diff options
| author | Jesper Dangaard Brouer <brouer@redhat.com> | 2020-03-02 14:46:28 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-03-02 11:29:37 -0800 |
| commit | 15070919f801348e9a9a2ea96f427d8b621f3cd5 (patch) | |
| tree | 5fb5a0f35bb7fb595f7765da01fbcf738d7ce9f3 /tools/testing/selftests/bpf/prog_tests/cgroup_attach_multi.c | |
| parent | 0b56a29f708e10d0ae81a6503cbe41edaaaefbc8 (diff) | |
mvneta: add XDP ethtool errors stats for TX to driver
Adding ethtool stats for when XDP transmitted packets overrun the TX
queue. This is recorded separately for XDP_TX and ndo_xdp_xmit. This
is an important aid for troubleshooting XDP based setups.
It is currently a known weakness and property of XDP that there isn't
any push-back or congestion feedback when transmitting frames via XDP.
It's easy to realise when redirecting from a higher speed link into a
slower speed link, or simply two ingress links into a single egress.
The situation can also happen when Ethernet flow control is active.
For testing the patch and provoking the situation to occur on my
Espressobin board, I configured the TX-queue to be smaller (434) than
RX-queue (512) and overload network with large MTU size frames (as a
larger frame takes longer to transmit).
Hopefully the upcoming XDP TX hook can be extended to provide insight
into these TX queue overflows, to allow programmable adaptation
strategies.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/cgroup_attach_multi.c')
0 files changed, 0 insertions, 0 deletions