Hi,

on one of several machines and only occasionally
my X-server (/usr/bin/X) takes nearly 100% CPU.
I have killed some applications but this didn't help
unless I killed X itself and restarted it.

Is there any way to find out what is hogging my X server?

Many thanks for a hint,
Helmut.

--
Helmut Jarausch

Lehrstuhl fuer Numerische Mathematik
RWTH - Aachen University
D 52056 Aachen, Germany

On Tuesday 24 November 2009 17:55:20 Helmut Jarausch wrote:
> Hi,
>
> on one of several machines and only occasionally
> my X-server (/usr/bin/X) takes nearly 100% CPU.
> I have killed some applications but this didn't help
> unless I killed X itself and restarted it.
>
> Is there any way to find out what is hogging my X server?
>
> Many thanks for a hint,

I'll be stating the obvious, like ps axf and lsof perhaps?
--
Regards,
Mick

On Wednesday 25 November 2009 01:34:55 Mick wrote:
> On Tuesday 24 November 2009 17:55:20 Helmut Jarausch wrote:
> > Hi,
> >
> > on one of several machines and only occasionally
> > my X-server (/usr/bin/X) takes nearly 100% CPU.
> > I have killed some applications but this didn't help
> > unless I killed X itself and restarted it.
> >
> > Is there any way to find out what is hogging my X server?
> >
> > Many thanks for a hint,
>
> I'll be stating the obvious, like ps axf and lsof perhaps?
>

xrestop is also useful


--
alan dot mckinnon at gmail dot com

2009/11/25 Helmut Jarausch <jarausch@igpm.rwth-aachen.de>:
> Hi,
>
> on one of several machines and only occasionally
> my X-server (/usr/bin/X) takes nearly 100% CPU.
> I have killed some applications but this didn't help
> unless I killed X itself and restarted it.
>
> Is there any way to find out what is hogging my X server?
>

Running accelerated graphics on my intel card (945GM) for things like
compiz would always make X eat my processor time like mad.

The workaround I used was not to accelerate graphics on a crappy card.

Not sure if this applies to you.

Regards,
daid

> 2009/11/25 Helmut Jarausch <jarausch@igpm.rwth-aachen.de>:
>> Hi,
>>
>> on one of several machines and only occasionally
>> my X-server (/usr/bin/X) takes nearly 100% CPU.
>> I have killed some applications but this didn't help
>> unless I killed X itself and restarted it.
>>
>> Is there any way to find out what is hogging my X server?
>>

Another thing worth note is what version of the kernel you are running
versus how updated X is. I noticed when I migrated to libxcb under a
2.6.27 kernel that X starts running much more slowly for strange cases
(like when audio is running, for example, X hogs the processor).

I don't have a lot of insight as to how to determine which program
makes X run hot, except for running very few things in X and starting
a program and keeping an eye on something like top.

But, in any case, another solution may be to keep the kernel updated
if you are running the latest X software.

~daid

daid kahl wrote:
>> 2009/11/25 Helmut Jarausch <jarausch@igpm.rwth-aachen.de>:
>>> Hi,
>>>
>>> on one of several machines and only occasionally
>>> my X-server (/usr/bin/X) takes nearly 100% CPU.
>>> I have killed some applications but this didn't help
>>> unless I killed X itself and restarted it.
>>>
>>> Is there any way to find out what is hogging my X server?
>>>
>
> Another thing worth note is what version of the kernel you are running
> versus how updated X is. I noticed when I migrated to libxcb under a
> 2.6.27 kernel that X starts running much more slowly for strange cases
> (like when audio is running, for example, X hogs the processor).
>
> I don't have a lot of insight as to how to determine which program
> makes X run hot, except for running very few things in X and starting
> a program and keeping an eye on something like top.
>
> But, in any case, another solution may be to keep the kernel updated
> if you are running the latest X software.
>
> ~daid
>
What is the process that causes the trouble? After the latest update I
also found my KDE to be under high cpu load. The offending process was
kwin. After some googling I found that switching off Vsync could help
me. This option is in System Setting -> Desktop -> Advanced Options.
That helped in my case.
Hope, that can help.

Thanks David, thanks Zhen!

I'm running the 2.6.31-gentoo-r6 kernel,
xorg-server-1.6.5-r1 and x11-drivers/ati-drivers-9.11
So, this is quite recent.
I've patched my xorg-server as described here
http://www.mail-archive.com/gentoo-amd64@lists.gentoo.org/msg11704.html

I don't run KDE and most of the time everything works just fine.
Then, suddenly X takes much CPU time, the mouse gets nearly
non-responsive. I have killed nearly any user process without any
change. Only killing X itself cures the problem.
Of course, I have reemerged x11-base/xorg-server x11-drivers/ati-drivers
and I have run revdep-rebuild.

Probably I have to somehow compare every lib on the "faulty" machine
to another once which should have identical packages.

Thanks again,
Helmut.

On 26 Nov, daid kahl wrote:
>> 2009/11/25 Helmut Jarausch <jarausch@igpm.rwth-aachen.de>:
>>> Hi,
>>>
>>> on one of several machines and only occasionally
>>> my X-server (/usr/bin/X) takes nearly 100% CPU.
>>> I have killed some applications but this didn't help
>>> unless I killed X itself and restarted it.
>>>
>>> Is there any way to find out what is hogging my X server?
>>>
>
> Another thing worth note is what version of the kernel you are running
> versus how updated X is. I noticed when I migrated to libxcb under a
> 2.6.27 kernel that X starts running much more slowly for strange cases
> (like when audio is running, for example, X hogs the processor).
>
> I don't have a lot of insight as to how to determine which program
> makes X run hot, except for running very few things in X and starting
> a program and keeping an eye on something like top.
>
> But, in any case, another solution may be to keep the kernel updated
> if you are running the latest X software.
>
> ~daid
>

--
Helmut Jarausch

Lehrstuhl fuer Numerische Mathematik
RWTH - Aachen University
D 52056 Aachen, Germany

> I'm running the 2.6.31-gentoo-r6 kernel,
> xorg-server-1.6.5-r1 and *x11-drivers/ati-drivers-9.11
> So, this is quite recent.

> Only killing X itself cures the problem.
> Of course, I have reemerged x11-base/xorg-server x11-drivers/ati-drivers
> and I have run revdep-rebuild.
>
> Probably I have to somehow compare every lib on the "faulty" machine
> to another once which should have identical packages.

Another thing you might try it to have X automatically reconfigure
itself. I find that my xorg.conf gets somewhat bloated from my manual
edits, lack of bad commenting, and trying lots of options. This
resulted in my machine loading a lot of modules, and I wasn't really
sure which ones i needed and which ones I enabled for what reasons
over the last three years since I compiled this machine.

Make a copy of xorg.conf....copy it to somewhere like /etc/X11/xorg.conf.backup

Then let it autoconfigure:

$ X -configure

That will make a temporary xorg.conf which you should move to /etc/X11
or ~/ depending on your setup. It could be that one of the modules
you're loading into X is the cause. I had done this recently as well
trying to solve my X processor problems, and it might be useful.

Alternatively, you can just comment out one-by-one any modules or
devices you're loading with xorg.conf and see if any of them are
responsible. It's more manual work than rebuilding all your
libraries, but it beats the hell out of re-emerging your whole system
on a guess....

Regards,
daid

Alan McKinnon mentions yet another cool utility:

> xrestop is also useful

Cooooool! Great tip! Again.

Wonko