'qos_pfc' test checks PFC behavior. The idea is to limit the traffic
using a shaper somewhere in the flow of the packets. In this area, the
buffer is smaller than the buffer at the beginning of the flow, so it fills
up until there is no more space left. The test configures there PFC
which is supposed to notice that the headroom is filling up and send PFC
Xoff to indicate the transmitter to stop sending traffic for the priorities
sharing this PG.
The Xon/Xoff threshold is auto-configured and always equal to
2*(MTU rounded up to cell size). Even after sending the PFC Xoff packet,
traffic will keep arriving until the transmitter receives and processes
the PFC packet. This amount of traffic is known as the PFC delay allowance.
Currently the buffer for the delay traffic is configured as 100KB. The
MTU in the test is 10KB, therefore the threshold for Xoff is about 20KB.
This allows 80KB extra to be stored in this buffer.
8-lane ports use two buffers among which the configured buffer is split,
the Xoff threshold then applies to each buffer in parallel.
The test does not take into account the behavior of 8-lane ports, when the
ports are configured to 400Gbps with 8 lanes or 800Gbps with 8 lanes,
packets are dropped and the test fails.
Check if the relevant ports use 8 lanes, in such case double the size of
the buffer, as the headroom is split half-half.
Cc: Shuah Khan <shuah@kernel.org>
Fixes: bfa804784e ("selftests: mlxsw: Add a PFC test")
Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/23ff11b7dff031eb04a41c0f5254a2b636cd8ebb.1705502064.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In the diagram of the topology, $swp3 and $swp4 are described as 1Gbps
ports. This is wrong information, the test does not configure such speed.
Cc: Shuah Khan <shuah@kernel.org>
Fixes: bfa804784e ("selftests: mlxsw: Add a PFC test")
Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/0087e2d416aff7e444d15f7c2958fc1d438dc27e.1705502064.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
mlxsw selftests often invoke a bail_on_lldpad() helper to make sure LLDPAD
is not running, to prevent conflicts between the QoS configuration applied
through TC or DCB command line tool, and the DCB configuration that LLDPAD
might apply. This helper might be useful to others. Move the function to
lib.sh, and parameterize to make reusable in other contexts.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Danielle Ratson <danieller@nvidia.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
A number of mlxsw-specific QoS tests use manual QoS DCB management. As
such, they need to make sure lldpad is not running, because it would
override the configuration the test has applied using other tools. To that
end, these selftests invoke the bail_on_lldpad() helper, which terminates
the selftest if th lldpad is running.
Some of these tests however first install the bash exit trap, which invokes
a cleanup() at the test exit. If bail_on_lldpad() has terminated the script
even before the setup part was run, the cleanup part will be very confused.
Therefore make sure bail_on_lldpad() is invoked before the cleanup is
registered.
While there are still edge cases where the user terminates the script
before the setup was fully done, this takes care of a common situation
where the cleanup would be invoked in an inconsistent state.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is a dedicated tool for configuration of DCB in iproute2 now. Use it
in the selftest instead of mlnx_qos.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The test was setting the headroom size of the wrong port. This was not
visible because of a firmware bug that canceled this bug.
Set the headroom size of the correct port, so that the test will pass
with both old and new firmware versions.
Fixes: bfa804784e ("selftests: mlxsw: Add a PFC test")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://lore.kernel.org/r/20201230114251.394009-1-idosch@idosch.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a test for PFC. Runs 10MB of traffic through a bottleneck and checks
that none of it gets lost.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
