[OpenAFS-devel] Re: [OpenAFS] 2.6 kernel support anytime soon? Workarounds?

[Neulinger, Nathan]

> I don't think that's a big deal.  There's not currently any=20
> benefit to=20
> GC'ing PAG's, since they're just numbers in a namespace we=20
> don't expect=20
> ever to reuse.  The tokens themselves will be GC'd once they=20
> are expired=20
> for some period of time, so the memory use is not an issue.

Is the kernel "afs users" hash a hash of tokens or a hash of pags?

If the hash is based on pags, then GC'ing most definately matters,
especially on linux if you have a significant multi-user system that
gets lots of pags - the behavior of the hash degrades very badly when it
gets large to the point of causing 1-10 second kernel hangs periodically
if it gets very large. We implemented our own external garbage
collection with kdump and scanning of /proc which helped the problem
tremendously.

-- Nathan