Re: [PATCH v4 net-next 6/6] Documentation: networking: cpsw: add MQPRIO & CBS offload examples

[Richard Cochran]

On Sat, Jul 21, 2018 at 02:59:23PM +0300, Ivan Khoronzhuk wrote:
> This document describes MQPRIO and CBS Qdisc offload configuration
> for cpsw driver based on examples. It potentially can be used in
> audio video bridging (AVB) and time sensitive networking (TSN).
> 
> Reviewed-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx>
> ---
>  Documentation/networking/ti-cpsw.txt | 540 +++++++++++++++++++++++++++
>  1 file changed, 540 insertions(+)
>  create mode 100644 Documentation/networking/ti-cpsw.txt
> 
> diff --git a/Documentation/networking/ti-cpsw.txt b/Documentation/networking/ti-cpsw.txt
> new file mode 100644
> index 000000000000..1e840346cae1
> --- /dev/null
> +++ b/Documentation/networking/ti-cpsw.txt
> @@ -0,0 +1,540 @@
> +* Texas Instruments CPSW ethernet driver
> +
> +Multiqueue & CBS & MQPRIO
> +=====================================================================
> +=====================================================================
> +
> +The cpsw has 3 CBS shapers for each external ports. This document
> +describes MQPRIO and CBS Qdisc offload configuration for cpsw driver
> +based on examples. It potentially can be used in audio video bridging
> +(AVB) and time sensitive networking (TSN).
> +
> +The following examples was tested on AM572x EVM and BBB boards.
> +
> +Test setup
> +==========
> +
> +Under consideration two examples with AM52xx EVM running cpsw driver
> +in dual_emac mode.

s/AM52xx/AM572x ?

Also, there are more mentions of AM52xx, below.

Thanks,
Richard


> +
> +Several prerequisites:
> +- TX queues must be rated starting from txq0 that has highest priority
> +- Traffic classes are used starting from 0, that has highest priority
> +- CBS shapers should be used with rated queues
> +- The bandwidth for CBS shapers has to be set a little bit more then
> +  potential incoming rate, thus, rate of all incoming tx queues has
> +  to be a little less
> +- Real rates can differ, due to discreetness
> +- Map skb-priority to txq is not enough, also skb-priority to l2 prio
> +  map has to be created with ip or vconfig tool
> +- Any l2/socket prio (0 - 7) for classes can be used, but for
> +  simplicity default values are used: 3 and 2
> +- only 2 classes tested: A and B, but checked and can work with more,
> +  maximum allowed 4, but only for 3 rate can be set.
> +
> +Test setup for examples
> +=======================
> +                                    +-------------------------------+
> +                                    |--+                            |
> +                                    |  |      Workstation0          |
> +                                    |E |  MAC 18:03:73:66:87:42     |
> ++-----------------------------+  +--|t |                            |
> +|                    | 1  | E |  |  |h |./tsn_listener -d \         |
> +|  Target board:     | 0  | t |--+  |0 | 18:03:73:66:87:42 -i eth0 \|
> +|  AM572x EVM        | 0  | h |     |  | -s 1500                    |
> +|                    | 0  | 0 |     |--+                            |
> +|  Only 2 classes:   |Mb  +---|     +-------------------------------+
> +|  class A, class B  |        |
> +|                    |    +---|     +-------------------------------+
> +|                    | 1  | E |     |--+                            |
> +|                    | 0  | t |     |  |      Workstation1          |
> +|                    | 0  | h |--+  |E |  MAC 20:cf:30:85:7d:fd     |
> +|                    |Mb  | 1 |  +--|t |                            |
> ++-----------------------------+     |h |./tsn_listener -d \         |
> +                                    |0 | 20:cf:30:85:7d:fd -i eth0 \|
> +                                    |  | -s 1500                    |
> +                                    |--+                            |
> +                                    +-------------------------------+
> +
> +*********************************************************************
> +*********************************************************************
> +*********************************************************************
> +Example 1: One port tx AVB configuration scheme for target board
> +----------------------------------------------------------------------
> +(prints and scheme for AM52xx evm, applicable for single port boards)
> +
> +tc - traffic class
> +txq - transmit queue
> +p - priority
> +f - fifo (cpsw fifo)
> +S - shaper configured
> +
> ++------------------------------------------------------------------+ u
> +| +---------------+  +---------------+  +------+ +------+          | s
> +| |               |  |               |  |      | |      |          | e
> +| | App 1         |  | App 2         |  | Apps | | Apps |          | r
> +| | Class A       |  | Class B       |  | Rest | | Rest |          |
