Help diagnose my Ryzen build problem

[Meowthink]

Hi peeter,

On 8/27/18, karu.pruun <karu.pruun at gmail.com> wrote:
> On Mon, Aug 27, 2018 at 3:21 PM Meowthink <meowthink at gmail.com> wrote:
>> That's kib, who has committed things in that script to both 12 [1] and
>> stable/11 [2].
>>
>> Unfortunately, that's for Ryzens family 17h model 00h-0fh, whereas my
>> Ryzen 5 2400G's model is 11h.
>>
>> On the microcode. It shall be updated through UEFI/BIOS updates. I
>> think mine is now PinnaclePI-AM4_1.0.0.4 with microcode patchlevel
>> 0x810100b.
>>
>> Seems like ... the only thing I can do is sit down and wait?
>
> The revision
>
> https://svnweb.freebsd.org/base/head/sys/x86/x86/cpu_machdep.c?r1=336763&r2=336762&pathrev=336763
>
> works around the mwait issue, i.e. it sets
>
> sysctl machdep.idle_mwait=0
> sysctl machdep.idle=hlt
>

I think that shall not apply to 2400G, which is model 11h not 1h.
Here're what I have now:

machdep.idle: acpi
machdep.idle_available: spin, mwait, hlt, acpi
machdep.idle_apl31: 0
machdep.idle_mwait: 1

> Now it may or may not relate to your problem, but it appears that
> Ryzen 2400G also has another issue with HLT, see the DragonFly bug
> report
>
> https://bugs.dragonflybsd.org/issues/3131
>

Thanks a lot for that info.
It's much easier to prove your problem, since it's reproducible. But
mine was so random to catch...
Anyway, it seems like the IRET issue [1] is still not fixed? I'm
highly doubt that my issue is this related because my system became
significantly more stable since I stop that irq storm from bluetooth
module - Though it still panics occasionally.
So could anybody tell, what's the difference between FreeBSD
workaround [2] and the DragonflyBSD one?

> which AMD is aware of and is possibly working on, but it may not have
> appeared in the errata yet. The bug report says that until this is
> fixed, the workaround is to also disable HLT in cpu_idle. I am not
> sure what is the correct value for the sysctl on FreeBSD, perhaps
>
> sysctl machdep.idle=0
>
> or some other value?

In the meantime, I have this microcode

# cpucontrol -m 0x8b /dev/cpuctl0
MSR 0x8b: 0x00000000 0x0810100b

Hence I should use mwait?
Still don't know what should I set. Any idea?

>
> Cheers
>
> Peeter
>
> --
>

Thank you for your direction.

Cheers,
meowthink

[1] http://lists.dragonflybsd.org/pipermail/commits/2017-August/626190.html
[2] https://reviews.freebsd.org/D11780