IB/ipath: Improve UD loopback performance by allocating temp array only once

Receive work queue entries are checked for L_Key validity, and
pointers to the memory region structure are saved in an allocated
structure.  For UD loopback packets, this structure is allocated and
freed for each packet.  This patch changes that to allocate/free
during QP creation and destruction.

Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 1 insertions, 18 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_ud.c b/drivers/infiniband/hw/ipath/ipath_ud.c
index 729446f56aab..91c74cc797ae 100644
--- a/drivers/infiniband/hw/ipath/ipath_ud.c
+++ b/drivers/infiniband/hw/ipath/ipath_ud.c
@@ -70,8 +70,6 @@ static void ipath_ud_loopback(struct ipath_qp *sqp, struct ipath_swqe *swqe)
 		goto done;
 	}
 
-	rsge.sg_list = NULL;
-
 	/*
 	 * Check that the qkey matches (except for QP0, see 9.6.1.4.1).
 	 * Qkeys with the high order bit set mean use the
@@ -115,21 +113,6 @@ static void ipath_ud_loopback(struct ipath_qp *sqp, struct ipath_swqe *swqe)
 		rq = &qp->r_rq;
 	}
 
-	if (rq->max_sge > 1) {
-		/*
-		 * XXX We could use GFP_KERNEL if ipath_do_send()
-		 * was always called from the tasklet instead of
-		 * from ipath_post_send().
-		 */
-		rsge.sg_list = kmalloc((rq->max_sge - 1) *
-					sizeof(struct ipath_sge),
-				       GFP_ATOMIC);
-		if (!rsge.sg_list) {
-			dev->n_pkt_drops++;
-			goto drop;
-		}
-	}
-
 	/*
 	 * Get the next work request entry to find where to put the data.
 	 * Note that it is safe to drop the lock after changing rq->tail
@@ -147,6 +130,7 @@ static void ipath_ud_loopback(struct ipath_qp *sqp, struct ipath_swqe *swqe)
 		goto drop;
 	}
 	wqe = get_rwqe_ptr(rq, tail);
+	rsge.sg_list = qp->r_ud_sg_list;
 	if (!ipath_init_sge(qp, wqe, &rlen, &rsge)) {
 		spin_unlock_irqrestore(&rq->lock, flags);
 		dev->n_pkt_drops++;
@@ -242,7 +226,6 @@ static void ipath_ud_loopback(struct ipath_qp *sqp, struct ipath_swqe *swqe)
 	ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
 		       swqe->wr.send_flags & IB_SEND_SOLICITED);
 drop:
-	kfree(rsge.sg_list);
 	if (atomic_dec_and_test(&qp->refcount))
 		wake_up(&qp->wait);
 done:;