lkml.org 
[lkml]   [2010]   [Jul]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [patch 134/149] x86, paravirt: Add a global synchronization point for pvclock
On Wed, Jul 07, 2010 at 10:05:36PM +0200, Peter Palfrader wrote:
> On Wed, 07 Jul 2010, Gleb Natapov wrote:
>
> > On Wed, Jul 07, 2010 at 04:33:39PM +0200, Peter Palfrader wrote:
> > > On Wed, 07 Jul 2010, Glauber Costa wrote:
> > >
> > > > > 2.6.32.16 fails to boot on my KVM domains using qemu-kvm 0.11.1.
> > > > >
> > > > > Bisecting between 2.6.32.14 which worked and .16 turned up this commit
> > > > > as the first culprit[0].
> > > > >
> > > > > The host is still running 2.6.32.14 and has 8 cores on 2 CPUs. The
> > > > > single-cpu KVM domain hangs just after printing 'Write protecting the
> > > > > kernel read-only data: 9492k'[1]. On a successful boot this line would
> > > > > usually be followed by 'INIT: version 2.86 booting'.
> > > > >
> > > > > A 2.6.32.16 with this patch reverted boots fine.
> > > > >
> > > > > If there's any info you need please just ask.
> > >
> > > > if you boot with another clocksource, and then switch to kvmclock with the machine already
> > > > running, do you see anything strange or suspicious?
> > >
> > > Booting with various clocksource=xxx kernel parameters does not change
> > > the behaviour at all, i.e. the boot still hangs.
> > >
> > And what if you provide -cpu qemu64,-kvmclock to qemu command line?
>
> Adding that to the glob of options that already were there from libvirt
> didn't disable it, but using an LD_PRELOAD wrapper[1] to that purpose on
> the host when starting kvm did help.
>
Strange. -kvmclock should have had the same effect. What qemu is it?
What is your command line?

> Now, with kvmclock no longer being available at all the system picks tsc
> and indeed boots 2.6.32.16 successfully.
>
> - Peter
> 1. http://people.debian.org/~paravoid/kvm-noclock-3.tar.gz
> --
> | .''`. ** Debian GNU/Linux **
> Peter Palfrader | : :' : The universal
> http://www.palfrader.org/ | `. `' Operating System
> | `- http://www.debian.org/

--
Gleb.


\
 
 \ /
  Last update: 2010-07-08 07:33    [W:0.377 / U:0.208 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site