Re: ULE realtime scheduler advice needed

On 11/22/22 20:28, mike tancsa wrote:
> 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 ?
> 

Yes, I have four of those, set to 50 by default. Let me try.

--HPS