From owner-freebsd-stable@freebsd.org Thu Oct 29 21:59:10 2015 Return-Path: Delivered-To: freebsd-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 58752A2107B for ; Thu, 29 Oct 2015 21:59:10 +0000 (UTC) (envelope-from 000.fbsd@quip.cz) Received: from elsa.codelab.cz (elsa.codelab.cz [94.124.105.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 184921110 for ; Thu, 29 Oct 2015 21:59:09 +0000 (UTC) (envelope-from 000.fbsd@quip.cz) Received: from elsa.codelab.cz (localhost [127.0.0.1]) by elsa.codelab.cz (Postfix) with ESMTP id 9C13A28435; Thu, 29 Oct 2015 22:59:01 +0100 (CET) Received: from illbsd.quip.test (ip-89-177-49-111.net.upcbroadband.cz [89.177.49.111]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by elsa.codelab.cz (Postfix) with ESMTPSA id 6946D2842E; Thu, 29 Oct 2015 22:59:00 +0100 (CET) Message-ID: <563296A4.70501@quip.cz> Date: Thu, 29 Oct 2015 22:59:00 +0100 From: Miroslav Lachman <000.fbsd@quip.cz> User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:35.0) Gecko/20100101 Firefox/35.0 SeaMonkey/2.32 MIME-Version: 1.0 To: Jeremy Chadwick CC: freebsd-stable@freebsd.org Subject: Re: stable/10: high load average when box is idle References: <20151027050508.GA7612@icarus.home.lan> <5631EE40.3020404@quip.cz> <20151029100910.GA52255@icarus.home.lan> <56320737.2060901@quip.cz> In-Reply-To: <56320737.2060901@quip.cz> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 29 Oct 2015 21:59:10 -0000 Miroslav Lachman wrote on 10/29/2015 12:47: > Jeremy Chadwick wrote on 10/29/2015 11:09: [...] >> I've seen it on both bare-metal and VMs. Please see c#8 in the ticket; >> there's an itemised list of where I've seen it, but I'm sure it's not >> limited to just those. > > OK, I have read your c#8 and did some tests on our affected VMs. > With sysctl kern.eventtimer.periodic=1 it is better. Where previously > load were about 0.40 is 0.15 now. > One of these three systems is FreeBSD 10.2 and on this machine the > positive effect of kern.eventtimer.periodic=1 is more visible - load is > now 0.00 - 0.05. > I don't know if this is some coincidence or something is different in 10.2. > > Settings of kern.eventtimer is the same on all VMs > > kern.eventtimer.et.LAPIC.flags: 7 > kern.eventtimer.et.LAPIC.frequency: 35071418 > kern.eventtimer.et.LAPIC.quality: 600 > kern.eventtimer.et.i8254.flags: 1 > kern.eventtimer.et.i8254.frequency: 1193182 > kern.eventtimer.et.i8254.quality: 100 > kern.eventtimer.et.RTC.flags: 17 > kern.eventtimer.et.RTC.frequency: 32768 > kern.eventtimer.et.RTC.quality: 0 > kern.eventtimer.choice: LAPIC(600) i8254(100) RTC(0) > kern.eventtimer.singlemul: 4 > kern.eventtimer.idletick: 0 > kern.eventtimer.timer: LAPIC > kern.eventtimer.periodic: 1 Just for the record - I added graphs of CPU load from these three VMs FreeBSD 10.1 http://imagebin.ca/v/2Kkyq29M13d3 FreeBSD 10.1 http://imagebin.ca/v/2KkzUccxJEoE FreeBSD 10.2 http://imagebin.ca/v/2Kl00mS4RQ3n And coresponding CPU idle percentages FreeBSD 10.1 http://imagebin.ca/v/2Kl0R0U1pRhg FreeBSD 10.1 http://imagebin.ca/v/2Kl0cYiB0mS4 FreeBSD 10.2 http://imagebin.ca/v/2Kl0lIipTKXc As I mentioned the difference with / without kern.eventtimer.periodic=1 is more visible on FreeBSD 10.2. The flat line on the graphs is interval where I disabled almost all services - crontab too - so no measurements in this time. Effect of kern.eventtimer.periodic=1 is visible from 18:00 when I started all usual services. Miroslav Lachman