[ofa-general] [PATCH] ib/ipoib: Reduce comparison size in data path

[Eli Cohen]

In the majority of cases, if the neighbour will change, it will
be reflected in the guid part of the GID (bytes 8-15). If the GID
prefix will change as well (bytes 0-7) it will be because the master
SM has changed, in which case we will get an SM change event resulting
in all paths flushed.

Signed-off-by: Eli Cohen <eli at mellanox.co.il>
---
 drivers/infiniband/ulp/ipoib/ipoib_main.c |    7 +++----
 1 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index c9f6077..e9a4f96 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -693,10 +693,9 @@ static int ipoib_start_xmit(struct sk_buff *skb, struct net_device *dev)
 				goto out;
 			}
 		} else if (neigh->ah) {
-			if (unlikely((memcmp(&neigh->dgid.raw,
-					    skb->dst->neighbour->ha + 4,
-					    sizeof(union ib_gid))) ||
-					 (neigh->dev != dev))) {
+			if (unlikely((memcmp(&neigh->dgid.raw[8],
+					     skb->dst->neighbour->ha + 12, 8)) ||
+					     (neigh->dev != dev))) {
 				spin_lock(&priv->lock);
 				/*
 				 * It's safe to call ipoib_put_ah() inside
-- 
1.5.3.6