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From:   Peilin Ye <yepeilin.cs@gmail.com>
To:     "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <eric.dumazet@gmail.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        David Ahern <dsahern@kernel.org>,
        Jamal Hadi Salim <jhs@mojatatu.com>,
        Cong Wang <xiyou.wangcong@gmail.com>,
        Jiri Pirko <jiri@resnulli.us>
Cc:     Peilin Ye <peilin.ye@bytedance.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, Cong Wang <cong.wang@bytedance.com>,
        Peilin Ye <yepeilin.cs@gmail.com>
Subject: [PATCH RFC v1 net-next 3/4] net/sched: sch_htb: Use Qdisc backpressure infrastructure
Date:   Fri,  6 May 2022 12:45:24 -0700
Message-Id: <ffcde45d06d12def0b9c2c9238b0325db252a5cc.1651800598.git.peilin.ye@bytedance.com>
In-Reply-To: <cover.1651800598.git.peilin.ye@bytedance.com>
References: <cover.1651800598.git.peilin.ye@bytedance.com>
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From: Peilin Ye <peilin.ye@bytedance.com>

Recently we introduced a Qdisc backpressure infrastructure for TCP and
UDP sockets.  Use it in HTB.

Suggested-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
---
 net/sched/sch_htb.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 23a9d6242429..21d78dff08e7 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -623,6 +623,7 @@ static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			__qdisc_enqueue_tail(skb, &q->direct_queue);
 			q->direct_pkts++;
 		} else {
+			qdisc_backpressure_overlimit(sch, skb);
 			return qdisc_drop(skb, sch, to_free);
 		}
 #ifdef CONFIG_NET_CLS_ACT
@@ -634,6 +635,7 @@ static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 #endif
 	} else if ((ret = qdisc_enqueue(skb, cl->leaf.q,
 					to_free)) != NET_XMIT_SUCCESS) {
+		qdisc_backpressure_overlimit(sch, skb);
 		if (net_xmit_drop_count(ret)) {
 			qdisc_qstats_drop(sch);
 			cl->drops++;
@@ -978,6 +980,9 @@ static struct sk_buff *htb_dequeue(struct Qdisc *sch)
 				goto ok;
 		}
 	}
+
+	qdisc_backpressure_throttle(sch);
+
 	if (likely(next_event > q->now))
 		qdisc_watchdog_schedule_ns(&q->watchdog, next_event);
 	else
-- 
2.20.1