> > > [...] But on the Athlon the IPI isnt going down a little side channel
> > > between cpus.
> >
> > but even in the Athlon case an IPI is still an IRQ entry, which will add
> > at least 200 cycles or more to the idle wakeup latency.
>
> It is an idle cpu that is spending those 200 cycles.
wrong. When it's woken up it's *not* an idle CPU anymore, and it's the
freshly woken up task that is going to execute 200 cycles later...
Ingo
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