[openib-general] Reregister Memory Region Verb

[Or Gerlitz]

Galen Shipman wrote:

> I would like to be able to extend an existing registration such that the 
> driver would take advantage of the fact that part of the extended 
> registration is already registered, i.e. only the "new" memory would be 
> pinned and made resident. 

Assuming you are referring to registration of virtual memory from user 
space, this seems as a request for the hw drivers to support overlapping 
memory regions in the sense that MR A can overlap with MR B such that 
till both A and B are unregistered the overlapped section is in place 
(pinned , resident, mapped in the HCA MMU etc).

> although we would prefer that it wouldn't block if possible 

mmm. All the current memory registration verbs both user and kernel
are blocking, is it an issue for you?

Or.