6.2 sporadically locks up

[John Baldwin]

On Tuesday 16 June 2009 11:03:34 am pluknet wrote:
> 2009/6/16 John Baldwin <jhb at freebsd.org>:
> As for allpcpu, I often see the picture, when one CPU runs the "irq17:
> bce1 aacu0" thread
> and another one runs arcconf. I wonder if that might be a source of
> bad locking or races, or..
> The arcconf utility uses ioctl that goes into aac/aacu(4) internals.

I wondered about that.  I would ask emaste@ as he has worked with arcconf.  I
do think he has mentioned problems with arcconf locking up aac(4) controllers
in the past.

> > Perhaps DDB in 6.2 doesn't know to
> > look in stoppcbs[].  Hmm, looks like 6.2 only does that if you are using
> > KDB_STOP_NMI.  Are you using that kernel option?  If not, you probably want
> > to.
> 
> No, I'm not. Will that add an additional visible overhead on a running system?

No, it actually allows the kernel to more reliably stop other CPUs during a
panic, etc.  It's enabled in GENERIC as 'STOP_NMI' in 7.0 and later.

-- 
John Baldwin