factor:performance tuning #9261

mattsu2020 · 2025-11-13T14:19:09Z

Performance improvement for large numbers

fix this issue
https://bugs.launchpad.net/ubuntu/+source/rust-coreutils/+bug/2131212

github-actions · 2025-11-13T14:40:22Z

GNU testsuite comparison:

Skip an intermittent issue tests/misc/tee (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/tail/overlay-headers (fails in this run but passes in the 'main' branch)

src/uu/factor/src/factor.rs

github-actions · 2025-11-14T00:02:49Z

GNU testsuite comparison:

Skipping an intermittent issue tests/tail/overlay-headers (passes in this run but fails in the 'main' branch)

github-actions · 2025-11-14T03:40:14Z

GNU testsuite comparison:

Skipping an intermittent issue tests/tail/overlay-headers (passes in this run but fails in the 'main' branch)

sylvestre · 2025-11-14T08:16:13Z

could you please run hyperfine with the three programs? gnu, without the patch and with the patch
and share the full results here? thanks :)

github-actions · 2025-11-14T10:40:24Z

GNU testsuite comparison:

Skip an intermittent issue tests/tail/overlay-headers (fails in this run but passes in the 'main' branch)

mattsu2020 · 2025-11-14T11:13:07Z

could you please run hyperfine with the three programs? gnu, without the patch and with the patch and share the full results here? thanks :)

Implementation Details

GMP 6.3.0 and GNU coreutils 9.5 were built and installed from source

Created factor_numbers_u128_repeat.txt (60 lines) as benchmark input, containing 6 composite numbers ranging from 64 to 128 bits repeated 10 times. Confirmed factorization completion across all 3 implementations and reran Hyperfine.
All commands used the release profile (target/profiling/factor).
Hyperfine execution results
Command: hyperfine --warmup 3 --runs 12 “ < factor_numbers_u128_repeat.txt”

Implementation	Average time (s)	Standard deviation (s)	Minimum–Maximum (s)
GNU coreutils 9.5 ( local-gnu/bin/factor)	6.718	0.106	6.594 – 7.020
Old implementation (prev_worktree/target/profiling/factor)	6.125	1.942	2.648 – 8.508
After patch application (target/profiling/factor)	6.993	1.585	4.299 – 9.457

To reduce variance, we adjusted to 3 warm-ups + 12 measurements, but the Rust version still shows relatively high dispersion due to its randomized algorithm. For greater stability, consider running at times of low system load or using CPU pinning.
Behavior with inputs exceeding 128 bits

For factor_numbers.txt (max ~260 bits), both the GNU version and the patched version achieved complete factorization. The old implementation returned factor: Factorization incomplete. Remainders exist. and exited with exit code 1. This confirms the improvement in support for large integers.
factor_numbers_u128_repeat.txt

src/uu/factor/src/factor.rs

codspeed-hq · 2025-11-16T14:04:59Z

Merging this PR will not alter performance

✅ 284 untouched benchmarks
⏩ 38 skipped benchmarks¹

_{Comparing mattsu2020:factor_fix (f7f0581) with main (dec633c)}

38 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

github-actions · 2025-11-16T14:40:36Z

GNU testsuite comparison:

Skipping an intermittent issue tests/tail/overlay-headers (passes in this run but fails in the 'main' branch)

github-actions · 2025-11-17T09:52:38Z

GNU testsuite comparison:

Skipping an intermittent issue tests/misc/tee (passes in this run but fails in the 'main' branch)

github-actions · 2025-12-01T12:31:12Z

GNU testsuite comparison:

Skip an intermittent issue tests/tail/overlay-headers (fails in this run but passes in the 'main' branch)

sylvestre · 2025-12-07T13:53:19Z

Any idea why codspeed does not detect it?

mattsu2020 · 2025-12-07T14:01:10Z

Any idea why codspeed does not detect it?

If I were to consider it, I would create test cases with large integers.

github-actions · 2025-12-07T14:05:49Z

GNU testsuite comparison:

Skip an intermittent issue tests/tail/overlay-headers (fails in this run but passes in the 'main' branch)

github-actions · 2025-12-08T10:39:41Z

GNU testsuite comparison:

Skip an intermittent issue tests/tail/overlay-headers (fails in this run but passes in the 'main' branch)

- Add num-integer dependency to support enhanced numeric operations. - Refactor factorization logic to avoid redundant parsing and optimize u64/u128 paths. - Improve handling of non-positive and invalid inputs to align with GNU factor behavior. - Enhance large BigUint factoring with additional algorithms and clearer limitations.

