On Sat, Feb 22, 2014 at 10:04:13PM +0000, Mindaugas Rasiukevicius wrote:
> Matt Thomas <[email protected]> wrote:
> >
> > I've been wondering...
> >
> > Should pmap_kenter_pa overwrite an existing entry should it be operating
> > on an unmapped VA.
>
> You mean already mapped VA?
>
> > I think that if you want to change a mapping, you
> > should do a pmap_kremove first.
>
> I tend to agree. I have not seen a need for such re-mapping (overwriting),
> but even if there is, it can be done efficiently by removing, entering and
> then calling pmap_update(). With the deferred update, that would result in
> a single TLB flush/invalidation.
Anything that uses a small KVA area to reference a large amount of
physical addresses?
I'd guess that you'd want a flag somewhere to know it was likely
(either for the call, but probably a property of the KVA address.
David
--
David Laight: [email protected]
