[issue1679] Machine unresponsive with cache_lock: blocked on... message

[Francois Tigeot]

On Tue, Mar 23, 2010 at 11:34:16PM +0000, Matthew Dillon (via DragonFly issue tracker) wrote:
> 
> Matthew Dillon <dillon at apollo.backplane.com> added the comment:
> 
> :I also had a new deadlock this night (possibly during the daily periodic run).
> :Symptoms were the same as usual: no keyboard input, no network activity, many
> :pmap_interlock messages on the console...
> :
> :The new crash dump is there: http://www.wolfpond.org/crash.dfly/
> :
> :-- 
> :Francois Tigeot
> 
>     It's STILL the rebalancing code.  This time it deadlocked waiting for
>     the VM system to free up memory while holding shared locks on a
>     HAMMER cursor.

I just got another deadlock today.

It was a bit better compared to the previous ones: the ssh connection I had
in a xterm was still available; screen(1) was running and it was possible
to change virtual terminals with Ctrl-n.
All other inputs were not taken into account.

The console had a bunch of the customary
  "Debug: pmap_interlock 00010003"
messages. The last 4 lines were
  "bio_page_alloc: WARNING emergency page allocation"

-- 
Francois Tigeot