dotnet/runtime

`Path.GetRandomFileName()` is 7 times slower on Linux compared to Windows

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#31,271 opened on Oct 23, 2019

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Hackathonarea-System.IOhelp wantedos-linuxtenet-performance

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Description

Path.GetRandomFileName() is 7 times slower on Linux compared to Windows.

Slower diff/base Windows Median (ns) Linux Median (ns) Modality
System.IO.Tests.Perf_Path.GetRandomFileName 7.48 100.47 751.86

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.IO.Tests.Perf_Path.GetRandomFileName
  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
Profile the Path.GetRandomFileName method on Linux using PerfCollect to identify the bottleneck. Investigate the underlying system calls (e.g., random number generation) and compare with Windows implementation.
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.
Half day
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
GitC#.NETLinux
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
50