[ofa-general] What should a ULP pass as ib_create_cq(..., comp_vector) ?

[Talpey, Thomas]

At 12:57 PM 7/11/2007, Roland Dreier wrote:
>However on another level your question gets to the reason why we
>haven't implemented support for multiple completion event vectors.
>Namely, it's not clear how consumers, kernel or userspace, can make a
>good choice of which vector to assign a given CQ to.

Got it, thanks. But aren't the vectors shared across all consumers on
an HCA? As such, it seems problematic to expect consumers to make
optimal choices, since they have no way of knowing what other consumers
are doing.

In any case, all NFS/RDMA does is to check the completion status, queue
the event and schedule a tasklet, so there is little or no parallelism to be
gained in the upcall. I'd prefer to not have to wait for other ULPs on the
same vector, of course.

Tom.