Commit b62767e7 authored by Dmytro Linkin's avatar Dmytro Linkin Committed by David S. Miller
Browse files

Documentation: devlink rate objects 



Add devlink rate objects section at devlink port documentation.
Add devlink rate support info at netdevsim devlink documentation.

Signed-off-by: default avatarDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: default avatarJiri Pirko <jiri@nvidia.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1a9c0482

Documentation/networking/devlink/devlink-port.rst

+35 −0
Original line number Diff line number Diff line
@@ -164,6 +164,41 @@ device to instantiate the subfunction device on particular PCI function. 
A subfunction device is created on the :ref:`Documentation/driver-api/auxiliary_bus.rst <auxiliary_bus>`.

At this point a matching subfunction driver binds to the subfunction's auxiliary device.



Rate object management

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



Devlink provides API to manage tx rates of single devlink port or a group.

This is done through rate objects, which can be one of the two types:



``leaf``

  Represents a single devlink port; created/destroyed by the driver. Since leaf

  have 1to1 mapping to its devlink port, in user space it is referred as

  ``pci/<bus_addr>/<port_index>``;



``node``

  Represents a group of rate objects (leafs and/or nodes); created/deleted by

  request from the userspace; initially empty (no rate objects added). In

  userspace it is referred as ``pci/<bus_addr>/<node_name>``, where

  ``node_name`` can be any identifier, except decimal number, to avoid

  collisions with leafs.



API allows to configure following rate object's parameters:



``tx_share``

  Minimum TX rate value shared among all other rate objects, or rate objects

  that parts of the parent group, if it is a part of the same group.



``tx_max``

  Maximum TX rate value.



``parent``

  Parent node name. Parent node rate limits are considered as additional limits

  to all node children limits. ``tx_max`` is an upper limit for children.

  ``tx_share`` is a total bandwidth distributed among children.



Driver implementations are allowed to support both or either rate object types

and setting methods of their parameters.



Terms and Definitions

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

Documentation/networking/devlink/netdevsim.rst

+26 −0
Original line number Diff line number Diff line
@@ -57,6 +57,32 @@ entries, FIB rule entries and nexthops that the driver will allow. 
    $ devlink resource set netdevsim/netdevsim0 path /nexthops size 16

    $ devlink dev reload netdevsim/netdevsim0



Rate objects

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



The ``netdevsim`` driver supports rate objects management, which includes:



- registerging/unregistering leaf rate objects per VF devlink port;

- creation/deletion node rate objects;

- setting tx_share and tx_max rate values for any rate object type;

- setting parent node for any rate object type.



Rate nodes and it's parameters are exposed in ``netdevsim`` debugfs in RO mode.

For example created rate node with name ``some_group``:



.. code:: shell



    $ ls /sys/kernel/debug/netdevsim/netdevsim0/rate_groups/some_group

    rate_parent  tx_max  tx_share



Same parameters are exposed for leaf objects in corresponding ports directories.

For ex.:



.. code:: shell



    $ ls /sys/kernel/debug/netdevsim/netdevsim0/ports/1

    dev  ethtool  rate_parent  tx_max  tx_share



Driver-specific Traps

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