Ouch! uvm panic in -current!

[Paul Goyette <paul%whooppee.com@localhost>]

I was just rebuild some packages (it was working on boost-libs), and my 
machine crashed hard!  It dropped into ddb, and the keyboard was active, 
for a single keystroke, after which it was unresponsive.

I did get a traceback, transcribed manually:

panic: kernel diagnostic assertion "uvmexp.swpgonly + npages <= 
uvmexp.swpginuse" failed: file ".../uvm_pager.c", line 472
cpu0: begin traceback...
vpanic() + 0x140
cd_play_msf()
uvm_aio_aiodone_pages + 0x541
uvm_aio_aiodone + 0x8a
workqueue_worker + 0xbc

I'm a bit concerned about the mention of cd_play_msf since I hadn't 
touched my cd drive (at least not explicitly) since previous boot.

This is with a 7.99.29 kernel built from sources that were updated on 
2016-05-02 at 22:46:42 UTC.

Does anyone have a clue?


+------------------+--------------------------+------------------------+
| Paul Goyette     | PGP Key fingerprint:     | E-mail addresses:      |
| (Retired)        | FA29 0E3B 35AF E8AE 6651 | paul at whooppee.com   |
| Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd.org |
+------------------+--------------------------+------------------------+