[ewg] Re: [PATCH] IPOIB/CM Increase retry counts for OFED-1.3

[Tziporet Koren]

Pradeep Satyanarayana wrote:
> This patch change retry counts to small values. This helps interoperability
> between ehca and mthca. Without this patch I had seen "send completion errors".
>
> Or Gerlitz has started a thread on the general mailing list and the complete
> discussion will be available there. This is the second part of the patch
> submitted yesterday and is split up as per Eli's request.
>
> Signed-off-by: Pradeep Satyanarayana <pradeeps at linux.vnet.ibm.com>
> ---
>
> --- ofa_kernel-1.3_a/drivers/infiniband/ulp/ipoib/ipoib_cm.c	2008-02-12 17:46:03.000000000 -0500
> +++ ofa_kernel-1.3_b/drivers/infiniband/ulp/ipoib/ipoib_cm.c	2008-02-12 17:46:58.000000000 -0500
> @@ -1016,8 +1016,8 @@ static int ipoib_cm_send_req(struct net_
>  	req.responder_resources	      = 4;
>  	req.remote_cm_response_timeout = 20;
>  	req.local_cm_response_timeout  = 20;
> -	req.retry_count 	      = 0; /* RFC draft warns against retries */
> -	req.rnr_retry_count 	      = 0; /* RFC draft warns against retries */
> +	req.retry_count 	      = 3;
> +	req.rnr_retry_count 	      = 3;
>  	req.max_cm_retries 	      = 15;
>  	req.srq 	              = ipoib_cm_has_srq(dev);
>  	return ib_send_cm_req(id, &req);
>
>
>   

I wish to see Roland's respond to this patch.
I think its enough to enlarge only the rnr_retry_count since the 
retry_count is for cases were packages are dropped by a very busy subnet.
The case you want to solve should be covered by the rnr_retry_count.

Regarding UC - we may consider this in the future since in ConnectX we 
have UC with SRQ support and indeed it will be the best for IPoIB CM

Tziporet