Re: Strange issue after early AP startup

On Tuesday, January 17, 2017 05:08:58 PM Cy Schubert wrote:
> In message <1492450.XZfNz8zFfg_at_ralph.baldwin.cx>, John Baldwin writes:
> > On Tuesday, January 17, 2017 12:53:19 PM Cy Schubert wrote:
> > > In message <b9c53237-4b1a-a140-f692-bf5837060b18_at_selasky.org>, Hans Petter 
> > > Sela
> > > sky writes:
> > > > Hi,
> > > > 
> > > > When booting I observe an additional 30-second delay after this print:
> > > > 
> > > > > Timecounters tick every 1.000 msec
> > > > 
> > > > ~30 second delay and boot continues like normal.
> > > > 
> > > > Checking "vmstat -i" reveals that some timers have been running loose.
> > > > 
> > > > > cpu0:timer                         44300        442
> > > > > cpu1:timer                         40561        404
> > > > > cpu3:timer                      48462822     483058
> > > > > cpu2:timer                      48477898     483209
> > > > 
> > > > Trying to add delays and/or prints around the Timecounters printout 
> > > > makes the issue go away. Any ideas for debugging?
> > > > 
> > > > Looks like a startup race to me.
> > > 
> > > just picking a random email to reply to, I'm seeing a different issue with 
> > > early AP startup. It affects one of my four machines, my laptop. My three 
> > > server systems downstairs have no problem however my laptop will reboot 
> > > repeatedly at:
> > > 
> > > Jan 17 11:55:16 slippy kernel: cd0: Attempt to query device size failed: 
> > > NOT READY, Medium not present - tray closed
> > 
> > So it panics and reboots after this?
> 
> Yes, it goes into a panic/reboot loop for a few iterations until it 
> successfully boots. Disabling early AP startup allows it to boot up without 
> the assumed race.

Can you add DDB to the kernel config (and remove DDB_UNATTENDED) to get it
to break into DDB when it panics to get the panic message (and a stack trace
as well)?

-- 
John Baldwin