Background:
After preliminary discussion with John (Zhihong) and Tim from Intel it was
decided that it would be beneficial to use AVX/SSE instructions for memcmp
similar to memcpy being implemeneted. In addition, we decided to use
librte_hash as a test candidate to test both functionality and performance.
Currently memcmp in librte_hash is used for key comparisons whose length
can vary and max key length is defined to 64 bytes. Preliminary tests on
memory comparison alone shows using AVX/SSE instructions takes 1/3rd
CPU ticks compared with regular memcmp function. Furthermore,
hash_perf_autotest shows better results in all categories. Please note
that memory comparison is a small portion in hash functionality and CPU
Ticks/Op is for hash operations (Add on Empty, Add update, Lookup). Only
hash lookup results are shown below. I can send complete results if
interested.
Test was conducted on Intel(R) Core(TM) i7-4790 CPU @ 3.60GHz, Ubuntu
14.04, x86_64, 16GB DDR3 system.
PS: I would like to keep "rte_memcmp" simple with return codes
0 - match
1 - no-match
since usage in DPDK is for equality or inequality and I have not seen
any instance where less-than/greater-than comparison is needed. Hence
"if (unlikely(...))" portion in the code will probably be removed and it
will be made specific to DPDK rather than being generic.
/*************Existing code**********************************/
*** Hash table performance test results ***
Hash Func. , Operation , Key size (bytes), Entries, Entries per bucket,
Errors , Avg. bucket entries, Ticks/Op.
rte_hash_crc, Lookup , 16 , 1024 , 1 ,
10000 , 0.00 , 88.55
rte_hash_crc, Lookup , 16 , 1024 , 2 ,
10000 , 0.00 , 99.28
rte_hash_crc, Lookup , 16 , 1024 , 4 ,
10000 , 0.00 , 106.73
rte_hash_crc, Lookup , 16 , 1024 , 8 ,
10000 , 0.00 , 126.99
rte_hash_crc, Lookup , 16 , 1024 , 16 ,
10000 , 0.00 , 159.80
rte_hash_crc, Lookup , 16 , 1048576, 1 ,
51 , 0.01 , 175.23
rte_hash_crc, Lookup , 16 , 1048576, 2 , 2
, 0.02 , 171.24
rte_hash_crc, Lookup , 16 , 1048576, 4 , 0
, 0.04 , 145.48
rte_hash_crc, Lookup , 16 , 1048576, 8 , 0
, 0.08 , 162.35
rte_hash_crc, Lookup , 16 , 1048576, 16 , 0
, 0.15 , 182.42
jhash , Lookup , 16 , 1048576, 1 ,
33 , 0.01 , 219.71
jhash , Lookup , 16 , 1048576, 2 , 1
, 0.02 , 216.44
jhash , Lookup , 16 , 1048576, 4 , 0
, 0.04 , 188.29
jhash , Lookup , 16 , 1048576, 8 , 0
, 0.08 , 203.70
jhash , Lookup , 16 , 1048576, 16 , 0
, 0.15 , 229.50
/**************New AVX/SSE code******************************/
Hash Func. , Operation , Key size (bytes), Entries, Entries per bucket,
Errors , Avg. bucket entries, Ticks/Op.
rte_hash_crc, Lookup , 16 , 1024 , 1 ,
10000 , 0.00 , 85.69
rte_hash_crc, Lookup , 16 , 1024 , 2 ,
10000 , 0.00 , 93.95
rte_hash_crc, Lookup , 16 , 1024 , 4 ,
10000 , 0.00 , 102.80
rte_hash_crc, Lookup , 16 , 1024 , 8 ,
10000 , 0.00 , 122.60
rte_hash_crc, Lookup , 16 , 1024 , 16 ,
10000 , 0.00 , 156.58
rte_hash_crc, Lookup , 16 , 1048576, 1 ,
41 , 0.01 , 156.84
rte_hash_crc, Lookup , 16 , 1048576, 2 , 0
, 0.02 , 157.90
rte_hash_crc, Lookup , 16 , 1048576, 4 , 0
, 0.04 , 134.92
rte_hash_crc, Lookup , 16 , 1048576, 8 , 0
, 0.08 , 150.99
rte_hash_crc, Lookup , 16 , 1048576, 16 , 0
, 0.15 , 174.08
jhash , Lookup , 16 , 1048576, 1 ,
45 , 0.01 , 212.03
jhash , Lookup , 16 , 1048576, 2 , 2
, 0.02 , 210.65
jhash , Lookup , 16 , 1048576, 4 , 0
, 0.04 , 185.90
jhash , Lookup , 16 , 1048576, 8 , 0
, 0.08 , 201.35
jhash , Lookup , 16 , 1048576, 16 , 0
, 0.15 , 223.54
Ravi Kerur (1):
Implement memcmp using AVX/SSE instructions.
app/test/test_hash_perf.c | 36 +-
.../common/include/arch/ppc_64/rte_memcmp.h | 62 +++
.../common/include/arch/x86/rte_memcmp.h | 421 +++++++++++++++++++++
lib/librte_eal/common/include/generic/rte_memcmp.h | 131 +++++++
lib/librte_hash/rte_hash.c | 59 ++-
5 files changed, 675 insertions(+), 34 deletions(-)
create mode 100644 lib/librte_eal/common/include/arch/ppc_64/rte_memcmp.h
create mode 100644 lib/librte_eal/common/include/arch/x86/rte_memcmp.h
create mode 100644 lib/librte_eal/common/include/generic/rte_memcmp.h
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1.9.1
