Re: [PATCH v4 9/9] IB/srpt: convert to the generic RDMA READ/WRITE API

quoted

  	WARN_ON(ioctx->n_rdma <= 0);
  	atomic_add(ioctx->n_rdma, &ch->sq_wr_avail);
+	ioctx->n_rdma = 0;

  	if (unlikely(wc->status != IB_WC_SUCCESS)) {
  		pr_info("RDMA_READ for ioctx 0x%p failed with status %d\n",

ioctx->n_rdma is reset by srpt_get_send_ioctx(). Do we really need to reset 
that member variable in srpt_rdma_read_done()?

Yes, otherwise the atomic_add in srpt_send_done will do the wrong thing.
Alernatively we could return WQE reservation in srpt_send_done always,
but given that we'd done with the RDMA READ commands it seems useful
to not hang onto them longer than necessary.

quoted

@@ -1832,8 +1626,11 @@ retry:
  	qp_init->srq = sdev->srq;
  	qp_init->sq_sig_type = IB_SIGNAL_REQ_WR;
  	qp_init->qp_type = IB_QPT_RC;
-	qp_init->cap.max_send_wr = srp_sq_size;
-	qp_init->cap.max_send_sge = SRPT_DEF_SG_PER_WQE;
+	qp_init->cap.max_send_wr = srp_sq_size / 2;
+	qp_init->cap.max_rdma_ctxs = srp_sq_size / 2;
+	qp_init->cap.max_send_sge = max(sdev->device->attrs.max_sge_rd,
+					sdev->device->attrs.max_sge);
+	qp_init->port_num = ch->sport->port;

  	ch->qp = ib_create_qp(sdev->pd, qp_init);
  	if (IS_ERR(ch->qp)) {

The QP max_send_wr parameter has been changed but not the ib_alloc_cq() 
argument. Is that perhaps an oversight?

The rdma_ctx add at least one to the send_wr count.  In case they
are all RDMA READs we will actually need one CQE per rdma_ctxs, although
we'll usually need less.  So I think the actualy count here is correct,
but I'll add a comment explaining things.
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