So, not too long ago I started wondering why my laptop sounds like a hairdryer at full power if I have so much as the browser open. I would open system monitor but could find no processes that would account for whatever was causing this. Funnily enough, after adding a top processes entry to my Conky, I found that a thing called "kworker" was eating anywhere from 25% to 50% of my CPU at any given time.
My first thought, of course, was "what the hell is kworker?" Googling around, I found that kworker controls the ACPI wakeup signals from the BIOS. I have no idea what this meant, but I did discover that this little bastard was gobbling up CPU across many distros, from Ubuntu to Arch to OpenSUSE and yes, to Mint as well. This worried me, and sure enough, I found it is indeed an upstream problem.
As you can see from the above links, there are numerous possible solutions to this problem. Some went back to the 3.5.0-12 kernel (something I'm personally not prepared to do), others went into /sys/firmware/acpi/interrupts and disabled gpe18 with echo (had no effect on me). These two were the most common solutions I found popping up, anyway.
Now, for me, running Mint 14 Cinnamon, I found the simplest, most elegant solution was to simply go into BIOS (in my case, restart>F10) and reset the default settings. That's it. The machine restarted, and everything ran smooth as silk, with kworker rendered nothing more than a soft breeze through my CPU (i.e., less than one hundredth of one percent).
At first this puzzled me - I get that kworker is directly related to BIOS, but the only changes I ever made to BIOS was changing the boot device order - but to be honest, to me it's like aspirin. I don't need to know why or how it works; just that it does.
Anyway, since I keep seeing "what is up with this kworker thingy eating 90% of my CPU???" question everywhere, I thought I'd put together some resources and suggestions in one post. Hope it might be of use to some of you!