until the softirq_exit. Sometimes there are bunch of interrupts piled up, and sometimes some delay between the softirq_entry and anything else happening, which perhaps just means I didn't figure out what else to enable in the trace to observe it. Anyway, it seems likely that there is no problem here after all. ... Doug