Can I set CONFIG_TICKLESS_KERNEL config to each core?

[chojpsh1]

Hello, I have a question about CONFIG_TICKLESS_KERNEL.
I wonder if CONFIG_TICKLESS_KERNEL can be set differently for each core (Activate the config only for specific cores)
I'd appreciate if you could reply. Thanks!

[ndrs-pst]

It looks like you want TICKLESS on one core and non-TICKLESS on another.
-> Before discussing whether this is possible or not, I’m curious about the specific challenge you're looking to address. 😃

[chojpsh1]

I apologize for the late response. You are correct in what you have mentioned.
The product we are developing is a 4-core device with an ARM architecture timer that operates per core. As an example, we want to fix our self-developed watchdog function on Core 1 and make the remaining cores operate as TICKLESS_KERNEL except for Core 1.
I was curious if this would be possible.

[ndrs-pst]

Thank you for your clarification.
As far as I know, Zephyr has a global scheduler regardless of how many cores the CPU has.
This implies that you can only select between TICKLESS or non-TICKLESS, but not both.

Hence, the suggestion might look like this:

• CONFIG_TICKLESS_KERNEL=y
• Use Timer APIs to periodically trigger a specified thread that has been pinned to CORE1 via k_thread_cpu_pin.

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A resource worth looking at.

• https://docs.zephyrproject.org/3.7.0/kernel/services/scheduling/index.html
• https://docs.zephyrproject.org/3.7.0/kernel/services/smp/smp.html

[chojpsh1]

Thank you for your detailed explanation, it was really helpful. Have a great day!