nvmet-rdma: use new shared CQ mechanism

Has the driver use shared CQs providing ~10%-20% improvement when
multiple disks are used. Instead of opening a CQ for each QP per
controller, a CQ for each core will be provided by the RDMA core driver
that will be shared between the QPs on that core reducing interrupt
overhead.

Signed-off-by: Yamin Friedman <[email protected]>
Signed-off-by: Max Gurtovoy <[email protected]>
Reviewed-by: Or Gerlitz <[email protected]>
Reviewed-by: Sagi Grimberg <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>

Author: yaminf

drivers/nvme/target/rdma.c

@@ -752,7 +752,7 @@ static void nvmet_rdma_read_data_done(struct ib_cq *cq, struct ib_wc *wc)
 {
 	struct nvmet_rdma_rsp *rsp =
 		container_of(wc->wr_cqe, struct nvmet_rdma_rsp, read_cqe);
-	struct nvmet_rdma_queue *queue = cq->cq_context;
+	struct nvmet_rdma_queue *queue = wc->qp->qp_context;
 	u16 status = 0;
 
 	WARN_ON(rsp->n_rdma <= 0);
@@ -1008,7 +1008,7 @@ static void nvmet_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc)
 {
 	struct nvmet_rdma_cmd *cmd =
 		container_of(wc->wr_cqe, struct nvmet_rdma_cmd, cqe);
-	struct nvmet_rdma_queue *queue = cq->cq_context;
+	struct nvmet_rdma_queue *queue = wc->qp->qp_context;
 	struct nvmet_rdma_rsp *rsp;
 
 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
@@ -1258,9 +1258,8 @@ static int nvmet_rdma_create_queue_ib(struct nvmet_rdma_queue *queue)
 	 */
 	nr_cqe = queue->recv_queue_size + 2 * queue->send_queue_size;
 
-	queue->cq = ib_alloc_cq(ndev->device, queue,
-			nr_cqe + 1, queue->comp_vector,
-			IB_POLL_WORKQUEUE);
+	queue->cq = ib_cq_pool_get(ndev->device, nr_cqe + 1,
+				   queue->comp_vector, IB_POLL_WORKQUEUE);
 	if (IS_ERR(queue->cq)) {
 		ret = PTR_ERR(queue->cq);
 		pr_err("failed to create CQ cqe= %d ret= %d\n",
@@ -1322,7 +1321,7 @@ static int nvmet_rdma_create_queue_ib(struct nvmet_rdma_queue *queue)
 err_destroy_qp:
 	rdma_destroy_qp(queue->cm_id);
 err_destroy_cq:
-	ib_free_cq(queue->cq);
+	ib_cq_pool_put(queue->cq, nr_cqe + 1);
 	goto out;
 }
 
@@ -1332,7 +1331,8 @@ static void nvmet_rdma_destroy_queue_ib(struct nvmet_rdma_queue *queue)
 	if (queue->cm_id)
 		rdma_destroy_id(queue->cm_id);
 	ib_destroy_qp(queue->qp);
-	ib_free_cq(queue->cq);
+	ib_cq_pool_put(queue->cq, queue->recv_queue_size + 2 *
+		       queue->send_queue_size + 1);
 }
 
 static void nvmet_rdma_free_queue(struct nvmet_rdma_queue *queue)