Re: [net] tipc: re-configure queue limit for broadcast link

[Jakub Kicinski <kuba@kernel.org>]

On Tue, 13 Oct 2020 13:18:10 +0700 Hoang Huu Le wrote:
> The queue limit of the broadcast link is being calculated base on initial
> MTU. However, when MTU value changed (e.g manual changing MTU on NIC
> device, MTU negotiation etc.,) we do not re-calculate queue limit.
> This gives throughput does not reflect with the change.
> 
> So fix it by calling the function to re-calculate queue limit of the
> broadcast link.
> 
> Acked-by: Jon Maloy <jmaloy@redhat.com>
> Signed-off-by: Hoang Huu Le <hoang.h.le@dektech.com.au>
> ---
>  net/tipc/bcast.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
> index 940d176e0e87..c77fd13e2777 100644
> --- a/net/tipc/bcast.c
> +++ b/net/tipc/bcast.c
> @@ -108,6 +108,7 @@ static void tipc_bcbase_select_primary(struct net *net)
>  {
>  	struct tipc_bc_base *bb = tipc_bc_base(net);
>  	int all_dests =  tipc_link_bc_peers(bb->link);
> +	int max_win = tipc_link_max_win(bb->link);
>  	int i, mtu, prim;
>  
>  	bb->primary_bearer = INVALID_BEARER_ID;
> @@ -121,8 +122,11 @@ static void tipc_bcbase_select_primary(struct net *net)
>  			continue;
>  
>  		mtu = tipc_bearer_mtu(net, i);
> -		if (mtu < tipc_link_mtu(bb->link))
> +		if (mtu < tipc_link_mtu(bb->link)) {
>  			tipc_link_set_mtu(bb->link, mtu);
> +			tipc_link_set_queue_limits(bb->link, max_win,
> +						   max_win);

Is max/max okay here? Other places seem to use BCLINK_WIN_MIN.

> +		}
>  		bb->bcast_support &= tipc_bearer_bcast_support(net, i);
>  		if (bb->dests[i] < all_dests)
>  			continue;