[ofa-general] [PATCH 3/3] mcast loopback block

[Ron Livne]

mcast block loopback patch [3/3]

IPOIB: blocking mcast loopback IPoIB packets


This patch makes any mcast packet sent via IPoIB
from any host, to be blocked when looped back
to the same host it was sent from.
The blocking is done by the HCA if possible.


This patch creates an improvement of up to 39% in bandwidth when
seding mcast packets with IPoIB.

There is also an improvment of 12% in cpu usage.


Signed-off-by: Ron Livne <ronli at voltaire.com>

Index: kernels/linux-2.6.26-rc2/drivers/infiniband/ulp/ipoib/ipoib_verbs.c
===================================================================
--- kernels.orig/linux-2.6.26-rc2/drivers/infiniband/ulp/ipoib/ipoib_verbs.c	2008-05-19 14:04:07.000000000 +0300
+++ kernels/linux-2.6.26-rc2/drivers/infiniband/ulp/ipoib/ipoib_verbs.c	2008-05-19 14:16:44.000000000 +0300
@@ -153,7 +153,8 @@ int ipoib_transport_dev_init(struct net_
 			.max_recv_sge = IPOIB_UD_RX_SG
 		},
 		.sq_sig_type = IB_SIGNAL_ALL_WR,
-		.qp_type     = IB_QPT_UD
+		.qp_type     = IB_QPT_UD,
+		.create_flags = 0
 	};

 	int ret, size;
@@ -201,7 +202,10 @@ int ipoib_transport_dev_init(struct net_
 	init_attr.recv_cq = priv->recv_cq;

 	if (priv->hca_caps & IB_DEVICE_UD_TSO)
-		init_attr.create_flags = IB_QP_CREATE_IPOIB_UD_LSO;
+		init_attr.create_flags |= IB_QP_CREATE_IPOIB_UD_LSO;
+
+	if (priv->hca_caps & IB_DEVICE_BLOCK_LOOPBACK)
+                init_attr.create_flags |= IB_QP_BLOCK_LOOPBACK;

 	if (dev->features & NETIF_F_SG)
 		init_attr.cap.max_send_sge = MAX_SKB_FRAGS + 1;