From owner-freebsd-virtualization@FreeBSD.ORG Fri Apr 10 23:14:56 2015 Return-Path: Delivered-To: freebsd-virtualization@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 40D6A587 for ; Fri, 10 Apr 2015 23:14:56 +0000 (UTC) Received: from mx2.shrew.net (mx2.shrew.net [38.97.5.132]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id E9B356B2 for ; Fri, 10 Apr 2015 23:14:55 +0000 (UTC) Received: from mail.shrew.net (mail.shrew.prv [10.24.10.20]) by mx2.shrew.net (8.14.7/8.14.7) with ESMTP id t3AMk8IM019973 for ; Fri, 10 Apr 2015 17:46:08 -0500 (CDT) (envelope-from mgrooms@shrew.net) Received: from [10.16.32.30] (72-48-144-84.static.grandenetworks.net [72.48.144.84]) by mail.shrew.net (Postfix) with ESMTPSA id 8763F18A82C for ; Fri, 10 Apr 2015 17:45:57 -0500 (CDT) Message-ID: <552852FB.1060901@shrew.net> Date: Fri, 10 Apr 2015 17:47:23 -0500 From: Matthew Grooms User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: freebsd-virtualization@freebsd.org Subject: Re: bhyve clock problem, solved by kern.timecounter.hardware="TSC-low" in /etc/sysctl.conf References: <552809F4.6070206@redbarn.org> In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.4.3 (mx2.shrew.net [10.24.10.11]); Fri, 10 Apr 2015 17:46:08 -0500 (CDT) X-BeenThere: freebsd-virtualization@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "Discussion of various virtualization techniques FreeBSD supports." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 10 Apr 2015 23:14:56 -0000 Perhaps applying this commit would have some positive effect ( HPET vs LAPIC )? https://docs.freebsd.org/cgi/getmsg.cgi?fetch=885358+0+archive/2015/svn-src-head/20150322.svn-src-head -Matthew On 4/10/2015 12:51 PM, Stephen Stuart wrote: > I think the right thing is to set (in /boot/loader.conf) > kern.timecounter.tc.TSC-low.quality to a value higher than that for HPET, > to force the clock choice over what the kernel decides for the hardware > that you're running on. See timecounters(4). > > Stephen > > On Fri, Apr 10, 2015 at 10:35 AM, Paul Vixie wrote: > >> here is a representative one-hour sample of ntp messages from >> /var/log/messages on a freebsd 10.1 bhyve guest: >> >>> Apr 10 12:00:46 family ntpd[634]: time reset -0.613057 s >>> Apr 10 12:17:02 family ntpd[634]: time reset -0.604933 s >>> Apr 10 12:33:51 family ntpd[634]: time reset -0.650622 s >>> Apr 10 12:55:06 family ntpd[634]: time reset -0.743930 s >> >> that's with kern.timecounter.hardware: HPET, which is the default. >> >> a "time reset" from ntpd means the clock either won't slew at all or >> can't slew fast enough. in other words a normal freebsd 10.1 server can >> run for months or even years without ever outputting one of these messages. >> >> google reports that some folks have had good luck with >> kern.timecounter.hardware: TSC-low. so i tried that on another freebsd >> 10.1 bhyve guest on the same bhyve server, with dramatic results -- no >> more ntpd messages. >> >> can we make TSC-low the default? >> >> vixie >> >> >> _______________________________________________ >> freebsd-virtualization@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-virtualization >> To unsubscribe, send any mail to " >> freebsd-virtualization-unsubscribe@freebsd.org" >> > _______________________________________________ > freebsd-virtualization@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-virtualization > To unsubscribe, send any mail to "freebsd-virtualization-unsubscribe@freebsd.org"