System lockup with recent pull from Bruce's git tree

[Trond Myklebust]

On Tue, 2006-10-31 at 20:49 +0100, Christophe Saout wrote:
> Hello,
> 
> here is some more useful information about my NFS client deadlock.
> 
> I just noticed that RPC and NFS debugging could be turned on (hah). When
> turning rpc_debug one the list of RPC tasks is spit out, which is quite
> large:
> 
> Oct 31 20:13:45 tuek -pid- proc flgs status -client- -prog- --rqstp- -timeout        -rpcwait -action-        ---ops--
> Oct 31 20:13:45 tuek 16141 0001 0481 000000 ffff88003ef13000 100003 ffff88003dbda4a0 00000000     none        ffffffff804dbb60 ffffffff80501d10
> Oct 31 20:13:45 tuek 16149 -001 0481 000000 ffff88003ef13000 100003                0 00000000 Seqid_waitqueue ffffffff804e0190 ffffffff80501d10

That looks like an rpciod bug. The first line there indicates a task
which is neither running nor sleeping on a wait queue. I've seen that
come up more often when I tried removing the BKL, but it appears that it
can happen on a standard kernel too.

I'm investigating...

Cheers,
  Trond