Processes stuck in *unp_m after recent uipc changes

[Robert Watson]

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!

Robert N M Watson
Computer Laboratory
University of Cambridge