On Sun, Sep 20, 2009 at 6:03 AM, Robert Ullmann rlullmann@gmail.com wrote:
It is happening on WinXP, FF 3.5.1, 3.5.2, 3.5.3, on "clean" setup as well.
It is apparently specific to Windows (not surprising), and is some side effect of the ABBR element; using lots and lots on a page causes endless or nearly endless CPU.
Attempting to turn it off with "abbr { display:none; }" makes it worse: it is then 100% CPU instead of 95-97%. FF renders the page, then goes back and re-renders the first occurrence of each ABBR element with a superscript giving the expansion. I suspect it is doing this (re-render) for all of the elements on the page, so with more than a few it goes CPU bound for a long time. But also in some way worse than that, since it doesn't stop. (quadratic with number of the elements? ;-)
Makes RC and watchlist unusable for now.
(mozilla seems to be susceptible to going CPU bound and thrashing VM under various odd conditions, almost always on Windoze ;-)
I've been meaning to investigate this, but haven't found the time yet. Have you come up with a minimal test case, or filed a bug with Mozilla? I'd be willing to look at this if I get the time, but I don't know how soon I will get the time, so it would help if someone else tried to debug it. Does it occur if you turn off JavaScript and/or CSS?