Re: [patch 134/149] x86, paravirt: Add a global synchronization point for pvclock

Gleb Natapov
2010-07-07T15:17:21Z

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?

--
Gleb.