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-rw-r--r--include/net/sch_generic.h11
-rw-r--r--net/sched/sch_generic.c3
2 files changed, 14 insertions, 0 deletions
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 31284c078d06..e227475e78ca 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -113,6 +113,9 @@ struct Qdisc {
spinlock_t busylock ____cacheline_aligned_in_smp;
spinlock_t seqlock;
+
+ /* for NOLOCK qdisc, true if there are no enqueued skbs */
+ bool empty;
struct rcu_head rcu;
};
@@ -143,11 +146,19 @@ static inline bool qdisc_is_running(struct Qdisc *qdisc)
return (raw_read_seqcount(&qdisc->running) & 1) ? true : false;
}
+static inline bool qdisc_is_empty(const struct Qdisc *qdisc)
+{
+ if (qdisc->flags & TCQ_F_NOLOCK)
+ return qdisc->empty;
+ return !qdisc->q.qlen;
+}
+
static inline bool qdisc_run_begin(struct Qdisc *qdisc)
{
if (qdisc->flags & TCQ_F_NOLOCK) {
if (!spin_trylock(&qdisc->seqlock))
return false;
+ qdisc->empty = false;
} else if (qdisc_is_running(qdisc)) {
return false;
}
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index a117d9260558..81356ef38d1d 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -671,6 +671,8 @@ static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc)
qdisc_qstats_cpu_backlog_dec(qdisc, skb);
qdisc_bstats_cpu_update(qdisc, skb);
qdisc_qstats_atomic_qlen_dec(qdisc);
+ } else {
+ qdisc->empty = true;
}
return skb;
@@ -880,6 +882,7 @@ struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
sch->enqueue = ops->enqueue;
sch->dequeue = ops->dequeue;
sch->dev_queue = dev_queue;
+ sch->empty = true;
dev_hold(dev);
refcount_set(&sch->refcnt, 1);