From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>,
Jamal Hadi Salim <jhs@mojatatu.com>,
Jiri Pirko <jiri@resnulli.us>,
Victor Nogueira <victor@mojatatu.com>,
netdev@vger.kernel.org, eric.dumazet@gmail.com,
Eric Dumazet <edumazet@google.com>
Subject: [PATCH v2 net-next 4/8] net/sched: add qdisc_qlen_lockless() helper
Date: Sun, 10 May 2026 09:14:51 +0000 [thread overview]
Message-ID: <20260510091455.4039245-5-edumazet@google.com> (raw)
In-Reply-To: <20260510091455.4039245-1-edumazet@google.com>
Used in contexts were qdisc spinlock is not held.
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
include/net/sch_generic.h | 7 ++++++-
net/sched/sch_mq.c | 2 +-
net/sched/sch_mqprio.c | 4 ++--
3 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 391ee85300172fced9bd7c8918727f01662c4a11..0edf05d56862b113a9468ef2175d203123814ec5 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 ec8c91d3fde04e59daec2aecdb14d6bf50715e15..4172ec24a43d1c2fe56789986a46da93eb522721 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 91a92992cd24ab6c30bf7db2288c08cd493c7bc3..3b4881c389c535368687454ea268bec892ecb942 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));
}
--
2.54.0.563.g4f69b47b94-goog
next prev parent reply other threads:[~2026-05-10 9:15 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-10 9:14 [PATCH v2 net-next 0/8] net/sched: prepare lockless qdisc dumps Eric Dumazet
2026-05-10 9:14 ` [PATCH v2 net-next 1/8] net/sched: add READ_ONCE() in gnet_stats_add_queue[_cpu] Eric Dumazet
2026-05-10 9:14 ` [PATCH v2 net-next 2/8] net/sched: add qdisc_qlen_inc() and qdisc_qlen_dec() Eric Dumazet
2026-05-10 9:14 ` [PATCH v2 net-next 3/8] net/sched: annotate data-races around sch->qstats.backlog Eric Dumazet
2026-05-10 9:14 ` Eric Dumazet [this message]
2026-05-10 9:14 ` [PATCH v2 net-next 5/8] net/sched: add const qualifiers to gnet_stats helpers Eric Dumazet
2026-05-10 9:14 ` [PATCH v2 net-next 6/8] net/sched: mq: no longer acquire qdisc spinlocks in dump operations Eric Dumazet
2026-05-10 9:14 ` [PATCH v2 net-next 7/8] net/sched: mq_prio: no longer acquire qdisc spinlocks in mqprio_dump() Eric Dumazet
2026-05-10 9:14 ` [PATCH v2 net-next 8/8] net/sched: mq_prio: no longer acquire qdisc spinlocks in mqprio_dump_class_stats() Eric Dumazet
2026-05-10 9:31 ` [PATCH v2 net-next 0/8] net/sched: prepare lockless qdisc dumps Toke Høiland-Jørgensen
2026-05-12 1:48 ` patchwork-bot+netdevbpf
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