Re: [OMPI users] MPI_Send doesn't work if the data >= 2GB

2010-12-05 Thread 孟宪军
hi, In my computers(X86-64), the sizeof(int)=4, but the sizeof(long)=sizeof(double)=sizeof(size_t)=8. when I checked my mpi.h file, I found that the definition about the sizeof(int) is correct. meanwhile, I think the mpi.h file was generated according to my compute environment when I compiled the

Re: [OMPI users] MPI_Send doesn't work if the data >= 2GB

2010-12-05 Thread Tim Prince
On 12/5/2010 7:13 PM, 孟宪军 wrote: hi, I met a question recently when I tested the MPI_send and MPI_Recv functions. When I run the following codes, the processes hanged and I found there was not data transmission in my network at all. BTW: I finished this test on two X86-64 computers with 16GB me

[OMPI users] MPI_Send doesn't work if the data >= 2GB

2010-12-05 Thread 孟宪军
hi, I met a question recently when I tested the MPI_send and MPI_Recv functions. When I run the following codes, the processes hanged and I found there was not data transmission in my network at all. BTW: I finished this test on two X86-64 computers with 16GB memory and installed Linux. 1 #in

Re: [OMPI users] Scalability issue

2010-12-05 Thread Benjamin Toueg
Unfortunately DRAGON is old FORTRAN77. Integers have been used instead of pointers. If I compile it in 64bits without -f-default-integer-8, the so-called pointers will remain in 32bits. Problems could also arise from its data structure handlers. Therefore -f-default-integer-8 is absolutely necessa

Re: [OMPI users] Scalability issue

2010-12-05 Thread Tim Prince
On 12/5/2010 3:22 PM, Gustavo Correa wrote: I would just rebuild OpenMPI withOUT the compiler flags that change the standard sizes of "int" and "float" (do a "make cleandist" first!), then recompile your program, and see how it goes. I don't think you are gaining anything by trying to change th

Re: [OMPI users] error mesages appeared but program runs successfully?

2010-12-05 Thread Gustavo Correa
Hi Daofeng It is hard to tell what is happening in the Infiniband side of the problem. Did somebody perhaps remove the Infiniband card from this machine? Was it ever there? Did somebody perhaps changed the Linux kernel modules that are loaded (perhaps changing /etc/module.config or similar)? Maybe

Re: [OMPI users] Scalability issue

2010-12-05 Thread Gustavo Correa
Hi Benjamin I would just rebuild OpenMPI withOUT the compiler flags that change the standard sizes of "int" and "float" (do a "make cleandist" first!), then recompile your program, and see how it goes. I don't think you are gaining anything by trying to change the standard "int/integer" and "re

Re: [OMPI users] Scalability issue

2010-12-05 Thread Benjamin Toueg
Hi, First of all thanks for your insight ! *Do you get a corefile?* I don't get a core file, but I get a file called _FIL001. It doesn't contain any debugging symbols. It's most likely a digested version of the input file given to the executable : ./myexec < inputfile. *there's no line numbers p

Re: [OMPI users] difference between single and double precision

2010-12-05 Thread Eugene Loh
Mathieu Gontier wrote: Dear OpenMPI users I am dealing with an arithmetic problem. In fact, I have two variants of my code: one in single precision, one in double precision. When I compare the two executable built with MPICH, one can observed an expected difference of performance: 115.7-se