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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 DCF4CC2D0A3 for ; Fri, 6 Nov 2020 16:14:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8DAE722228 for ; Fri, 6 Nov 2020 16:14:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727186AbgKFQOS (ORCPT ); Fri, 6 Nov 2020 11:14:18 -0500 Received: from mail.monom.org ([188.138.9.77]:48096 "EHLO mail.monom.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727020AbgKFQOR (ORCPT ); Fri, 6 Nov 2020 11:14:17 -0500 Received: from mail.monom.org (localhost [127.0.0.1]) by filter.mynetwork.local (Postfix) with ESMTP id 39DD6500609; Fri, 6 Nov 2020 17:14:14 +0100 (CET) Received: from localhost (unknown [94.31.100.251]) by mail.monom.org (Postfix) with ESMTPSA id DD6EE500596; Fri, 6 Nov 2020 17:14:13 +0100 (CET) Date: Fri, 6 Nov 2020 17:14:13 +0100 From: Daniel Wagner To: Sebastian Andrzej Siewior Cc: Thomas Gleixner , LKML , linux-rt-users , Steven Rostedt Subject: Re: [ANNOUNCE] v5.10-rc2-rt4 Message-ID: <20201106161413.7c65uxenamy474uh@beryllium.lan> References: <20201103195731.erjkgyzxzzjylhui@linutronix.de> <20201104103809.bhl2iorbwv6xowtw@beryllium.lan> <20201104104617.ueefmpdou4t3t2ce@linutronix.de> <20201104111948.vpykh3ptmysqhmve@beryllium.lan> <20201104124746.74jdsig3dffomv3k@beryllium.lan> <20201104130930.llx56gtqt532h7c7@linutronix.de> <20201104160650.b63zqof74wohgpa2@beryllium.lan> <20201106105447.2lasulgjrbqdhnlh@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201106105447.2lasulgjrbqdhnlh@linutronix.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 06, 2020 at 11:54:47AM +0100, Sebastian Andrzej Siewior wrote: > > rpi3 signaltest 5.9.0-rc8-rt12 > > 813 0_signaltest t0-max-latency : fail 214.00 > > rpi3 signaltest 5.9.0-rc8-rt12 > > 874 0_signaltest t0-max-latency : fail 217.00 > > rpi3 signaltest 5.9.0-rt16 > > 963 0_signaltest t0-max-latency : fail 321.00 > > Here, rt 13,14,15 would be interesting so we could narrow down the > ~100us. > v5.9-rc8-rt14 got new migrate-disable but I wouldn't expect it to cause > it. The other changes look also harmless (like the rtmutex redo which > should be a 0 change but then it mighe behave differently in regard to > workqueue in some corner cases). rpi3 signaltest 5.9.0-rc8-rt13 1196 0_signaltest t0-max-latency : fail 207.00 1196 0_signaltest t0-avg-latency : pass 46.00 1196 0_signaltest t0-min-latency : pass 22.00 rpi3 signaltest 5.9.0-rc8-rt14 1197 0_signaltest t0-max-latency : fail 301.00 1197 0_signaltest t0-avg-latency : pass 47.00 1197 0_signaltest t0-min-latency : pass 20.00 rpi3 signaltest 5.9.0-rt15 1198 0_signaltest t0-max-latency : fail 323.00 1198 0_signaltest t0-avg-latency : pass 47.00 1198 0_signaltest t0-min-latency : pass 21.00 > > rpi3 signaltest 5.9.1-rt19 > > 1038 0_signaltest t0-max-latency : fail 341.00 > > rpi3 signaltest 5.9.1-rt20 > > 1079 0_signaltest t0-max-latency : fail 318.00 > > So I have nothing to explain 20us improvement. I think 20us is in the range of the standard deviation for this test. So I don't think you should be concerned too much about it as long I don't have proper statistical numbers. One thing I also see is that the average was pretty constant at 47us for 5.9-rt and for 5.10-rt series it's around 55us. So something makes the whole operation slightly more expensive. > > rpi3 signaltest 5.10.0-rc1-rt1 > > 1118 0_signaltest t0-max-latency : fail 415.00 > > rpi3 signaltest 5.10.0-rc2-rt4 > > 1163 0_signaltest t0-max-latency : fail 340.00 > > -rt2 gained new kmap code. > -rt3 received an update of the above rpi3 signaltest 5.10.0-rc1-rt2 1199 0_signaltest t0-max-latency : fail 399.00 1199 0_signaltest t0-avg-latency : pass 55.00 1199 0_signaltest t0-min-latency : pass 25.00 rpi3 signaltest 5.10.0-rc2-rt3 1200 0_signaltest t0-max-latency : fail 420.00 1200 0_signaltest t0-avg-latency : pass 55.00 1200 0_signaltest t0-min-latency : pass 25.00 > But all this is only signal right? Correct. I've observed this only for signaltest and sigwaittest. > Nothing on the cyclictest front? Correct, cyclictest doesn't show any regression. > If lazy-preempt broke in a way then it should be only noticed by > cyclictest. You can however disable lazy-preempt just to be sure. Sure, will do a full run on Monday.