> +| | Eth0          |  | Eth0          |  | Eth0 | | Eth1 |          | s
> +| | VLAN100       |  | VLAN100       |  |   |  | |   |  |          | p
> +| | 40 Mb/s       |  | 20 Mb/s       |  |   |  | |   |  |          | a
> +| | SO_PRIORITY=3 |  | SO_PRIORITY=2 |  |   |  | |   |  |          | c
> +| |   |           |  |   |           |  |   |  | |   |  |          | e
> +| +---|-----------+  +---|-----------+  +---|--+ +---|--+          |
> ++-----|------------------|------------------|--------|-------------+
> +    +-+     +------------+                  |        |
> +    |       |             +-----------------+     +--+
> +    |       |             |                       |
> ++---|-------|-------------|-----------------------|----------------+
> +| +----+ +----+ +----+ +----+                   +----+             |
> +| | p3 | | p2 | | p1 | | p0 |                   | p0 |             | k
> +| \    / \    / \    / \    /                   \    /             | e
> +|  \  /   \  /   \  /   \  /                     \  /              | r
> +|   \/     \/     \/     \/                       \/               | n
> +|    |     |             |                        |                | e
> +|    |     |       +-----+                        |                | l
> +|    |     |       |                              |                |
> +| +----+ +----+ +----+                          +----+             | s
> +| |tc0 | |tc1 | |tc2 |                          |tc0 |             | p
> +| \    / \    / \    /                          \    /             | a
> +|  \  /   \  /   \  /                            \  /              | c
> +|   \/     \/     \/                              \/               | e
> +|   |      |       +-----+                        |                |
> +|   |      |       |     |                        |                |
> +|   |      |       |     |                        |                |
> +|   |      |       |     |                        |                |
> +| +----+ +----+ +----+ +----+                   +----+             |
> +| |txq0| |txq1| |txq2| |txq3|                   |txq4|             |
> +| \    / \    / \    / \    /                   \    /             |
> +|  \  /   \  /   \  /   \  /                     \  /              |
> +|   \/     \/     \/     \/                       \/               |
> +| +-|------|------|------|--+                  +--|--------------+ |
> +| | |      |      |      |  | Eth0.100         |  |     Eth1     | |
> ++---|------|------|------|------------------------|----------------+
> +    |      |      |      |                        |
> +    p      p      p      p                        |
> +    3      2      0-1, 4-7  <- L2 priority        |
> +    |      |      |      |                        |
> +    |      |      |      |                        |
> ++---|------|------|------|------------------------|----------------+
> +|   |      |      |      |             |----------+                |
> +| +----+ +----+ +----+ +----+       +----+                         |
> +| |dma7| |dma6| |dma5| |dma4|       |dma3|                         |
> +| \    / \    / \    / \    /       \    /                         | c
> +|  \S /   \S /   \  /   \  /         \  /                          | p
> +|   \/     \/     \/     \/           \/                           | s
> +|   |      |      | +-----            |                            | w
> +|   |      |      | |                 |                            |
> +|   |      |      | |                 |                            | d
> +| +----+ +----+ +----+p            p+----+                         | r
> +| |    | |    | |    |o            o|    |                         | i
> +| | f3 | | f2 | | f0 |r            r| f0 |                         | v
> +| |tc0 | |tc1 | |tc2 |t            t|tc0 |                         | e
> +| \CBS / \CBS / \CBS /1            2\CBS /                         | r
> +|  \S /   \S /   \  /                \  /                          |
> +|   \/     \/     \/                  \/                           |
> ++------------------------------------------------------------------+
> +========================================Eth==========================>
> +
> +1)
> +// Add 4 tx queues, for interface Eth0, and 1 tx queue for Eth1
> +$ ethtool -L eth0 rx 1 tx 5
> +rx unmodified, ignoring
> +
> +2)
> +// Check if num of queues is set correctly:
> +$ ethtool -l eth0
> +Channel parameters for eth0:
> +Pre-set maximums:
> +RX:             8
> +TX:             8
> +Other:          0
> +Combined:       0
> +Current hardware settings:
> +RX:             1
> +TX:             5
> +Other:          0
> +Combined:       0
> +
> +3)
> +// TX queues must be rated starting from 0, so set bws for tx0 and tx1
> +// Set rates 40 and 20 Mb/s appropriately.
> +// Pay attention, real speed can differ a bit due to discreetness.
