[arch-general] System like glue, High IO Wait.

[Carsten Feuls]

Am Samstag, 2. April 2016, 21:53:52 CEST schrieb Mike Cloaked:
> On Sat, Apr 2, 2016 at 8:11 PM, Carsten Feuls <liste at carstenfeuls.de> wrote:
> > snip
> > The Systems are very unresponsive (long waiting on gui interaction).
> > In Htop I can see a high CPU wait time,and a high cpu load, but in iftop
> > no IO
> > load is on the drives.
> > I have these Probelem with 3 Arch Installations.
> > These systems run kf5.
> > All installations runs ArchLinux Stable (not testing), and the
> > Installations
> > are up to date.
> > On my parents PC the problem only appear after the last update.
> > I have copy the output to pastebin.
> > http://pastebin.com/E4xnQKhJ
> > 
> > For me it looks like a graphics bug.
> > I have downgraded the kernel to an older version but it does not resolve
> > the
> > problem.
> > Maybe anybody know something about that. Or have an larger expertise in
> > investigating this bug.
> > 
> > I use archlinux now longer than six years. I have solved much problems.
> > But
> > this bug makes me crazy..
> 
> One question is what your hardware is - certainly for newer machines with
> recent graphics hardware I have not had any serious slow response issues,
> but for machines that are 5 or 6 years old I have had very considerable
> limitations attempting to run plasma with its much more extensive demands
> on the graphics hardware.  I have had to make the decision to only run
> plasma on my machines here that are Ivybridge processor family or later.
> On machines where the graphics hardware is a serious limitation I have
> found that some performance can be regained by switching off all desktop
> effects, and turning off desktop cube animation for switching between
> desktops within plasma.  You might want to check or list the hardware on
> the machines affected?  Others may have other suggestions but you would
> need to provide information about your hardware and possibly diagnostics
> from log files before people might be able to suggest what the problem is.
My Desktop PC:
CPU: Intel(R) Core(TM) i7-3930K CPU @ 3.20GHz
RAM: 32GB
GPU: GeForce GTX 680
Harddrive: 
	OS: Samsung 830 (250GB)
        Data: Raid 1 over two Seagate SV35 (3TB)

My Notebook:
Lenovo X230t
CPU: INtel i7 Mobile Version
RAM: 16GB
GPU: Intel Onboard
Harddrive: Samsung 840 Evo

My Parents PC:
Lenovo ThinkCenter:
CPU: Intel i5
RAM: 8GB
GPU: Intel OnBoard
Harddrive: 1TB Hitachi

I dont like the Desktop Effekts. I have only some small effekts running.
I have tested if the desktop effekt could the problem and disabled all of 
them. But nothing solved it.

I can understand when the desktop effekts slow down the system.
But when I hear Music. It stops playing. Video Stops playing. Website loading 
stops. Only I can move the mouse cursor.

The hang time is mostly 30sec. But sometimes it takes much longer.

On my desktop with the nvidia card. I am running the propertry driver from 
nvidia.

I had run memtest on all machines and a long smart self test on all drives.
No Problem appeared.

The log files does not provide any Information about the slow responding 
system. Or I dont find them.
The only answer I get is in dmesg from Akonadi.
INFO: task akonadi_imap_re:25437 blocked for more than 120 seconds.
Tainted: P         C O    4.4.5-1-ARCH #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.