Re: ULE realtime scheduler advice needed

On 11/17/2022 11:47 PM, Hans Petter Selasky wrote:
> Hi,
>
> I'm doing some work with audio and have noticed some problems with the 
> ULE scheduler. I have a program that generate audio based on 
> key-presses. When no keys are pressed, the load is near 0%, but as 
> soon as you start pressing keys, the load goes maybe to 80% of a CPU 
> core. This program I run with rtprio 8 xxx. The issue I observe or 
> hear actually, is that it takes too long until the scheduler grasps 
> that this program needs it's own CPU core and stops time-sharing the 
> program. When I however use cpuset -l xxx rtprio 8 yyy everything is 
> good, and the program outputs realtime audio in-time.
>
> Or is this perhaps a CPU frequency stepping issue?
>
> Any advice on where to look?
>
A long shot, but I am curious if by chance you have hwpstate_intel for 
your cpu frequency driver. If so, does setting 
dev.hwpstate_intel.0.epp=0 make any difference ?

     ---Mike