[dpdk-dev] [PATCH v3 00/18] librte_table: add key mask for hash tables

[Cristian Dumitrescu]

Main changes:

1. The key_mask parameter is added to all the hash tables that were
   previously missing it, as well to the hash compute function. This was
   first started in DPDK 2.0, but was only implemented for a couple of
   hash tables. The benefit of this approach is that it allows for better
   performance for large keys (bigger than 16 bytes), while it preserves
   the same performance for small keys [Q&A1].

2. The precomputed key signature (i.e. non-"do-sig") versions have been
   removed for all the hash tables, so now the key signature is always
   computed on every lookup. Note that this approach also allows for the
   precomputed key signature scheme [Q&A2].

3. API cleanup: single parameter structure common for all hash tables.

Q&A:

Q1: How is better lookup performance achieved by using key mask approach
   for hash tables?
A1: This approach eliminates the need to consolidate the lookup key in a
   single contiguous buffer where the relevant packet fields are written
   one by one, which is a very costly operation that also hash strong data
   dependencies.

Q2: How can the pre-computed key signature scheme be implemented with
    current approach?
A2: The application can implement a straightforward custom hash function
    that simply reads the pre-computed key signature from a given offset
    in the input key buffer where it has been stored prior to the lookup
    operation.

Cristian Dumitrescu (18):
  test: removing calls to deprecated hash tables
  librte_table: remove deprecated 8-byte key hash tables
  librte_table: remove deprecated 16-byte key hash tables
  librte_table: remove deprecated variable size key ext hash tables
  librte_table: remove deprecated variable size key lru hash tables
  librte_table: rename cuckoo hash table ops
  librte_table: add unified params structure and mask-based hash func
  librte_table: rework variable size key ext hash tables
  librte_table: rework variable size key lru hash table
  librte_table: rework 8-byte key hash tables
  librte_table: rework 16-byte key hash tables
  librte_table: rework 32-byte key hash tables
  librte_table: rework cuckoo hash table
  test: add mask-based hash functions
  librte_table: cosmetic enhancements in api file
  librte_table: copyright cosmetic updates
  librte_table: map file updates
  doc: remove deprecation notice for librte_table

 doc/guides/rel_notes/deprecation.rst               |   6 -
 examples/ip_pipeline/pipeline/hash_func.h          | 176 +++--
 .../pipeline/pipeline_flow_classification.c        |  10 +-
 .../pipeline/pipeline_flow_classification_be.c     |  51 +-
 .../ip_pipeline/pipeline/pipeline_passthrough_be.c |  10 +-
 .../ip_pipeline/pipeline/pipeline_routing_be.c     |  14 +-
 lib/librte_table/rte_table_hash.h                  | 305 +--------
 lib/librte_table/rte_table_hash_cuckoo.c           | 205 +++---
 lib/librte_table/rte_table_hash_ext.c              | 417 ++++--------
 lib/librte_table/rte_table_hash_key16.c            | 750 ++++++---------------
 lib/librte_table/rte_table_hash_key32.c            | 436 +++++++-----
 lib/librte_table/rte_table_hash_key8.c             | 716 ++++++--------------
 lib/librte_table/rte_table_hash_lru.c              | 513 ++++++--------
 lib/librte_table/rte_table_version.map             |  23 +-
 test/test-pipeline/main.h                          |   5 +-
 test/test-pipeline/pipeline_hash.c                 | 107 +--
 test/test/test_table.c                             |   1 +
 test/test/test_table.h                             |   3 +-
 test/test/test_table_combined.c                    | 137 ++--
 test/test/test_table_tables.c                      | 150 ++---
 20 files changed, 1440 insertions(+), 2595 deletions(-)

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2.7.4