Capture a system trace on the command line

    This document explains how to generate Systrace reports from the command line.On devices running Android 9 (API level 28) or higher, you can also generateSystrace reports using the .

    • Install Python and include it in yourworkstation's execution path.

    To generate the HTML report for app, you need to run systrace from thecommand line using the following syntax:

    Tip: If you want to see the names of tasks inthe trace output, you must include the sched category inyour command parameters.

    If you don't specify any categories or options, systrace generates a reportthat includes all available categories and uses default settings. The categoriesavailable depend on the connected device you're using.

    Commands and command options

    Commands and optionsDescription
    -o fileWrite the HTML trace report to the specified file. If you don't specify this option, systrace saves your report to the same directory as systrace.py and names it trace.html.
    -t N | —time=NTrace device activity for N seconds. If you don't specify this option, systrace prompts you to end the trace by pressing the Enter key from the command line.
    -b N | —buf-size=NUse a trace buffer size of N kilobytes. This option lets you limit the total size of the data collected during a trace.
    Trace the activity of specific kernel functions, specified in a comma-separated list.
    -a app-name
    |
    —app=app-name    		Enable tracing for apps, specified as a comma-separated list of . The apps must contain tracing instrumentation calls from the Trace class. You should specify this option whenever you profile your app—many libraries, such as , include tracing instrumentation calls that provide useful information when you enable app-level tracing. For more information, go to the section about how to instrument your app code.
    —from-file=file-pathCreate an interactive HTML report from a file, such as TXT files that include raw trace data, instead of running a live trace.
    -e device-serial
    |
    —serial=device-serial    		Conduct the trace on a specific connected device, identified by its .
    categoriesInclude tracing information for the system processes you specify, such as gfx for system processes that render graphics. You can run systrace with the command to see a list of services available to your connected device.