> +// Leave last 2 tx queues not rated.
> +$ echo 40 > /sys/class/net/eth0/queues/tx-0/tx_maxrate
> +$ echo 20 > /sys/class/net/eth0/queues/tx-1/tx_maxrate
> +
> +4)
> +// Check maximum rate of tx (cpdma) queues:
> +$ cat /sys/class/net/eth0/queues/tx-*/tx_maxrate
> +40
> +20
> +0
> +0
> +0
> +
> +5)
> +// Map skb->priority to traffic class:
> +// 3pri -> tc0, 2pri -> tc1, (0,1,4-7)pri -> tc2
> +// Map traffic class to transmit queue:
> +// tc0 -> txq0, tc1 -> txq1, tc2 -> (txq2, txq3)
> +$ tc qdisc replace dev eth0 handle 100: parent root mqprio num_tc 3 \
> +map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 queues 1@0 1@1 2@2 hw 1
> +
> +5a)
> +// As two interface sharing same set of tx queues, assign all traffic
> +// coming to interface Eth1 to separate queue in order to not mix it
> +// with traffic from interface Eth0, so use separate txq to send
> +// packets to Eth1, so all prio -> tc0 and tc0 -> txq4
> +// Here hw 0, so here still default configuration for eth1 in hw
> +$ tc qdisc replace dev eth1 handle 100: parent root mqprio num_tc 1 \
> +map 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 queues 1@4 hw 0
> +
> +6)
> +// Check classes settings
> +$ tc -g class show dev eth0
> ++---(100:ffe2) mqprio
> +|    +---(100:3) mqprio
> +|    +---(100:4) mqprio
> +|
> ++---(100:ffe1) mqprio
> +|    +---(100:2) mqprio
> +|
> ++---(100:ffe0) mqprio
> +     +---(100:1) mqprio
> +
> +$ tc -g class show dev eth1
> ++---(100:ffe0) mqprio
> +     +---(100:5) mqprio
> +
> +7)
> +// Set rate for class A - 41 Mbit (tc0, txq0) using CBS Qdisc
> +// Set it +1 Mb for reserve (important!)
> +// here only idle slope is important, others arg are ignored
> +// Pay attention, real speed can differ a bit due to discreetness
> +$ tc qdisc add dev eth0 parent 100:1 cbs locredit -1438 \
> +hicredit 62 sendslope -959000 idleslope 41000 offload 1
> +net eth0: set FIFO3 bw = 50
> +
> +8)
> +// Set rate for class B - 21 Mbit (tc1, txq1) using CBS Qdisc:
> +// Set it +1 Mb for reserve (important!)
> +$ tc qdisc add dev eth0 parent 100:2 cbs locredit -1468 \
> +hicredit 65 sendslope -979000 idleslope 21000 offload 1
> +net eth0: set FIFO2 bw = 30
> +
> +9)
> +// Create vlan 100 to map sk->priority to vlan qos
> +$ ip link add link eth0 name eth0.100 type vlan id 100
> +8021q: 802.1Q VLAN Support v1.8
> +8021q: adding VLAN 0 to HW filter on device eth0
> +8021q: adding VLAN 0 to HW filter on device eth1
> +net eth0: Adding vlanid 100 to vlan filter
> +
> +10)
> +// Map skb->priority to L2 prio, 1 to 1
> +$ ip link set eth0.100 type vlan \
> +egress 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
> +
> +11)
> +// Check egress map for vlan 100
> +$ cat /proc/net/vlan/eth0.100
> +[...]
