Strange 100% CPU usage with Xorg 7 (latest update)

[Julio Biason]

On 03/02/06, Mario Vukelic <mario.vukelic at dantian.org> wrote:
> If I kill update-notifier, my CPU is at just a few percent when no
> application uses it. (Pentium M, 1.5 GHz).

CPU was just a few percent, but it was at full scale. I have a Pentium
M too, 1.6GHz and the CPU speed applet pointed it was running at full
1.6Ghz when it usually sits on 800Mhz.

> >  (on breezy, it usually stayed on 50%).
>
> Why? It shouldn't

I agree, but it never went below that. :)

[E.g., when nothing is running, it should go way below that, to save
battery life. And, oh, I was talking about CPU scaling, not CPU usage]

> > Also, I see some flickering when I type anything on any program, so I
> > think it is a Cairo/Pango issue
>
> Might be, but is probably very dependent on which graphics adapter you
> have. I don#t see it (Ati with proprietary drivers)

Probably. My laptop has a NVidia geforce and I'm using the open source
drivers to be able to "hibernate"; if I use the closed source drivers,
the display won't work (stays black all the time) on wake up -- at
least, it doesn't work on Breezy, I didn't tried with Dapper.

> > Good thing installing Breezy is easy. :)
>
> I must say that after the usual frequent and heavy breakage a while ago,
> it has currently settled down and works very well.
> You can simply go to System > Administration > Software Properties and
> disable "Automatically check for updates". Then it won't run again

I like to switch to Dapper from time to time (and probably should set
up a partition just for that -- but it would require resizing my home
partition and I really don't want to backup everything again just for
another install) just to check how the things are going or when I'm
really bored. My experience with Ubuntu shows that, during development
cycle, things go really really bad, but when it gets into final, it
goes very very smoothly. :)

I did last update to check some occasional lock ups I'm getting with
breezy which I couldn't pinpoint yet (it seems to be a mix of using
ipw2200 with bittorrent [the official versionnot ubuntu version],
several torrent files running at the same time [seeding] and
snd_intel8x0, but I couldn't stand the general slowness of the system
and the flickering).

But back to your problem, one thing I noted is that if I closed
everything, the CPU went to normal. But opening Bittorrent (the
graphical interface) again, which keeps updating the screen all the
time (ETA, percent, etc), slowed the system and CPU scaling went to
100%. That's why I'm guessing the problem lies on Cairo/Pango.

--
Julio Biason <julio.biason at gmail.com>