net_sched: gred: actually perform idling in WRED mode (ba1bf474) · Commits · 戴 / test

gred_dequeue() and gred_drop() do not seem to get called when the queue is empty, meaning that we never start idling while in WRED mode. And since qidlestart is not stored by gred_store_wred_set(), we would never stop idling while in WRED mode if we ever started. This messes up the average queue size calculation that influences packet marking/dropping behavior. Now, we start WRED mode idling as we are removing the last packet from the queue. Also we now actually stop WRED mode idling when we are enqueuing a packet. Cc: Bruce Osler <brosler@cisco.com> Signed-off-by:

David Ward <david.ward@ll.mit.edu> Acked-by:

Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/sched/sch_gred.c

+15 −11

Original line number	Diff line number	Diff line
		@@ -136,6 +136,7 @@ static inline void gred_store_wred_set(struct gred_sched *table,
		struct gred_sched_data *q)
		{
		table->wred_set.qavg = q->vars.qavg;
		table->wred_set.qidlestart = q->vars.qidlestart;
		}

		static inline int gred_use_ecn(struct gred_sched *t)
		@@ -259,16 +260,18 @@ static struct sk_buff gred_dequeue(struct Qdisc sch)
		} else {
		q->backlog -= qdisc_pkt_len(skb);

		if (!q->backlog && !gred_wred_mode(t))
		if (gred_wred_mode(t)) {
		if (!sch->qstats.backlog)
		red_start_of_idle_period(&t->wred_set);
		} else {
		if (!q->backlog)
		red_start_of_idle_period(&q->vars);
		}
		}

		return skb;
		}

		if (gred_wred_mode(t) && !red_is_idling(&t->wred_set))
		red_start_of_idle_period(&t->wred_set);

		return NULL;
		}

		@@ -290,19 +293,20 @@ static unsigned int gred_drop(struct Qdisc *sch)
		q->backlog -= len;
		q->stats.other++;

		if (!q->backlog && !gred_wred_mode(t))
		if (gred_wred_mode(t)) {
		if (!sch->qstats.backlog)
		red_start_of_idle_period(&t->wred_set);
		} else {
		if (!q->backlog)
		red_start_of_idle_period(&q->vars);
		}
		}

		qdisc_drop(skb, sch);
		return len;
		}

		if (gred_wred_mode(t) && !red_is_idling(&t->wred_set))
		red_start_of_idle_period(&t->wred_set);

		return 0;

		}

		static void gred_reset(struct Qdisc *sch)

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