PIT vs. APIC Timer

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jal
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Post by jal »

z180 wrote:a lot of os cant change the internal timing frequency
That's not the point, is it? For all you know the SMM does it. That would seriously screw up your APIC timing.


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AJ
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Post by AJ »

bewing wrote:It sounds, then, like there has to be a method for a Mobo driver to broadcast to the rest of the system when there is an FSB speed change -- so the rest of the system knows to recalibrate timing.
I guess one way to do this would be to have your scheduler having a function like scheduler.SetFrequency(hz). Assuming a modular monolithic kernel (like mine), this scheduler function would obviously need to make a call to your architecture-dependent code to set the APIC frequency appropriately, based on the current ACPI driver data.

Cheers,
Adam
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