[Perf] Linux/arm64: 3 Regressions on 9/22/2025 7:32:29 PM +00:00

[performanceautofiler]

Run Information

Name	Value
Architecture	arm64
OS	ubuntu 22.04
Queue	AmpereUbuntu
Baseline	171bbb1de92f1e4e31b3aaf46054185eb88bb117
Compare	2a9066e3dc2c0a48f6bbbf38d23f3f989322efec
Diff	Diff
Configs	CompilationMode:tiered, RunKind:micro

Regressions in System.Collections.Perf_LengthBucketsFrozenDictionary

Benchmark	Baseline	Test	Test/Base	Test Quality	Edge Detector	Baseline IR	Compare IR	IR Ratio
TryGetValue_True_FrozenDictionary - Duration of single invocation ADX - Test Multi Config Graph	131.43 ns	140.81 ns	1.07	0.01	False
TryGetValue_True_FrozenDictionary - Duration of single invocation ADX - Test Multi Config Graph	15.36 μs	16.37 μs	1.07	0.01	False
TryGetValue_True_FrozenDictionary - Duration of single invocation ADX - Test Multi Config Graph	1.39 μs	1.47 μs	1.06	0.01	False

Test Report

Repro

General Docs link: https://github.com/dotnet/performance/blob/main/docs/benchmarking-workflow-dotnet-runtime.md

git clone https://github.com/dotnet/performance.git
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Collections.Perf_LengthBucketsFrozenDictionary*'

System.Collections.Perf_LengthBucketsFrozenDictionary.TryGetValue_True_FrozenDictionary(Count: 10, ItemsPerBucket: 5)

ETL Files

Histogram

JIT Disasms

System.Collections.Perf_LengthBucketsFrozenDictionary.TryGetValue_True_FrozenDictionary(Count: 1000, ItemsPerBucket: 5)

ETL Files

Histogram

JIT Disasms

System.Collections.Perf_LengthBucketsFrozenDictionary.TryGetValue_True_FrozenDictionary(Count: 100, ItemsPerBucket: 5)

ETL Files

Histogram

JIT Disasms

Docs

Profiling workflow for dotnet/runtime repository
Benchmarking workflow for dotnet/runtime repository

[LoopedBard3]

Likely caused by dotnet/runtime#119940 (PGO).