Oh yes, with the old NUMAQ hardware here, one can mix nodes of different
speed cpus. Once I get a chance, I'm going to begin working on this
issue for 2.5. My plan right now is to keep per-cpu last_tsc_low and
fast_gettimeoffset_quotient values, then round robin the timer
interrupt.
> Needless to say tsc does not work well on such boxes. Thats why I don't
> trust the tsc at all in such cases. Since you'll have the nice cyclone
> timer for the Summit it seems best not to trust it, and on the summit to
> use the cyclone for udelay as well ?
>
> I agree dodgy_tsc needs to change name. Perhaps we actually want
>
> int tsc = select_tsc();
>
> switch(tsc)
> {
> case TSC_CYCLONE:
> case TSC_PROCESSOR:
> case TSC_NONE:
> ..
> }
Sounds good. I'll re-work my patch and resubmit.
thanks!
-john
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