dotnet/runtime

Initializing the "ja" culture takes 200ms when using ICU

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#31,273 opened on Oct 23, 2019

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 (16 comments) (1 reaction) (0 assignees)C# (5,445 forks)batch import
area-System.Globalizationhelp wantedos-linuxtenet-performance

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Description

DateTime.Parse for "ja" culture (ONLY) is 10x times slower on Linux compared to Windows

Slower diff/base Windows Median (ns) Linux Median (ns)
System.Globalization.Tests.Perf_DateTimeCultureInfo.Parse(culturestring: ja) 8.87 454.24 4029.00
System.Globalization.Tests.Perf_DateTimeCultureInfo.ToString(culturestring: da) 1.08 236.39 254.59
System.Globalization.Tests.Perf_DateTimeCultureInfo.ToString(culturestring: ) 1.05 245.69 258.02
System.Globalization.Tests.Perf_DateTimeCultureInfo.ToString(culturestring: ja) 1.05 245.61 257.00
System.Globalization.Tests.Perf_DateTimeCultureInfo.ToString(culturestring: fr) 1.05 245.56 256.82
Faster Win/Lin Windows Median (ns) Linux Median (ns)
System.Globalization.Tests.Perf_DateTimeCultureInfo.Parse(culturestring: da) 1.24 531.21 428.73
System.Globalization.Tests.Perf_DateTimeCultureInfo.Parse(culturestring: fr) 1.05 450.44 428.87
System.Globalization.Tests.Perf_DateTimeCultureInfo.ToStringHebrewIsrael 1.04 509.37 488.81

The contributor who wants to work on this issue should:

  1. Run this simple benchmark from dotnet/performance repository and confirm the problem
git clone https://github.com/dotnet/performance.git
python3 ./performance/scripts/benchmarks_ci.py -f netcoreapp5.0 --filter System.Globalization.Tests.Perf_DateTimeCultureInfo.Parse
  1. Build CoreCLR locally: https://github.com/dotnet/performance/blob/master/docs/profiling-workflow-corefx.md#Build
  2. Create a small repro app: https://github.com/dotnet/performance/blob/master/docs/profiling-workflow-corefx.md#repro
  3. Use PerfCollect to identify issue https://github.com/dotnet/performance/blob/master/docs/profiling-workflow-corefx.md#PerfCollect
  4. Solve the issue

Contributor guide

Research direction
Run the benchmark to reproduce the slow performance, build CoreCLR locally, create a minimal repro app, and use PerfCollect to profile and identify the root cause of the initialization delay for the Japanese culture.
Tech stack
csharp
Domain
backend
Issue type
Performance
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Git
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
50