3.16.62-rc1 review patch. If anyone has any objections, please let me know.
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From: Denis Drozdov denisd@mellanox.com
commit 75da96067ade4e7854379ec2f7834f3497652b1a upstream.
The change of ipoib_ah data structure with adding "valid" flag and checks of ah->valid in ipoib_start_xmit affected multicast packet flow.
Since the multicast flow doesn't invoke path_rec_start, "ah->valid" flag remains unset, so that ipoib_start_xmit end up with neigh_refresh_path instead of sending the packet using neigh.
"ah->valid" has to be set in multicast send flow. As a result IPoIB starts sending packets via neigh immediately and eliminates 60sec delay of neigh keep alive interval.
The typical example of this issue are two sequential arpings:
arping 11.134.208.9 -> got response (mcast_send) arping 11.134.208.9 -> no response (ah->valid = 0)
Fixes: fa9391dbad4b ("RDMA/ipoib: Update paths on CLIENT_REREG/SM_CHANGE events") Signed-off-by: Denis Drozdov denisd@mellanox.com Reviewed-by: Erez Shitrit erezsh@mellanox.com Reviewed-by: Feras Daoud ferasda@mellanox.com Signed-off-by: Leon Romanovsky leonro@mellanox.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/infiniband/ulp/ipoib/ipoib_multicast.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c @@ -734,6 +734,7 @@ out: if (neigh && list_empty(&neigh->list)) { kref_get(&mcast->ah->ref); neigh->ah = mcast->ah; + neigh->ah->valid = 1; list_add_tail(&neigh->list, &mcast->neigh_list); } }