On Wed, Aug 13, 2008 at 08:42:38PM +1000, Herbert Xu wrote:

On Wed, Aug 13, 2008 at 10:27:01AM +0000, Jarek Poplawski wrote:

quoted

- in net_tx_action() we can hit a place just after clear_bit() where
none of these bits is set. Of course, hitting this 2 times in a row
seems to be very unprobable, yet possible, and a lock isn't helpful
here, so probably some change around this would make this nicer.

- isn't there possible some longer ping-pong between qdic_run() and
net_tx_action() when dev_requeue_skb() would get it back to
__netif_schedule() and so on (with NETDEV_TX_BUSY)?

Good point.  I think we should add an aliveness check in both
net_tx_action and qdisc_run.  In fact the net_tx_action problem
existed previously as well.  But it is pretty darn unlikely.

Yes, it seems qdisc_reset() doesn't have to help with this, so
probably there is needed some requeue counter or something...

Jarek P.