> +INGRESS priority mappings: 0:0  1:0  2:0  3:0  4:0  5:0  6:0 7:0
> +EGRESS priority mappings: 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
> +
> +12)
> +// Run your appropriate tools with socket option "SO_PRIORITY"
> +// to 3 for class A and/or to 2 for class B
> +// (I took at https://www.spinics.net/lists/netdev/msg460869.html)
> +./tsn_talker -d 18:03:73:66:87:42 -i eth0.100 -p3 -s 1500&
> +./tsn_talker -d 18:03:73:66:87:42 -i eth0.100 -p2 -s 1500&
> +
> +13)
> +// run your listener on workstation (should be in same vlan)
> +// (I took at https://www.spinics.net/lists/netdev/msg460869.html)
> +./tsn_listener -d 18:03:73:66:87:42 -i enp5s0 -s 1500
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39000 kbps
> +
> +14)
> +// Restore default configuration if needed
> +$ ip link del eth0.100
> +$ tc qdisc del dev eth1 root
> +$ tc qdisc del dev eth0 root
> +net eth0: Prev FIFO2 is shaped
> +net eth0: set FIFO3 bw = 0
> +net eth0: set FIFO2 bw = 0
> +$ ethtool -L eth0 rx 1 tx 1
> +
> +*********************************************************************
> +*********************************************************************
> +*********************************************************************
> +Example 2: Two port tx AVB configuration scheme for target board
> +----------------------------------------------------------------------
> +(prints and scheme for AM52xx evm, for dual emac boards only)
> +
> ++------------------------------------------------------------------+ u
> +| +----------+  +----------+  +------+  +----------+  +----------+ | s
> +| |          |  |          |  |      |  |          |  |          | | e
> +| | App 1    |  | App 2    |  | Apps |  | App 3    |  | App 4    | | r
> +| | Class A  |  | Class B  |  | Rest |  | Class B  |  | Class A  | |
> +| | Eth0     |  | Eth0     |  |   |  |  | Eth1     |  | Eth1     | | s
> +| | VLAN100  |  | VLAN100  |  |   |  |  | VLAN100  |  | VLAN100  | | p
> +| | 40 Mb/s  |  | 20 Mb/s  |  |   |  |  | 10 Mb/s  |  | 30 Mb/s  | | a
> +| | SO_PRI=3 |  | SO_PRI=2 |  |   |  |  | SO_PRI=3 |  | SO_PRI=2 | | c
> +| |   |      |  |   |      |  |   |  |  |   |      |  |   |      | | e
> +| +---|------+  +---|------+  +---|--+  +---|------+  +---|------+ |
> ++-----|-------------|-------------|---------|-------------|--------+
> +    +-+     +-------+             |         +----------+  +----+
> +    |       |             +-------+------+             |       |
> +    |       |             |              |             |       |
> ++---|-------|-------------|--------------|-------------|-------|---+
> +| +----+ +----+ +----+ +----+          +----+ +----+ +----+ +----+ |
> +| | p3 | | p2 | | p1 | | p0 |          | p0 | | p1 | | p2 | | p3 | | k
> +| \    / \    / \    / \    /          \    / \    / \    / \    / | e
> +|  \  /   \  /   \  /   \  /            \  /   \  /   \  /   \  /  | r
> +|   \/     \/     \/     \/              \/     \/     \/     \/   | n
> +|   |      |             |                |             |      |   | e
> +|   |      |        +----+                +----+        |      |   | l
> +|   |      |        |                          |        |      |   |
> +| +----+ +----+ +----+                        +----+ +----+ +----+ | s
> +| |tc0 | |tc1 | |tc2 |                        |tc2 | |tc1 | |tc0 | | p
> +| \    / \    / \    /                        \    / \    / \    / | a
> +|  \  /   \  /   \  /                          \  /   \  /   \  /  | c
> +|   \/     \/     \/                            \/     \/     \/   | e
> +|   |      |       +-----+                +-----+      |       |   |
> +|   |      |       |     |                |     |      |       |   |
> +|   |      |       |     |                |     |      |       |   |
> +|   |      |       |     |    E      E    |     |      |       |   |
> +| +----+ +----+ +----+ +----+ t      t +----+ +----+ +----+ +----+ |
> +| |txq0| |txq1| |txq4| |txq5| h      h |txq6| |txq7| |txq3| |txq2| |
> +| \    / \    / \    / \    / 0      1 \    / \    / \    / \    / |
> +|  \  /   \  /   \  /   \  /  .      .  \  /   \  /   \  /   \  /  |
> +|   \/     \/     \/     \/   1      1   \/     \/     \/     \/   |
> +| +-|------|------|------|--+ 0      0 +-|------|------|------|--+ |
> +| | |      |      |      |  | 0      0 | |      |      |      |  | |
> ++---|------|------|------|---------------|------|------|------|----+
> +    |      |      |      |               |      |      |      |
> +    p      p      p      p               p      p      p      p
> +    3      2      0-1, 4-7   <-L2 pri->  0-1, 4-7      2      3
> +    |      |      |      |               |      |      |      |
> +    |      |      |      |               |      |      |      |
> ++---|------|------|------|---------------|------|------|------|----+
> +|   |      |      |      |               |      |      |      |    |
> +| +----+ +----+ +----+ +----+          +----+ +----+ +----+ +----+ |
> +| |dma7| |dma6| |dma3| |dma2|          |dma1| |dma0| |dma4| |dma5| |
> +| \    / \    / \    / \    /          \    / \    / \    / \    / | c
> +|  \S /   \S /   \  /   \  /            \  /   \  /   \S /   \S /  | p
> +|   \/     \/     \/     \/              \/     \/     \/     \/   | s
> +|   |      |      | +-----                |      |      |      |   | w
> +|   |      |      | |                     +----+ |      |      |   |
> +|   |      |      | |                          | |      |      |   | d
> +| +----+ +----+ +----+p                      p+----+ +----+ +----+ | r
> +| |    | |    | |    |o                      o|    | |    | |    | | i
> +| | f3 | | f2 | | f0 |r        CPSW          r| f3 | | f2 | | f0 | | v
> +| |tc0 | |tc1 | |tc2 |t                      t|tc0 | |tc1 | |tc2 | | e
> +| \CBS / \CBS / \CBS /1                      2\CBS / \CBS / \CBS / | r
> +|  \S /   \S /   \  /                          \S /   \S /   \  /  |
> +|   \/     \/     \/                            \/     \/     \/   |
> ++------------------------------------------------------------------+
> +========================================Eth==========================>
> +
> +1)
> +// Add 8 tx queues, for interface Eth0, but they are common, so are accessed
> +// by two interfaces Eth0 and Eth1.
