Use a lock-free datastructure for source_span

[oli-obk]

follow up to the perf regression in #105462

The main regression is likely the CStore, but let's evaluate the perf impact of this on its own

[rustbot]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @eholk (or someone else) soon.

Please see the contribution instructions for more information.

[oli-obk]

@bors try @rust-timer queue

[rustbot]

These commits modify the Cargo.lock file. Random changes to Cargo.lock can be introduced when switching branches and rebasing PRs.
This was probably unintentional and should be reverted before this PR is merged.

If this was intentional then you can ignore this comment.

[bors]

⌛ Trying commit decfb4d with merge d9f8ba9ac6c5b66fa889991d907f5612d562cac7...

[bors]

☀️ Try build successful - checks-actions
Build commit: d9f8ba9ac6c5b66fa889991d907f5612d562cac7 (d9f8ba9ac6c5b66fa889991d907f5612d562cac7)

[rust-timer]

Finished benchmarking commit (d9f8ba9ac6c5b66fa889991d907f5612d562cac7): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

@bors rollup=never
@rustbot label: -S-waiting-on-perf -perf-regression

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)	-	-	0
Improvements ✅ (primary)	-0.2%	[-0.3%, -0.2%]	9
Improvements ✅ (secondary)	-0.4%	[-0.5%, -0.3%]	5
All ❌✅ (primary)	-0.2%	[-0.3%, -0.2%]	9

Max RSS (memory usage)

Results

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)	3.4%	[3.0%, 3.9%]	2
Regressions ❌ (secondary)	1.3%	[1.3%, 1.3%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.2%	[-2.4%, -2.0%]	3
All ❌✅ (primary)	3.4%	[3.0%, 3.9%]	2

Cycles

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

[eholk]

@oli-obk Did you want to merge this or was it just to do a perf run?

If you want to merge, it looks good to me so feel free to r=me.

[oli-obk]

yes, I wanted to land this.

@bors r=eholk

[bors]

📌 Commit decfb4d has been approved by eholk

It is now in the queue for this repository.

[bors]

⌛ Testing commit decfb4d with merge bd4a96a...

[bors]

☀️ Test successful - checks-actions
Approved by: eholk
Pushing bd4a96a to master...

[bors]

☀️ Test successful - checks-actions
Approved by: eholk
Pushing bd4a96a to master...

[rust-timer]

Finished benchmarking commit (bd4a96a): 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

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)	-	-	0
Improvements ✅ (primary)	-2.6%	[-2.6%, -2.6%]	1
Improvements ✅ (secondary)	-2.9%	[-5.2%, -2.0%]	15
All ❌✅ (primary)	-2.6%	[-2.6%, -2.6%]	1

Cycles

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

[oli-obk]

Hmm looks like that was noise but I guess it becomes easier to use the lockfree data structures for CStore