net: sched: run ingress qdisc without locks (087c1a60) · Commits · 戴 / test

TC classifiers/actions were converted to RCU by John in the series: http://thread.gmane.org/gmane.linux.network/329739/focus=329739 and many follow on patches. This is the last patch from that series that finally drops ingress spin_lock. Single cpu ingress+u32 performance goes from 22.9 Mpps to 24.5 Mpps. In two cpu case when both cores are receiving traffic on the same device and go into the same ingress+u32 the performance jumps from 4.5 + 4.5 Mpps to 23.5 + 23.5 Mpps Signed-off-by:

John Fastabend <john.r.fastabend@intel.com> Signed-off-by:

Alexei Starovoitov <ast@plumgrid.com> Signed-off-by:

Jamal Hadi Salim <jhs@mojatatu.com> Acked-by:

Daniel Borkmann <daniel@iogearbox.net> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/core/dev.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -3547,10 +3547,8 @@ static int ing_filter(struct sk_buff skb, struct netdev_queue rxq)

		q = rcu_dereference(rxq->qdisc);
		if (q != &noop_qdisc) {
		spin_lock(qdisc_lock(q));
		if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state)))
		result = qdisc_enqueue_root(skb, q);
		spin_unlock(qdisc_lock(q));
		}

		return result;

net/sched/sch_ingress.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -65,11 +65,11 @@ static int ingress_enqueue(struct sk_buff skb, struct Qdisc sch)

		result = tc_classify(skb, fl, &res);

		qdisc_bstats_update(sch, skb);
		qdisc_bstats_update_cpu(sch, skb);
		switch (result) {
		case TC_ACT_SHOT:
		result = TC_ACT_SHOT;
		qdisc_qstats_drop(sch);
		qdisc_qstats_drop_cpu(sch);
		break;
		case TC_ACT_STOLEN:
		case TC_ACT_QUEUED:
		@@ -91,6 +91,7 @@ static int ingress_enqueue(struct sk_buff skb, struct Qdisc sch)
		static int ingress_init(struct Qdisc sch, struct nlattr opt)
		{
		net_inc_ingress_queue();
		sch->flags \|= TCQ_F_CPUSTATS;

		return 0;
		}

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