> +$ ethtool -L eth1 rx 1 tx 8
> +rx unmodified, ignoring
> +
> +2)
> +// Check if num of queues is set correctly:
> +$ ethtool -l eth0
> +Channel parameters for eth0:
> +Pre-set maximums:
> +RX:             8
> +TX:             8
> +Other:          0
> +Combined:       0
> +Current hardware settings:
> +RX:             1
> +TX:             8
> +Other:          0
> +Combined:       0
> +
> +3)
> +// TX queues must be rated starting from 0, so set bws for tx0 and tx1 for Eth0
> +// and for tx2 and tx3 for Eth1. That is, rates 40 and 20 Mb/s appropriately
> +// for Eth0 and 30 and 10 Mb/s for Eth1.
> +// Real speed can differ a bit due to discreetness
> +// Leave last 4 tx queues as not rated
> +$ echo 40 > /sys/class/net/eth0/queues/tx-0/tx_maxrate
> +$ echo 20 > /sys/class/net/eth0/queues/tx-1/tx_maxrate
> +$ echo 30 > /sys/class/net/eth1/queues/tx-2/tx_maxrate
> +$ echo 10 > /sys/class/net/eth1/queues/tx-3/tx_maxrate
> +
> +4)
> +// Check maximum rate of tx (cpdma) queues:
> +$ cat /sys/class/net/eth0/queues/tx-*/tx_maxrate
> +40
> +20
> +30
> +10
> +0
> +0
> +0
> +0
> +
> +5)
> +// Map skb->priority to traffic class for Eth0:
> +// 3pri -> tc0, 2pri -> tc1, (0,1,4-7)pri -> tc2
> +// Map traffic class to transmit queue:
> +// tc0 -> txq0, tc1 -> txq1, tc2 -> (txq4, txq5)
> +$ tc qdisc replace dev eth0 handle 100: parent root mqprio num_tc 3 \
> +map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 queues 1@0 1@1 2@4 hw 1
> +
> +6)
> +// Check classes settings
> +$ tc -g class show dev eth0
> ++---(100:ffe2) mqprio
> +|    +---(100:5) mqprio
> +|    +---(100:6) mqprio
> +|
> ++---(100:ffe1) mqprio
> +|    +---(100:2) mqprio
> +|
> ++---(100:ffe0) mqprio
> +     +---(100:1) mqprio
> +
> +7)
> +// Set rate for class A - 41 Mbit (tc0, txq0) using CBS Qdisc for Eth0
> +// here only idle slope is important, others ignored
> +// Real speed can differ a bit due to discreetness
> +$ tc qdisc add dev eth0 parent 100:1 cbs locredit -1470 \
> +hicredit 62 sendslope -959000 idleslope 41000 offload 1
> +net eth0: set FIFO3 bw = 50
> +
> +8)
> +// Set rate for class B - 21 Mbit (tc1, txq1) using CBS Qdisc for Eth0
> +$ tc qdisc add dev eth0 parent 100:2 cbs locredit -1470 \
> +hicredit 65 sendslope -979000 idleslope 21000 offload 1
> +net eth0: set FIFO2 bw = 30
> +
> +9)
> +// Create vlan 100 to map sk->priority to vlan qos for Eth0
> +$ ip link add link eth0 name eth0.100 type vlan id 100
> +net eth0: Adding vlanid 100 to vlan filter
> +
> +10)
> +// Map skb->priority to L2 prio for Eth0.100, one to one
> +$ ip link set eth0.100 type vlan \
> +egress 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
> +
> +11)
> +// Check egress map for vlan 100
> +$ cat /proc/net/vlan/eth0.100
> +[...]
