From 1b844afe9e67d6cd441ae6df71051b4004f31dd2 Mon Sep 17 00:00:00 2001 From: Roland Dreier Date: Tue, 10 Jul 2007 13:43:53 -0700 Subject: [PATCH] IPoIB: Recycle loopback skbs instead of freeing and reallocating InfiniBand HCAs replicate multicast packets back to the QP that sent them if that QP is attached to the destination multicast group. This means that IPoIB multicasts are often replicated back to the receive queue of the interface that generated them. To avoid confusing the network stack, we drop these duplicates within the IPoIB driver. However, there's no reason to free the skb that received the duplicate and then immediately allocate a new skb to post to the receive queue. We can be more efficient and just repost the same skb. Signed-off-by: Roland Dreier --- drivers/infiniband/ulp/ipoib/ipoib_ib.c | 33 +++++++++++++------------ 1 file changed, 17 insertions(+), 16 deletions(-) diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ib.c b/drivers/infiniband/ulp/ipoib/ipoib_ib.c index 8404f05b2b..10944888cf 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_ib.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_ib.c @@ -196,6 +196,13 @@ static void ipoib_ib_handle_rx_wc(struct net_device *dev, struct ib_wc *wc) return; } + /* + * Drop packets that this interface sent, ie multicast packets + * that the HCA has replicated. + */ + if (wc->slid == priv->local_lid && wc->src_qp == priv->qp->qp_num) + goto repost; + /* * If we can't allocate a new RX buffer, dump * this packet and reuse the old buffer. @@ -213,24 +220,18 @@ static void ipoib_ib_handle_rx_wc(struct net_device *dev, struct ib_wc *wc) skb_put(skb, wc->byte_len); skb_pull(skb, IB_GRH_BYTES); - if (wc->slid != priv->local_lid || - wc->src_qp != priv->qp->qp_num) { - skb->protocol = ((struct ipoib_header *) skb->data)->proto; - skb_reset_mac_header(skb); - skb_pull(skb, IPOIB_ENCAP_LEN); + skb->protocol = ((struct ipoib_header *) skb->data)->proto; + skb_reset_mac_header(skb); + skb_pull(skb, IPOIB_ENCAP_LEN); - dev->last_rx = jiffies; - ++priv->stats.rx_packets; - priv->stats.rx_bytes += skb->len; + dev->last_rx = jiffies; + ++priv->stats.rx_packets; + priv->stats.rx_bytes += skb->len; - skb->dev = dev; - /* XXX get correct PACKET_ type here */ - skb->pkt_type = PACKET_HOST; - netif_receive_skb(skb); - } else { - ipoib_dbg_data(priv, "dropping loopback packet\n"); - dev_kfree_skb_any(skb); - } + skb->dev = dev; + /* XXX get correct PACKET_ type here */ + skb->pkt_type = PACKET_HOST; + netif_receive_skb(skb); repost: if (unlikely(ipoib_ib_post_receive(dev, wr_id))) -- 2.20.1