Re: Ryzen 4000 (Mobile) Softlocks/Micro-stutters

[Jan Beulich <jbeulich@xxxxxxxx>]

On 15.10.2020 11:14, Dylanger Daly wrote:
> Indeed this is for dom0, I only recently tried limiting a domU to 1 core and 
> observed absolutely no softlocks, UI animations are smooth as butter with 1 
> core only.
> 
> Indeed I believe this is a CPU Scheduling issue, I've tried both the older 
> credit and RTDS however both don't boot correctly.

This wants reporting (with sufficient data, i.e. at least a serial log)
as separate issues.

> The number of cores on this CPU is 8, 16 threads however Qubes by default 
> disables SMT, sched_credit2_max_cpus_runqueue is 16 by default, I've tried 
> testing with setting this to 7 or 8 however it'll either not boot, or nothing 
> will change.

Failure to boot, unless with insane command line options, should always
be reported to it can be fixed.

I'm afraid neither part of the reply gets you/us any closer to an
understanding of your softlockup issues. As a random thought, have you
tried disabling use of (deep) C-states? This is known to have helped
to work around errata on other hardware, so may be worth a try.

Jan