Xorg issue I can't stand...

[Roland Scheidegger]

Paulo J. Matos wrote:
> On 4/11/07, Roland Scheidegger <sroland at tungstengraphics.com> wrote:
>> Paulo J. Matos wrote:
>> > Hello all,
>> >
>> > I'm having, what I guess, being a Xorg problem. My version is
>> > xorg-server 1.1.1. I have an ATI Radeon Mobility 7500. Laptop is a
>> > Pentium4 2.2Ghz. The symptoms I have range over all my apps but one is
>> > consistently there: X.
>> > For example, whenever I'm browsing, from time to time, X goes up to
>> > share 66% of CPU against 33% of firefox. When I'm seeing a movie, be
>> > it with Xine or mplayer, everything is ok for the first couple of
>> > minutes and suddently X starts eating my CPU again which hinders me
>> > the possibility of continuing to watch the movie since the player
>> > video stops (although audio keeps going). This happens no matter if I
>> > use KDE, Gnome, or Enlightenment. I can't seem to know where to start.
>> > I've enabled/disabled dozens of options in my xorg.conf but things do
>> > not change. I've even tried (when X started eating my CPU) to strace
>> > it by (as root) attaching strace to X process but as soon as I did
>> > that my system blocked and I had to turn it off and on again.
>> >
>> > I'm just curious if I can do anything to debug, test, or anything. I'm
>> > getting depressed as my system gets unusable and it seems I can't to
>> > anything. Worst is, I'm not 100% sure it is Xorg. It might as well be
>> > something else but I've already gone through kernels 2.6.18, 2.6.19
>> > and 2.6.20 and the issue remains... :-/
>> >
>> > Any suggestions, advice is extremely welcome.
>>
>> You could try oprofile to see where all the cpu time is spent. That
>> said, since it works initially, something strange must happen. Are you
>> sure your cpu isn't going into thermal throttling? It could possibly
>> cause what you're seeing. P4 are not suitable for notebooks, if the
>> manufacturer skimped on cooling you're likely to get thermal throttling.
>>
> 
> Thermal throttling, heh? Never heard of it but I'll look into it. My
> laptop has always been extremelly hot so that might be it. Not really
> X-related but is there any solution to it?

Put the notebook in the freezer? I don't think there's a solution to
this, unless you can improve cpu cooling (which you usually can't with
notebooks).
Note that that the kernel log should indicate when the cpu goes into
throttling mode, if the kernel option for it is enabled.

Roland