[xorcist]

> all of Firefox's users have at least two cores,

As an end user, it concerns me slightly that the visible change will be that Firefox pegs two cores instead of just one.

An absolute explosion in Javascript usage on the web together, of low quality haphazardly put together at runtime, together with the convenience of tabs makes this a problem. Mozilla may do everything right but that doesn't necessarily help the end user.

Is there anything I could do easily to remedy this, without bothering with white listing Javascript? And is there any activities at Mozilla concerning this, perhaps with identifying the most trivial cases of scripts spinning without doing useful work? Maybe pausing DOM changes for documents that aren't visible?

[mdahlstrand]

Disable javascript? Not that it's massively fun for you without javascript on the web, but it sounds like you have a very performance dependent workload on your computer. I don't think it's anything most people will have to worry about though, cpu scheduling is pretty good most of the time, and people's javascript suck less and less.

[pcwalton]

> Maybe pausing DOM changes for documents that aren't visible?

We already throttle background tabs heavily in various ways.