High kernel_task and WindowServer CPU Usage optimization

[lucas-www]

Do I need to optimize my macOS? Sometimes,kernel_task and WindowServer CPU Usage are much more higher than the screenshot below, thank you for your any suggestions.
Reference: https://apple.stackexchange.com/questions/363337/how-to-find-cause-of-high-kernel-task-cpu-usage

@tylernguyen @benbender

[velaar]

This is something we are investigating at the moment. Unsure as to the cause and we suspect that it is also causing the CPU to stay in C3 state instead of C7+

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[benbender]

Be careful as those description are far too general to be meaningful. Its dangerous to mix up things before they got pinned down as it might lead to false conclusions.

@lucas-www any more specific details? Atm you are saying basically: "sometimes my laptop does work under unspecified conditions"?

@velaar I didn't see constant cpu-load above the usual on those pm-problems atm

[lucas-www]

@benbender I got it, It is more obvious when the laptop's temperature becomes higher.

[benbender]

Problem is simple: it can be anything from cloudd went crazy, spotlight-index-broken, TB-controller crashed until a faulty network-driver by apple for the unused 100mbit-ethernet-port in your usb-c-to-dp-dongle...

seen everything of the above ;)

[velaar]

@benbender the CPU load isn't usual but the Idle Wake-Ups are there. This is for my laptop that remained on overnight:

[tylernguyen]

@lucas-www

Does this issue only happens when you are charging the laptop? And if so, which port, or both?

As far as I've been looking, kernel_task is macOS's mean of throttling the CPU down. I have noticed the process on my system but never as high as 13.4%. Though my machine is re-pasted with after market paste, that would be the first suggestion for you since that should lower temperature of the machine.

In addition, check your machine's fan. See: https://www.reddit.com/r/thinkpad/comments/c7zpah/x1_carbon_6th_gen_horrible_cooling_fan_design/

EDIT: I'll add notes about this in 3_README-other.md

[velaar]

@tylernguyen
kernel_task manages all kernel interrupts. Including the TMR events, not only thermal. So unfortunately this is not the case. Apple documentation on the subject is misleading. I do have a Delta fan with LM repaste. CPU temp is 55C

WindowServer is probably iGPU related so I tried to play quite a bit with GuC loading (might help if works, but it doesn't work at the moment).

[tylernguyen]

Got it, thanks for the clarification.

WindowServer is probably iGPU related so I tried to play quite a bit with GuC loading (might help if works, but it doesn't work at the moment).

Unfortunately, I do not think GuC loading will ever work on our machine.

[benbender]

BTW, as this would really help with iGPU-PM, has anyone ever been successful loading apples' GuC (aka working igfxfw=2)?

[velaar]

@benbender
No. I have somewhat a vector to work on - ptresearch/IntelTXE-PoC#23 it might be possible to extract the ME certificate and re-sign Apple's GuC. acidanthera/bugtracker#586 and acidanthera/bugtracker#987 are also informative as to what is going on.

[tylernguyen]

I'll move loading GuC into a separate issue and mark it as help wanted.

[tylernguyen]

Linked to #106

Refer to that issue for discussion and solution.