Sandbox::https://github.com/rust-lang/rust/pull/164971

bit-aloo · 2026-10-26T09:45:58Z

I am trying a few things out in the search graph to see if any of them have an impact on performance. These are very small changes, mostly early returns or memoizing a few operations that we do quite a lot (though it might not be necessary). Just curious to see how it goes.

r? @ghost

bit-aloo · 2026-10-26T09:48:07Z

@bors try @rust-timer queue

… r=<try> [DO NOT MERGE] search graph exploration

rust-bors · 2026-10-26T10:51:48Z

☀️ Try build successful (CI)
Build commit: 85ebe97 (85ebe973c39a5222d23fa22d9d24cfc34c4e9621)
Base parent: aaf324d (aaf324d50a7dcb17aae7f2a37e15ff143d980c6e)

rust-timer · 2026-10-26T19:44:45Z

Finished benchmarking commit (85ebe97): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking means the PR may be perf-sensitive. Consider adding rollup=never if this change is not fit for rolling up.

@bors rollup=iffy rustc-perf
@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%, -0.0%]	12
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary -0.0%, 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)	0.6%	[0.4%, 0.9%]	7
Regressions ❌ (secondary)	0.5%	[0.5%, 0.5%]	1
Improvements ✅ (primary)	-0.8%	[-1.5%, -0.4%]	6
Improvements ✅ (secondary)	-0.5%	[-0.5%, -0.5%]	1
All ❌✅ (primary)	-0.0%	[-1.5%, 0.9%]	13

Cycles

Results (primary -0.0%, secondary 2.7%)

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

	mean	range	count
Regressions ❌ (primary)	1.0%	[0.5%, 2.6%]	7
Regressions ❌ (secondary)	2.7%	[0.8%, 4.7%]	2
Improvements ✅ (primary)	-0.9%	[-1.7%, -0.5%]	8
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.0%	[-1.7%, 2.6%]	15

Binary size

Results (primary 0.1%, secondary 0.1%)

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

	mean	range	count
Regressions ❌ (primary)	0.1%	[0.0%, 0.2%]	67
Regressions ❌ (secondary)	0.1%	[0.0%, 0.3%]	56
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.1%	[0.0%, 0.2%]	67

Bootstrap: 488.092s -> 487.544s (-0.11%)
Artifact size: 405.81 MiB -> 406.05 MiB (0.06%)

bit-aloo · 2026-10-29T04:18:04Z

@bors try @rust-timer queue

… r=<try> [DO NOT MERGE] search graph exploration

rust-bors · 2026-10-29T05:21:59Z

☀️ Try build successful (CI)
Build commit: e0c36dc (e0c36dcc3496f515e0f58bc7c0d3f1efe765203c)
Base parent: 92ffebe (92ffebeceaa0a071066f233873c2438e73d70fe7)

rust-timer · 2026-10-29T06:55:19Z

Finished benchmarking commit (e0c36dc): comparison URL.

Overall result: ❌ regressions - please read:

Benchmarking means the PR may be perf-sensitive. Consider adding rollup=never if this change is not fit for rolling up.

Next, please: If you can, justify the regressions found in this try perf run in writing along with @rustbot label: +perf-regression-triaged. If not, fix the regressions and do another perf run. Neutral or positive results will clear the label automatically.

@bors rollup=iffy rustc-perf
@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)	0.3%	[0.0%, 0.5%]	10
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary 1.0%)

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

	mean	range	count
Regressions ❌ (primary)	1.6%	[0.6%, 6.8%]	8
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.1%	[-1.3%, -0.9%]	2
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	1.0%	[-1.3%, 6.8%]	10

Cycles

Results (primary -0.3%, secondary -2.4%)

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

	mean	range	count
Regressions ❌ (primary)	0.7%	[0.5%, 1.2%]	7
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.2%	[-2.9%, -0.6%]	9
Improvements ✅ (secondary)	-2.4%	[-2.5%, -2.3%]	2
All ❌✅ (primary)	-0.3%	[-2.9%, 1.2%]	16

Binary size

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

Bootstrap: 488.483s -> 488.641s (0.03%)
Artifact size: 405.90 MiB -> 406.12 MiB (0.05%)

bit-aloo · 2026-10-29T06:59:23Z

@bors try @rust-timer queue

… r=<try> [DO NOT MERGE] search graph exploration

rust-bors · 2026-10-29T07:57:29Z

☀️ Try build successful (CI)
Build commit: b71d391 (b71d391fa0186b2b0f8b7253f66d758353032074)
Base parent: ce37c4f (ce37c4ff837c5c5dc45cddf9e1e3704e42ca67ea)

rust-timer · 2026-10-29T08:52:54Z

Finished benchmarking commit (b71d391): comparison URL.

Overall result: no relevant changes - no action needed

Benchmarking means the PR may be perf-sensitive. Consider adding rollup=never if this change is not fit for rolling up.

