Re: [tip:x86/urgent] x86, apic: Map the local apic when parsing the MP table.

Eric W. Biederman
2010-08-07T02:49:15Z

Yinghai Lu <yinghai@kernel.org> writes:

> On 08/06/2010 06:21 PM, H. Peter Anvin wrote:
>> On 08/06/2010 06:08 PM, Eric W. Biederman wrote:
>>>>
>>>> I'm not sure the above is decipherable. Please provide an incremental
>>>> patch with a more detailed description.
>>>
>>> YH was saying I overoptimized, and it looks like he is right,
>>> although there are only one or two machines in existence that
>>> are likely to be affected.
>>>
>>> Untested patch to remove the cleverness below. It it boots all
>>> is well.
>>>
>>
>> This makes sense to me. Yinghai, do you have a system that is actually
>> affected, and if so, could you test this patch?
>
> no, i don't have those kind of system.

I don't know if anyone does. It looks like sfi aka moorestown
and visws are what are affected.

That is why I made a patch that any boot where we exercise a local
apic will exercise.

Arguably if it is best to just remove that hunk from my patch, so
we have something that is safe to backport to 2.6.35.1.

> found it when i was preparing more smp_register_lapic_address patcheset.
>
> I suggest we still keep !acpi_lapic checking, that should always right.

Ultimately we want to remove the code duplication entirely.

Eric