[PLUG] Firefox and Xorg

[John Jason Jordan]

On Sun, 03 Jul 2011 07:41:09 -0700
MJang <mike at linuxexam.com> dijo:

>Folks, 
>
>Every now and then, Firefox seems impossible to handle -- I see a thick
>vertical black bar (approx 2" in a 12" wide screen) in the left hand
>side of the screen, and Firefox windows become almost impossible to
>read. 
>
>When I switch into a terminal and run the top command, the number one
>user is Xorg, using like 80+% of the CPU. (That's always seemed odd on
>an i7 laptop, but I think that's a different issue.) It is followed
>closely by Firefox at about 10% of CPU. 
>
>After a few minutes, the problem dissipates, the black bar disappears,
>and I'm able to use Firefox again. My wild guess is that it might be
>java related, as it happens only on certain websites, but don't know. 
>
>While this is "just an annoyance" on my (i7, T410, 8GB) RHEL 6 laptop
>(haven't seen this in Ubuntu 10.04, but use that less frequently), I
>would appreciate some insight, if available. 

I have had similar problems with Firefox on Fedora 14 x86_64, although
not so much recently, and I never get a wonky display. Usually the whole
computer bogs down and I note that the CPU monitors that I have
installed in the Gnome panel indicate that at least one of the cores is
running at 100%.

I usually use one of the GUIs (Gnome/KDE System Monitor) instead of
top. Invariably it shows Firefox using a lot of RAM but not much CPU.
However, scrolling down I see several Java processes running, usually
as zombies, but one that is hogging most of one of the cores. If I kill
the offending Java the system returns to normal. Moreover, Firefox
seems to be unaffected by the missing Java process. 

My theory is that I was browsing and hit a web site with some Java code
that messed up whatever flavor of Java Firefox is using (I have several
Javas installed). 

I would second your hunch that it is Java related.