Re: WARNING at switch_mm_irqs_off, followed by frozen machine

[Ilkka Prusi]

Hi,

On 18.6.2020 13.21, Peter Zijlstra wrote:
> On Wed, Jun 17, 2020 at 02:32:39AM +0300, Ilkka Prusi wrote:
> > Hi,
> >
> > Yesterday my computer with kernel version 5.7.2 was frozen badly enough that
> > hard reset was necessary (did not react to SysRq keys). Upon checking logs I
> > found following warning and information from the time just before resetting
> > it.
> >
> > Computer has AMD Ryzen 7 2700, Asus B450 motherboard.
> >
> > 5.8-rc1 encountered BUG() and did not boot (iommu and smp_processor_id()
> > called from wrong context, I'll see if I can catch log somehow).
> Since you're building your own kernels, can you make sure to always
> have:
>
>   - CONFIG_DEBUG_BUGVERBOSE=y
>   - CONFIG_DEBUG_INFO=y
>
> and then when reporting, run the thing through:
>
>    ./scripts/decode_stacktrace.sh

Ok, thanks for letting me know, I'll try that.


> And then pattern match that against my local defconfig build of
> arch/x86/mm/tlb.o and pray my compiler did anyting like your
> (unspecified) compiler.

Forgot to mention that, currently it is:

gcc (Debian 9.3.0-13) 9.3.0

I'll try your suggestions, sorry for not replying sooner.

--

Â- Ilkka Prusi