[ofa-general] Re: Requesting CQ notifications

[Michael S. Tsirkin]

> In this case it brings up an interesting question. If the adaptor will 
> only generate an event for a "new" CQE added, how do you tell that 
> you've successfully polled all the CQEs that triggered the first event? 
> You could continuously call ibv_poll_cq() until it returned zero, but 
> this has the side effect of potentially starving other CQs in the case 
> of a high CQE rate.

You can limit the number of polls by CQ size. So

<poll any number of times you like (could be 0), or until CQ is empty>
request notification
<poll up to CQ size or until CQ is empty>

solves the starvation problem, and will guarantee that no event is missed.

-- 
MST