Hey guys. I'm running slackware 11.0. I've tried both E16 and E17 desktops and the problem continues to happen on both.

I'm running FF 2.0 from the slackware repository. I leave it up and it seems every 3 days, the CPU will peg at 100%. Using top/htop, it shows the firefox-bin process using 90% or so of the CPU. And this is completely at idle.

Has anyone else ran into this problem?

I dunno, I've never had FF up for that long of a time. Why do you need it up that long ?

If you're downloading something, use wget.

agree with that
i'm using Firefox package from Mozilla (not from Slackware package) and i experience the same thing. It consumes too much resources and it didn't only happened in Linux, but in Windows also

i hope Firefox 3.0 will less hunger for memory consumption

Why do I need it open that long? Because it's the most used application on my machine. I drop it onto desktop 2 and just leave it open. No reason to close applications that I'll just have to reopen the next time I sit down in the chair.

What's strange is that the CPU usage starts at 0 for the first day or so. Then all of a sudden it spikes to 100%. Resource hog I can understand. But it shouldn't be processing anything. I fail to see how sitting on www.google.com for any length of time would cause CPU usage, let along 100% usage.

Which extensions/themes do you have installed?
Some are known to let the CPU usage go nuts.

Although I agree that keeping FF up and running for three days is 'a bit long'.
Don't you ever sleep?
You can get it up and running with the same session as you closed it down.

FWIW i've noticed FF2 will eat all my memory, then swap, so the system starts swapping ... that usually raises the CPU after a day or two. I'm considering rolling back to 1.5 ... as yet I can't decide if there are any features in 2 that i need.

Either that or Opera =)

- Piete.

Extensions in use:
NoScript
AdBlock Plus
ForecastFox
RefControl
Web Developer
Download Statusbar

All are updated to the most recent version. And whether or not I leave my browser open for "a long time", I think we can all agree that is should not be behaving as it is.

Kick out ForecastFox, which has a reputation on this field.

I just ssh'd into my box to check on it. Nobody is home and the browser is most likely sitting on www.google.com. Here's the relevant output from top.

CPU is once again pegged. As you can see, the swap space is untouched.

Edit: I'll try disabling forecastfox when I get home.

Edit: another update
OK, so after 2 days of googling "firefox CPU usage" and getting nothing, I took your advice and searched for "forecastfox CPU usage". BAM, answers. Several website including forecastfox's own website state the following:
Looks promising. I'll keep you all posted.

Opera 9.10 FTW!

I've got the same issue as you and I too have forcastfox installed. The only other extension I have installed in common is download statusbar.

I leave firefox running a lot because I'm often in the middle of doing something, 8 or 9 tabs open and then get called away. I might not get back to it for a couple of days. Until I finish my research or whatever I'm doing, why would I close out firefox ? It should be able to run indefinitely.

Are you using Firefox 2.*?
You can restart your closed session by selecting this option in Preferences --> General --> When Firefox starts "open my windows and tabs of the previous session" (could be slightly different, my FF is Dutch )

Another thing that can cause this behavior is a corrupted FF-profile. Create an new one, move important stuff from you old to your new profile (bookmarks, passwords etc.) but NOT your extensions/themes! Of course, then you will have to install those extensions again.

What you're describing is a classic memory leak, and yes, it can eat up processor cycles. I agree with sn9ke_eyes it should be able to run indefinitely, but sometimes programs don't work that way. This is a well known problem with ff too. I don't use forcastfox, but I have two other extensions in common with you and I've had the same type of problem on 1.5 I know this isn't much of an answer but all I do is quit firefox for a minute and then reload - no more memory leak!