Experimental Physics and
Industrial Control System

"Rodney R. Porter" <[email protected]> · Wed, 25 Jun 2008 10:07:32 -0500

We see much the same problem with displays freezing using medm on FC6. No
problems with FC4.  Manual refreshes work, but only closing and restarting
MEDM restores normal updates.  This can occur every couple of days to every
couple of hours.  We see this problem on both the standard APS HP hardware
with APS installed FC6 OS and on our own FC6 boxes that use MAC hardware
with Nvidia drivers.  The last freeze I looked at corresponded roughly to
the 3 day DNS credential update, but it did not recur after an additional 3
days, so this may be a red herring.
Rodney Porter
Sector 26

On 6/20/08 1:36 PM, "David Wetherholt" <[email protected]> wrote:

> Hello Epics Collaboration,
> 
>   We are using EDM on HPUX here at Jefferson Lab and it is running
> as expected.  However, while attempting to convert all our workstations
> to Linux, we are encountering EDM "freezes" (sometimes partial with
> other open displays updating, sometimes complete with all displays
> frozen.)  We have noted that is frequently happens with either closing
> or opening related displays.  It happens anywhere between hours or a
> couple of days in frequency.
> 
>   There are usually no console messages when this happens, however one
> operator did get the following error:
> X error: code=3, msg: BadWindow (invalid Window parameter)
> 
>   I am by no means an expert on the X-Server, but a after a little
> googling it appears code 3 is something dealing with closing child
> windows and no clear solution exists. However, sometimes using
> -sync with QT users fixes the problem. This error may be related
> to our freezing, or not.
> 
>   We are running a very vanilla build of Linux:
> RedHat Linux version 4WS
> uname: Linux 2.6.9-67.0.1.ELsmp #1 SMP i686 i386 GNU/Linux
> 
>   (BTW, we updated to Red Hat 5 just to see if this fixed the
> EDM problem... it did not).
> 
>   We are running an unmodified version of EDM (EDM 1-11-0zi) built
> against the 3.14.9 version of the channel access libraries. Our
> parameters are something like this:
>   $EDM -x -noedit -port $port -m $2 -open $argv[3-]
> 
>   I was wondering if any other users in the collaboration have
> experienced this problem with EDM and if so, if they have found
> solutions.
> 
>   The system guys would also like to find out what version of Linux
> is being used by other groups who haven't had these type of problems
> with EDM.
> 
>   It was also thought it might be helpful to include a full list of
> the "system-level" debugging that was done. This problem was tested and
> exhibited itself under all of the following conditions:
> 
> - Multiple different kernels (all 32-bit)
> - Multiple versions of the Xorg Xserver.
> - Every module of the Xserver was also individually tested. The problem
>   persists with no extra modules loaded at all (i.e. all commented out).
> - Multiple versions of the NVIDIA video card driver.
> - Multiple versions of the default X.org nv driver.
> - At least one version of an ATI video card driver.
> - A wide variety of hardware platforms (motherboards and video cards).
> - RedHat Enterprise Linux 4 (update 2-6) and 5.
> - Multiple versions of KDE and GNOME.
> - Multi-head and Single Head configurations were both tested and exhibited
>   this problem.
> 
>   It is also worth noting that no other application has exhibited this
> specific behavior in the 5 years of Linux use in our environment.
> 
>   Thanks!
> 
> David Wetherholt
> Thomas Jefferson National Accelerator Facility
> 
> 

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System