RTC vs PIT for scheduler

operating-system, osdev

Solution

I personally would use the PIT (if you can Only choose between these two, modern OSes use the HPET iirc)

One, it can generate interrupts at a faster frequency (although I question if preempting a process within milliseconds is beneficial)

two, it has a higher priority on the PIC chip, which means it can't be interrupted by other IRQs.

Personally I use the PIT for the scheduler and the RTC timer for wall clock time keeping.

Problem

My professor said that it is recommended to use the PIT instead of the RTC to implement a epoch based round robin scheduler. He didn't really mention any concrete reasons and I can't think of any either. Any thoughts?

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