Jakub Kicinski says: ==================== net: sched: update default qdisc visibility after Tx queue cnt changes Matthew noticed that number of children reported by mq does not match number of queues on reconfigured interfaces. For example if mq is instantiated when there is 8 queues it will always show 8 children, regardless of config being changed: # ethtool -L eth0 combined 8 # tc qdisc replace dev eth0 root handle 100: mq # tc qdisc show dev eth0 qdisc mq 100: root qdisc pfifo_fast 0: parent 100:8 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:7 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:6 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:5 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:4 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:3 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:2 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:1 bands 3 priomap 1 2 ... # ethtool -L eth0 combined 1 # tc qdisc show dev eth0 qdisc mq 100: root qdisc pfifo_fast 0: parent 100:8 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:7 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:6 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:5 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:4 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:3 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:2 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:1 bands 3 priomap 1 2 ... # ethtool -L eth0 combined 32 # tc qdisc show dev eth0 qdisc mq 100: root qdisc pfifo_fast 0: parent 100:8 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:7 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:6 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:5 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:4 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:3 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:2 bands 3 priomap 1 2 ... qdisc pfifo_fast 0: parent 100:1 bands 3 priomap 1 2 ... This patchset fixes this by hashing and unhasing the default child qdiscs as number of queues gets adjusted. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>