How to: Instrument a Stand-Alone .NET Framework Component and Collect Timing Data with the Profiler from the Command Line

This topic describes how to use Visual Studio Profiling Tools command-line tools to instrument a .NET Framework component such as an .exe or .dll file, and to collect detailed timing data.


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 Specifying the Path to Profiling Tools Command Line Tools.

To collect detailed timing 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.

When the instrumented component is executed, timing 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.

Starting the Profiling Session

To start profiling by using the instrumentation method

  1. Open a Command Prompt window. If necessary, add the profiler tools directory to your PATH environment variable. The path is not added at installation.

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

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

    VSPerfClrEnv /traceon

  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 one of the following options with the /start:trace option.




    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.


    Enables profiling of processes in other sessions. This option is required if the ASP.NET application is running in a different session. The session idenitifier is listed in the Session ID column on the Processes tab of Windows Task Manager. /CS can be specified as an abbreviation for /crosssession.


    Starts the profiler with data collection paused. Use /globalon to resume profiling.


    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.


    Specifies a Windows performance counter to be collected during profiling.


    Use with /wincounter only. Specifies the number of milliseconds between Windows performance counter collection events. Default is 500 ms.


    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.

Controlling Data Collection

When the target application is running, you can control data collection by starting and stopping the writing of data to the profiler data 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 options start and stop data collection. Specify each option on a separate command line. You can turn data collection on and off multiple times.



    /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 specified by the process ID (PID).

    /threadon:TID /threadoff:TID

    Starts (/threadon) or stops (/threadoff) data collection for the thread specified by the thread ID (TID).

  • You can also use the VSPerfCmd.exe /mark option to insert a profiling mark into the data file. The /mark command adds an identifier, a time stamp, and an optional user-defined text string. Marks can be used to filter the data in profiler reports and data views.

Ending the Profiling Session

To end a profiling session, close the application that is running the instrumented component. 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:

    VSPerfClrEnv /off

See Also


Command-Line Profiling of Stand-Alone Applications

Other Resources

Profiler Instrumentation Method Data Views