Preserve caches in a call to shrink_to_fit

[tmiasko]

A small follow up to #142542.

[rustbot]

r? @davidtwco

rustbot has assigned @davidtwco.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

[rustbot]

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

[oli-obk]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 8e266d9 with merge 727e41c...

[bors]

☀️ Try build successful - checks-actions
Build commit: 727e41c (727e41c33fc009ee06a8772ab70f61754bf486ec)

[rust-timer]

Finished benchmarking commit (727e41c): 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)	-1.2%	[-1.2%, -1.2%]	1
Improvements ✅ (secondary)	-1.1%	[-1.1%, -1.1%]	1
All ❌✅ (primary)	-1.2%	[-1.2%, -1.2%]	1

Max RSS (memory usage)

Results (primary -2.0%, secondary -0.6%)

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)	2.7%	[2.7%, 2.7%]	1
Improvements ✅ (primary)	-2.0%	[-2.0%, -2.0%]	1
Improvements ✅ (secondary)	-3.9%	[-3.9%, -3.9%]	1
All ❌✅ (primary)	-2.0%	[-2.0%, -2.0%]	1

Cycles

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)	1.0%	[0.8%, 1.1%]	5
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	1.0%	[0.8%, 1.1%]	5

Binary size

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

Bootstrap: 693.627s -> 697.572s (0.57%)
Artifact size: 371.96 MiB -> 371.98 MiB (0.01%)

[oli-obk]

@bors r+

[bors]

📌 Commit 8e266d9 has been approved by oli-obk

It is now in the queue for this repository.

[bors]

⌛ Testing commit 8e266d9 with merge 9972ebf...

[bors]

☀️ Test successful - checks-actions
Approved by: oli-obk
Pushing 9972ebf to master...

[github-actions]

What is this?

This is an experimental post-merge analysis report that shows differences in test outcomes between the merged PR and its parent PR.

Comparing 8051f01 (parent) -> 9972ebf (this PR)

Test differences

No test diffs found

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard 9972ebfcc2b1ab322dc6611c1c997344078e05cd --output-dir test-dashboard

And then open test-dashboard/index.html in your browser to see an overview of all executed tests.

Job duration changes

1. x86_64-apple-1: 8767.5s -> 6622.2s (-24.5%)
2. x86_64-apple-2: 6536.7s -> 5319.5s (-18.6%)
3. mingw-check-tidy: 80.8s -> 66.3s (-18.0%)
4. dist-i686-msvc: 6688.8s -> 7758.8s (16.0%)
5. dist-aarch64-apple: 5963.1s -> 5186.1s (-13.0%)
6. mingw-check-1: 1735.0s -> 1513.1s (-12.8%)
7. i686-gnu-2: 6232.0s -> 5445.3s (-12.6%)
8. dist-apple-various: 6762.1s -> 7576.9s (12.1%)
9. x86_64-rust-for-linux: 2881.2s -> 2534.4s (-12.0%)
10. i686-gnu-1: 8016.1s -> 7207.8s (-10.1%)

How to interpret the job duration changes?

Job durations can vary a lot, based on the actual runner instance
that executed the job, system noise, invalidated caches, etc. The table above is provided
mostly for t-infra members, for simpler debugging of potential CI slow-downs.

[rust-timer]

Finished benchmarking commit (9972ebf): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

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

Max RSS (memory usage)

Results (primary 1.4%, 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)	3.4%	[2.3%, 4.2%]	3
Regressions ❌ (secondary)	2.9%	[1.6%, 3.8%]	14
Improvements ✅ (primary)	-4.5%	[-4.5%, -4.5%]	1
Improvements ✅ (secondary)	-4.6%	[-4.6%, -4.6%]	1
All ❌✅ (primary)	1.4%	[-4.5%, 4.2%]	4

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: 690.748s -> 691.157s (0.06%)
Artifact size: 371.94 MiB -> 371.94 MiB (0.00%)