[Radiance-general] starting rpict -S 1 -P pfile

[Gregory J. Ward]

There's no sense in using the -P option if you're after parallel  
runs, because -P insists on serial runs -- it's a mechanism to  
connect sequential invocations to the same process.  It's exactly the  
opposite of what you need.  Just use multiple rpicts if OpenMosix  
doesn't support shared memory.  It will be the same as using -PP in  
that case, since there's nothing about the -PP option that *requires*  
shared memory.  It just ends up using it if it's available.

-Greg

> From: "Lars O. Grobe" <grobe at gmx.net>
> Date: October 15, 2005 11:50:29 AM PDT
>
>> It may just be that you need to use the -PP option rather than -P,  
>> which doesn't do parallel processing.  (The -P "persist mode" is a  
>> relatively little-used option that permits serial execution  
>> without the associated startup costs -- it's more valuable for  
>> rtrace than rpict.)
>>
>> Also, each of your rpict -PP commands should be handed the same  
>> set of views on the standard input.  Otherwise, nothing will happen.
>>
>
> I cannot use -PP because my openmosix doesn't support shared  
> memory. I forgot to pass the view file, as I read that command line  
> parameters don't have to be passed. Of course, I don't pass views  
> as command line parameters, but from stdin, so I have to feed the  
> view file for each process, right? ;-)
>
> I think that if I start more than one -P process, they WILL run  
> parallel (even if they use much more memory than the shared -PP  
> processes), right?
>
> Thank You, CU Lars.
>