[next-queue,v7,3/6] net/sched: Add select_queue() class_ops for mqprio

Message ID 20171013004005.17416-4-vinicius.gomes@intel.com
State Superseded
Headers show
  • TSN: Add qdisc based config interface for CBS
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Commit Message

Vinicius Costa Gomes Oct. 13, 2017, 12:40 a.m.
From: Jesus Sanchez-Palencia <jesus.sanchez-palencia@intel.com>

When replacing a child qdisc from mqprio, tc_modify_qdisc() must fetch
the netdev_queue pointer that the current child qdisc is associated
with before creating the new qdisc.

Currently, when using mqprio as root qdisc, the kernel will end up
getting the queue #0 pointer from the mqprio (root qdisc), which leaves
any new child qdisc with a possibly wrong netdev_queue pointer.

Implementing the Qdisc_class_ops select_queue() on mqprio fixes this
issue and avoid an inconsistent state when child qdiscs are replaced.

Signed-off-by: Jesus Sanchez-Palencia <jesus.sanchez-palencia@intel.com>
 net/sched/sch_mqprio.c | 7 +++++++
 1 file changed, 7 insertions(+)


diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c
index 6bcdfe6e7b63..8c042ae323e3 100644
--- a/net/sched/sch_mqprio.c
+++ b/net/sched/sch_mqprio.c
@@ -396,6 +396,12 @@  static void mqprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
+static struct netdev_queue *mqprio_select_queue(struct Qdisc *sch,
+						struct tcmsg *tcm)
+	return mqprio_queue_get(sch, TC_H_MIN(tcm->tcm_parent));
 static const struct Qdisc_class_ops mqprio_class_ops = {
 	.graft		= mqprio_graft,
 	.leaf		= mqprio_leaf,
@@ -403,6 +409,7 @@  static const struct Qdisc_class_ops mqprio_class_ops = {
 	.walk		= mqprio_walk,
 	.dump		= mqprio_dump_class,
 	.dump_stats	= mqprio_dump_class_stats,
+	.select_queue	= mqprio_select_queue,
 static struct Qdisc_ops mqprio_qdisc_ops __read_mostly = {