Re: [PATCH v3] xen: Fix x86 sched_clock() interface for xen

From: Thomas Gleixner
Date: Tue Jan 15 2019 - 05:44:17 EST


On Mon, 14 Jan 2019, Juergen Gross wrote:

> Commit f94c8d11699759 ("sched/clock, x86/tsc: Rework the x86 'unstable'
> sched_clock() interface") broke Xen guest time handling across
> migration:
>
> [ 187.249951] Freezing user space processes ... (elapsed 0.001 seconds) done.
> [ 187.251137] OOM killer disabled.
> [ 187.251137] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
> [ 187.252299] suspending xenstore...
> [ 187.266987] xen:grant_table: Grant tables using version 1 layout
> [18446743811.706476] OOM killer enabled.
> [18446743811.706478] Restarting tasks ... done.
> [18446743811.720505] Setting capacity to 16777216

I see that it's broken, but the changelog could do with an explanation WHY
it broke.

Other than that this looks about right.

Thanks,

tglx