net_sched: implement ->change_tx_queue_len() for pfifo_fast
pfifo_fast used to drop based on qdisc_dev(qdisc)->tx_queue_len,
so we have to resize skb array when we change tx_queue_len.
Other qdiscs which read tx_queue_len are fine because they
all save it to sch->limit or somewhere else in qdisc during init.
They don't have to implement this, it is nicer if they do so
that users don't have to re-configure qdisc after changing
tx_queue_len.
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 08f9fa2..190570f 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -763,6 +763,23 @@ static void pfifo_fast_destroy(struct Qdisc *sch)
}
}
+static int pfifo_fast_change_tx_queue_len(struct Qdisc *sch,
+ unsigned int new_len)
+{
+ struct pfifo_fast_priv *priv = qdisc_priv(sch);
+ struct skb_array *bands[PFIFO_FAST_BANDS];
+ int prio;
+
+ for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
+ struct skb_array *q = band2list(priv, prio);
+
+ bands[prio] = q;
+ }
+
+ return skb_array_resize_multiple(bands, PFIFO_FAST_BANDS, new_len,
+ GFP_KERNEL);
+}
+
struct Qdisc_ops pfifo_fast_ops __read_mostly = {
.id = "pfifo_fast",
.priv_size = sizeof(struct pfifo_fast_priv),
@@ -773,6 +790,7 @@ struct Qdisc_ops pfifo_fast_ops __read_mostly = {
.destroy = pfifo_fast_destroy,
.reset = pfifo_fast_reset,
.dump = pfifo_fast_dump,
+ .change_tx_queue_len = pfifo_fast_change_tx_queue_len,
.owner = THIS_MODULE,
.static_flags = TCQ_F_NOLOCK | TCQ_F_CPUSTATS,
};
