panic: non-current pmap on RPI3 on CURRENT (GENERIC) #4 r356366

[bob prohaska]

On Sun, Jun 28, 2020 at 05:21:33PM -0700, Mark Millard wrote:
> On 2020-Jun-28, at 12:50, bob prohaska <fbsd at www.zefox.net> wrote:
> 
> > I'll  update OS sources and try again, if somebody can tell me
> > how to capture more useful information I'll try that.
> 
> Do you have your system set up to allow it to
> dump to the swap/paging space for panics and
> then to put a copy in the /var/crash/ area during
> the next boot? Konstantin B. was asking for
> information from such a dump.
> 
Ahh, that might be a little beyond my skill level....
The system is basically default -current, no kernel
options. In fact, I'm no longer sure where to put them
when using buildkernel.
 
> Note: A dump can be requested at the db> prompt
> by typing a "dump" command at the prompt, if you
> have set up to have a dump target identified,
> usually a swap/paging partition. If it works, the
> next boot would take some time putting material
> into /var/crash.
> 
I'll try next time it happens. Looks like the system
defaults turn on dumpdev and savecore.
 
> Do you have devel/gdb installed? It supplies a
> /usr/local/bin/kgdb for looking at such vmcore.*
> files.

Not yet.

> 
> It is important that the kernel debug information
> still match the vmcore as I understand, even if
> that means needing to boot a different,
> sufficiently-working kernel that does not match the
> debug information in order to get the /var/crash
> materials in place and to inspect them.
> 
> I'm not sure you could do as Konstantin requested
> based on a non-debug kernel build done the usual
> way, even with debug information present.
>
One step at a time..... 8-)
 
> Are you using a non-debug kernel? A debug-kernel?

The embarrasing truth is I don't know. Whatever is
default in -current for the Pi3.

> You might need to try reproducing with a debug
> kernel. (But that likely will make builds
> take longer.)
> 
Any sense of how much longer?  A chromium build, 
when it worked, took a week. 

Thanks for writing!

bob prohaska