[ubuntu-uk] Xorg problem using too much CPU

[ByteSoup]

On 20/07/10 09:47, Simon Greenwood wrote:
>
> I have a similar problem with 64-bit (both 9.10 and 10.04) on a Dell 
> XPS M1330. Flash and java applications, primarily in web browsers, 
> cause the CPU usage to spin up to 100%. It even started happening with 
> Thunderbird 3. My solution was to have Flash disabled by default to 
> stop it happening, but that's difficult if you're developing video apps.
>
> It's possible to recover by logging out of the desktop and restarting 
> Xorg from a terminal, and that's really as far as I got with 
> diagnosing the problem, that it is an issue with Xorg and possibly 
> with the Nvidia drivers. However, it did really render the system 
> unusable so I've had to go back to my Mac to get work done. I haven't 
> raised a bug for it because, as you've found, it's very difficult to 
> get any useful diagnosis.
>
> Simon

It seems like me and Simon are in the same boat. I need to run up a 
32bit system on the same machine using an external HDD  to compare. I do 
think its something to do with flash, so although its not the system as 
such. I do think it shows up a flaw in the way it seems hard to corner 
the problem and deal with it.

Ive tried the CTRL+ALT+BACKSPACE option as suggested by Alan and the 
"sudo restart gdm" and some other combinations. I think they all 
effectively restart the desktop. The problem is they dont seem to 
release the CPU, the Xorg process seems to be very busy doing something 
so my conclusion is that there is another process running thats causing 
this and its grabbing hold of the Xorg when it comes up again.

Interestingly enough even when I drop out to a tty session (CTRL+ALT+F1) 
"top" shows load averages of 1.x and it doesnt really settle down to 
below 0.5 even when nothing is showing running apart from  top itself. I 
know networking is probably still running though, but I cant make sense 
of this. I mean at the moment im using the desktop, typing this email 
with Thunderbird open also I have firefox open with a number of tabs and 
my load averages are showing 0.54 0.41 0.26

It seems the problem does go away if I wait 10-15 mins before restarting 
gdm, but its far quicker to reboot. So is there a way to find out the 
process tree of whats using Xorg if there is such a thing?

Thanks

Mark