Processes stuck in *unp_m after recent uipc changes

[John Baldwin]

On Tuesday 27 February 2007 04:05, Robert Watson wrote:
> On Tue, 27 Feb 2007, Robert Watson wrote:
> 
> > On Tue, 27 Feb 2007, Jiawei Ye wrote:
> >
> >> With the latest uipc locking changes, I experienced a hard lockup on my 
> >> -current machine. Many processes got stuck in *unp_m state and 
> >> ctrl-alt-delete at the console cannot properly restart the machine and I 
> >> had to hard-reset (no coredump available). Is there anyway to diagnose 
> >> this?
> >
> > Please configure WITNESS, DDB, and BREAK_TO_DEBUGGER on a box with a 
serial 
> > console.  Then attach the output of "ps", "show alllocks", and "alltrace" 
to 
> > an e-mail.  With any luck, this is a leaked lock in some missed error case 
> > and we can just add a missing unlock.  Thanks!
> 
> Obviously, INVARIANTS also good on general principle. :-)
> 
> See the handbook chapter on debugging, and in particular live DDB debugging, 
> if you're running into any problems.

'show allchains' also considered helpful as it will reveal any deadlocks.

-- 
John Baldwin