Ping: [PATCH v3 0/4] x86/time: calibration rendezvous adjustments

[Jan Beulich <jbeulich@xxxxxxxx>]

Ian?

On 09.02.2021 14:02, Jan Beulich wrote:
> On 09.02.2021 13:53, Jan Beulich wrote:
>> The middle two patches are meant to address a regression reported on
>> the list under "Problems with APIC on versions 4.9 and later (4.8
>> works)". In the course of analyzing output from a debugging patch I
>> ran into another anomaly again, which I thought I should finally try
>> to address. Hence patch 1. Patch 4 is new in v3 and RFC for now.
> 
> Of course this is the kind of change I'd prefer doing early in a
> release cycle. I don't think there are severe risks from patch 1, but
> I'm not going to claim patches 2 and 3 are risk free. They fix booting
> Xen on a system left in rather awkward state by the firmware. And
> they shouldn't affect well behaved modern systems at all (due to
> those using a different rendezvous function). While we've been having
> this issue for years, I also consider this set a backporting
> candidate. Hence I can see reasons pro and con inclusion in 4.15.
> 
> Jan
> 
>> 1: change initiation of the calibration timer
>> 2: adjust time recording time_calibration_tsc_rendezvous()
>> 3: don't move TSC backwards in time_calibration_tsc_rendezvous()
>> 4: re-arrange struct calibration_rendezvous
>>
>> Jan
>>
>