Profiling the Java Code

Mark Finkle mfinkle at
Wed Jan 8 16:26:54 PST 2014

For many of the pageload performance bugs [1], we used profiles of the Java code to uncover the issues. This is just a quick post covering what you need to do in order to get profiles. 

1. The Fennec build needs to be "debuggable" [2]. Nightlies are not, but local developer builds are. 
2. For profiling pageload, you can generally use Monitor/DDMS [3]. Just press the "start method tracing" button, load a page, wait, press the "stop method tracing" button. 
3. For profiling startup time, you really need to add Debug.startMethodTracing(...) and Debug.stopMethodTracing(). I added a simple patch [4] to show what I mean. 

I created some example profiles for startup and pageload. You can download them [5] and open them in Monitor/DDMS using the "File | Open File..." menu. 


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