Re: PUFFS lookup/reclaim race

[Emmanuel Dreyfus <manu%netbsd.org@localhost>]

On Fri, Jul 13, 2012 at 07:30:47AM +0100, David Laight wrote:
> Reference count the cookie somehow?

I already do this [in uncommitted code] and it does not help since
this is a mismatch between kernel and userland refcounts.

> Maybe a 3-way handshake somewhere - so userspace doesn't actually free
> the cookie until later, you might only need a sequence number for
> these requests.

That would introduce a horrible performance degradation. We do a lot
of lookups...

-- 
Emmanuel Dreyfus
manu%netbsd.org@localhost