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Profiler

Script, ScriptBlock and module performance profiler for PowerShell 5, and PowerShell 7 that works in Windows, Linux and MacOS.

Demo

See my Profiler talks on Youtube, together with other people's talks about PowerShell performance.

Quick start

Install the module from PowerShell gallery:

Install-Module Profiler
$trace =  Trace-Script -ScriptBlock { & "demo-scripts/Get-Icons.ps1" } -ExportPath icons
$trace.Top50SelfDuration

Inspect the output, SelfPercent, and SelfDuration represent time that is spent only in the function, excluding all the code it calls.

Percent and Duration represent time that is takes by the function an all the code it calls.

In our screenshot 98.6% of the execution time is taken by Invoke-WebRequest, which runs inside of Get-EmojiInternal function inside of Avocado module.

You also specified export path which exports the results in https://speedscope.app format. Importing the file will show this result:

Which shows us graphical representation of the run. We can see that two paths, Get-Avocado and Get-Unicorn both end up calling Get-EmojiInternal where most of the time in the script is spent.

More Features

  • Profile module functions, or any scriptblock.
$scriptBlock = { 
    Import-Module Pester
    Invoke-Pester
}
Trace-Script -ScriptBlock $scriptBlock

(Excluding files, e.g. Pester internals from the profiling is coming later.)

  • Run code multiple times, comparing performance before and after your changes.
$flag = @{ _profiler = $true }
Invoke-Script -ScriptBlock $scriptBlock -Preheat 0 -Repeat 3 -Flag $flag

  • Retrieve the last profile when you did not assign it to a variable
Invoke-Script -ScriptBlock $scriptBlock -Preheat 0 -Repeat 3 -Flag $flag

# Output:
# Looks like you did not assign the output to a variable. Use Get-LatestTrace to retrieve the trace, e.g.: $trace = Get-LatestTrace

$trace = Get-LatestTrace
$trace.Top50Duration
  • Progress of your changes

Running profiling multiple times in a row keeps the previous times to show you your progress. Indicating Before and After with B and A.

  • And more, like breakdown of a given line (.CommandHits), seeing who called given line (.Hits) and seeing the call stack that lead to the current call. All of them just need to be documented first.

Known Limitations:

This module is under heavy development. Here are some limitations of my current design that I know how to fix, but that are not high on the priority list:

  • Using Set-PSDebug -Off, or Set-PSDebug -Trace 0 stops the tracing, because that is what we internally use to enable and disable it. If this is a must for you let me know in issues.

  • Removing all breakpoints from the current session stops tracing. We add a synthetic breakpoint to prevent this, but if your code needs to remove all breakpoints, including the ones that are not "your own" let me know in issues.