Re: [PATCH v6 04/12] x86/smpboot.c: Don't offline CPU0 if any irqcan not be migrated out of it and remove CPU0 check in smp_callin()

From: H. Peter Anvin
Date: Thu May 17 2012 - 23:34:56 EST


On 05/17/2012 06:47 PM, Yu, Fenghua wrote:
>
> Then booting up AP via INIT and putting AP online back via NMI/mwait
> will have different wakeup method and code. We probably need a way to
> tell if it is first AP bringup or online AP/BSP during run time.
>
> And if offlined CPU is not in mwait (e.g. CPU without mwait feature),
> mwait based bringup won't work. Do we need to fall back to NMI wakeup
> if offlined CPU is not in mwait?
>

I guess we need NMI (or just re-SIPI) in that case, since we're spinning
in CLI; HLT...

-hpa


--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.

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