@@ -566,9 +566,6 @@ static int taprio_enqueue_one(struct sk_buff *skb, struct Qdisc *sch,
return qdisc_drop(skb, sch, to_free);
}
- if (taprio_skb_exceeds_queue_max_sdu(sch, skb))
- return qdisc_drop(skb, sch, to_free);
-
qdisc_qstats_backlog_inc(sch, skb);
sch->q.qlen++;
@@ -593,7 +590,14 @@ static int taprio_enqueue_segmented(struct sk_buff *skb, struct Qdisc *sch,
qdisc_skb_cb(segs)->pkt_len = segs->len;
slen += segs->len;
- ret = taprio_enqueue_one(segs, sch, child, to_free);
+ /* FIXME: we should be segmenting to a smaller size
+ * rather than dropping these
+ */
+ if (taprio_skb_exceeds_queue_max_sdu(sch, segs))
+ ret = qdisc_drop(segs, sch, to_free);
+ else
+ ret = taprio_enqueue_one(segs, sch, child, to_free);
+
if (ret != NET_XMIT_SUCCESS) {
if (net_xmit_drop_count(ret))
qdisc_qstats_drop(sch);
@@ -625,13 +629,18 @@ static int taprio_enqueue(struct sk_buff *skb, struct Qdisc *sch,
if (unlikely(!child))
return qdisc_drop(skb, sch, to_free);
- /* Large packets might not be transmitted when the transmission duration
- * exceeds any configured interval. Therefore, segment the skb into
- * smaller chunks. Drivers with full offload are expected to handle
- * this in hardware.
- */
- if (skb_is_gso(skb))
- return taprio_enqueue_segmented(skb, sch, child, to_free);
+ if (taprio_skb_exceeds_queue_max_sdu(sch, skb)) {
+ /* Large packets might not be transmitted when the transmission
+ * duration exceeds any configured interval. Therefore, segment
+ * the skb into smaller chunks. Drivers with full offload are
+ * expected to handle this in hardware.
+ */
+ if (skb_is_gso(skb))
+ return taprio_enqueue_segmented(skb, sch, child,
+ to_free);
+
+ return qdisc_drop(skb, sch, to_free);
+ }
return taprio_enqueue_one(skb, sch, child, to_free);
}
Improve commit 497cc00224cf ("taprio: Handle short intervals and large packets") to only perform segmentation when skb->len exceeds what taprio_dequeue() expects. In practice, this will make the biggest difference when a traffic class gate is always open in the schedule. This is because the max_frm_len will be U32_MAX, and such large skb->len values as Kurt reported will be sent just fine unsegmented. What I don't seem to know how to handle is how to make sure that the segmented skbs themselves are smaller than the maximum frame size given by the current queueMaxSDU[tc]. Nonetheless, we still need to drop those, otherwise the Qdisc will hang. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de> --- v1->v2: use the new taprio_skb_exceeds_queue_max_sdu() helper net/sched/sch_taprio.c | 31 ++++++++++++++++++++----------- 1 file changed, 20 insertions(+), 11 deletions(-)