Re: 2.6.37 dom0 under Xen 4.1 clocksource not working

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Mon, Jan 10, 2011 at 10:06:19AM -0500, Daniel De Graaf wrote:
> When booting 2.6.37 (from kernel.org) under Xen 4.1, there are
> apparently issues with timer interrupts being delivered to the dom0.
> Repeatedly causing an interrupt (for example, the ACPI power button) will
> allow the system to boot, as does adding "clocksource=jiffies" to the
> kernel command line. This is only present under Xen, not when booting the
> same kernel on real hardware.
> 
> When boot with clocksource=jiffies, the system will sometimes freeze
> for about 30 seconds and then continue; however, this could be related
> to kernel debugging that I have enabled.
> 
> The only clock-related message in dmesg is:
> [  153.483813] Clocksource tsc unstable (delta = -77312555973 ns)

I see it too.
> 
> /sys/devices/system/clocksource/clocksource0/available_clocksource:
>   xen jiffies tsc
> 
> I can attach kernel config or other information as required. I have
> observed this on at least two platforms; the 2.6.32.x xen kernels do not
> exhibit this behavior.

I think we are just missing some of the Xen time code that is in 2.6.32
but has not been ported over to 2.6.37. I don't remember the name of the
patches thought..