On Sun, Sep 20, 2009 at 6:03 AM, Robert Ullmann <rlullmann(a)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?