[OpenAFS] PAG garbage collection on linux

[Chaskiel Grundman]

>>
>> /proc/sys/afs/GCPAGS gets set to 8, which from my understanding means it
>> was unable to walk the process tree.
>
> I've had this problem for some time, and I don't know what causes it.  As
> near as I can tell, the process tree walk is not working properly with
> Debian kernels.  I get the same behavior with 1.4.7 on a 2.6.25 Debian
> kernel.
afs_osi_TraverseProcTable is a noop when working keyring support is 
detected. This is why GCPAGs ends up appearing to be disabled. When 
keyrings are used, pag garbage collection should not be needed, as pags 
should be discarded as soon as they are unreferenced (via the destroy 
callback on the afs key object) Clearly there is some problem though....