global object question in multiprocessor

[Francesco Poletti]

Hy, I'm reading the multiprocessor's doc and I have these two simple
question:
-When a task use a global object which don't reside on its processor,
RTEMS "calls" the MPCI layer for have the object from another processor.
Those passages are used every time that task make operation over the
global object? 
-Is possible, for a task,  sending an "event" or a signal to another
task which is global but don't reside on same processor? If yes in this
case an RQ (which need answer) or an RP wich don't block the first task?
Thanks to all Francesco