[issue713] shutdown freeze and forced unmounts

[Chris Turner]

Matthew Dillon wrote:
> :Am I the only one that is not able to 'reboot' their machine?
> 
>     I think so :-).
> 

I got this once or twice somewhere along the lines,
but not reproducibly so, so I've been silent.

do get the occasional:

unmount(0xd9f157c0): Forced unmount: 0 namecache references still present

kinds of things however, but overall, reboot / shutdown tends to work.

affected systems (as I recall) are mostly 'bare',
but do use lots of "nfs -o tcp" mounts via amd..

perhaps this might interact with the sockets you were mentioning ?

(in the netisr.c diff grok attempt, lacking my ip-stack-foo was)