From: Eric Dumazet <edumazet@google.com>
Date: Sun, 10 May 2026 09:14:51 +0000 (+0000)
Subject: net/sched: add qdisc_qlen_lockless() helper
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=554e96a47a84e19abca8d2b1fea1de81cd2c8657;p=thirdparty%2Flinux.git

net/sched: add qdisc_qlen_lockless() helper

Used in contexts were qdisc spinlock is not held.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Link: https://patch.msgid.link/20260510091455.4039245-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 391ee8530017..0edf05d56862 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -542,6 +542,11 @@ static inline int qdisc_qlen(const struct Qdisc *q)
 	return q->q.qlen;
 }
 
+static inline int qdisc_qlen_lockless(const struct Qdisc *q)
+{
+	return READ_ONCE(q->q.qlen);
+}
+
 static inline void qdisc_qlen_inc(struct Qdisc *q)
 {
 	WRITE_ONCE(q->q.qlen, q->q.qlen + 1);
@@ -561,7 +566,7 @@ static inline int qdisc_qlen_sum(const struct Qdisc *q)
 		for_each_possible_cpu(i)
 			qlen += READ_ONCE(per_cpu_ptr(q->cpu_qstats, i)->qlen);
 	} else {
-		qlen += READ_ONCE(q->q.qlen);
+		qlen += qdisc_qlen_lockless(q);
 	}
 
 	return qlen;
diff --git a/net/sched/sch_mq.c b/net/sched/sch_mq.c
index ec8c91d3fde0..4172ec24a43d 100644
--- a/net/sched/sch_mq.c
+++ b/net/sched/sch_mq.c
@@ -163,7 +163,7 @@ void mq_dump_common(struct Qdisc *sch, struct sk_buff *skb)
 				     &qdisc->bstats, false);
 		gnet_stats_add_queue(&sch->qstats, qdisc->cpu_qstats,
 				     &qdisc->qstats);
-		qlen += qdisc_qlen(qdisc);
+		qlen += qdisc_qlen_lockless(qdisc);
 
 		spin_unlock_bh(qdisc_lock(qdisc));
 	}
diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c
index 91a92992cd24..3b4881c389c5 100644
--- a/net/sched/sch_mqprio.c
+++ b/net/sched/sch_mqprio.c
@@ -576,7 +576,7 @@ static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb)
 				     &qdisc->bstats, false);
 		gnet_stats_add_queue(&sch->qstats, qdisc->cpu_qstats,
 				     &qdisc->qstats);
-		qlen += qdisc_qlen(qdisc);
+		qlen += qdisc_qlen_lockless(qdisc);
 
 		spin_unlock_bh(qdisc_lock(qdisc));
 	}
@@ -691,7 +691,7 @@ static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 					     &qdisc->bstats, false);
 			gnet_stats_add_queue(&qstats, qdisc->cpu_qstats,
 					     &qdisc->qstats);
-			qlen += qdisc_qlen(qdisc);
+			qlen += qdisc_qlen_lockless(qdisc);
 
 			spin_unlock_bh(qdisc_lock(qdisc));
 		}