[ofa-general] [PATCH 1/4] ib/ipoib: specify TClass and FlowLabel with PR queries for QoS support

[Or Gerlitz]

Sean Hefty wrote:
> To support QoS within and between subnets, modify IPoIB to request
> specific TClass and FlowLabel values with path record queries, using
> the values associated with the IPoIB broadcast group.
> 
> This allows QoS to be defined for a given IPoIB broadcast group.
> 
> Signed-off-by: Sean Hefty <sean.hefty at intel.com>

> diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
> index 894b1dc..e22680f 100644
> --- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
> +++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
> @@ -468,9 +468,11 @@ static struct ipoib_path *path_rec_create(struct net_device *dev, void *gid)
>  	INIT_LIST_HEAD(&path->neigh_list);
>  
>  	memcpy(path->pathrec.dgid.raw, gid, sizeof (union ib_gid));
> -	path->pathrec.sgid      = priv->local_gid;
> -	path->pathrec.pkey      = cpu_to_be16(priv->pkey);
> -	path->pathrec.numb_path = 1;
> +	path->pathrec.sgid          = priv->local_gid;
> +	path->pathrec.pkey          = cpu_to_be16(priv->pkey);
> +	path->pathrec.numb_path     = 1;
> +	path->pathrec.flow_label    = priv->broadcast->mcmember.flow_label;
> +	path->pathrec.traffic_class = priv->broadcast->mcmember.traffic_class;

Sean, I think you want to ask for a specific SL here (that is add 
IB_SA_PATH_REC_SL to the mask and ask for the broadcast group SL).

Roland, I realized now that the current IPoIB implementation does not 
set IB_SA_PATH_REC_MTU and IB_SA_PATH_REC_RATE (and their selectors) in 
the SA path query where it does so for SA multicast joins. Is there a 
specific reason for that? do you assume that if the remote node has 
managed to join the broadcast group as this node this the SA enforced 
some sort of MTU and RATE compliance which you would get in the returned 
path record?

Or.