12.1 bug: app on external monitor suddenly uses 100% CPU

[Kafka]

12.1 introduced an issue on my system:

I'm using a 14" MBP with 2 external 4k monitors. One them is on default scaling, the other is on the scale setting just "above" default, so what is on the screen is smaller. This screen's only use is the Tradingview charting app, fullscreen.

Everything was perfect up to now but since 12.1, Tradingview occasionally becomes extremely slow and choppy. When this happens, Activity Monitor shows Tradingview is intermitently using more than 100% CPU. 110%, back to normal. 120%, back to normal. Etc.
The only way to get things back to normal is to go to system settings, set the monitor scaling back to default and then back to my prefered setting. Then I'm ok for a few hours.

I updated fast because I hoped the tap to click issue would be fixed but it's not, and now I have this new issue...

 

[cfm56d7b]

Is WindowsServer process also consuming more CPU cycles than normal?

 

[Kafka]

Is WindowsServer process also consuming more CPU cycles than normal?

It's constantly up in the list, in the top 5 or top 3, but I never paid attention to it before so I don't know if that's normal. Actually it's almost always at 20% CPU usage minimum (40% right now), this doesn't look right.

 

[cfm56d7b]

This is an excellent explanation of what WindowServer does: https://www.howtogeek.com/312755/what-is-the-process-windowserver-and-why-is-it-running-on-my-mac/

In short - WindowServer will be doing more work with more open windows and additional monitors. The question is what CPU consumption happens to be reasonable. There isn't any guidance from Apple.

 

[Kafka]

Thanks for the link this is interesting. But I don't mind WindowServer being at 20%, what's annying me is Tradingview going to 100%+ untill I reset the scalling setting of the monitor it's showing on... Both could be linked.
I didn't have a problem on 12.0.1...

 

[cfm56d7b]

M1 has 3 types of CPU cores: performance cores, efficiency cores, and GPU cores.

Humbly speaking, this is most likely a case of MacOS software lagging the hardware capabilities. Ideally, more work performed by WindowServer would be shifted to GPU cores but this may not be yet implemented.

 

[Kafka]

Ok it's happening again right now: Tradingview shoots up to 80% then to 110% etc, laggy as hell, but WindowServer is just like usual, around 15-20%.