Use jemalloc for Clippy #142286

Kobzol · 2025-06-10T09:20:54Z

The tool macros are annoying, we should IMO just get rid of them, create separate steps for each tool and (re)use some builders in them to share the build code.

r? @ghost

rustbot · 2025-06-10T09:20:58Z

Some changes occurred in src/tools/opt-dist

cc @Kobzol

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

Kobzol · 2025-06-10T09:21:05Z

@bors2 try

(Creating artifacts for local benchmarks)

rust-bors · 2025-06-10T09:21:09Z

⌛ Trying commit 0c6bbfb with merge df45868…

To cancel the try build, run the command @bors2 try cancel.

[experiment] Use jemalloc for Clippy The tool macros are annoying, we should IMO just get rid of them, create separate steps for each tool and (re)use some builders in them to share the build code. r? `@ghost`

rust-bors · 2025-06-10T11:51:18Z

☀️ Try build successful (CI)
Build commit: df45868 (df45868f04767f218ec5cc3d611eab803eaf32ec)

Kobzol · 2025-06-10T12:34:02Z

Confirmed that previously, Clippy used glibc malloc, but with this PR, it uses jemalloc, using rustc-perf:

cargo run --bin collector profile_local cachegrind `rustup +df45868f04767f218ec5cc3d611eab803eaf32ec which rustc` --profiles Clippy --scenarios Full --exact-match helloworld

In terms of performance, it looks pretty good!

Kobzol · 2025-06-12T05:00:38Z

r? @flip1995

flip1995

LGTM. I want r? @blyxyas to take another look. r=me if it looks good to you too 👍

blyxyas · 2025-06-17T13:58:29Z

I'm finding some differences in my results (although I'm checking them directly with the cachegrind annotations, not through the UI). I'll perform some more benchmarks but I have some questions. In my outputs cargo is 8.6% better, but for example syn is considerably worse (12.16b -> 13.01b), and serde is too (24b -> 28b).

Did you use RUSTFLAGS="-Wclippy:all"? With the command you provided it seems that the benchmarks fail because of some deny-level lints? Also, did you use multithreading with -Zthreads=XX?

I'll make sure that this is not a result from some background noise today, just sharing my current results. Let's hope that I can figure it out and make sure that these results are just background noise.

NOTE: Seems that although the benchmark fails, cgann- files are still created. So it doesn't really matter if the benchmark fails in this case (?)

Kobzol · 2025-06-17T14:04:48Z

I just used the default --profiles=Clippy in rustc-perf, which was recently fixed to actually use Clippy instead of doing a debug build 😆 No multi-threading was used, and I only ran the benchmarks presented above. I haven't actually tried Clippy on the whole benchmark suite, if it fails on some benchmarks, then we should definitely pass RUSTFLAGS="-Wclippy:all"! Would you like to send a PR to rustc-perf that adds this flag?

blyxyas · 2025-06-18T14:23:08Z

Finally got to benchmark it on a separate server, and in this server with -Wclippy::all (I'll open a PR to change this in rustc-perf) I've found improvements between 3.6% to 4.3% in manual revision. (Notably, single-threaded, but I don't think that multithreading will affect this significantly)

RUSTFLAGS="-Wclippy::all" cargo run -r --bin collector profile_local cachegrind `rustup +clippy-jemalloc which rustc` --profiles Clippy --scenarios Full --id clippy_jemalloc

blyxyas

LGTM, thanks! ❤️

Kobzol · 2025-06-18T14:26:27Z

Thank you for the benchmark!

@bors r=flip1995,blyxyas rollup=never

bors · 2025-06-18T14:26:30Z

📌 Commit 723dae8 has been approved by flip1995,blyxyas

It is now in the queue for this repository.

blyxyas · 2025-06-18T14:27:04Z

So nostalgic using bors again

bors · 2025-06-20T00:19:16Z

⌛ Testing commit 723dae8 with merge c4c766b...

Use jemalloc for Clippy The tool macros are annoying, we should IMO just get rid of them, create separate steps for each tool and (re)use some builders in them to share the build code. r? `@ghost`

rust-log-analyzer · 2025-06-20T02:53:58Z

The job dist-x86_64-msvc failed! Check out the build log: (web) (plain)

