High CPU usage and no sleep after upgrading to 4.4.4 I have a Sony Xperia E3. I recently upgraded to Android 4.4.4 from 4.4.2. I don't know if that is causing my issue, but it didn't happen before that.

I recently started noticing that my phone becomes very hot during normal usage (talking about 50-60 degrees Celcius, and in particular near the top of the screen, where the CPU is). When I looked into it I saw that I was using about 80% CPU under no load and that the device had been constantly awake in the past 24 hours, even though the screen was off most of the time.

It used to also be constantly using internet, but after I removed a certain app, that went away. It also improved on the heat a bit, but it's having the same problem again.

I ran a virus scan, and nothing came out.

I installed a task killer just to find out what app was using all the CPU, and it's the Android System. (I am aware that a task killer is unnecessary.)

What could be causing this, and how do I fix it?

Edit: I disabled Media Storage as described here and I am going to see if it helped. Looking at the CPU usage right after I disabled it, it didn't.

Edit: It worked after a few hours.
You could disable the Media storage app, which solves the issue, but also breaks the stock Gallery, video, and music apps, and completely breaks ringtone selection, even if you use another app to select one. If you could live with that, disable the Media Storage app. You will need root for this. If you don't want that, you can install Advanced Permissions Manager, and remove the permission Keep Device Awake from the Media Storage app. You will NOT need root for this, and everything will keep working, and the MS app will not keep the device awake all night.