# Startup Tracing with MemoryInfra [MemoryInfra](README.md) 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 ## Related Pages * [General information about startup tracing](https://sites.google.com/a/chromium.org/dev/developers/how-tos/trace-event-profiling-tool/recording-tracing-runs) * [Memory tracing with MemoryInfra](README.md)