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

[2025-06-20T01:21:42Z DEBUG collector::compile::benchmark] Benchmark iteration 1/1
[2025-06-20T01:21:42Z INFO  collector::compile::execute] run_rustc with incremental=false, profile=Opt, scenario=Some(Full), patch=None, backend=Llvm, target=X86_64UnknownLinuxGnu, phase=benchmark
[2025-06-20T01:21:42Z DEBUG collector::compile::execute] "\\\\?\\C:\\a\\rust\\rust\\build\\x86_64-pc-windows-msvc\\stage0\\bin\\cargo.exe" "rustc" "--manifest-path" "Cargo.toml" "-p" "path+file:///C:/Users/RUNNER~1/AppData/Local/Temp/.tmpkOmtjQ#[email protected]" "--release" "--" "--wrap-rustc-with" "Eprintln"
[2025-06-20T01:21:43Z INFO  collector::compile::execute] run_rustc with incremental=true, profile=Opt, scenario=Some(IncrFull), patch=None, backend=Llvm, target=X86_64UnknownLinuxGnu, phase=benchmark
[2025-06-20T01:21:43Z DEBUG collector::compile::execute] "\\\\?\\C:\\a\\rust\\rust\\build\\x86_64-pc-windows-msvc\\stage0\\bin\\cargo.exe" "rustc" "--manifest-path" "Cargo.toml" "-p" "path+file:///C:/Users/RUNNER~1/AppData/Local/Temp/.tmpkOmtjQ#[email protected]" "--release" "--" "--wrap-rustc-with" "Eprintln" "-C" "incremental=C:\\Users\\RUNNER~1\\AppData\\Local\\Temp\\.tmpkOmtjQ\\incremental-state"
[2025-06-20T01:21:45Z INFO  collector::compile::execute] run_rustc with incremental=true, profile=Opt, scenario=Some(IncrUnchanged), patch=None, backend=Llvm, target=X86_64UnknownLinuxGnu, phase=benchmark
[2025-06-20T01:21:45Z DEBUG collector::compile::execute] "\\\\?\\C:\\a\\rust\\rust\\build\\x86_64-pc-windows-msvc\\stage0\\bin\\cargo.exe" "rustc" "--manifest-path" "Cargo.toml" "-p" "path+file:///C:/Users/RUNNER~1/AppData/Local/Temp/.tmpkOmtjQ#[email protected]" "--release" "--" "--wrap-rustc-with" "Eprintln" "-C" "incremental=C:\\Users\\RUNNER~1\\AppData\\Local\\Temp\\.tmpkOmtjQ\\incremental-state"
Finished benchmark match-stress (6/9)
Executing benchmark serde-1.0.219-new-solver (7/9)
Preparing serde-1.0.219-new-solver
[2025-06-20T01:21:46Z INFO  collector::compile::execute] run_rustc with incremental=false, profile=Check, scenario=None, patch=None, backend=Llvm, target=X86_64UnknownLinuxGnu, phase=dependencies
[2025-06-20T01:21:46Z INFO  collector::compile::execute] run_rustc with incremental=false, profile=Debug, scenario=None, patch=None, backend=Llvm, target=X86_64UnknownLinuxGnu, phase=dependencies

bors · 2025-06-20T02:54:35Z

💔 Test failed - checks-actions

Kobzol · 2025-06-20T05:30:15Z

Looks like some spurious Windows file path error..

@bors retry

bors · 2025-06-20T06:33:38Z

⌛ Testing commit 723dae8 with merge 18491d5...

bors · 2025-06-20T09:58:13Z

☀️ Test successful - checks-actions
Approved by: flip1995,blyxyas
Pushing 18491d5 to master...

github-actions · 2025-06-20T10:01:17Z

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 5b74275 (parent) -> 18491d5 (this PR)

Test differences

No test diffs found

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard 18491d5be00eb3ed2f1ccee2ac5b792694f2a7a0 --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

i686-msvc-2: 7297.0s -> 11171.8s (53.1%)
dist-i686-msvc: 6854.1s -> 10368.1s (51.3%)
dist-x86_64-apple: 7868.7s -> 11661.7s (48.2%)
x86_64-apple-1: 6732.2s -> 8569.5s (27.3%)
x86_64-apple-2: 4546.3s -> 5596.5s (23.1%)
dist-aarch64-apple: 6379.9s -> 5483.3s (-14.1%)
aarch64-apple: 4932.8s -> 4363.8s (-11.5%)
x86_64-rust-for-linux: 2819.3s -> 2543.9s (-9.8%)
dist-apple-various: 6970.2s -> 6401.2s (-8.2%)
dist-riscv64-linux: 4962.6s -> 4605.6s (-7.2%)

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 · 2025-06-20T12:06:51Z

Finished benchmarking commit (18491d5): 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 1.6%, 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)	1.6%	[1.1%, 2.6%]	4
Regressions ❌ (secondary)	2.7%	[1.2%, 7.1%]	17
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-5.3%	[-5.3%, -5.3%]	1
All ❌✅ (primary)	1.6%	[1.1%, 2.6%]	4

Cycles

Results (secondary -3.2%)

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)	3.8%	[3.8%, 3.8%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-4.6%	[-9.0%, -2.3%]	5
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 692.705s -> 691.482s (-0.18%)
Artifact size: 372.00 MiB -> 371.94 MiB (-0.01%)

Kobzol added 2 commits June 10, 2025 11:09

Add jemalloc feature to Clippy

3d9c46e

Pass jemalloc feature to Clippy in bootstrap

723dae8

rustbot added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Jun 10, 2025

rustbot added the T-bootstrap Relevant to the bootstrap subteam: Rust's build system (x.py and src/bootstrap) label Jun 10, 2025

Kobzol changed the title ~~[experiment] Use jemalloc for Clippy~~ Use jemalloc for Clippy Jun 12, 2025

Kobzol force-pushed the clippy-jemalloc branch from 0c6bbfb to 723dae8 Compare June 12, 2025 05:00

rustbot assigned flip1995 Jun 12, 2025

flip1995 approved these changes Jun 12, 2025

View reviewed changes

rustbot assigned blyxyas and unassigned flip1995 Jun 12, 2025

blyxyas approved these changes Jun 18, 2025

View reviewed changes

bors 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 18, 2025

bors added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Jun 20, 2025

bors 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 20, 2025

bors added the merged-by-bors This PR was explicitly merged by bors. label Jun 20, 2025

bors merged commit 18491d5 into rust-lang:master Jun 20, 2025
11 checks passed

rustbot added this to the 1.89.0 milestone Jun 20, 2025

Use jemalloc for Clippy #142286

Use jemalloc for Clippy #142286

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Kobzol commented Jun 10, 2025

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github-actions bot commented Jun 20, 2025

Test differences

Job duration changes

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rust-timer commented Jun 20, 2025

Overall result: no relevant changes - no action needed

Instruction count

Max RSS (memory usage)

Cycles

Binary size

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blyxyas commented Jun 17, 2025 •

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