Help diagnose my Ryzen build problem

[karu.pruun]

On Mon, Aug 27, 2018 at 6:07 PM Meowthink <meowthink at gmail.com> wrote:

> >> 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?


If I was you, I'd play around with the sysctls mentioned above and see
if it helps. Start with disabling both mwait and hlt, perhaps

machdep.idle=spin
machdep.idle_mwait=0

(assuming that 'spin' means hlt will not used) and then if that does
not lead to a panic, try enabling mwait. I can't test 2400G since I
don't have it any more. I booted FreeBSD a couple of times but did not
run it over long periods of time.

Cheers

Peeter

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