From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [Qemu-devel] TSC in qem[-kvm] 1.1+ and in-kernel irqchip Date: Mon, 13 Aug 2012 15:41:28 +0200 Message-ID: <50290408.8020404@siemens.com> References: <5024011F.2020200@msgid.tls.msk.ru> <20120810073346.GD24410@redhat.com> <5024D336.5090108@msgid.tls.msk.ru> <20120812081038.GJ3341@redhat.com> <50277631.2080808@msgid.tls.msk.ru> <5028FC02.4090205@siemens.com> <5028FE26.9090504@msgid.tls.msk.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Avi Kivity , Gerd Hoffmann , KVM list , Gleb Natapov , qemu-devel To: Michael Tokarev Return-path: Received: from thoth.sbs.de ([192.35.17.2]:15120 "EHLO thoth.sbs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750963Ab2HMNlg (ORCPT ); Mon, 13 Aug 2012 09:41:36 -0400 In-Reply-To: <5028FE26.9090504@msgid.tls.msk.ru> Sender: kvm-owner@vger.kernel.org List-ID: On 2012-08-13 15:16, Michael Tokarev wrote: > On 13.08.2012 17:07, Jan Kiszka wrote: > [] >>> The bisecion leads to this commit: >>> >>> commit 17ee47418e65b1593defb30edbab33ccd47fc1f8 >>> Merge: 13b0496 5d17c0d >>> Author: Jan Kiszka >>> Date: Tue Apr 10 16:26:23 2012 +0200 >>> >>> Merge commit '5d17c0d2df4998598e6002b27b8e47e792899a0f' into queues/qemu-merge > [] >>> Cc'ing Jan for help. The short story: tsc timer calibration >>> broke in 1.1+ with in-kernel irqchip (only) for several >>> apps (seabios and grub are two examples), the time is ticking >>> about 100 times faster. In grub the timer is calibrated >>> using pit. The above commit is the result of bisection. >> >> Did the versions you tested include the commit 0cdd3d1444 (kvm: i8254: >> Fix conversion of in-kernel to userspace state)? > > While bisecting I didn't have this commit applied, since it were > applied past (qemu)-1.1. It is included into qemu-kvm 1.1.0 > (as 960d355dc60d9), and that version behaves _exactly_ the same - > the time in grub is ticking 100 times faster. I mentioned in this > thread that the problem persists in current qemu (and qemu-kvm) > git too. > > I can repeat the bisection with this commit applied after the > above "bad" commit. Should I? Don't think this will make a difference. There is some other issue. I reproduced the bug, will see if I can analyze it. Jan -- Siemens AG, Corporate Technology, CT RTC ITP SDP-DE Corporate Competence Center Embedded Linux