Comment 29 for bug 1372413

(see also comment #5 above)

sudo add-apt-repository ppa:colin-king/white
sudo apt-get update
sudo apt-get install cpustat

cpustat blocks on a select() system call. While the phone is not suspended it will log all CPU process activity every 2 seconds. This will consume ~0.25% of the CPU, so in real terms that's almost nothing. cpustat will not block the phone from deep sleep. The kernel will freeze it when the phone goes into deep sleep. please do the following:

adb into the phone and type:

nohup cpustat 2 > cpustat.log &
exit

then disconnect the USB and let it run.

Once the phone is drained, or whenever you want to stop the test, copy the cpustat.log over and we can analyze it.