[dpdk-dev] [PATCH v2 0/6] Add read-write concurrency to rte_hash library

[Yipeng Wang]

This patch set adds the read-write concurrency support in rte_hash.
A new flag value is added to indicate if read-write concurrency is needed
during creation time. Test cases are implemented to do functional and
performance tests.

The new concurrency model is based on rte_rwlock. When Intel TSX is
available and the users indicate to use it, the TM version of the
rte_rwlock will be called. Both multi-writer and read-write concurrency
are protected by the rte_rwlock instead of the x86 specific RTM
instructions, so the x86 specific header rte_cuckoo_hash_x86.h is removed
and the code is infused into the main .c file.

A new rte_hash_count API is proposed to count how many keys are inserted
into the hash table.

v2->v1:
1. Split each commit into two commits for easier review (Pablo).
2. Add more comments in various places (Pablo).
3. hash: In key insertion function, move duplicated key checking to
earlier location and protect it using locks. Checking duplicated key
should happen first and data updates should be protected.
4. hash: In lookup bulk function, put signature comparison in lock,
since writers could happen between signature match on two buckets.
5. hash: Add write locks to reset function as well to protect resets.
5. test: Fix 32-bit compilation error in read-write test (Pablo).
6. test: Check total physical core count in read-write test. Don't
test with thread count that larger than physical core count.
7. Other minor fixes such as typos (Pablo).

Yipeng Wang (6):
  hash: make duplicated code into functions
  hash: add read and write concurrency support
  test: add tests in hash table perf test
  test: add test case for read write concurrency
  hash: fix to have more accurate key slot size
  hash: add new API function to query the key count

 lib/librte_hash/meson.build           |   1 -
 lib/librte_hash/rte_cuckoo_hash.c     | 695 +++++++++++++++++++++-------------
 lib/librte_hash/rte_cuckoo_hash.h     |  18 +-
 lib/librte_hash/rte_cuckoo_hash_x86.h | 164 --------
 lib/librte_hash/rte_hash.h            |  14 +
 lib/librte_hash/rte_hash_version.map  |   8 +
 test/test/Makefile                    |   1 +
 test/test/test_hash.c                 |  12 +
 test/test/test_hash_multiwriter.c     |   9 +
 test/test/test_hash_perf.c            |  36 +-
 test/test/test_hash_readwrite.c       | 645 +++++++++++++++++++++++++++++++
 11 files changed, 1155 insertions(+), 448 deletions(-)
 delete mode 100644 lib/librte_hash/rte_cuckoo_hash_x86.h
 create mode 100644 test/test/test_hash_readwrite.c

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2.7.4