Re: [PATCH 07/13] IB: add a proper completion queue abstraction

On Thu, Dec 10, 2015 at 10:42:22AM -0800, Bart Van Assche wrote:

quoted

+struct ib_cq *ib_alloc_cq(struct ib_device *dev, void *private,
+		int nr_cqe, int comp_vector, enum ib_poll_context poll_ctx)
+{
[ ... ]
+	cq->wc = kmalloc_array(IB_POLL_BATCH, sizeof(*cq->wc), GFP_KERNEL);

Why is the wc array allocated separately instead of being embedded in 
struct ib_cq ? I think the faster completion queues can be created the 
better so if it is possible to eliminate the above kmalloc() call I would 
prefer that.

I originally allocated an embedded aray, but Sagi pointed out that
we'd waste memory for CQs not using the new API, so I changed it.
The embedded one would be quite a bit simpler indeed.

quoted

--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c

@@ -457,10 +457,11 @@ static struct srp_fr_pool *srp_alloc_fr_pool(struct srp_target_port *target)
  static void srp_destroy_qp(struct srp_rdma_ch *ch)
  {
  	static struct ib_qp_attr attr = { .qp_state = IB_QPS_ERR };
-	static struct ib_recv_wr wr = { .wr_id = SRP_LAST_WR_ID };
+	static struct ib_recv_wr wr = { 0 };
  	struct ib_recv_wr *bad_wr;
  	int ret;

Is explicit initialization to "{ 0 }" really needed for static structures ?

It shouldn't be needed, but I can't see how it harms either.