netdev - [PATCH v3 net-next 14/14] net_sched: use qdisc_dequeue_drop() in cake, codel, fq

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Message-ID: <20251121083256.674562-15-edumazet@google.com>
Date: Fri, 21 Nov 2025 08:32:56 +0000
From: Eric Dumazet <edumazet@...gle.com>
To: "David S . Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>, 
	Paolo Abeni <pabeni@...hat.com>
Cc: Simon Horman <horms@...nel.org>, Jamal Hadi Salim <jhs@...atatu.com>, 
	Cong Wang <xiyou.wangcong@...il.com>, Jiri Pirko <jiri@...nulli.us>, 
	"Toke Høiland-Jørgensen" <toke@...hat.com>, Kuniyuki Iwashima <kuniyu@...gle.com>, 
	Willem de Bruijn <willemb@...gle.com>, netdev@...r.kernel.org, eric.dumazet@...il.com, 
	Eric Dumazet <edumazet@...gle.com>
Subject: [PATCH v3 net-next 14/14] net_sched: use qdisc_dequeue_drop() in
 cake, codel, fq_codel

cake, codel and fq_codel can drop many packets from dequeue().

Use qdisc_dequeue_drop() so that the freeing can happen
outside of the qdisc spinlock scope.

Add TCQ_F_DEQUEUE_DROPS to sch->flags.

Signed-off-by: Eric Dumazet <edumazet@...gle.com>
---
 net/sched/sch_cake.c     | 4 +++-
 net/sched/sch_codel.c    | 4 +++-
 net/sched/sch_fq_codel.c | 5 ++++-
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 5948a149129c6de041ba949e2e2b5b6b4eb54166..0ea9440f68c60ab69e9dd889b225c1a171199787 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -2183,7 +2183,7 @@ static struct sk_buff *cake_dequeue(struct Qdisc *sch)
 		b->tin_dropped++;
 		qdisc_tree_reduce_backlog(sch, 1, qdisc_pkt_len(skb));
 		qdisc_qstats_drop(sch);
-		kfree_skb_reason(skb, reason);
+		qdisc_dequeue_drop(sch, skb, reason);
 		if (q->rate_flags & CAKE_FLAG_INGRESS)
 			goto retry;
 	}
@@ -2724,6 +2724,8 @@ static int cake_init(struct Qdisc *sch, struct nlattr *opt,
 	int i, j, err;
 
 	sch->limit = 10240;
+	sch->flags |= TCQ_F_DEQUEUE_DROPS;
+
 	q->tin_mode = CAKE_DIFFSERV_DIFFSERV3;
 	q->flow_mode  = CAKE_FLOW_TRIPLE;
 
diff --git a/net/sched/sch_codel.c b/net/sched/sch_codel.c
index fa0314679e434a4f84a128e8330bb92743c3d66a..c6551578f1cf8d332ca20ea062e858ffb437966a 100644
--- a/net/sched/sch_codel.c
+++ b/net/sched/sch_codel.c
@@ -52,7 +52,7 @@ static void drop_func(struct sk_buff *skb, void *ctx)
 {
 	struct Qdisc *sch = ctx;
 
-	kfree_skb_reason(skb, SKB_DROP_REASON_QDISC_CONGESTED);
+	qdisc_dequeue_drop(sch, skb, SKB_DROP_REASON_QDISC_CONGESTED);
 	qdisc_qstats_drop(sch);
 }
 
@@ -182,6 +182,8 @@ static int codel_init(struct Qdisc *sch, struct nlattr *opt,
 	else
 		sch->flags &= ~TCQ_F_CAN_BYPASS;
 
+	sch->flags |= TCQ_F_DEQUEUE_DROPS;
+
 	return 0;
 }
 
diff --git a/net/sched/sch_fq_codel.c b/net/sched/sch_fq_codel.c
index a141423929394d7ebe127aa328dcf13ae67b3d56..dc187c7f06b10d8fd4191ead82e6a60133fff09d 100644
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
@@ -275,7 +275,7 @@ static void drop_func(struct sk_buff *skb, void *ctx)
 {
 	struct Qdisc *sch = ctx;
 
-	kfree_skb_reason(skb, SKB_DROP_REASON_QDISC_CONGESTED);
+	qdisc_dequeue_drop(sch, skb, SKB_DROP_REASON_QDISC_CONGESTED);
 	qdisc_qstats_drop(sch);
 }
 
@@ -519,6 +519,9 @@ static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt,
 		sch->flags |= TCQ_F_CAN_BYPASS;
 	else
 		sch->flags &= ~TCQ_F_CAN_BYPASS;
+
+	sch->flags |= TCQ_F_DEQUEUE_DROPS;
+
 	return 0;
 
 alloc_failure:
-- 
2.52.0.460.gd25c4c69ec-goog