Re: [RFC PATCH v4 05/21] x86/hpet: Reserve timer for the HPET hardlockup detector

From: Thomas Gleixner
Date: Tue Jun 11 2019 - 15:59:16 EST

On Thu, 23 May 2019, Ricardo Neri wrote:

> HPET timer 2 will be used to drive the HPET-based hardlockup detector.
> Reserve such timer to ensure it cannot be used by user space programs or
> for clock events.
> When looking for MSI-capable timers for clock events, skip timer 2 if
> the HPET hardlockup detector is selected.

Why? Both the changelog and the code change lack an explanation why this
timer is actually touched after it got reserved for the platform. The
reservation should make it inaccessible for other things.