On 3/29/17 11:39 AM, Sagi Grimberg wrote:
For each I/O we post up to 2 work requests, 1 for memory registration
and 1 for sending an I/O request (and 1 for local invalidation if the
target doesn't do it for us, but that is not the case here). So if our
queue depth is X, we size our completion queue to be X*3, and we need
to make sure we signal every (X*3)/2.
??? If your SQ is X and your CQ is X*3 you need to signal at X/2.
Sorry, I confused SQ with CQ (which made it even more confusing..)
Our application queue-depth is X, we size our SQ to be X*3
(send+reg+inv), we size our RQ to be X (resp) and our CQ to be
X*4 (SQ+RQ).
So we should signal every (X*3)/2
You say above "we post *up to* 2 work requests", unless you wish to
change that to "we always post at least 2 work requests per queue
entry", Jason is right, your frequency of signaling needs to be X/2
regardless of your CQ size, you need the signaling to control the queue
depth tracking.
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
