Merge branch 'pkt_sched_cond_resched'

Eric Dumazet says:

====================
pkt_sched: allow scheduling points

We have seen delays of more than 50ms in class or qdisc dumps, in case
device is under high TX stress, even with the prior 4KB per skb limit.

With the new 16KB limit, this could translate to 200ms delays.

Add cond_resched() to give a chance to higher prio tasks to get cpu.

But before doing so, we need to remove the rcu locking from tc_dump_qdisc()
as David spotted.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/sch_api.c

@@ -1303,6 +1303,7 @@ static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
 	struct gnet_dump d;
 	struct qdisc_size_table *stab;
 
+	cond_resched();
 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
 	if (!nlh)
 		goto out_nlmsg_trim;
@@ -1434,9 +1435,9 @@ static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
 	s_idx = cb->args[0];
 	s_q_idx = q_idx = cb->args[1];
 
-	rcu_read_lock();
 	idx = 0;
-	for_each_netdev_rcu(net, dev) {
+	ASSERT_RTNL();
+	for_each_netdev(net, dev) {
 		struct netdev_queue *dev_queue;
 
 		if (idx < s_idx)
@@ -1459,8 +1460,6 @@ static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
 	}
 
 done:
-	rcu_read_unlock();
-
 	cb->args[0] = idx;
 	cb->args[1] = q_idx;
 
@@ -1617,6 +1616,7 @@ static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
 	struct gnet_dump d;
 	const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
 
+	cond_resched();
 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
 	if (!nlh)
 		goto out_nlmsg_trim;