IPoIB: Use separate CQ for UD send completions

Use a dedicated CQ for UD send completions. Also, do not arm the UD
send CQ, which reduces the number of interrupts generated.  This patch
farther reduces overhead by not calling poll CQ for every posted send
WR -- it does polls only when there 16 or more outstanding work requests.

Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 26 insertions, 19 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ib.c b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
index 7cf1fa7..97b815c 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_ib.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
@@ -364,7 +364,6 @@ static void ipoib_ib_handle_tx_wc(struct net_device *dev, struct ib_wc *wc)
 	struct ipoib_dev_priv *priv = netdev_priv(dev);
 	unsigned int wr_id = wc->wr_id;
 	struct ipoib_tx_buf *tx_req;
-	unsigned long flags;
 
 	ipoib_dbg_data(priv, "send completion: id %d, status: %d\n",
 		       wr_id, wc->status);
@@ -384,13 +383,11 @@ static void ipoib_ib_handle_tx_wc(struct net_device *dev, struct ib_wc *wc)
 
 	dev_kfree_skb_any(tx_req->skb);
 
-	spin_lock_irqsave(&priv->tx_lock, flags);
 	++priv->tx_tail;
 	if (unlikely(--priv->tx_outstanding == ipoib_sendq_size >> 1) &&
 	    netif_queue_stopped(dev) &&
 	    test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags))
 		netif_wake_queue(dev);
-	spin_unlock_irqrestore(&priv->tx_lock, flags);
 
 	if (wc->status != IB_WC_SUCCESS &&
 	    wc->status != IB_WC_WR_FLUSH_ERR)
@@ -399,6 +396,17 @@ static void ipoib_ib_handle_tx_wc(struct net_device *dev, struct ib_wc *wc)
 			   wc->status, wr_id, wc->vendor_err);
 }
 
+static int poll_tx(struct ipoib_dev_priv *priv)
+{
+	int n, i;
+
+	n = ib_poll_cq(priv->send_cq, MAX_SEND_CQE, priv->send_wc);
+	for (i = 0; i < n; ++i)
+		ipoib_ib_handle_tx_wc(priv->dev, priv->send_wc + i);
+
+	return n == MAX_SEND_CQE;
+}
+
 int ipoib_poll(struct napi_struct *napi, int budget)
 {
 	struct ipoib_dev_priv *priv = container_of(napi, struct ipoib_dev_priv, napi);
@@ -414,7 +422,7 @@ poll_more:
 		int max = (budget - done);
 
 		t = min(IPOIB_NUM_WC, max);
-		n = ib_poll_cq(priv->cq, t, priv->ibwc);
+		n = ib_poll_cq(priv->recv_cq, t, priv->ibwc);
 
 		for (i = 0; i < n; i++) {
 			struct ib_wc *wc = priv->ibwc + i;
@@ -425,12 +433,8 @@ poll_more:
 					ipoib_cm_handle_rx_wc(dev, wc);
 				else
 					ipoib_ib_handle_rx_wc(dev, wc);
-			} else {
-				if (wc->wr_id & IPOIB_OP_CM)
-					ipoib_cm_handle_tx_wc(dev, wc);
-				else
-					ipoib_ib_handle_tx_wc(dev, wc);
-			}
+			} else
+				ipoib_cm_handle_tx_wc(priv->dev, wc);
 		}
 
 		if (n != t)
@@ -439,7 +443,7 @@ poll_more:
 
 	if (done < budget) {
 		netif_rx_complete(dev, napi);
-		if (unlikely(ib_req_notify_cq(priv->cq,
+		if (unlikely(ib_req_notify_cq(priv->recv_cq,
 					      IB_CQ_NEXT_COMP |
 					      IB_CQ_REPORT_MISSED_EVENTS)) &&
 		    netif_rx_reschedule(dev, napi))
@@ -562,12 +566,16 @@ void ipoib_send(struct net_device *dev, struct sk_buff *skb,
 
 		address->last_send = priv->tx_head;
 		++priv->tx_head;
+		skb_orphan(skb);
 
 		if (++priv->tx_outstanding == ipoib_sendq_size) {
 			ipoib_dbg(priv, "TX ring full, stopping kernel net queue\n");
 			netif_stop_queue(dev);
 		}
 	}
+
+	if (unlikely(priv->tx_outstanding > MAX_SEND_CQE))
+		poll_tx(priv);
 }
 
 static void __ipoib_reap_ah(struct net_device *dev)
@@ -714,7 +722,7 @@ void ipoib_drain_cq(struct net_device *dev)
 	struct ipoib_dev_priv *priv = netdev_priv(dev);
 	int i, n;
 	do {
-		n = ib_poll_cq(priv->cq, IPOIB_NUM_WC, priv->ibwc);
+		n = ib_poll_cq(priv->recv_cq, IPOIB_NUM_WC, priv->ibwc);
 		for (i = 0; i < n; ++i) {
 			/*
 			 * Convert any successful completions to flush
@@ -729,14 +737,13 @@ void ipoib_drain_cq(struct net_device *dev)
 					ipoib_cm_handle_rx_wc(dev, priv->ibwc + i);
 				else
 					ipoib_ib_handle_rx_wc(dev, priv->ibwc + i);
-			} else {
-				if (priv->ibwc[i].wr_id & IPOIB_OP_CM)
-					ipoib_cm_handle_tx_wc(dev, priv->ibwc + i);
-				else
-					ipoib_ib_handle_tx_wc(dev, priv->ibwc + i);
-			}
+			} else
+				ipoib_cm_handle_tx_wc(dev, priv->ibwc + i);
 		}
 	} while (n == IPOIB_NUM_WC);
+
+	while (poll_tx(priv))
+		; /* nothing */
 }
 
 int ipoib_ib_dev_stop(struct net_device *dev, int flush)
@@ -826,7 +833,7 @@ timeout:
 		msleep(1);
 	}
 
-	ib_req_notify_cq(priv->cq, IB_CQ_NEXT_COMP);
+	ib_req_notify_cq(priv->recv_cq, IB_CQ_NEXT_COMP);
 
 	return 0;
 }