Commit 15dc36eb authored Mar 10, 2014 by Eric Dumazet Committed by David S. Miller Mar 11, 2014

pkt_sched: do not use rcu in tc_dump_qdisc()



Like all rtnetlink dump operations, we hold RTNL in tc_dump_qdisc(),
so we do not need to use rcu protection to protect list of netdevices.

This will allow preemption to occur, thus reducing latencies.
Following patch adds explicit cond_resched() calls.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent a19a7ec8

net/sched/sch_api.c

+2 −4

Original line number	Diff line number	Diff line
		@@ -1434,9 +1434,9 @@ 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 +1459,6 @@ cont:
		}

		done:
		rcu_read_unlock();

		cb->args[0] = idx;
		cb->args[1] = q_idx;