How to: Instrument a Native Service and Collect Detailed Timing Data by Using the Profiler Command Line

This topic describes how to use Visual Studio Profiling Tools command-line tools to instrument a native (C/C++) service and collect detailed timing data.


You cannot profile a service with the instrumentation method if the service cannot be restarted after the computer starts, such a service that start only when the operating system starts.

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 to the command itself. For more information, see Specifying the Path to Profiling Tools Command Line Tools.

To collect detailed timing data from a native service by using the instrumentation method, you use the VSInstr.exe tool to generate an instrumented version of the component. You then replace the non-instrumented version of the service with the instrumented version, making sure that the service is configured to start manually. You then start the profiler.

When the service is started, 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 turn off the service and then explicitly shut down the profiler.

To start profiling a native service

  1. Open a command prompt window.

  2. Use the VSInstr tool to generate an instrumented version of the service binary.

  3. Replace the original binary with the instrumented version. In Windows Service Control Manager, make sure that the service Startup Type is set to Manual.

  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.


    The /user and /crosssession options are usually required for ASP.NET applications.




    Specifies the domain and user name of the account that owns the ASP.NET worker process. This option is required 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 logon sessions. This option is required if the ASP.NET application is running in a different session. The session id is listed in the Session ID column on the the Processes tab of Windows Task Manager. /CS can be specified as an abbreviation for /crosssession.


    Specifies the number of seconds to wait for the profiler to initialize before it returns an error. If Interval is not specified, the profiler waits indefinitely. By default, /start returns immediately.


    To start the profiler with data collection paused, add the /globaloff option to the /start command line. Use /globalon to resume profiling.


    Collects information from the processor performance counter specified in Config. Counter information is added to the data 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 service from Service Control Manager.

When the service is running, you can use VSPerfCmd.exe options to start and stop the writing of data to the profiler data file. Controlling data collection enables you to collect data for a specific part of program execution, such as starting or shutting down the service.

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.



    /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 timestamp, and an optional user-defined text string. Marks can be used to filter the data in profiler reports and data views.

To end a profiling session, stop the service that is running the instrumented component, and then call the VSPerfCmd /shutdown option to turn the profiler off and close the profiling data file.

To end a profiling session

  1. Stop the service from Service Control Manager.

  2. Shut down the profiler. Type:

    VSPerfCmd /shutdown

  3. Replace the instrumented module with the original. If necessary, reconfigure the Startup Type of the service.

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