Re: [PATCH 2/9] mac80211: Limit amount of HWMP frames and forwarded data packets in queues on mesh interfaces

[Johannes Berg <johannes@sipsolutions.net>]

On Wed, 2011-08-24 at 18:40 -0700, Thomas Pedersen wrote:
> From: Pedro Larbig <pedro.larbig@carhs.de>
> 
> To avoid contention problems in a mesh network's high load areas, this patch
> adds a 2-stage packet dropping mechanism:
> * If the transmit queue for HWMP frames is filled with 256 or more packets,
> additional HWMP frames will be dropped
> * If the transmit queue for forwarded packets is at 384 or more, drop those,
> too

> +	/* Frames going through ieee80211_tx_skb will be on the voice queue,
> +	 * Therefor we need to check only IEEE80211_AC_VO */
> +	if (unlikely(skb_queue_len(&local->pending[IEEE80211_AC_VO]) >=
> +	   MESH_MGMT_QUEUE_LEN)) {
> +		kfree_skb(skb);
> +		I802_DEBUG_INC(local->tx_handlers_drop_mesh_mgmt);
> +		return;
> +	}

I still don't think this should be done. If the HW queue is full, we
will get a stop_queue from the driver, this could also tell mesh to stop
forwarding or so.

johannes