- Integrate jemalloc allocator in factor benchmark suite for better memory profiling - Add jemalloc-ctl and jemallocator dependencies with OS-specific dev-dependencies - Implement logging of allocated and resident memory stats before benchmark runs - Update CI workflow to show output for uu_factor benchmarks without suppressing it - Enables precise memory usage tracking on Linux, macOS, and FreeBSD during benchmarking

Add technical terms for memory allocation libraries to the cspell dictionary to prevent false positives in spellchecking.

github-actions · 2025-12-24T23:38:16Z

GNU testsuite comparison:

Congrats! The gnu test tests/tail/follow-name is no longer failing!

sylvestre · 2025-12-26T23:42:21Z

many jobs are failing

Replace positional placeholders with named parameters in println! macro for improved readability and consistency with modern Rust formatting.

Install GNU make (gmake) in the FreeBSD workflow prepare step to support building and testing, as the process requires GNU make utilities alongside existing tools like jq and GNU coreutils.

Ignore security advisory RUSTSEC-2024-0436 for the unmaintained "paste" crate, which is used via jemalloc-ctl in the uu_factor benchmark. This suppresses the warning without impacting functionality, as the crate is not actively maintained.

github-actions · 2025-12-27T06:56:18Z

GNU testsuite comparison:

GNU test failed: tests/sort/sort-stale-thread-mem. tests/sort/sort-stale-thread-mem is passing on 'main'. Maybe you have to rebase?
Skipping an intermittent issue tests/timeout/timeout (passes in this run but fails in the 'main' branch)

github-actions · 2026-01-10T06:20:34Z

GNU testsuite comparison:

Skipping an intermittent issue tests/timeout/timeout (passes in this run but fails in the 'main' branch)

github-actions · 2026-01-25T10:16:56Z

GNU testsuite comparison:

Skipping an intermittent issue tests/shuf/shuf-reservoir (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/sort/sort-stale-thread-mem (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tty/tty-eof (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/tail/retry is no longer failing!

src/uu/factor/benches/factor_bench.rs

sylvestre · 2026-01-25T16:19:44Z

please add a test to verify that factor 15111234931751377131713914373267893176342349831 is indeed fixed

The jemalloc allocator and related dependencies (jemalloc-ctl, jemalloc-sys, paste) were removed from the factor utility's benchmark code. This change simplifies the dependency tree and removes platform-specific allocator logic that was only used for memory profiling in benchmarks. The benchmark functionality remains intact, just without jemalloc-specific memory statistics collection. Additionally, a new regression test was added to verify correct factorization of a very large number (15111234931751377131713914373267893176342349831) to ensure the utility handles large inputs properly.

…ger literals This commit adds numeric separators (`_`) to large integer literals in the factor.rs file to improve code readability. The changes include: - Adding separators to base arrays for Miller-Rabin primality testing - Adding separators to LCG constants used in Pollard's rho algorithm - Adding separators to LCG default seed value These changes make the large numeric values easier to read and understand without changing any functionality.

Reformatted the bases_64 array initialization to use proper indentation and line breaks for better code readability. The array elements are now aligned vertically, making the code easier to read and maintain.

github-actions · 2026-02-13T03:35:00Z

GNU testsuite comparison:

GNU test failed: tests/pr/bounded-memory. tests/pr/bounded-memory is passing on 'main'. Maybe you have to rebase?
Congrats! The gnu test tests/factor/t34 is no longer failing!
Note: The gnu test tests/basenc/bounded-memory is now being skipped but was previously passing.
Note: The gnu test tests/cut/bounded-memory is now being skipped but was previously passing.
Note: The gnu test tests/dd/no-allocate is now being skipped but was previously passing.
Note: The gnu test tests/tail/pipe-f is now being skipped but was previously passing.
Congrats! The gnu test tests/printf/printf-surprise is now passing!

sylvestre reviewed Nov 13, 2025

View reviewed changes