Commit Graph

3 Commits

Author SHA1 Message Date
DaiZhiwei
26293c89a6 crc32c_arm64 performance optimization (#5675)
Summary:
Crc32c Parallel computation coding optimization:
Macro unfolding removes the "for" loop and is good to decrease branch-miss in arm64 micro architecture
1024 Bytes is divided into  8(head) + 1008( 6 * 7 * 3 * 8 ) + 8(tail)  three parts
Macro unfolding 42 loops to 6 CRC32C7X24BYTESs
1 CRC32C7X24BYTES containing 7 CRC32C24BYTESs

1, crc32c_test
[==========] Running 4 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 4 tests from CRC
[ RUN      ] CRC.StandardResults
[       OK ] CRC.StandardResults (1 ms)
[ RUN      ] CRC.Values
[       OK ] CRC.Values (0 ms)
[ RUN      ] CRC.Extend
[       OK ] CRC.Extend (0 ms)
[ RUN      ] CRC.Mask
[       OK ] CRC.Mask (0 ms)
[----------] 4 tests from CRC (1 ms total)

[----------] Global test environment tear-down
[==========] 4 tests from 1 test case ran. (1 ms total)
[  PASSED  ] 4 tests.

2, db_bench --benchmarks="crc32c"
crc32c : 0.218 micros/op 4595390 ops/sec; 17950.7 MB/s (4096 per op)

3, repeated crc32c_test case  60000 times
perf stat -e branch-miss -- ./crc32c_test
before optimization:
739,426,504      branch-miss
after optimization:
1,128,572      branch-miss
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5675

Differential Revision: D16989210

fbshipit-source-id: 7204e6069bb6ed066d49c2d1b3ac385065a98557
2019-08-23 11:04:08 -07:00
Yuqi Gu
a3c1832e86 Arm64 CRC32 parallel computation optimization for RocksDB (#5494)
Summary:
Crc32c Parallel computation optimization:
Algorithm comes from Intel whitepaper: [crc-iscsi-polynomial-crc32-instruction-paper](https://www.intel.com/content/dam/www/public/us/en/documents/white-papers/crc-iscsi-polynomial-crc32-instruction-paper.pdf)
 Input data is divided into three equal-sized blocks
Three parallel blocks (crc0, crc1, crc2) for 1024 Bytes
One Block: 42(BLK_LENGTH) * 8(step length: crc32c_u64) bytes

1. crc32c_test:
```
[==========] Running 4 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 4 tests from CRC
[ RUN      ] CRC.StandardResults
[       OK ] CRC.StandardResults (1 ms)
[ RUN      ] CRC.Values
[       OK ] CRC.Values (0 ms)
[ RUN      ] CRC.Extend
[       OK ] CRC.Extend (0 ms)
[ RUN      ] CRC.Mask
[       OK ] CRC.Mask (0 ms)
[----------] 4 tests from CRC (1 ms total)

[----------] Global test environment tear-down
[==========] 4 tests from 1 test case ran. (1 ms total)
[  PASSED  ] 4 tests.
```

2. RocksDB benchmark: db_bench --benchmarks="crc32c"

```
Linear Arm crc32c:
  crc32c: 1.005 micros/op 995133 ops/sec; 3887.2 MB/s (4096 per op)
```

```
Parallel optimization with Armv8 crypto extension:
  crc32c: 0.419 micros/op 2385078 ops/sec; 9316.7 MB/s (4096 per op)
```

It gets ~2.4x speedup compared to linear Arm crc32c instructions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5494

Differential Revision: D16340806

fbshipit-source-id: 95dae9a5b646fd20a8303671d82f17b2e162e945
2019-07-17 11:22:38 -07:00
Yuqi Gu
03c7ae24c2 RocksDB CRC32c optimization with ARMv8 Intrinsic (#5221)
Summary:
1. Add Arm linear crc32c implemtation for RocksDB.
2. Arm runtime check for crc32
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5221

Differential Revision: D15013685

Pulled By: siying

fbshipit-source-id: 2c2983743d26656d93f212dc7c1a3cf66a1acf12
2019-04-30 10:59:05 -07:00