Start a perf check whenever you think it's ready. 👍

Honestly I kinda want a baseline to see if a few tiny changes like this will show up at all or not.

Even if it shows up as no change, that is useful data for future optimization attempts.

@bors try @rust-timer queue

☀️ Try build successful (CI)
Build commit: 05c0f81 (05c0f818fe424341111ec6f6ccc79df099d0a142, parent: b779120cad2c93e53c0dfb7007c1214b2b275183)

Ok yeah, this is about what I expected, a small but measurable improvement to build_impl (actually around 2% of the functions runtime, which seems about right for eliminating a few branches in a loop), and somewhat noisy changes to memory usage (i believe we're reducing heap fragmentation when doc_only is set, but otherwise it may actually increase it? depends on the specifics of the allocator used and what state its in).

Confident the first change is worth it, unsure about the second.

The only improvement I see is:

Which is quite minor and could be noise.

If you look at the branch-misses metric there's quite a lot of improvements which would be what I expect.

https://perf.rust-lang.org/compare.html?start=b779120cad2c93e53c0dfb7007c1214b2b275183&end=05c0f818fe424341111ec6f6ccc79df099d0a142&stat=branch-misses

Didn't even know there were other metrics. O.o

Anyway, only improvements so feel free to r=me.

@bors r=GuillaumeGomez

📌 Commit f16d1fc has been approved by GuillaumeGomez

It is now in the queue for this repository.

@bors r-

whoops, meant to push to a new branch (reset the branch back to the approved commit)

@bors r=GuillaumeGomez

📌 Commit f16d1fc has been approved by GuillaumeGomez

It is now in the queue for this repository.

⌛ Testing commit f16d1fc with merge cdb45c8...

☀️ Test successful - checks-actions
Approved by: GuillaumeGomez
Pushing cdb45c8 to master...

A job failed! Check out the build log: (web) (plain enhanced) (plain)

Prepare workflow directory
Prepare all required actions
Getting action download info
Download action repository 'actions/checkout@v5' (SHA:08c6903cd8c0fde910a37f88322edcfb5dd907a8)
Complete job name: DockerHub mirror
##[group]Run actions/checkout@v5
with:
 persist-credentials: false
 repository: rust-lang/rust
 token: ***
---
http.https://github.com/.extraheader
[command]/usr/bin/git config --local --unset-all http.https://github.com/.extraheader
[command]/usr/bin/git submodule foreach --recursive sh -c "git config --local --name-only --get-regexp 'http\.https\:\/\/github\.com\/\.extraheader' && git config --local --unset-all 'http.https://github.com/.extraheader' || :"
##[endgroup]
##[group]Run echo "***" | docker login ghcr.io -u rust-lang --password-stdin
echo "***" | docker login ghcr.io -u rust-lang --password-stdin
shell: /usr/bin/bash -e {0}
##[endgroup]
Error response from daemon: Get "https://ghcr.io/v2/": Get "https://ghcr.io/token?account=rust-lang&client_id=docker&offline_token=true&service=ghcr.io": net/http: request canceled (Client.Timeout exceeded while awaiting headers) (Client.Timeout exceeded while awaiting headers)
##[error]Process completed with exit code 1.
Post job cleanup.

Comparing d829133 (parent) -> cdb45c8 (this PR)

Test differences

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
 test-dashboard cdb45c87e2cd43495379f7e867e3cc15dcee9f93 --output-dir test-dashboard

Job duration changes

1. aarch64-apple: 6093.1s -> 16222.6s (166.2%)
2. dist-aarch64-apple: 7603.6s -> 6594.5s (-13.3%)
3. dist-x86_64-solaris: 5910.2s -> 5274.3s (-10.8%)
4. dist-sparcv9-solaris: 4948.3s -> 5449.8s (10.1%)
5. x86_64-gnu-llvm-19: 2673.4s -> 2455.3s (-8.2%)
6. dist-armhf-linux: 4782.8s -> 5137.6s (7.4%)
7. dist-armv7-linux: 5125.5s -> 5472.4s (6.8%)
8. x86_64-msvc-ext3: 6734.5s -> 6292.9s (-6.6%)
9. dist-ohos-aarch64: 4463.4s -> 4195.0s (-6.0%)
10. x86_64-msvc-ext1: 7229.9s -> 7584.5s (4.9%)