Add Rust for Linux auto CI job

[Kobzol]

This PR adds an auto CI job that checks if Rust for Linux (RfL) still compiles with the latest version of the compiler and the standard library. If not, we should ideally ping the RfL ping group.

try-job: rfl

[ojeda]

Thanks for this again! Some more comments/thoughts below...

I guess depending on how things go, i.e. how many failures we get and where they fail most, we could consider reducing or increasing the scope.

[Kobzol]

I think that the last thing required here is to select some reasonable initial commit. @ojeda any suggestions? I tried the commit that you have sent me before, but it was not found in the repo I think (maybe git just couldn't work with the shorter SHA though).

Is there any more up-to-date commit that I could use instead of master?

[ojeda]

I tried the commit that you have sent me before, but it was not found in the repo I think (maybe git just couldn't work with the shorter SHA though).

The commit exists, but you probably need something like:

mkdir linux
git -C linux init
git -C linux remote add origin https://github.com/torvalds/linux.git
git -C linux fetch --depth 1 origin 8f5b5f78113e881cb8570c961b0dc42b218a1b9e
git -C linux checkout FETCH_HEAD

instead of --branch. Another way is using the archive URL, e.g. https://github.com/torvalds/linux/archive/8f5b5f78113e.tar.gz.

Also, later today Linus will likely tag v6.10-rc1, which we could also use.

[ojeda]

Is there any more up-to-date commit that I could use instead of master?

Not sure what you mean, master is the latest in Linus' (and generally should not be used, since it will move). Do you mean something in the RFL repository?

[Kobzol]

Not sure what you mean, master is the latest in Linus' (and generally should not be used, since it will move). Do you mean something in the RFL repository?

Sorry, I meant "what is the most up-to-date commit SHA that works with RfL". master is not a stable ref, ofc.

[ojeda]

Both should work (i.e. the one I gave you as well as the current master, i.e. c13320499ba0efd93174ef6462ae8a7a2933f6e7).

[ojeda]

If you want to use the RFL repository as the base URL, I can push those commits there too.

[rust-timer]

Finished benchmarking commit (d402830): comparison URL.

Overall result: ❌ regressions - ACTION NEEDED

Next Steps: If you can justify the regressions found in this perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please open an issue or create a new PR that fixes the regressions, add a comment linking to the newly created issue or PR, and then add the perf-regression-triaged label to this PR.

@rustbot label: +perf-regression
cc @rust-lang/wg-compiler-performance

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	4.3%	[2.5%, 6.1%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary 2.3%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	2.3%	[2.3%, 2.3%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.3%	[2.3%, 2.3%]	1

Cycles

Results (secondary 5.9%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	5.9%	[2.9%, 7.7%]	6
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 675.838s -> 673.509s (-0.34%)
Artifact size: 320.09 MiB -> 320.06 MiB (-0.01%)

[lqd]

Only adds a new CI job and does not change the compiler @rustbot label: +perf-regression-triaged