Newsgroups: comp.parallel.pvm
From: Graham Edward Fagg <sssfagg@reading.ac.uk>
Subject: Re: mcast problem please help
Organization: University of Reading, U.K.
Date: Tue, 2 May 1995 11:10:54 +0100
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Message-ID: <Pine.SUN.3.91.950502105722.28157D-100000@sssscsc3.reading.ac.uk>

On 29 Apr 1995, MISS EM Fitzgerald wrote:

Ok I'll try and help solve your mcast bad param error,

>                 tids = (int *) malloc(P * sizeof(int));
>                 tids[0] = mytid;
>                 me = 0;
>                 pvm_spawn(PROGNAME,(char**)0, 0, 0, P-1, &tids[1]);

Always check the number returned by the spawn command, its the number 
really started up. You mcast error could be due to invalid TIDS in tids[] 
as they never started up. Also for the where value, its better to give "" 
as some compiler don't like a zero that isn't casted to a char*
<code snipped>
>                         pvm_mcast(&tids[1],P-1,BCAST);

You may be able to say pvm_mcast(tids,P-1,BCAST) as it will not send a 
message to itself and it will attempt to send P-1 messages anyway.

> libpvm [t40007]: pvm_mcast() : Bad parameter
> I know this means pvm_mcast is giving a msgtag of < 0 but can someone 
> please explain this to me. I am using SUN4 and LINUX machines.
> Evanna Fitzgerald

As I said, I think this may be due to an invalid tid in the tids list. 
check the value returned by the pvm_spawn call and print out the tid 
array. Any value less than zero are error as listed in pvm3/include/pvm3.h

Graham.
===============================================================================
Graham Edward Fagg ||| *** Cluster Computing Lab. ***  ||| e-mail me some time
 Computer Science ||  Software Engineering Subject Grp.  ||  G.E.Fagg@rdg.ac.uk
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