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Subject: Re: [OMPI users] glut display 'occasionally' opens
From: brad baker (bl.baker.85_at_[hidden])
Date: 2010-12-06 22:36:32


Without including the -x DISPLAY, glut doesn't know what display to open.
 For instance, without the -x DISPLAY parameter glut returns an error from
each process stating that it could not find display "" (empty string). This
strategy is briefly described in the openmpi
FAQs<http://www.open-mpi.org/faq/?category=running#mpirun-gui> for
launching gui applications with openmpi.

I'm assuming that by setting the DISPLAY envar to :0.0, each process will
render to their local display, which is my intention, and as I previously
stated works for up to 2 processes. So I believe it to be necessary.

But I'm thinking I may have to configure some kind of X11 forwarding. I'm
not sure...

Thanks for your reply! Any more ideas?
Brad

On Mon, Dec 6, 2010 at 6:31 PM, Ralph Castain <rhc_at_[hidden]> wrote:

> Guess I'm not entirely sure I understand how this is supposed to work. All
> the -x does is tell us to pickup an envar of the given name and forward its
> value to the remote apps. You can't set the envar's value on the cmd line.
> So you told mpirun to pickup the value of an envar called "DISPLAY=:0.0".
>
> So yes - I would expect this would be behaving strangely.
>
> If you tell us -x DISPLAY, we'll pickup the local value of DISPLAY and
> forward it. What that will cause your app to do is, I suppose, up to it.
>
>
> On Dec 6, 2010, at 12:42 PM, brad baker wrote:
>
> > Hello,
> >
> > I'm working on an mpi application that opens a glut display on each node
> of a small cluster for opengl rendering (each node has its own display). My
> current implementation scales great with mpich2, but I'd like to use openmpi
> infiniband, which is giving me trouble.
> >
> > I've had some success with the -x DISPLAY=:0.0 parameter to mpirun, which
> will open the display on up to 2 of my nodes... any 2. But when I attempt
> to run the application on 4 nodes, the display is non-deterministic. If any
> open at all process 0 definately will, and sometimes process 3 along with
> that. I haven't observed much behavior from process 1 or 2.
> >
> > My command:
> >
> > mpirun -x DISPLAY=:0.0 -np 4 -hostfile ~/openmpi.hosts ./myapp
> >
> > I've tried adding the -d option with no success.
> >
> > Does anyone have any suggestions or comments? I'll certainly provide
> more information if required.
> >
> > Thanks,
> > Brad
> > _______________________________________________
> > users mailing list
> > users_at_[hidden]
> > http://www.open-mpi.org/mailman/listinfo.cgi/users
>
>
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