[mpich-discuss] Running MPI jobs without mpiexec

Jayesh Krishna jayesh at mcs.anl.gov
Wed Aug 17 11:40:01 CDT 2011 

Hi,

 I am not sure what you mean by "...we would like the dll to be run on multiple processors...". AFAIK, there needs to be at least a stub exe (that uses the dll) so that the OS can run it on a processor.

Regards,
Jayesh
----- Original Message -----
From: "Amar K. Patel" <PATEL_AMAR_K at cat.com>
To: mpich-discuss at mcs.anl.gov
Sent: Monday, August 15, 2011 1:45:08 PM
Subject: Re: [mpich-discuss] Running MPI jobs without mpiexec



Hi Jayesh, 

Apologies if I was not clear in the previous email. My main executable loads the dll in the beginning and while it (exe) is running calls the dll for performing CPU intensive math. Previously the dll used to be an executable that was run as a separate program with MPI. What we are trying to do now, is to couple two separate programs into one such that one of them becomes the main program and the second one needs is called by first. For this reason we are converting the second program into a dll that is loaded by the main as a shared library. 

However when the main program calls the dll, we would like the dll to be run on multiple processors just as it used to be run when it (the dll) was a standalone executable. 

Thanks, 
Amar 

---------------------------------------------------------------------------------- 
Engine Performance & Emissions 
Advanced Virtual Product Development , PD & GT 
Caterpillar Inc. 
Phone : (309) 578-1283 
Email : PATEL_AMAR_K at cat.com 
---------------------------------------------------------------------------------- 


	Jayesh Krishna <jayesh at mcs.anl.gov> 
Sent by: mpich-discuss-bounces at mcs.anl.gov 

08/15/2011 01:31 PM 	
Please respond to 
mpich-discuss at mcs.anl.gov 
		
To 	"Amar K. Patel" <PATEL_AMAR_K at cat.com> 
	
cc 	mpich-discuss at mcs.anl.gov 
	
Subject 	Re: [mpich-discuss] Running MPI jobs without mpiexec 
		


Caterpillar: Confidential Green Retain Until: 09/14/2011 




Hi, 
I am not sure what you mean by "running" a dll (Are you referring to using "rundll" etc ? ). 
What is the advantage that you get by running dlls instead of executables ? 

Regards, 
Jayesh 

----- Original Message ----- 
From: "Amar K. Patel" <PATEL_AMAR_K at cat.com> 
To: jayesh at mcs.anl.gov 
Cc: mpich-discuss at mcs.anl.gov 
Sent: Monday, August 15, 2011 10:58:37 AM 
Subject: Re: [mpich-discuss] Running MPI jobs without mpiexec 


Hi Jayesh, 

Thanks for suggesting the two options earlier. I have been exploring them since your recommendations and I would appreciate if you could answer these follow-up questions. 

1. I have been looking at MPI_Comm_spawn_multiple and MPI_Comm_spawn under MPI dynamic processes and I have concluded that for either of these options to work, the callee binary should be an exe. Am I correct to conclude this? 

Meaning that if I have the following line in my main code (call it myCode2.exe), 

MPI_Comm_spawn_multiple(NHOST, progs, MPI_ARGVS_NULL, nproc, infos, 0, MPI_COMM_WORLD, &intercomm, MPI_ERRCODES_IGNORE); 

the binary specified under "Progs" argument should be an exe and not a dll or a lib file. Is this correct ? 

Here is a little background on what I am trying to do here. 
I am trying to call a shared library (dll) that needs to be run on multiple processors but I do not want the main calling program to be run on multiple PCs. So basically, I need to run the main program (myCode2.exe) as a singleton process which at run time needs to call a dll (myCode1.dll) and that dll needs to be run on multiple processors. 
I have tried putting in MPI_Comm_spawn_multiple in the main program and tried to call the dll through MPI_Comm_spawn_multiple but I get a runtime error indicating that the program being called by MPI_Comm_spawn_multiple is not an executable. 

2. Your other suggestion was launching mpiexec from the main program (myCode2.exe). Are you suggesting using the system() function in myCode2.exe to launch mpiexec which then launches myCode1? Wont this require myCode1 to be an exe file to be launched with mpiexec command? In my case myCode1 used to be compiled as a standalone exe file before, but we would now wish to compile it as a dll that is loaded as a shared library and called by another larger executable at run time. 

Thanks for your help. 

Amar 




Jayesh Krishna <jayesh at mcs.anl.gov> 
Sent by: mpich-discuss-bounces at mcs.anl.gov 

08/04/2011 03:28 PM 
Please respond to 
mpich-discuss at mcs.anl.gov 

To mpich-discuss at mcs.anl.gov 

cc PATEL_AMAR_K at cat.com 

Subject Re: [mpich-discuss] Running MPI jobs without mpiexec 



Caterpillar: Confidential Green Retain Until: 09/03/2011 




Hi, 
Two options come to my mind, 

# Take a look at MPI dynamic processes (http://www.mpi-forum.org/docs/mpi21-report/node197.htm#Node197). 
# Launch mpiexec from myCode2. 

Regards, 
Jayesh 
----- Original Message ----- 
From: "Amar K. Patel" <PATEL_AMAR_K at cat.com> 
To: mpich-discuss at mcs.anl.gov 
Sent: Thursday, August 4, 2011 11:35:58 AM 
Subject: [mpich-discuss] Running MPI jobs without mpiexec 



Hello, 

I have MPI program that runs fine when it started with the command mpiexec -n # myCode1.exe. I now need to call myCode1 from another code (say myCode2) in such a way that myCode1 is a dll file which is loaded and called when myCode2 is being executed. myCode2 is started without using mpiexec commad. 

With this new setup I would like to call myCode1.dll and be able to use the MPI features that have been embedded in it such that myCode1.dll can be run on more than one CPU. Is such a thing possible ? If so, then I would appreciate if someone could point me to a documentation or an example that illustrates how to implement the changes needed in myCode1 and/or myCode2. 

Here is an crude version of myCode1 and myCode2 that I am using. 

void myCode1() 
{ 
int rank; 
MPI_Init(x, x); 
MPI_Comm_rank(MPI_COMM_WORLD, &rank); 
...... 
...... 
...... 
...... 
...... 
...... 
...... 
...... 
MPI_Finalize(); 
return; 
} 


int myCode2(int argc, char **argv) 
{ 
myCode1(); 
return 0; 
} 
_______________________________________________ 
mpich-discuss mailing list 
mpich-discuss at mcs.anl.gov 
https://lists.mcs.anl.gov/mailman/listinfo/mpich-discuss 
_______________________________________________ 
mpich-discuss mailing list 
mpich-discuss at mcs.anl.gov 
https://lists.mcs.anl.gov/mailman/listinfo/mpich-discuss 

_______________________________________________ 
mpich-discuss mailing list 
mpich-discuss at mcs.anl.gov 
https://lists.mcs.anl.gov/mailman/listinfo/mpich-discuss 


_______________________________________________
mpich-discuss mailing list
mpich-discuss at mcs.anl.gov
https://lists.mcs.anl.gov/mailman/listinfo/mpich-discuss

More information about the mpich-discuss mailing list