> > On Wed, May 14, 2008 at 11:40:28AM +0400, Evgeniy Polyakov (
johnpol@2ka.mipt.ru) wrote:
> > > > If any thread takes more than one kmap() at a time, it is deadlockable.
> > > > Because there is a finite pool of kmaps. Everyone can end up holding
> > > > one or more kmaps, then waiting for someone else to release one.
> > >
> > > It never takes the whole LAST_PKMAP maps. So the same can be applied to
> > > any user who kmaps at least one page - while user waits for free slot,
> > > it can be reused by someone else and so on.
> >
> > Actually CIFS uses the same logic: maps multiple pages in wrteback path
> > and release them after received reply.
>
> Yes. Only a pagevec at a time, though... apparently 14 is a small enough
> number not to bite too many people in practice?
>
