How to test the performance of an Android application?

If you want to profile your application to find performance bottlenecks you can use the traceview tool. This gives you a graphical view of performance traces of your application.

To create a trace add the following to your code where you want to start tracing:

Debug.startMethodTracing("myapp");

and then put the following when you want to stop tracing:

Debug.stopMethodTracing();

This will create a trace file call myapp.trace in the root directory of the SD Card. As it is written to the SD Card:

• If you're using the emulator you'll need to add an SD card to your AVD.

• You'll need to give you app permission to write the SD card by adding the following to your Manifest:

  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Once the file has been created you'll need to copy it to your PC. You can do this using the adb command:

adb pull /sdcard/myapp.trace c:/my/dir/myapp.trace

Finally, start traceview giving it the full path to the trace file:

traceview c:/my/dir/myapp.trace

I did have some problems with traceview failing with OutOfMemory exceptions. I fixed this on Windows by changing the last line of traceview.bat from:

call java -Djava.ext.dirs=%javaextdirs% -Dcom.android.traceview.toolsdir= -jar %jarpath% %*

to:

call java -Xmx1g -Djava.ext.dirs=%javaextdirs% -Dcom.android.traceview.toolsdir= -jar %jarpath% %*

Adding the -Xmx1g option allows traceview to use more memory.

Also, theoretically, DDMS can get memory allocations for your program and then you can analyze the dump using profilers.DDMS Reference.
The reason why I have theoretically in italics is that I myself have not tried doing anything such, yet.

I think traceView contains too much information, you can easily get lost.

My solution is just log the system time at three place in the code.

Before and after and center at the potiential slow code.

like binary search, next time, narrow it down step by step, then finally find the culprit code.