kernel reports package temperature above threshold, cpu clock throttled, mce event logged

[Chris Murphy]

Starting with kernel 3.9, I get frequent messages "CPU5: Package temperature above threshold, cpu clock throttled" followed by "CPU5: Package temperature/speed normal" and occasionally:

kernel: mce: [Hardware Error]: Machine check events logged
mcelog[581]: Hardware event. This is not a software error.

This happens on three different Mac models, each running OS X and Fedora. They all get way hotter, run fans much faster, running Linux than OS X. I've had one of those models die inexplicably while it was exceptionally hot, but since it can't be booted at all now I can't say whether there's cause-effect or it's just coincidence.

Since I'm down to just one Mac at the moment, I'm reluctant to do any further baremetal Linux testing until I better understand what these messages mean.

https://bugzilla.redhat.com/show_bug.cgi?id=924570   ## my original bug on this from over a year ago
https://bugzilla.redhat.com/show_bug.cgi?id=1050106 ## recent bug that has different diagnostic info

Chris Murphy