Re: U2 panic: "!cpu_intr_p()" failed

[David Brownlee <abs%absd.org@localhost>]

On Fri, 28 Jun 2019 at 22:30, Julian Coleman <jdc%coris.org.uk@localhost> wrote:
>
> Hi Martin,
>
> > I'll try and add some debugging around this and see what I can spot.
>
> So, with some debugging in xc__highpri_intr(), I can see that ci_idepth is
> 1 just before we crash (not unexpectedly).  So, I added more debugging.
> With the appended diff, I don't see the crash.  Guessing that something
> with the extra time spend in xc_highpri() is changing the timing.  With
> the commented out part, I saw:
>
> [   1.2900220] xc_highpri: cur_cpu = 1, ci = 1717792621
>
> and later:
>
> [   2.4700180] cpu0: data fault: pc=13fadb4 rpc=178901bc8 addr=0
> [   2.4700180] kernel trap 30: data access exception

Might it make sense to try stashing some debugging information in
memory where you could get it from DDB instead of printing? (ISTR some
ringbuffer used for this type of purpose somewhere else)

(Just another random suggestion from someone not having to do any of the work :)

David