Mark Hahn wrote:
>
> > As I mentioned before, MPS specs actually call for the support of
> > different TSC's.
>
> oh? B8 of the v1.4 MPS spec is the only thing I see adressing
> this, and it says "Operating system writers should factor in processor
> variations, such as processor type, family, model and features, to arrive at
> a configuration that maximizes overall system performance. At a minimum, the
> MO OS should remain operational and should support the common features of
> unequal processors."
>
> doesn't address mixed clocks. and if "call for" means "suggest",
> sure, it suggests that misconfigured machines shoudl be functional
> to some level.
And where did you find the word misconfigured in the quote?
Look at E2. "Bit 6 of MP feature information byte 2, the Multiple Clock
Source bit, is used by operating system to determine how processors
derive clock sources. If the system does not provide for a single clock
source shared by all processors then this bit is set." How on earth can
you expect to have syncronized TSC's, if the clocks are coming from
diffrent sources?
In any case, blindly assuming that TSC's are the same is as bad as
assuming that TSC is present at all, and it's not any harder to check,
so if your application works on 80386 it can work as well with different
TSC's. Frankly,
I don't see your point.
Boris
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This archive was generated by hypermail 2b29 : Fri Mar 31 2000 - 21:00:24 EST