Re: [PATCH] Disable SMP on the MacBook by default

[Marco Gerards <mgerards@xs4all.nl>]

Keir Fraser <Keir.Fraser@cl.cam.ac.uk> writes:

> On 13/9/06 23:11, "Marco Gerards" <mgerards@xs4all.nl> wrote:
>
>> The second core can not be initialized because the INIT IPI does not
>> arrive.  It only happens on the MacBook and not on the desktop Intel
>> Macs.  On the MacBook the second core is put into deep sleep mode.  It
>> should get out of sleep mode when an IPI or interrupt is received.
>> 
>> That does not happen.  It looks like the keyboard interrupt does
>> wakeup the second core, after which the IPI is received.
>
> Have you tried tickling the second core with some interrupt or NMI IPIs from
> the boot core? Sounds like a slightly harder kick is required.

Yes I did try NMI IPIs, that did not have any effect.  IIRC I tried
generating interrupts using the APIC, but I do not remember if I
succeed, but if I did it didn't fix the problem.

Is there any other way I can have a look at to easily generate an
interrupt without causing weird side effects?

> What about tracing what the Linux ACPI interpreter kicks out in terms of
> hardware accesses? Perhaps you can work out what the ACPI goop actually does
> in low-level terms, which could then perhaps be applied in a simpler form
> (than ACPI interpreting) to Xen?

How would that work?  To be honest I do not know much about ACPI and
what's possible with it.  A few pointers to get me started is highly
appreciated.

Thanks,
Marco