Re: EDM screens not updating on Linux

[John Sinclair <sinclairjw@ornl.gov>]

Brian,

Here's something to try.

When edm gets in this state, mouse over some widget that should be 
updating and do a ctl-middle-button press. A window will pop up showing 
the connection info for the pv and the number of value changes that have 
occurred. Then use another utility such as probe to watch value-change 
events. When you are certain a significant value change has occurred, do 
another ctl-middle-button press to see if edm agrees (by indicating a 
greater number of value changes than before and a new timestamp). If so, 
I would suspect some component of XWindows. If not, it could be a bug in 
edm or a channel access issue.

John sinclair

Brian Bevins wrote:
> Hi Dirk,
>
> We haven't been running MEDM on RHEL so I don't know if it's showing 
> the same problem for us. I can confirm that the behavior you describe 
> matches what has been reported to me by operators using EDM on RHEL. 
> Exposing the window seems to solve the problem.
>
> An X/Motif problem does seem like a possibility. We recently had to 
> turn off the BIG-REQUESTS extension on the RHEL X servers because it 
> generated errors for certain other (non-EPICS) applications. Does 
> anyone know if this might be a problem for EDM? We're using xorg-x11 
> 6.8.2 release 1.EL.19.
>
> --Brian
>
> Dirk Zimoch wrote:
> > Hi Brian,
> >
> > we have seen the same effect with MEDM. I suspect a problem with 
> > either the X-server or the motif library. It is very strange that the 
> > effect appears only on some computers.
> >
> > It seems that the screens don't get update requests when new values 
> > arrive. Minimizing and maximizing, or just "wiping" the screen with 
> > some other window generates the update events and the current value 
> > is shown. From this I conclude that there is no problem in EPICS and 
> > the monitor events correctly arrive. The values are just not updated 
> > on the screen. Can you verify this with EDM?
> >
> > Dirk
> >
> > Brian Bevins wrote:
> > > We are in the process of converting our control room machines from 
> > > HP-UX 11.11 to RedHat Enterprise Linux (rhel) 4WS. Most things seem 
> > > to be working fine, but an odd problem has cropped up with EDM that 
> > > we did not have on HP-UX.
> > >
> > > Every now and then an EDM display will simply stop showing any 
> > > updates to the PV's. Closing and re-opening the display gets it 
> > > working again. Writes from the screen to the ioc's seem to work 
> > > normally.
> > >
> > > Has anybody else experienced a problem like this?
> > >
> > > We are using EDM 1-10-2 on rhel 4WS (Nahant Update 5). This is the 
> > > same version we have bee using on HP-UX with no problems.
> > >
> > > Our operators love how zippy EDM runs on their new Linux boxes 
> > > compared to the ancient HP hardware, but this is really denting 
> > > their enthusiasm.
> > >
> > > Thanks,
> > > --Brian