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SubjectRe: GRR!! SMP=1 sucks
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> >SMP=1 isnt safe on some boxes.
> Please tell me more about this.

It looks for the APIC and it may not exist. I don't know any box that
poking around for an invisible APIC crashes _but_...

> >SMP=1 is upto 10% slower for single CPU
> >on real tasks and 40% slower on certain FPU/sleep/FPU/sleep patterns
>
> Is this situation permanent or just a matter of some tuning
> needing to be done (e.g, the granularity of some locks needing to be
> adjusted)? I would hope, for example, that spin locks to do not
> actually "spin" if there is only one CPU.

Permanent. The FPU lazy restore doesnt work SMP

Alan

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