2007-09-12 10:00:37

by Steve Wise

Subject: [PATCH] RDMA/CMA: Use neigh_event_send() to initiate neighbour discovery.

RDMA/CMA: Use neigh_event_send() to initiate neighbour discovery.

Calling arp_send() to initiate neighbour discovery (ND) doesn't do the
full ND protocol. Namely, it doesn't handle retransmitting the arp
request if it is dropped. The function neigh_event_send() does all this.
Without doing full ND, rdma address resolution fails in the presence of
dropped arp bcast packets.

Signed-off-by: Steve Wise <[email protected]>
---

drivers/infiniband/core/addr.c | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c
index c5c33d3..5381c80 100644
--- a/drivers/infiniband/core/addr.c
+++ b/drivers/infiniband/core/addr.c
@@ -161,8 +161,7 @@ static void addr_send_arp(struct sockadd
if (ip_route_output_key(&rt, &fl))
return;

- arp_send(ARPOP_REQUEST, ETH_P_ARP, rt->rt_gateway, rt->idev->dev,
- rt->rt_src, NULL, rt->idev->dev->dev_addr, NULL);
+ neigh_event_send(rt->u.dst.neighbour, NULL);
ip_rt_put(rt);
}

2007-09-12 18:13:33

by Hefty, Sean

Subject: RE: [PATCH] RDMA/CMA: Use neigh_event_send() to initiate neighbour discovery.

>RDMA/CMA: Use neigh_event_send() to initiate neighbour discovery.
>
>Calling arp_send() to initiate neighbour discovery (ND) doesn't do the
>full ND protocol. Namely, it doesn't handle retransmitting the arp
>request if it is dropped. The function neigh_event_send() does all this.
>Without doing full ND, rdma address resolution fails in the presence of
>dropped arp bcast packets.
>
>Signed-off-by: Steve Wise <[email protected]>

Acked-by: Sean Hefty <[email protected]>

Roland - can you please queue this up for 2.6.24?

2007-09-16 07:51:18

by Or Gerlitz

Subject: Re: [ofa-general] [PATCH] RDMA/CMA: Use neigh_event_send() to initiate neighbour discovery.

Steve Wise wrote:
> RDMA/CMA: Use neigh_event_send() to initiate neighbour discovery.
>
> Calling arp_send() to initiate neighbour discovery (ND) doesn't do the
> full ND protocol. Namely, it doesn't handle retransmitting the arp
> request if it is dropped. The function neigh_event_send() does all this.
> Without doing full ND, rdma address resolution fails in the presence of
> dropped arp bcast packets.

Jay,

Is there a way to deploy something similar for the gratuitous arp being
sent by the bonding driver at bond_arp_send()?

We have seen rare situations where the skb was dropped by the stack and
hence bonding fail-over was detected by the remote peer only when its
neighboring subsystem probe failures dictated that a new arp must be issued.

Or.
>
> Signed-off-by: Steve Wise <[email protected]>
> ---
>
> drivers/infiniband/core/addr.c | 3 +--
> 1 files changed, 1 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c
> index c5c33d3..5381c80 100644
> --- a/drivers/infiniband/core/addr.c
> +++ b/drivers/infiniband/core/addr.c
> @@ -161,8 +161,7 @@ static void addr_send_arp(struct sockadd
> if (ip_route_output_key(&rt, &fl))
> return;
>
> - arp_send(ARPOP_REQUEST, ETH_P_ARP, rt->rt_gateway, rt->idev->dev,
> - rt->rt_src, NULL, rt->idev->dev->dev_addr, NULL);
> + neigh_event_send(rt->u.dst.neighbour, NULL);
> ip_rt_put(rt);
> }

2007-09-18 17:24:01

by Steve Wise

Subject: Re: [PATCH] RDMA/CMA: Use neigh_event_send() to initiate neighbour discovery.

Once this is applied upstream, I can pull it back in to ofed-1.2.5 and
ofed-1.3.

Steve.

Sean Hefty wrote:
>> RDMA/CMA: Use neigh_event_send() to initiate neighbour discovery.
>>
>> Calling arp_send() to initiate neighbour discovery (ND) doesn't do the
>> full ND protocol. Namely, it doesn't handle retransmitting the arp
>> request if it is dropped. The function neigh_event_send() does all this.
>> Without doing full ND, rdma address resolution fails in the presence of
>> dropped arp bcast packets.
>>
>> Signed-off-by: Steve Wise <[email protected]>
>
> Acked-by: Sean Hefty <[email protected]>
>
> Roland - can you please queue this up for 2.6.24?

2007-09-20 16:31:58

by Roland Dreier

Subject: Re: [PATCH] RDMA/CMA: Use neigh_event_send() to initiate neighbour discovery.

> Roland - can you please queue this up for 2.6.24?

Done, thanks.