[ubuntu-uk] Xorg high CPU usage

[Grant Phillips-Sewell]

On Tue, 06 Mar 2012 18:45:23 +0000
Pete Smout wrote:

> On 06/03/12 18:15, Grant Phillips-Sewell wrote:
> > On Tue, 06 Mar 2012 18:07:08 +0000
> > Pete Smout wrote:
> >
> >> On 05/03/12 21:10, Pete Smout wrote:
> >>> Hi,
> >>>
> >>> For about a week now my laptop (ubuntu 10.04 LTS fully updated)
> >>> has been freezing up for approx 30 secs, with gkrellm and top
> >>> showing xorg using 100% cpu usage?
> >>> There seems to be no pattern to what programs I am using,
> >>> everything from open office to clementine to smplayer or
> >>> thunderbird, not at any certain time of day or day of the week,
> >>> or even weather using the inbuilt screen or external one.
> >>>
> >>> My understanding (admittedly limited) is that xorg is the bit that
> >>> works the display (screen). Has anyone else come across this?
> >>>
> >>> For reference the laptop specs are:
> >>>
> >>> Acer Aspire 5720
> >>> Intel T5250 Dual core processor
> >>> Ram 2.0 gb
> >>> Internal graphics (intel)
> >>> Internal sound (intel)
> >>>
> >>> Thanks in advance for any ideas
> >>>
> >>> Regards
> >>>
> >>> Pete
> >>>
> >>>
> >> just for reference my xorg.conf:
> >>
> >> Section "Device"
> >> 	Identifier	"Configured Video Device"
> >> 	Driver		"fbdev"
> >> EndSection
> >
> > Might want to look into that bit.
> >
> > You should have a specific Xorg "driver" for your onboard Intel
> > graphics chip.
> >
> > Run the following command to find out your graphics chip:
> >   lspci
> >
> > Look for the line that has VGA on it.
> >
> > If it does indeed say something about an Intel chip, then make sure
> > you have the following package installed:
> >   xserver-xorg-video-intel
> >
> > (That package deals with all i8xx and i9xx chips)
> >
> > Once that's installed, remove the xorg.conf file and restart X.
> >
> > You can restart X by going to a terminal (NOT a terminal window...
> > press CTRL+ALT+F2 and log in) and then run:
> >   sudo service lightdm restart
> >
> > (Or just reboot... up to you.)
> >
> > Grant.
> >
> Hi Grant,
> 
> Thanks for your reply, the lspci command produces (relevant lines
> only I hope)
> 
> 00:02.0 VGA compatible controller: Intel Corporation Mobile
> GM965/GL960 Integrated Graphics Controller (rev 03)
> 00:02.1 Display controller: Intel Corporation Mobile GM965/GL960 
> Integrated Graphics Controller (rev 03)
> 
> Synaptic shows xserver-xorg-video-intel is installed (reinstalled for 
> good measure) moved the xorg.conf file to my documents folder and 
> rebooted, opened t-bird to reply to you and the machine 'greyed out'
> for approx 20 secs with gkrellm showing xorg as using 100% CPU!
> Please note that last time it happened was with clementine running,
> when playback stopped mid song so I cannot blame t-bird!
> 
> As an aside but possibly related?! when I open a tty shell
> (ctrl-alt-f1) log in it tells me 'Your CPU appears to be lacking
> expected security protections. Please check your BIOS settings, for
> more information please run /usr/bin/check-bios-nx --verbose which
> produces
> 
> smouty at smouty-laptop:~$ /usr/bin/check-bios-nx --verbose
> This CPU is family 6, model 15, and has NX capabilities but is unable
> to use these protective features because the BIOS is configured to
> disable the capability.  Please enable this in your BIOS.  For more
> details, see: https://wiki.ubuntu.com/Security/CPUFeatures
> 
> I am unable to find any related settings in BIOS, if this is
> unrelated to my original question please ignore it and I will do
> further research
> 
> Regards
> 
> Pete

Hi Pete,

That is interesting, about your CPU security extensions, but I do not
believe it is related to this.

Your original post showed that your xorg.conf file was using "fbdev" as
the graphics driver - this *should* work on most machines and so it is
useful as a "fall back" if all else fails. The fbdev driver means that
the CPU is doing all the graphics donkey-work rather than the GPU.

Essentially all I suggested was that you ensure you have the correct
xorg driver available (which you do) and you (re)move the xorg.conf
file so that xorg regenerates it (or creates on on-the-fly) when you
reboot... which you've done.

It is still entirely possible that xorg is still using fbdev, so you
may want to re-instate your xorg.conf file but edit the "fbdev" entry
to say "intel" instead.

Essentially, as I understand it, if there is an xorg.conf file present
then XOrg will use it; if there is no xorg.conf file then XOrg will try
to detect what's going on and make up a configuration on-the-fly.

Since the on-the-fly thing doesn't seem to be working for you, let's
try *making* it use the Intel driver by having an xorg.conf file that
specifies to use the Intel driver and nothing else.

I hope that makes sense.

Grant.