Edit : I am running fully stock, non-rooted and OTA updated Kit Kat 4.4.2
I noticed that a high Android OS usage and wake lock (in my case) comes from the cpu Governor locking all cores to 2.0-2.3 GHz despite nothing happening on the phone. I checked this using the system monitor tool. I have screenshots added.
The problem is that I can't see what apps are causing the governor to never make the other 3 cores go offline. When I check "Top apps" everything is at 0% cpu usage. What is causing the cores to never go offline and stay locked at 2.0GHz+ and drain battery?? It is only when this happens that I get high Android OS usage. A reboot fixes it, but it happens randomly. When I feel that my battery is draining badly, I check my cpu in system monitor and see all cores online even when idle. I just don't get it.
I'm thinking it may have something to do with dashclock/BBS or some combination, as every time this happens, the BBS add on in dashclock shows 0% drain (so it seems broken when it happens).
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