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

[Jan Beulich <jbeulich@xxxxxxxx>]

On 15.10.2020 02:38, Dylanger Daly wrote:
> I'm currently using Xen 4.14 (Qubes 4.1 OS) on a Ryzen 7 4750U PRO, by 
> default I'll experience softlocks where the mouse for example will jolt from 
> time to time, in this state it's not usable.

>From what you say below I imply this is in Dom0?

> Adding `dom0_max_vcpus=1 dom0_vcpus_pin` to Xen's CMDLINE results in no more 
> jolting however performance isn't what it should be on an 8 core CPU, 
> softlocks are still a problem within domU's, any sort of UI animation for 
> example.
> 
> Reverting [this commit 
> (8e2aa76dc1670e82eaa15683353853bc66bf54fc)](https://github.com/xen-project/xen/commit/8e2aa76dc1670e82eaa15683353853bc66bf54fc)
>  results in even worse performance with or without the above changes to 
> CMDLINE, and it's not usable at all.

You saying this surely has a reason, but making the connection would
help. I don't consider it surprising that a revert of an improvement
makes things worse. You having bothered to find a certain code change
also makes me suspect you've experimented with other scheduler
related settings - if so, please share all data you've got. (FAOD -
with the information provided I have no idea what to suggest, sorry.)

Jan