[OpenAFS-devel] Joinable PAG's

[David Thompson]

Nathan Neulinger wrote:
>I use this capability on linux systems and hpux systems to go in
>periodically and scan for PAGs/Tokens in the kernel that are unused and
>clean them up manually by unlogging within the unused pag.
>
>GCPags support is supposed to do this, but I don't believe it is on by
>default for linux, and a while back at least, it wasn't usable on linux.
>
>The reason it's a problem (search the archive) is that the kernel tokens
>list in afs kernel module degrades badly when it gets too large,
>resulting in significant hangs frequently when you start having too many
>left over tokens in kernel.

Instead of requiring that we join an existing pag to fix this problem (which 
we do also at Madison), let's fix that problem in the kernel by immediately 
removing PAGs when the last process in the PAG exits.

I would argue even further that the PAG should be part of the process struct, 
copied on fork, which goes away when the process exits.  That would represent 
a significant paradym shift for most folks, though.

Dave