Startup Tracing with MemoryInfra

MemoryInfra supports startup tracing.

The Simple Way

Start Chrome as follows:

$ chrome --no-sandbox \
         --trace-startup=-*,disabled-by-default-memory-infra \
         --trace-startup-file=/tmp/trace.json \
         --trace-startup-duration=7

On Android, first ensure that Chrome can write output files to storage. Replace “org.chromium.chrome” with the Chrome package you are tracing:

$ adb shell pm grant org.chromium.chrome android.permission.READ_EXTERNAL_STORAGE
$ adb shell pm grant org.chromium.chrome android.permission.WRITE_EXTERNAL_STORAGE

Then enable startup tracing and start Chrome as follows:

$ build/android/adb_chrome_public_command_line \
      --trace-startup=-*,disabled-by-default-memory-infra \
      --trace-startup-file=/sdcard/Download/trace.json \
      --trace-startup-duration=7

$ build/android/adb_run_chrome_public

$ adb pull /sdcard/Download/trace.json  # After tracing.

Note that startup tracing will be enabled upon every Chrome launch until you delete the command-line flags:

$ build/android/adb_chrome_public_command_line ""

This will use the default configuration: one memory dump every 250 ms with a detailed dump ever two seconds.

The Advanced Way

If you need more control over the granularity of the memory dumps, you can specify a custom trace config file as follows:

$ cat > /tmp/trace.config
{
  "startup_duration": 4,
  "result_file": "/tmp/trace.json",
  "trace_config": {
    "included_categories": ["disabled-by-default-memory-infra"],
    "excluded_categories": ["*"],
    "memory_dump_config": {
      "triggers": [
        { "mode": "light", "periodic_interval_ms": 50 },
        { "mode": "detailed", "periodic_interval_ms": 1000 }
      ]
    }
  }
}

$ chrome --no-sandbox --trace-config-file=/tmp/trace.config

On Android, the config file has to be pushed to a fixed file location:

$ adb root
$ adb push /tmp/trace.config /data/local/chrome-trace-config.json

$ build/android/adb_run_chrome_public

$ adb pull /sdcard/Download/trace.json  # After tracing.

Make sure that the “result_file” location is writable by the Chrome process on Android (e.g. “/sdcard/Download/trace.json”). To ensure Chrome has permissions to write to /sdcard, run the following, replacing “org.chromium.chrome” with the Chrome package you are tracing:

$ adb shell pm grant org.chromium.chrome android.permission.READ_EXTERNAL_STORAGE
$ adb shell pm grant org.chromium.chrome android.permission.WRITE_EXTERNAL_STORAGE

Note that startup tracing will be enabled upon every Chrome launch until you delete the config file:

$ adb shell rm /data/local/chrome-trace-config.json

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