[dpdk-dev] [PATCH v2 0/3] Reorganize resources of flow tables

[Bing Zhao <bingz@mellanox.com>]

From: Bing Zhao <bingz@mtbc-r640-01.mtbc.labs.mlnx>

Number of flow tables is limited by the memory resource, and the index could be
to as large as 2^^32 - 1. In the past, the flow tables are organized by arrays,
and this organization has some advantages and disadvantages. The lookup for the
table resource from a linear array is quite fast, the ID could be used as the
index in the array. But it will cost some extra memory resource after system
bring up and if only a small number of tables are created. In the meanwhile,
since we could not create the array with a huge number, so the maximal index of
the table is limited and it is  unreasonable.
If we change the array into some other tables, like some open addressing hash
table, the static memory cost is still to huge. But the index of the table
limitation could be get rid of. But in the meanwhile, it will introduce some
new issue that two tables with different ID may generate the same address index
in the table. Then it will degrade the performance of the lookup, creating and
deleting. Moreover, sometimes it will cause a failure if the collisions rate
are too heavy.
Then the simple hash list is used as the first step to get rid of this
limitations. The only static memory over head is array of the LIST HEADs. In
the next step, we could use some extendable hash tables for this. This will of
course introduce some performance degradation when lookup, creating and
removing tables in the lists if there are a lot of tables created in the
system. We need to trade off among the functionality, memory and performance.
Some other resources are associated with each flow tables and not global, like
flow matchers and jump table object used by driver. They could also be
reorganized and put into the flow table resources structure. Then the lookup
process of these resources will be speeded up significantly.

Bing Zhao (3):
  net/mlx5: reorganize flow tables with hash list
  net/mlx5: reorganize jump table resources
  net/mlx5: reorganize flow matcher resources

 drivers/net/mlx5/mlx5.c         |  16 ++
 drivers/net/mlx5/mlx5.h         |  25 ++--
 drivers/net/mlx5/mlx5_flow.h    |  24 ++-
 drivers/net/mlx5/mlx5_flow_dv.c | 316 +++++++++++++++++++++++-----------------
 4 files changed, 230 insertions(+), 151 deletions(-)

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