net: caif: avoid using qdisc_qlen()

Such helper does not cope correctly with NOLOCK qdiscs.
In the following patches we will move back qlen to per CPU
values for such qdiscs, so qdisc_qlen_sum() is not an option,
too.
Instead, use qlen only for lock qdiscs, and always set
flow off for NOLOCK qdiscs with a not empty tx queue.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Paolo Abeni 2019-04-10 14:32:37 +02:00 committed by David S. Miller
parent 4c75be07f9
commit b0a231a26d

View File

@ -186,15 +186,19 @@ static int transmit(struct cflayer *layer, struct cfpkt *pkt)
goto noxoff;
if (likely(!netif_queue_stopped(caifd->netdev))) {
struct Qdisc *sch;
/* If we run with a TX queue, check if the queue is too long*/
txq = netdev_get_tx_queue(skb->dev, 0);
qlen = qdisc_qlen(rcu_dereference_bh(txq->qdisc));
if (likely(qlen == 0))
sch = rcu_dereference_bh(txq->qdisc);
if (likely(qdisc_is_empty(sch)))
goto noxoff;
/* can check for explicit qdisc len value only !NOLOCK,
* always set flow off otherwise
*/
high = (caifd->netdev->tx_queue_len * q_high) / 100;
if (likely(qlen < high))
if (!(sch->flags & TCQ_F_NOLOCK) && likely(sch->q.qlen < high))
goto noxoff;
}