At last week's Mozilla QA Meetup in Mountain View, California I demonstrated how to effectively profile Gecko in Firefox for Android on a device. By targeting a device running Firefox for Android, one can measure responsiveness and performance costs of executed code in Gecko. By measuring sample set intervals, we can focus on a snapshot of a stack and pinpoint functions and application resources produced by a sampling run. With this knowledge, one can provide a valuable sampling of information back to developers to better filed bug reports. Typically, as we have seen, these are helpful in bug reports for measuring page-load and scrolling and panning performance problems, frame performance and other GPU issues.
How to Help
- Install this (available here) Gecko Profiler add-on in Firefox on your desktop (it is the Gecko profiler used for platform execution), and follow the instructions outlined here for setting up an environment
- If you encounter odd slowdown in Firefox for Android, profile it! You can save the profile locally or share it via URL
- Add it to a (or your) bug report on Bugzilla
- Talk to us on IRC about your experience or problems
Here is an example bug report, bug 1047127 (panning stutters on a page with overflow-x) where a profile may prove helpful for further investigation.
Detailed information on profiling in general is available on MDN here.