[PERF] see if my fork of `stringdex` affects perf #147918

yotamofek · 2025-10-20T18:37:10Z

please disregard the actual changes in my fork on stringdex, it's all "wip" commits and a bunch of different changes I was experimenting with..
I just wanna see if it actually has an effect on the rustc benchmarks (not just the stringdex benchmarks) to see if it's worth pursuing

Kobzol · 2025-10-20T18:46:01Z

@bors try @rust-timer queue

[PERF] see if my fork of `stringdex` affects perf

rust-bors · 2025-10-21T00:51:13Z

💥 Test timed out after 21600s

notriddle · 2025-10-21T04:22:36Z

@bors try @rust-timer queue

[PERF] see if my fork of `stringdex` affects perf

rust-bors · 2025-10-21T06:42:40Z

☀️ Try build successful (CI)
Build commit: cc4f770 (cc4f7703e067e4e62f404b76a3a1bd7c1d67b4ec, parent: c7a635f33c5fbd1ead110243a2f4a5f0561d79b0)

rust-timer · 2025-10-21T07:53:44Z

Finished benchmarking commit (cc4f770): comparison URL.

Overall result: ❌✅ regressions and improvements - please read the text below

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please do so in sufficient writing along with @rustbot label: +perf-regression-triaged. If not, please fix the regressions and do another perf run. If its results are neutral or positive, the label will be automatically removed.

@bors rollup=never
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.6%	[0.6%, 0.6%]	1
Improvements ✅ (primary)	-0.4%	[-0.9%, -0.1%]	12
Improvements ✅ (secondary)	-0.5%	[-0.9%, -0.3%]	3
All ❌✅ (primary)	-0.4%	[-0.9%, -0.1%]	12

Max RSS (memory usage)

Results (secondary -4.0%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-4.0%	[-4.0%, -4.0%]	1
All ❌✅ (primary)	-	-	0

Cycles

Results (primary -2.4%, secondary 2.0%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	2.0%	[2.0%, 2.0%]	1
Improvements ✅ (primary)	-2.4%	[-2.4%, -2.4%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-2.4%	[-2.4%, -2.4%]	1

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 472.842s -> 473.067s (0.05%)
Artifact size: 388.69 MiB -> 388.71 MiB (0.01%)

JonathanBrouwer · 2025-10-21T08:24:19Z

Performance looks excellent, the coercions result is clearly bimodal noise

GuillaumeGomez · 2025-10-21T09:32:04Z

@yotamofek: Do you want to merge this one already?

yotamofek · 2025-10-21T09:53:19Z

Nah, my changes to stringdex are a complete mess at the moment, I think it'll be better to first get a few of them up as PRs and have @notriddle go over them, and then released to crates.io. No point in depending on a fork when it's a crate that's owned by a project member.
(unless they don't have the capacity to review and/or work on stringdex)

notriddle · 2025-10-21T17:06:26Z

It's fine. Send me the PR on GitLab, and I'll look at them ASAP.

yotamofek · 2025-10-26T06:55:05Z

Still a WIP, but I've started PR-ing my changes and notriddle has merged a few of them already, and I'm interested in the interim perf results. Would love another perf run please 🙏
(the stringdex dep now points at the upstream repo, and not my fork)

JonathanBrouwer · 2025-10-26T07:23:40Z

@bors try @rust-timer queue

[PERF] see if my fork of `stringdex` affects perf

rust-bors · 2025-10-26T09:39:05Z

☀️ Try build successful (CI)
Build commit: 8d6db5f (8d6db5f9d35b2db7123c580a6181f6cf3c9a4db6, parent: e5177985a5493c783d6ba20960d2723d9d2e9214)

rust-timer · 2025-10-26T12:33:27Z

Finished benchmarking commit (8d6db5f): comparison URL.

Overall result: ❌✅ regressions and improvements - please read the text below

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please do so in sufficient writing along with @rustbot label: +perf-regression-triaged. If not, please fix the regressions and do another perf run. If its results are neutral or positive, the label will be automatically removed.

@bors rollup=never
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.1%	[0.1%, 0.1%]	1
Improvements ✅ (primary)	-0.1%	[-0.2%, -0.1%]	4
Improvements ✅ (secondary)	-0.3%	[-0.3%, -0.3%]	1
All ❌✅ (primary)	-0.1%	[-0.2%, -0.1%]	4

Max RSS (memory usage)

This benchmark run did not return any relevant results for this metric.

Cycles

This benchmark run did not return any relevant results for this metric.

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 475.08s -> 474.988s (-0.02%)
Artifact size: 390.51 MiB -> 390.49 MiB (-0.00%)

yotamofek · 2025-10-31T16:58:05Z

Another perf run here please

GuillaumeGomez · 2025-10-31T16:59:43Z

Yes sir!

@bors try @rust-timer queue

[PERF] see if my fork of `stringdex` affects perf

rust-bors · 2025-10-31T19:14:23Z

☀️ Try build successful (CI)
Build commit: 72862a9 (72862a960c5ecb3f6eee2ffc8a089317105dbad8, parent: 51f5892019f8fb07864647d46c4eb577d3b0719f)

rust-timer · 2025-10-31T20:50:03Z

Finished benchmarking commit (72862a9): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

@bors rollup=never
@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.2%	[-0.2%, -0.1%]	2
Improvements ✅ (secondary)	-0.3%	[-0.3%, -0.3%]	1
All ❌✅ (primary)	-0.2%	[-0.2%, -0.1%]	2

Max RSS (memory usage)

Results (secondary -2.2%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.2%	[-2.2%, -2.2%]	1
All ❌✅ (primary)	-	-	0

Cycles

This benchmark run did not return any relevant results for this metric.

Binary size

Results (secondary 0.0%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.0%	[0.0%, 0.0%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Bootstrap: 474.501s -> 472.654s (-0.39%)
Artifact size: 390.85 MiB -> 390.89 MiB (0.01%)