Re: tstile lockup

[Edgar Fuß <ef%math.uni-bonn.de@localhost>]

On Wed, Oct 31, 2012 at 05:42:12PM +0100, Edgar Fuß wrote:
> > Invoke crash(8), then just perform "ps" and "t/a address" on each LWP
> > which seems to be stuck (on "tstile" or elsewhere).
> So it seems I can sort of lock up the machine for minutes with a simple
>       dd if=/dev/zero of=/dev/dk14 bs=64k count=1000
> (In case it matters, dk14 is on a RAID5 on 4+1 mpt(4) SAS discs)
> I get an impressive dd throughput of around 350kB/s
> 
> Here's the crash(8) output during one of the partial lock-ups:
[...]
> Does that help?
Apparently not.
What can I do to debug this?
The problem is that this "lock-up", artificial as the dd to the block device 
may seem, appears to happen "real-world" during an svn update command: the
other nfsd threads get stuck to the point where other clients get "nfs server 
not responding" messages.