proposed PAG handling changes for Arla

[Assar Westerlund]

Chris Wing <wingc at engin.umich.edu> writes:
> I believe Arla's 'fs' command has a PAG garbage collection option which
> does this automatically.

Yes, `fs gcpags' will do a pioctl VIOC_GCPAGS.  (Which is a nop in
Arla :-)

> In Arla, it's less of an issue since the tokens are stored in user
> space, not kernel space. (arlad does all the real work)

Yes.  Expanding on this a little bit, arlad stores the credentials of
the actual users in a hash table from which credentials get deleted
when you do `unlog' or when the credential expires.

> > If we don't, things get really slow cause the token/pag structures get
> > enormous.
> 
> I haven't tried Arla on a machine with hundreds of users yet, though...

Me neither, but I've no reason to believe it should behave badly.

/assar