TAPRIO on Azure VMs

This also failed.

Create two Azure VMs (tico, tico2) and place them in the same VLAN subnet. tico is the client, and tico2 is server. Execute on the client port:

sudo tc qdisc replace dev eth0 parent root handle 100 taprio \
                     num_tc 3 \
                     map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 \
                     queues 1@0 1@0 1@0 \
                     base-time 1528743495910289987 \
                     sched-entry S 01 300000 \
                     sched-entry S 02 300000 \
                     sched-entry S 04 400000 \
                     flags 0x1 \
                     txtime-delay 200000 \
                     clockid CLOCK_TAI

# tc qdisc show dev eth0
qdisc taprio 100: root refcnt 65 tc 3 map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2
queues offset 0 count 1 offset 0 count 1 offset 0 count 1
clockid TAI flags 0x1 txtime delay 200000   base-time 1528743495910289987 cycle-time 1000000 cycle-time-extension 0
    index 0 cmd S gatemask 0x1 interval 300000
    index 1 cmd S gatemask 0x2 interval 300000
    index 2 cmd S gatemask 0x4 interval 400000

Set three priority in iperf

------------------------------------------------------------
Client connecting to 10.0.0.5, TCP port 5001
TCP window size:  230 KByte (default)
------------------------------------------------------------
[  3] local 10.0.0.4 port 48656 connected with 10.0.0.5 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0- 5.4 sec  6.88 MBytes  10.6 Mbits/sec

Either add tc or not the three priority remains the same. This is because queues 1@0 1@0 1@0 means the three priority goes in the same queue.

sudo tc qdisc replace dev eth0 parent root handle 100 taprio \
                     num_tc 3 \
                     map 1 2 3 0 0 0 0 0 0 0 0 0 0 0 0 0 \
                     queues 1@0 1@1 1@2 \
                     base-time 200 \
                     sched-entry S 00 300000 \
                     sched-entry S 02 300000 \
                     sched-entry S 04 800000 \
                     flags 0x1 \
                     txtime-delay 200000 \
                     clockid CLOCK_TAI

Get error

Changing the traffic mapping of a running schedule is not supported.

Just delete the qdisc setting.

Invalid traffic class in priority to traffic class mapping.

This is because num_tc 3 so the number of map can only set to 2.

1@0 2@0 1@0
1@0 1@1 1@0

both settings can’t work.

Invalid queue in traffic class to queue mapping.

ethtool -l eth0
Channel parameters for eth0:
Pre-set maximums:
RX:             0
TX:             0
Other:          0
Combined:       1
Current hardware settings:
RX:             0
TX:             0
Other:          0
Combined:       1

The NIC only has 1 queue. So we can’t use more than 1 queue.