[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] RFC: [0/2] Remove netloop by lazy copying in netback



On 27/3/07 08:36, "Keir Fraser" <Keir.Fraser@xxxxxxxxxxxx> wrote:

> This is quite a shame, since the swap-grant-mapping-for-memory hypercall
> simply is not very nice. What if we wanted to swap a grant mapping for
> another grant mapping in future? Or some other kind of mapping? We end up
> needing a new, complicated, grant-table hypercall every time. Or in six
> months time we decide this wasn't such a good idea, implement another
> scheme, but have this special-purpose grant-table hypercall hanging around
> unused forever more.
> 
> Could we shatter the ia64 guest large mappings easily? They have no benefit
> on Xen anyway apart from some inconsequential memory saving.

Also bear in mind the plan to avoid the grant mapping at all in the
direct-to-wire transmit case. This also will rely on a #PF (or some other
fault, potentially) if the guest tries to access that pseudophysical page of
memory. If we can work out a way to make this work on ia64 then the
delayed-copy implementation problems are solved too.

 -- Keir



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.