[OE-core] Fix for the APIC hangs in qemux86-64

[Bruce Ashfield]

On 12/13/2017 09:05 AM, Richard Purdie wrote:
> On Wed, 2017-12-13 at 08:38 -0500, Bruce Ashfield wrote:
>> On 12/13/2017 07:34 AM, Richard Purdie wrote:
>>>
>>> Hi Bruce,
>>>
>>> https://bugzilla.yoctoproject.org/show_bug.cgi?id=12301
>>>
>>> We've root caused the hangs we're seeing in qemux86-64 on our
>>> autobuilder workers. We've identified a commit on 4.15-rc3 which
>>> fixes
>>> the issue but backporting it to the autobuilder's host kernels will
>>> be
>>> a pain.
>>>
>>> As a workaround I'd like to enable x2apic on qemux86-64. Since that
>>> works via MSRs it avoids the problem.
>>>
>>> Would it be a big issue to set CONFIG_X86_X2APIC=y for qemux86-64?
>> Nope. No big deal at all. I've used the same config i the past
>> when doing work with rt-KVM, so I know it well.
>>
>> I'll prep a commit, and send it along as part of a rebased set
>> of kernel patches.
> 
> Thanks, much appreciated.
> 
> Did we get to the bottom of the 4.12 selftest failures?
> 

Not yet no. I was distracted for a day, but need to learn how
to run them myself. I was able to log in via serial in my normal
boot flow, so that didn't get me anywhere.

Is the selftest HOWO in the yocto docs ? I'll google it up this
morning.

> We may also need to backport the defconfig change back to the older
> releases so we don't get the hangs in those builds either...

Not a problem either. I'll prepare several.

Bruce

> 
> Cheers,
> 
> Richard
>