> +INGRESS priority mappings: 0:0  1:0  2:0  3:0  4:0  5:0  6:0 7:0
> +EGRESS priority mappings: 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
> +
> +12)
> +// Map skb->priority to traffic class for Eth1:
> +// 3pri -> tc0, 2pri -> tc1, (0,1,4-7)pri -> tc2
> +// Map traffic class to transmit queue:
> +// tc0 -> txq2, tc1 -> txq3, tc2 -> (txq6, txq7)
> +$ tc qdisc replace dev eth1 handle 100: parent root mqprio num_tc 3 \
> +map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 queues 1@2 1@3 2@6 hw 1
> +
> +13)
> +// Check classes settings
> +$ tc -g class show dev eth1
> ++---(100:ffe2) mqprio
> +|    +---(100:7) mqprio
> +|    +---(100:8) mqprio
> +|
> ++---(100:ffe1) mqprio
> +|    +---(100:4) mqprio
> +|
> ++---(100:ffe0) mqprio
> +     +---(100:3) mqprio
> +
> +14)
> +// Set rate for class A - 31 Mbit (tc0, txq2) using CBS Qdisc for Eth1
> +// here only idle slope is important, others ignored
> +// Set it +1 Mb for reserve (important!)
> +$ tc qdisc add dev eth1 parent 100:3 cbs locredit -1453 \
> +hicredit 47 sendslope -969000 idleslope 31000 offload 1
> +net eth1: set FIFO3 bw = 31
> +
> +15)
> +// Set rate for class B - 11 Mbit (tc1, txq3) using CBS Qdisc for Eth1
> +// Set it +1 Mb for reserve (important!)
> +$ tc qdisc add dev eth1 parent 100:4 cbs locredit -1483 \
> +hicredit 34 sendslope -989000 idleslope 11000 offload 1
> +net eth1: set FIFO2 bw = 11
> +
> +16)
> +// Create vlan 100 to map sk->priority to vlan qos for Eth1
> +$ ip link add link eth1 name eth1.100 type vlan id 100
> +net eth1: Adding vlanid 100 to vlan filter
> +
> +17)
> +// Map skb->priority to L2 prio for Eth1.100, one to one
> +$ ip link set eth1.100 type vlan \
> +egress 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
> +
> +18)
> +// Check egress map for vlan 100
> +$ cat /proc/net/vlan/eth1.100
> +[...]
> +INGRESS priority mappings: 0:0  1:0  2:0  3:0  4:0  5:0  6:0 7:0
> +EGRESS priority mappings: 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
> +
> +19)
> +// Run appropriate tools with socket option "SO_PRIORITY" to 3
> +// for class A and to 2 for class B. For both interfaces
> +./tsn_talker -d 18:03:73:66:87:42 -i eth0.100 -p2 -s 1500&
> +./tsn_talker -d 18:03:73:66:87:42 -i eth0.100 -p3 -s 1500&
> +./tsn_talker -d 20:cf:30:85:7d:fd -i eth1.100 -p2 -s 1500&
> +./tsn_talker -d 20:cf:30:85:7d:fd -i eth1.100 -p3 -s 1500&
> +
> +20)
> +// run your listener on workstation (should be in same vlan)
> +// (I took at https://www.spinics.net/lists/netdev/msg460869.html)
> +./tsn_listener -d 18:03:73:66:87:42 -i enp5s0 -s 1500
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39012 kbps
> +Receiving data rate: 39000 kbps
> +
> +21)
> +// Restore default configuration if needed
> +$ ip link del eth1.100
> +$ ip link del eth0.100
> +$ tc qdisc del dev eth1 root
> +net eth1: Prev FIFO2 is shaped
> +net eth1: set FIFO3 bw = 0
> +net eth1: set FIFO2 bw = 0
> +$ tc qdisc del dev eth0 root
> +net eth0: Prev FIFO2 is shaped
> +net eth0: set FIFO3 bw = 0
> +net eth0: set FIFO2 bw = 0
> +$ ethtool -L eth0 rx 1 tx 1
> -- 
> 2.17.1
>