@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

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

Max RSS (memory usage)

Results (primary 0.2%)

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

	mean	range	count
Regressions ❌ (primary)	0.5%	[0.4%, 0.7%]	6
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.6%	[-1.0%, -0.4%]	3
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.2%	[-1.0%, 0.7%]	9

Cycles

Results (primary 0.6%, secondary 1.7%)

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

	mean	range	count
Regressions ❌ (primary)	1.2%	[0.4%, 2.6%]	12
Regressions ❌ (secondary)	1.7%	[0.4%, 3.5%]	4
Improvements ✅ (primary)	-1.0%	[-1.4%, -0.7%]	4
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.6%	[-1.4%, 2.6%]	16

Binary size

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

Bootstrap: 490.291s -> 491.174s (0.18%)
Artifact size: 406.63 MiB -> 406.76 MiB (0.03%)

… r=<try> [DO NOT MERGE] search graph exploration

rust-bors · 2026-11-03T16:43:27Z

☀️ Try build successful (CI)
Build commit: bc7feaa (bc7feaa26934e410626d4844397442ffa7ff0792)
Base parent: 6a98084 (6a98084e4a21b04504c034dfc640e35e32ab9854)

rust-timer · 2026-11-03T18:06:55Z

Finished benchmarking commit (bc7feaa): comparison URL.

Overall result: ❌ regressions - please read:

Benchmarking means the PR may be perf-sensitive. Consider adding rollup=never if this change is not fit for rolling up.

Next, please: If you can, justify the regressions found in this try perf run in writing along with @rustbot label: +perf-regression-triaged. If not, fix the regressions and do another perf run. Neutral or positive results will clear the label automatically.

@bors rollup=iffy rustc-perf
@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)	0.4%	[0.2%, 0.7%]	13
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary 1.2%, secondary -2.3%)

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

	mean	range	count
Regressions ❌ (primary)	1.2%	[1.2%, 1.2%]	1
Regressions ❌ (secondary)	2.5%	[2.5%, 2.5%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.9%	[-4.3%, -1.4%]	8
All ❌✅ (primary)	1.2%	[1.2%, 1.2%]	1

Cycles

Results (primary -2.7%, secondary -2.9%)

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)	-	-	0
Improvements ✅ (primary)	-2.7%	[-2.7%, -2.7%]	1
Improvements ✅ (secondary)	-2.9%	[-3.7%, -2.0%]	2
All ❌✅ (primary)	-2.7%	[-2.7%, -2.7%]	1

Binary size

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

Bootstrap: 482.475s -> 481.881s (-0.12%)
Artifact size: 406.38 MiB -> 406.48 MiB (0.02%)

bit-aloo · 2026-11-04T01:36:43Z

@bors try @rust-timer queue

… r=<try> [DO NOT MERGE] search graph exploration

rust-bors · 2026-11-04T02:42:29Z

☀️ Try build successful (CI)
Build commit: 73b8677 (73b8677fccb815aa7ec1117ec3c838b97f1cb7e9)
Base parent: 708c94e (708c94ef093ecc42fb8851e17d8383d999727abc)

rust-timer · 2026-11-04T03:31:12Z

Finished benchmarking commit (73b8677): comparison URL.

Overall result: no relevant changes - no action needed

Benchmarking means the PR may be perf-sensitive. Consider adding rollup=never if this change is not fit for rolling up.

@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

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

Max RSS (memory usage)

Results (primary 2.2%, secondary 2.1%)

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

	mean	range	count
Regressions ❌ (primary)	2.2%	[2.2%, 2.2%]	1
Regressions ❌ (secondary)	2.1%	[2.1%, 2.1%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.2%	[2.2%, 2.2%]	1

Cycles

Results (secondary 11.9%)

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)	26.2%	[26.2%, 26.2%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.3%	[-2.3%, -2.3%]	1
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 483.649s -> 483.96s (0.06%)
Artifact size: 406.38 MiB -> 406.36 MiB (-0.01%)

bit-aloo · 2026-11-04T15:51:30Z

@bors try @rust-timer queue

rust-timer · 2026-11-04T15:51:33Z

Awaiting bors try build completion.

@rustbot label: +S-waiting-on-perf

… r=<try> [DO NOT MERGE] search graph exploration

rust-bors · 2026-11-04T15:51:38Z

⌛ Trying commit 08be60b with merge f089070…

To cancel the try build, run the command @bors try cancel.

Workflow: https://github.com/rust-lang/rust/actions/runs/41862079576

rust-log-analyzer · 2026-11-04T16:26:22Z

The job test-pr-check-2 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

    Checking sharded-slab v0.1.7
error: using `.clone()` on a ref-counted pointer
   --> compiler/rustc_type_ir/src/search_graph/mod.rs:555:69
    |
555 |                     .map(|(step, nested)| (step_kind.extend(*step), nested.clone())),
    |                                                                     ^^^^^^^^^^^^^^ help: try: `std::sync::Arc::<search_graph::NestedGoals<X>>::clone(nested)`
    |
    = help: for further information visit https://clippy.rust-lang.org/main/index.html#clone_on_ref_ptr
    = note: requested on the command line with `-D clippy::clone-on-ref-ptr`

error: using `.clone()` on a ref-counted pointer
   --> compiler/rustc_type_ir/src/search_graph/mod.rs:558:44
    |
558 |             self.children.push((step_kind, child.clone()));
    |                                            ^^^^^^^^^^^^^ help: try: `std::sync::Arc::<search_graph::NestedGoals<X>>::clone(child)`
    |
    = help: for further information visit https://clippy.rust-lang.org/main/index.html#clone_on_ref_ptr

[RUSTC-TIMING] sharded_slab test:false 0.702
   Compiling nix v0.30.1

rust-bors · 2026-11-04T21:54:03Z

💥 Test timed out after 21600s

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 Oct 26, 2026