adb_trace

Android Debug Bridge + Chrome Tracing

Requires Android Chrome version 25+

Prerequisites

1. Ensure that the Android SDK is installed and that adb is in your path
   • http://developer.android.com/sdk/index.html
2. Ensure that your Android device is connected and USB debugging is enabled
   • http://developer.android.com/tools/device.html
3. Ensure that USB debugging is enabled in Chrome (enabled automatically for 28+)
   • https://developers.google.com/chrome-developer-tools/docs/remote-debugging

Grabbing a capture from a stable Chrome build

$ python ./adb_profile_chrome.py --time 5
Capturing 5-second chrome trace. Press Ctrl-C to stop early...done
Downloading...done
Trace written to chrome-profile-results-2013-10-25-181905

Using beta?

$ python ./adb_profile_chrome.py --time 5 --browser beta

Using dev channel or developer build? --browser dev and --browser build

See below for complete list of supported browsers.

Grabbing a Systrace

An Android Systrace provides more detailed low-level statistics from the operating system. This is how to capture one:

$ python ./adb_profile_chrome.py --time 5 --systrace gfx,input,view,sched,freq

By default we also record a normal Chrome trace in addition to the Systrace. This can be controlled with the --categories flag.

Viewing a capture

On the computer your Android is connected to:

1. Navigate to about:tracing
2. Click the Load button
3. Select chrome-profile-results-YYYY-MM-DD-hhmmss.json that was copied to your PC.

Command Line Options

• -h, --help: show this help message and exit
• -o OUTPUT, --output=OUTPUT: Save profile output to file.
• -b BROWSER, --browser=BROWSER: Select among installed browsers. One of android_webview_shell, beta, build, chrome, chrome_beta, chrome_dev, chrome_stable, chromium_test_shell, content_shell, dev, stable, "stable" is used by default.
• -v, --verbose: Verbose logging.
• -z, --compress: Compress the resulting trace with gzip.
• --view: Run trace-event-viewer upon completion.

Timed tracing

• -t N, --time=N: Profile for N seconds and download the resulting trace.

Continuous tracing

• --continuous: Profile continuously until stopped.
• --ring-buffer: Use the trace buffer as a ring buffer and save its contents when stopping instead of appending events into one long trace.

Trace categories

• -c CHROME_CATEGORIES, --categories=CHROME_CATEGORIES: Select Chrome tracing categories with comma-delimited wildcards, e.g., "", "cat1,-cat1a". Omit this option to trace Chrome's default categories. Chrome tracing can be disabled with "--categories=''".
• -s SYS_CATEGORIES, --systrace=SYS_CATEGORIES: Capture a systrace with the chosen comma-delimited systrace categories. You can also capture a combined Chrome + systrace by enabling both types of categories. Use "list" to see the available categories. Systrace is disabled by default.
• --trace-cc: Enable extra trace categories for compositor frame viewer data.
• --trace-gpu: Enable extra trace categories for GPU data.

trace-event-viewer

trace-event-viewer is a standalone version of Chrome's about:tracing UI for viewing multithreaded performance traces. Works on OSX and Linux and even Windows using Chrome Apps v2 to make it look like a regular app.

You can grab it from here: https://github.com/natduca/trace_event_viewer