I was under the impression that OS X, with its protected-memory and multi-tasking, was virtually immune to system-wide freezes - that is, a single application couldn't bring down the whole system. Since a while, Webkit has been quite buggy, slow and a memory hog. However, I noticed that sometimes, it will bring the whole system to a halt: the mouse would disappear (not always), the Dock won't magnify when hovered over, I can't switch to other apps and even the clock stops! It will resume normally after less than a minute, but I'm surprised by this behavior. Is my system borked or it is "normal"?
When this happens, when I look at my Activiy Monitor history, there will be a huge CPU-usage spike on one core, from the System part (red). The other core is not maxed (to the contrary, its usage drops) so I don't understand why won't the system continue to function. Also, sometimes the Dock will not show a part of its icons when I magnify it over a Webkit window. I included a screenshot and a mockup to show what I mean.