From owner-freebsd-current@freebsd.org Sun Oct 22 16:16:46 2017 Return-Path: Delivered-To: freebsd-current@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 4B746E55DA6; Sun, 22 Oct 2017 16:16:46 +0000 (UTC) (envelope-from bsam@passap.ru) Received: from forward100p.mail.yandex.net (forward100p.mail.yandex.net [IPv6:2a02:6b8:0:1472:2741:0:8b7:100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "forwards.mail.yandex.net", Issuer "Yandex CA" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id E16C86C409; Sun, 22 Oct 2017 16:16:45 +0000 (UTC) (envelope-from bsam@passap.ru) Received: from mxback5o.mail.yandex.net (mxback5o.mail.yandex.net [IPv6:2a02:6b8:0:1a2d::1f]) by forward100p.mail.yandex.net (Yandex) with ESMTP id BEFE45103A95; Sun, 22 Oct 2017 19:16:42 +0300 (MSK) Received: from smtp1j.mail.yandex.net (smtp1j.mail.yandex.net [2a02:6b8:0:801::ab]) by mxback5o.mail.yandex.net (nwsmtp/Yandex) with ESMTP id W3U1j44byJ-GgHWOQ8b; Sun, 22 Oct 2017 19:16:42 +0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=passap.ru; s=mail; t=1508689002; bh=xQCui/wG8ltvuXaxMBNG3fAMoJRanYRvllWtwATHlNo=; h=Subject:To:Cc:References:From:Message-ID:Date:In-Reply-To; b=actaExz1izBcKqZb53PTFO2uYncumFdblXnqBs3HVChZVz+8P0ZNgvRQfHM3x/onO Z/zXZhHVev2lrEtWWy3nVW0EXrHtx2Hq+Nwbfer6q8z61FZzKqZ68bR82NevjxDrml 9EyCpATExrF4Y9nquUkCjK/QpstO9hoDtp8Fypzs= Received: by smtp1j.mail.yandex.net (nwsmtp/Yandex) with ESMTPSA id crX7XuOydV-GgZGaJF9; Sun, 22 Oct 2017 19:16:42 +0300 (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client certificate not present) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=passap.ru; s=mail; t=1508689002; bh=xQCui/wG8ltvuXaxMBNG3fAMoJRanYRvllWtwATHlNo=; h=Subject:To:Cc:References:From:Message-ID:Date:In-Reply-To; b=actaExz1izBcKqZb53PTFO2uYncumFdblXnqBs3HVChZVz+8P0ZNgvRQfHM3x/onO Z/zXZhHVev2lrEtWWy3nVW0EXrHtx2Hq+Nwbfer6q8z61FZzKqZ68bR82NevjxDrml 9EyCpATExrF4Y9nquUkCjK/QpstO9hoDtp8Fypzs= Authentication-Results: smtp1j.mail.yandex.net; dkim=pass header.i=@passap.ru Subject: Re: host, bhyve vm and ntpd To: Ian Lepore Cc: freebsd-current@FreeBSD.org, freebsd-virtualization@FreeBSD.org References: <2931f1cc-6574-b58d-4b94-5f77fa5cdb85@passap.ru> <1508512327.1383.55.camel@freebsd.org> <39bf2426-2edf-d485-7c81-519e931154be@passap.ru> <1508517160.1383.63.camel@freebsd.org> <76ff7afb-3d3a-96f6-1275-89472ff5683d@passap.ru> <1508522667.1383.69.camel@freebsd.org> <30992c14-7b78-ab9f-5693-931e6ca41f1b@passap.ru> <1508523696.1383.75.camel@freebsd.org> <23019.46875.929719.481108@atom.mcvau.net> <1508624153.1383.107.camel@freebsd.org> <6dc189a0-e7bc-6c3b-2be6-80154e7ece42@passap.ru> <1508688144.1383.114.camel@freebsd.org> From: Boris Samorodov Message-ID: <4494cefa-5fe9-8482-e0de-14d7e7c09e75@passap.ru> Date: Sun, 22 Oct 2017 19:16:41 +0300 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <1508688144.1383.114.camel@freebsd.org> Content-Type: text/plain; charset=koi8-r Content-Language: en-US Content-Transfer-Encoding: 8bit X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 22 Oct 2017 16:16:46 -0000 22.10.2017 19:02, Ian Lepore ÐÉÛÅÔ: > On Sun, 2017-10-22 at 11:31 +0300, Boris Samorodov wrote: >> 22.10.2017 01:15, Ian Lepore ÐÉÛÅÔ: >>> >>> On Sat, 2017-10-21 at 17:07 -0400, Michael Voorhis wrote: >>>> >>>> Ian Lepore writes: >>>>> >>>>> >>>>> Beyond that, I'm not sure what else to try. šIt might be necessary to >>>>> get some bhyve developers involved (I know almost nothing about it). >>>> NTPD behaves more normally on uniprocessor VMs. >>>> >>>> A FreeBSD bhyve-guest running on a freebsd host will select a >>>> different timecounter depending on whether it is a multiprocessor or a >>>> uniprocessor.ššMy uniprocessor bhyve-vm selected TSC-low as the best >>>> timecounter in a uniprocessor.ššNTP functions there as expected. >>>> >>>> kern.timecounter.choice: TSC-low(1000) ACPI-fast(900) HPET(950) i8254(0) dummy(-1000000) >>>> kern.timecounter.hardware: TSC-low >>>> >>>> The very same VM, when given two total CPUs, selected HPET (if I >>>> recall) and the timekeeping with NTPD was unreliable, with many >>>> step-resets to the clock. >>>> >>> Hmm, I just had glance at the code inšsys/amd64/vmm/io/vhpet.c and it >>> looks right. šI wonder if this is just a simple roundoff error in >>> converting between 10.0MHz and SBT units? šIf so, that could be wished >>> away easily by using a power-of-2 frequency for the virtual HPET. šI >>> wonder if the attached patch is all that's needed? >> I've tried the patch (at bhyve guest) and nothing has changed. Should >> the patched system be tested at bhyve guest or bhyve host? >> > > Oh, I'm sorry, I should have mentioned that's for the host side. NP, that's OK. However, the host is busy now, and I'll have an opportunity to test host only tomorrow evening. Ian, thank you for your help! -- WBR, bsam