Hi Dave,
Introducing ConnectX-4 CQE (Completion Queue Entry) compression feature
for mlx5 etherent driver.
CQE Compressing reduces PCI overhead by coalescing and compressing multiple
CQEs into a
single merged CQE. Successful compressing improves message rate especially for
small packet
traffic.
CQE Compressing in details:
Instead of writing full CQEs to memory, multiple almost identical CQEs are
merged and compressed.
Information that is shared between the CQEs is written once, regardless of the
number of
compressed CQEs. In addition, only the unique information (small amount of
bytes compared to
full CQE size) is written per CQE.
CQE Compression Block:
This block contains multiple compressed CQEs. CQE Compression Block contains a
single copy
of CQEs properties which are shared between all the compressed CQEs (called
Title, see below)
and multiple mini CQEs (CQEs in compressed form).
Title:
The Title holds information which is shared between all the compressed CQEs in
the CQE Compression
Block. In each Compression Block there is only a single Title regardless of
the number
of compressed CQEs.
Mini CQE:
A CQE in compressed form that holds some data needed to extract a single full
CQE, for example
8 Bytes instead of 64 Bytes.
The shared information between all compressed CQEs, which belong to the same
CQE Compression
Block called Title, is written once, and only the unique information in each
compressed
CQE, for example 8 bytes, is written per compressed CQE, called mini CQE.
Since CQE Compression can add overhead to the software (CPU),
it will be only enabled on "weak/slow" PCI slots, where it can actually help.
Applied on top: c047c3b1af62 ('netfilter: conntrack: remove uninitialized
shadow variable')
Thanks,
Saeed.
Saeed Mahameed (1):
net/mlx5e: Enable CQE compression when PCI is slower than link
Tariq Toukan (2):
net/mlx5e: CQE compression
net/mlx5e: Expand WQE stride when CQE compression is enabled
drivers/net/ethernet/mellanox/mlx5/core/en.h | 24 ++-
drivers/net/ethernet/mellanox/mlx5/core/en_clock.c | 4 +
.../net/ethernet/mellanox/mlx5/core/en_ethtool.c | 19 +++
drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 81 ++++++++-
drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 188 ++++++++++++++++++---
drivers/net/ethernet/mellanox/mlx5/core/en_stats.h | 8 +
include/linux/mlx5/device.h | 34 ++++
7 files changed, 328 insertions(+), 30 deletions(-)
--
2.8.0
