Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Paolo Abeni
authored
Oz Shlomo says:
====================
add support for per action hw stats
There are currently two mechanisms for populating hardware stats:
1. Using flow_offload api to query the flow's statistics.
The api assumes that the same stats values apply to all
the flow's actions.
This assumption breaks when action drops or jumps over following
actions.
2. Using hw_action api to query specific action stats via a driver
callback method. This api assures the correct action stats for
the offloaded action, however, it does not apply to the rest of the
actions in the flow's actions array, as elaborated below.
The current hw_action api does not apply to the following use cases:
1. Actions that are implicitly created by filters (aka bind actions).
In the following example only one counter will apply to the rule:
tc filter add dev $DEV prio 2 protocol ip parent ffff: \
flower ip_proto tcp dst_ip $IP2 \
action police rate 1mbit burst 100k conform-exceed drop/pipe \
action mirred egress redirect dev $DEV2
2. Action preceding a hw action.
In the following example the same flow stats will apply to the sample and
mirred actions:
tc action add police rate 1mbit burst 100k conform-exceed drop / pipe
tc filter add dev $DEV prio 2 protocol ip parent ffff: \
flower ip_proto tcp dst_ip $IP2 \
action sample rate 1 group 10 trunc 60 pipe \
action police index 1 \
action mirred egress redirect dev $DEV2
3. Meter action using jump control.
In the following example the same flow stats will apply to both
mirred actions:
tc action add police rate 1mbit burst 100k conform-exceed jump 2 / pipe
tc filter add dev $DEV prio 2 protocol ip parent ffff: \
flower ip_proto tcp dst_ip $IP2 \
action police index 1 \
action mirred egress redirect dev $DEV2
action mirred egress redirect dev $DEV3
This series provides the platform to query per action stats for in_hw flows.
The first four patches are preparation patches with no functionality change.
The fifth patch re-uses the existing flow action stats api to query action
stats for both classifier and action dumps.
The rest of the patches add per action stats support to the Mellanox driver.
====================
Link: https://lore.kernel.org/r/20230212132520.12571-1-ozsh@nvidia.com
Signed-off-by: 
Paolo Abeni <pabeni@redhat.com>