Eric Dumazet a écrit :

David, here is the followup I promised

Thanks

[PATCH] net: skb_tx_hash() improvements

When skb_rx_queue_recorded() is true, we dont want to use jhash distribution
as the device driver exactly told us which queue was selected at RX time.
jhash makes a statistical shuffle, but this wont work with only 8 different inputs.

We also need to implement a true reciprocal division, to not disturb
symmetric setups (when number of tx queues matches number of rx queues)
and cpu affinities.

This patch introduces a new helper, dev_real_num_tx_queues_set()
to set both real_num_tx_queues and its reciprocal value,
and makes all drivers use this helper.

Oh well, this was wrong, I took divide result while we want a modulo !

Need to think a litle bit more :)