Commit efe10306 authored by Hariprasad Kelam's avatar Hariprasad Kelam Committed by David S. Miller
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docs: octeontx2: Add Documentation for QOS 



Add QOS example configuration along with tc-htb commands

Signed-off-by: default avatarHariprasad Kelam <hkelam@marvell.com>
Reviewed-by: default avatarSimon Horman <simon.horman@corigine.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6cebb6a4

Documentation/networking/device_drivers/ethernet/marvell/octeontx2.rst

+45 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ Contents 
- `Drivers`_

- `Basic packet flow`_

- `Devlink health reporters`_

- `Quality of service`_



Overview

========
@@ -287,3 +288,47 @@ For example:: 
	 NIX_AF_ERR:

	        NIX Error Interrupt Reg : 64

	        Rx on unmapped PF_FUNC





Quality of service

==================





Hardware algorithms used in scheduling

--------------------------------------



octeontx2 silicon and CN10K transmit interface consists of five transmit levels

starting from SMQ/MDQ, TL4 to TL1. Each packet will traverse MDQ, TL4 to TL1

levels. Each level contains an array of queues to support scheduling and shaping.

The hardware uses the below algorithms depending on the priority of scheduler queues.

once the usercreates tc classes with different priorities, the driver configures

schedulers allocated to the class with specified priority along with rate-limiting

configuration.



1. Strict Priority



      -  Once packets are submitted to MDQ, hardware picks all active MDQs having different priority

         using strict priority.



2. Round Robin



      - Active MDQs having the same priority level are chosen using round robin.





Setup HTB offload

-----------------



1. Enable HW TC offload on the interface::



        # ethtool -K <interface> hw-tc-offload on



2. Crate htb root::



        # tc qdisc add dev <interface> clsact

        # tc qdisc replace dev <interface> root handle 1: htb offload



3. Create tc classes with different priorities::



        # tc class add dev <interface> parent 1: classid 1:1 htb rate 10Gbit prio 1



        # tc class add dev <interface> parent 1: classid 1:2 htb rate 10Gbit prio 7