perf: Make stable_crate_ids reads lock-free after crate loading by xmakro · Pull Request #158185 · rust-lang/rust

xmakro · 2026-06-20T18:38:07Z

No description provided.

workingjubilee · 2026-06-20T22:34:06Z

perf: Make stable_crate_ids reads lock-free after crate loading

rust-bors · 2026-06-21T00:43:19Z

☀️ Try build successful (CI)
Build commit: ba63cbe (ba63cbef0d118b3293af7c2e748a9f44efbabd3a)
Base parent: 8b6558a (8b6558a02b2774acfb25cf15e199467c37ba7490)

rust-timer · 2026-06-21T01:23:38Z

Finished benchmarking commit (ba63cbe): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing 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%, -0.2%]	1
Improvements ✅ (secondary)	-0.3%	[-0.6%, -0.2%]	8
All ❌✅ (primary)	-0.2%	[-0.2%, -0.2%]	1

Max RSS (memory usage)

Results (primary 1.4%, secondary 1.2%)

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

	mean	range	count
Regressions ❌ (primary)	1.4%	[0.7%, 2.1%]	2
Regressions ❌ (secondary)	3.2%	[2.5%, 3.6%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.8%	[-2.8%, -0.7%]	2
All ❌✅ (primary)	1.4%	[0.7%, 2.1%]	2

Cycles

Results (primary -0.5%, secondary 1.3%)

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

	mean	range	count
Regressions ❌ (primary)	1.4%	[1.4%, 1.4%]	1
Regressions ❌ (secondary)	3.3%	[2.7%, 3.8%]	2
Improvements ✅ (primary)	-2.4%	[-2.4%, -2.4%]	1
Improvements ✅ (secondary)	-2.6%	[-2.6%, -2.6%]	1
All ❌✅ (primary)	-0.5%	[-2.4%, 1.4%]	2

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 482.01s -> 480.669s (-0.28%)
Artifact size: 391.28 MiB -> 391.17 MiB (-0.03%)

rustbot · 2026-06-26T15:19:21Z

r? @mu001999

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mu001999 · 2026-06-26T16:25:08Z

LGTM, thanks!

@bors r+ rollup

rust-bors · 2026-06-26T16:25:11Z

📌 Commit 7c96471 has been approved by mu001999

It is now in the queue for this repository.

🌲 The tree is currently closed for pull requests below priority 1. This pull request will be tested once the tree is reopened.

…uwer Rollup of 15 pull requests Successful merges: - #153697 (Add arg splat experiment initial tuple impl) - #158360 (Various borrowck cleanups and param_env/opaque_types_defined_by query simplifications for typeck children) - #158438 (Use rigidness marker in fast_reject) - #157127 (cg_LLVM: Stop needing an alloca for volatile loads) - #158376 (Suggest `>=` for `=>` typo in closure and call argument positions) - #158185 (perf: Make stable_crate_ids reads lock-free after crate loading) - #158244 (Attribute docs `deprecated` , `warn`, `allow`, `cfg`, `deny`, and `forbid` ) - #158355 (Fixup the refactoring errors in #156246) - #158361 (Move `check_ffi_pure` into the attribute parser) - #158382 (Add safety section for SliceIndex::get_unchecked(mut)) - #158399 (std: truncate thread names on NetBSD) - #158418 (Eliminate double length check in `Vec::into_array`) - #158430 (Guard clone suggestion against empty obligation errors) - #158446 (Update Enzyme submodule) - #158448 (Cleanup `NumBuffer` comment and replace `ilog(10)` with `ilog10()`)

…uwer Rollup of 15 pull requests Successful merges: - rust-lang/rust#153697 (Add arg splat experiment initial tuple impl) - rust-lang/rust#158360 (Various borrowck cleanups and param_env/opaque_types_defined_by query simplifications for typeck children) - rust-lang/rust#158438 (Use rigidness marker in fast_reject) - rust-lang/rust#157127 (cg_LLVM: Stop needing an alloca for volatile loads) - rust-lang/rust#158376 (Suggest `>=` for `=>` typo in closure and call argument positions) - rust-lang/rust#158185 (perf: Make stable_crate_ids reads lock-free after crate loading) - rust-lang/rust#158244 (Attribute docs `deprecated` , `warn`, `allow`, `cfg`, `deny`, and `forbid` ) - rust-lang/rust#158355 (Fixup the refactoring errors in rust-lang/rust#156246) - rust-lang/rust#158361 (Move `check_ffi_pure` into the attribute parser) - rust-lang/rust#158382 (Add safety section for SliceIndex::get_unchecked(mut)) - rust-lang/rust#158399 (std: truncate thread names on NetBSD) - rust-lang/rust#158418 (Eliminate double length check in `Vec::into_array`) - rust-lang/rust#158430 (Guard clone suggestion against empty obligation errors) - rust-lang/rust#158446 (Update Enzyme submodule) - rust-lang/rust#158448 (Cleanup `NumBuffer` comment and replace `ilog(10)` with `ilog10()`)

JonathanBrouwer · 2026-06-27T10:52:05Z

@rust-timer build 9087db2
Perf run for #158455
Perf improvement expected

@mu001999 This should probably have been rollup=iffy because of the perf effect <3

mu001999 · 2026-06-27T11:53:45Z

This should probably have been rollup=iffy because of the perf effect <3

Sorry, I’d thought iffy/never was only needed when there was a perf regression. I know now, thanks <3

rust-timer · 2026-06-27T12:52:31Z

Finished benchmarking commit (9087db2): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing 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
Improvements ✅ (secondary)	-0.3%	[-0.5%, -0.2%]	9
All ❌✅ (primary)	-	-	0

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

Results (secondary -0.9%)

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)	3.0%	[3.0%, 3.0%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.8%	[-2.8%, -2.8%]	2
All ❌✅ (primary)	-	-	0

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 486.597s -> 484.816s (-0.37%)
Artifact size: 395.64 MiB -> 395.15 MiB (-0.12%)

perf: Make stable_crate_ids reads lock-free after crate loading

7c96471

rustbot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Jun 20, 2026

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rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Jun 20, 2026

rust-bors Bot pushed a commit that referenced this pull request Jun 20, 2026

Auto merge of #158185 - xmakro:perf/stable-crate-ids-lockfree, r=<try>

ba63cbe

perf: Make stable_crate_ids reads lock-free after crate loading

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rustbot removed the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Jun 21, 2026

xmakro marked this pull request as ready for review June 26, 2026 15:19

rustbot added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Jun 26, 2026

rustbot assigned mu001999 Jun 26, 2026

rustbot removed the S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. label Jun 26, 2026

rust-bors Bot added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Jun 26, 2026

JonathanBrouwer mentioned this pull request Jun 26, 2026

Rollup of 15 pull requests #158455

Merged

rust-bors Bot merged commit 4631799 into rust-lang:main Jun 27, 2026
14 checks passed

rustbot added this to the 1.98.0 milestone Jun 27, 2026

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perf: Make stable_crate_ids reads lock-free after crate loading#158185

perf: Make stable_crate_ids reads lock-free after crate loading#158185
rust-bors[bot] merged 1 commit into
rust-lang:mainfrom
xmakro:perf/stable-crate-ids-lockfree

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Overall result: ✅ improvements - no action needed

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Overall result: ✅ improvements - no action needed

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