How to: Instrument a stand-alone .NET Framework component and collect memory data with the profiler by using the command line

This article describes how to use Visual Studio Profiling Tools command-line tools to instrument a .NET Framework component of a stand-alone application such as an .exe or .dll file and collect memory information by using the profiler.


Command-line tools of the Profiling Tools are located in the \Team Tools\Performance Tools subdirectory of the Visual Studio installation directory. On 64-bit computers, both 64-bit and 32-bit versions of the tools are available. To use the profiler command-line tools, you must add the tools path to the PATH environment variable of the Command Prompt window or add it to the command itself. For more information, see Specify the path to command line tools.

To collect memory data from a .NET Framework component by using the instrumentation method, you use the VSInstr.exe tool to generate an instrumented version of the component and the VSPerfCLREnv.cmd tool to initialize profiling environment variables. You then start the profiler by using the VSPerfCmd.exe tool.

When the instrumented component is executed, memory data is automatically collected to a data file. You can pause and resume data collection during the profiling session.

To end a profiling session, you close the target application and explicitly shut down the profiler. In most cases, we recommend clearing the profiling environment variables at the end of a session.

Start the application with the profiler

To attach the profiler to a running .NET Framework application

  1. Open a Command Prompt window.

  2. Use the VSInstr tool to generate an instrumented version of the target application.

  3. Initialize the .NET Framework profiling environment variables. Type:

    VSPerfClrEnv {/tracegc | /tracegclife}

    • The /tracegc and /tracegclife options initialize the environment variables to collect only memory allocation data, or to collect both memory allocation and object lifetime data.

      Option Description
      /tracegc Enables collection of memory allocation data only.
      /tracegclife Enables collection of both memory allocation and object lifetime data.
  4. Start the profiler. Type:

    VSPerfCmd /start:trace /output: OutputFile [Options]

    • The /start:trace option initializes the profiler.

    • The /output:OutputFile option is required with /start. OutputFile specifies the name and location of the profiling data (.vsp) file.

      You can use any of the following options with the /start:trace option.

    Option Description
    /user :[Domain\]UserName Specifies the domain and user name of the account that owns the profiled process. This option is required only if the process is running as a user other than the logged-on user. The process owner is listed in the User Name column on the Processes tab of Windows Task Manager.
    /crosssession Enables profiling of processes in other sessions. This option is required if the application is running in a different session. The session idenitifer is listed in the Session ID column on the Processes tab of Windows Task Manager. /CS can be specified as an abbreviation for /crosssession.
    /globaloff To start the profiler with data collection paused, add the /globaloff option to the /start command line. Use /globalon to resume profiling.
    /wincounter : WinCounterPath Specifies a Windows performance counter to be collected during profiling.
    /automark : Interval Use with /wincounter only. Specifies the number of milliseconds between Windows performance counter collection events. Default is 500 ms.
    /counter : Config Collects information from the processor performance counter that is specified in Config. Counter information is added to the data that is collected at each profiling event.
    events : Config Specifies an Event Tracing for Windows (ETW) event to be collected during profiling. ETW events are collected in a separate (.etl) file.
  5. Start the target application from the Command Prompt window.

Control data collection

While the target application is running, you can control data collection by starting and stopping the writing of data to the file by using VSPerfCmd.exe options. Controlling data collection enables you to collect data for a specific part of program execution, such as starting or shutting down the application.

To start and stop data collection

  • The following pairs of VSPerfCmd options start and stop data collection. Specify each option on a separate command line. You can turn data collection on and off multiple times.

    Option Description
    /globalon /globaloff Starts (/globalon) or stops (/globaloff) data collection for all processes.
    /processon : PID /processoff : PID Starts (/processon) or stops (/processoff) data collection for the process that is specified by the process ID (PID).
    /threadon : TID /threadoff : TID Starts (/threadon) or stops (/threadoff) data collection for the thread that is specified by the thread ID (TID).

End the profiling session

To end a profiling session, close the application that is running the instrumented component, and then call the VSPerfCmd /shutdown option to turn off the profiler and close the profiling data file. The VSPerfClrEnv /off command clears the profiling environment variables.

To end a profiling session

  1. Close the target application.

  2. Shut down the profiler. Type:

    VSPerfCmd /shutdown

  3. (Optional) Clear the profiling environment variables. Type:

    VSPerfCmd /off

See also

Profile stand-alone applications
.NET memory data views