flutter / devtools

Performance tools for Flutter
https://flutter.dev/docs/development/tools/devtools/
BSD 3-Clause "New" or "Revised" License
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DevTools sample rate is incorrect. #7126

Open miyoyo opened 9 months ago

miyoyo commented 9 months ago

Steps to reproduce

  1. Open Devtools
  2. Connect to an App
  3. Select the CPU profiler tab
  4. Set the cpu sampling rate to high
  5. Record some data
  6. Once the data is recorded, note the smallest available sample, which reveals how often the stack is sampled
  7. Look at the bottom of the graph, where the supposed sample rate is stored

Expected results

The minimum possible sample would be 0.05 milliseconds The number of samples taken would be the sample's length divided by the sample rate.

Actual results

The minimum possible sample is variable, lowest I saw was 0.9ms There are sometimes only a few dozen samples when doing multi-second recordings.

image

Code sample

Not necessary.

Screenshots or Video

Screenshots / Video demonstration [Youtube upload, because github doesn't like MKV](https://youtu.be/H41i-UdTRhE)

Logs

No response

Flutter Doctor output

Doctor output ```console PS C:\Users\Hidden> flutter doctor Doctor summary (to see all details, run flutter doctor -v): [✓] Flutter (Channel stable, 3.16.8, on Microsoft Windows [Version 10.0.22631.3085], locale en-BE) [✓] Windows Version (Installed version of Windows is version 10 or higher) [✓] Android toolchain - develop for Android devices (Android SDK version 33.0.2) [✓] Chrome - develop for the web [✓] Visual Studio - develop Windows apps (Visual Studio Community 2022 17.7.6) [✓] Android Studio (version 2022.2) [✓] VS Code (version 1.85.2) [✓] Connected device (4 available) [✓] Network resources • No issues found! ```
darshankawar commented 9 months ago

@miyoyo I think this issue belongs to devtools repo so transferring it.

elliette commented 3 months ago

FYI @kenzieschmoll