Re: [PATCH] xen/netfront: handle compound page fragments on transmit

On Tue, 2012-11-20 at 14:45 +0000, Eric Dumazet wrote:

quoted

+		/* Skip unused frames from start of page */

'frame' in the comment means an order-0 page ?

Yes. Confusing in the context of a network driver I know! I couldn't
think of a better term.

quoted

+			id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
+			np->tx_skbs[id].skb = skb_get(skb);

BTW this skb_get() means extra atomic operations for every 4096 bytes
unit, and an extra atomic op (and test for final 0) at TX completion.
This could be avoided, by setting np->tx_skbs[id].skb = skb only for the
very last unit.

Thanks. Might be tricky because guests can ack the individual requests
in any order but it's something worth having a look at.

quoted

 	np->tx.req_prod_pvt = prod;

Acked-by: Eric Dumazet <redacted>

Thanks !

Thanks for the review.

Ian.