[openib-general] Some Missing Features from mthca/user MAD ac cess

[Sean Hefty]

Eitan Zahavi wrote:
> However, from your response it seems like only one client is allowed to
> register as the receiver for incoming requests of specific attribute. Is
> this correct? If this is the case then a careless application can block the
> SM from obtaining any SMInfo or other queries. 

This restriction is to avoid performing data copies on received MADs. 
In the kernel, clients are handed the data buffer(s) associated with a 
receive.

Since user-mode requires a data copy anyway, I'm wondering if it makes 
more sense for all user-mode clients to register in the kernel to snoop 
MADs, rather than to receive them.  The user-mode interface could then 
be modified to support more flexible filtering options.

- Sean