[go: up one dir, main page]
More Web Proxy on the site http://driver.im/
Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

blake2 simd benches produce unexpected results #407

Open
nazar-pc opened this issue Sep 13, 2022 · 1 comment
Open

blake2 simd benches produce unexpected results #407

nazar-pc opened this issue Sep 13, 2022 · 1 comment

Comments

@nazar-pc
Copy link

I ran blake2 tests with and without simd feature enabled and found that behavior is strange and doesn't make a lot of sense.

Default (no simd):

$ cargo +nightly bench
...
running 8 tests
test blake2b512_10    ... bench:           8 ns/iter (+/- 0) = 1250 MB/s
test blake2b512_100   ... bench:          74 ns/iter (+/- 4) = 1351 MB/s
test blake2b512_1000  ... bench:         708 ns/iter (+/- 85) = 1412 MB/s
test blake2b512_10000 ... bench:       7,005 ns/iter (+/- 531) = 1427 MB/s
test blake2s256_10    ... bench:          13 ns/iter (+/- 0) = 769 MB/s
test blake2s256_100   ... bench:         121 ns/iter (+/- 7) = 826 MB/s
test blake2s256_1000  ... bench:       1,155 ns/iter (+/- 62) = 865 MB/s
test blake2s256_10000 ... bench:      11,791 ns/iter (+/- 1,005) = 848 MB/s

test result: ok. 0 passed; 0 failed; 0 ignored; 8 measured; 0 filtered out; finished in 28.22s

Simd:

$ cargo +nightly bench --features simd
...
running 8 tests
test blake2b512_10    ... bench:          11 ns/iter (+/- 0) = 909 MB/s
test blake2b512_100   ... bench:         102 ns/iter (+/- 0) = 980 MB/s
test blake2b512_1000  ... bench:       1,010 ns/iter (+/- 11) = 990 MB/s
test blake2b512_10000 ... bench:      10,076 ns/iter (+/- 68) = 992 MB/s
test blake2s256_10    ... bench:          16 ns/iter (+/- 0) = 625 MB/s
test blake2s256_100   ... bench:         152 ns/iter (+/- 1) = 657 MB/s
test blake2s256_1000  ... bench:       1,483 ns/iter (+/- 12) = 674 MB/s
test blake2s256_10000 ... bench:      14,750 ns/iter (+/- 344) = 677 MB/s

test result: ok. 0 passed; 0 failed; 0 ignored; 8 measured; 0 filtered out; finished in 2.43s

I expected simd version to produce better results and judging by the total execution time it is the case, but throughput reported by the benchmark says the opposite.

I suspect something is wrong with benchmarking code.

Using latest master (cc52373 right now) and rustc 1.65.0-nightly (20ffea693 2022-08-11).
@newpavlov
Copy link
Member

The simd backend is a very old piece of code inherited from blake2-rfc and probably should not be used. We plan to completely replace implementation, see #228.

@nazar-pc nazar-pc mentioned this issue Sep 15, 2022
Merged
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
None yet
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
2 participants
@newpavlov @nazar-pc