Optimize QueryArena allocation

[Mark-Simulacrum]

This shifts the WorkerLocal wrapper to be outside the QueryArena, meaning that instead of having each query allocate distinct arenas per-worker we allocate the full set of arenas per-worker. This is primarily a code size optimization (locally, ~85 kilobytes, perf is reporting >100 kilobytes), saving a bunch of code in the initialization of the arenas which was previously duplicated lots of times (per arena type).

Additionally this tells LLVM that the thread count can't be zero in this code (I believe this is true?) which shaves some small amount of bytes off as well since we eliminate checks for zero in the vec allocations.

[rustbot]

r? @cjgillot

(rustbot has picked a reviewer for you, use r? to override)

[Mark-Simulacrum]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 107ea5d with merge 884c95a...

[bors]

☀️ Try build successful - checks-actions
Build commit: 884c95a (884c95a3f1fe8d28630ec3cdb0c8f95b2e539fde)

[rust-timer]

Finished benchmarking commit (884c95a): comparison URL.

Overall result: ❌✅ regressions and 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)	0.3%	[0.1%, 0.4%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.4%	[-0.4%, -0.4%]	1
All ❌✅ (primary)	-	-	0

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)	1.6%	[1.6%, 1.6%]	1
Regressions ❌ (secondary)	2.1%	[1.4%, 5.0%]	6
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.5%	[-4.8%, -1.1%]	4
All ❌✅ (primary)	1.6%	[1.6%, 1.6%]	1

Cycles

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)	2.1%	[2.1%, 2.1%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 675.686s -> 675.115s (-0.08%)
Artifact size: 313.72 MiB -> 313.54 MiB (-0.06%)

[cjgillot]

@bors r+

[bors]

📌 Commit 107ea5d has been approved by cjgillot

It is now in the queue for this repository.

[bors]

⌛ Testing commit 107ea5d with merge 34c5ab9...

[bors]

☀️ Test successful - checks-actions
Approved by: cjgillot
Pushing 34c5ab9 to master...

[rust-timer]

Finished benchmarking commit (34c5ab9): comparison URL.

Overall result: ❌✅ regressions and improvements - no action needed

@rustbot label: -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)	0.2%	[0.1%, 0.3%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.5%	[-0.5%, -0.5%]	1
All ❌✅ (primary)	-	-	0

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)	1.7%	[0.8%, 5.0%]	10
Improvements ✅ (primary)	-1.0%	[-1.0%, -1.0%]	1
Improvements ✅ (secondary)	-2.4%	[-3.3%, -1.4%]	3
All ❌✅ (primary)	-1.0%	[-1.0%, -1.0%]	1

Cycles

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)	2.2%	[2.0%, 2.4%]	6
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-6.3%	[-6.3%, -6.3%]	1
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 676.299s -> 673.904s (-0.35%)
Artifact size: 313.50 MiB -> 313.23 MiB (-0.08%)