the attachment
Diego
On 8 January 2015 at 19:44, Diego Avesani <[email protected]> wrote:
> Dear all,
> I found the error.
> There is a Ndata2send(iCPU) instead of Ndata2recv(iCPU).
> In the attachment there is the correct version of the program.
>
> Only one thing, could do you check if the use of MPI_WAITALL
> and MPI_BARRIER is correct?
>
> Thanks again
>
>
>
> Diego
>
>
> On 8 January 2015 at 18:48, Diego Avesani <[email protected]> wrote:
>
>> Dear all,
>> thanks thank a lot, I am learning a lot.
>>
>> I have written a simple program that send vectors of integers from a CPU
>> to another.
>>
>> The program is written (at least for now) for 4 CPU.
>>
>> The program is quite simple:
>> Each CPU knows how many data has to send to the other CPUs. This info is
>> than send to the other CPUS. In this way each CPU knows how may data has to
>> receive from other CPUs.
>>
>> This part of the program works.
>>
>> The problem is in the second part.
>>
>> In the second part, each processor sends a vector of integer to the other
>> processor. The size is given and each CPU knows the size of the incoming
>> vector form the first part of the program.
>>
>> In this second part the program fails and I do not know why.
>>
>> In the attachment you can find the program. Could you please help me.
>> Problably I didn't understand properly the ISEND and IRECV subroutine.
>>
>> Thanks again
>>
>>
>> Diego
>>
>>
>
MODULE MOD_PRECISION
integer, parameter :: dp = selected_real_kind(p=16)
ENDMODULE MOD_PRECISION
PROGRAM TEST
USE MOD_PRECISION
USE MPI
IMPLICIT NONE
!
INTEGER :: iCPU,icount,iTag,ip,sendcount,sendrecv,i
!
TYPE tMPI
INTEGER :: myrank, nCPU, iErr, status
END TYPE tMPI
!
INTEGER, ALLOCATABLE,DIMENSION(:) :: Ndata2send
INTEGER, ALLOCATABLE,DIMENSION(:) :: Ndata2recv
INTEGER, ALLOCATABLE,DIMENSION(:) :: DATASEND
INTEGER, ALLOCATABLE,DIMENSION(:) :: DATARECV
!
INTEGER :: send_request ( 3)
INTEGER :: recv_request ( 3)
INTEGER :: send_status_list (MPI_STATUS_SIZE,3)
INTEGER :: recv_status_list (MPI_STATUS_SIZE,3)
!
TYPE(tMPI) :: MPIdata
CALL MPI_INIT(MPIdata%iErr)
CALL MPI_COMM_RANK(MPI_COMM_WORLD, MPIdata%myrank, MPIdata%iErr)
CALL MPI_COMM_SIZE(MPI_COMM_WORLD, MPIdata%nCPU, MPIdata%iErr)
!
ALLOCATE(Ndata2send(0:MPIdata%nCPU-1))
ALLOCATE(Ndata2recv(0:MPIdata%nCPU-1))
!
Ndata2send=0
Ndata2recv=0
!
IF(MPIdata%myrank==0)THEN
Ndata2send(0)=0
Ndata2send(1)=100
Ndata2send(2)=100
Ndata2send(3)=160
ENDIF
IF(MPIdata%myrank==1)THEN
Ndata2send(0)=130
Ndata2send(1)=0
Ndata2send(2)=160
Ndata2send(3)=160
ENDIF
IF(MPIdata%myrank==2)THEN
Ndata2send(0)=130
Ndata2send(1)=160
Ndata2send(2)=0
Ndata2send(3)=160
ENDIF
IF(MPIdata%myrank==3)THEN
Ndata2send(0)=160
Ndata2send(1)=160
Ndata2send(2)=160
Ndata2send(3)=0
ENDIF
!
CALL MPI_BARRIER(MPI_COMM_WORLD, MPIdata%iErr)
icount=1
DO iCPU=0,MPIdata%nCPU-1
IF(iCPU.NE.MPIdata%myrank)THEN
iTag=iCPU
CALL MPI_ISEND(Ndata2send(iCPU),1,MPI_INTEGER,iCPU,iTag,MPI_COMM_WORLD,send_request(icount),MPIdata%iErr)
icount=icount+1
ENDIF
ENDDO
!
icount=1
DO iCPU=0,MPIdata%nCPU-1
IF(iCPU.NE.MPIdata%myrank)THEN
iTag=MPIdata%myrank
CALL MPI_IRECV(Ndata2recv(iCPU),1,MPI_INTEGER,iCPU,iTag,MPI_COMM_WORLD,recv_request(icount),MPIdata%iErr)
icount=icount+1
ENDIF
ENDDO
!
CALL MPI_WAITALL(MPIdata%nCPU-1,send_request,send_status_list,MPIdata%iErr)
CALL MPI_WAITALL(MPIdata%nCPU-1,recv_request,recv_status_list,MPIdata%iErr)
!
!+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
!+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
!+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
!
sendcount=1
DO iCPU=0,MPIdata%nCPU-1
IF(MPIdata%myrank.NE.iCPU)THEN
!
ALLOCATE(DATASEND(Ndata2send(iCPU)))
!
DO ip=1,Ndata2send(iCPU)
DATASEND(ip) = ip
ENDDO
!
iTag=iCPU
CALL MPI_ISEND(DATASEND(:),Ndata2send(iCPU),MPI_INTEGER,iCPU,iTag,MPI_COMM_WORLD,send_request(icount),MPIdata%iErr)
sendcount=sendcount+1
DEALLOCATE(DATASEND)
!
ENDIF
ENDDO
!
!
CALL MPI_BARRIER(MPI_COMM_WORLD, MPIdata%iErr)
!
!
sendrecv=1
DO iCPU=0,MPIdata%nCPU-1
!
ALLOCATE(DATARECV(Ndata2recv(iCPU)))
!
IF(MPIdata%myrank.NE.iCPU)THEN
iTag=MPIdata%myrank
CALL MPI_IRECV(DATARECV,Ndata2recv(iCPU),MPI_INTEGER,iCPU,iTag,MPI_COMM_WORLD,recv_request(sendrecv),MPIdata%iErr)
sendrecv=sendrecv+1
ENDIF
DO i=1,Ndata2recv(iCPU)
WRITE(*,*) DATARECV(i)
ENDDO
!
DEALLOCATE(DATARECV)
!
ENDDO
CALL MPI_WAITALL(MPIdata%nCPU-1,send_request,send_status_list,MPIdata%iErr)
CALL MPI_WAITALL(MPIdata%nCPU-1,recv_request,recv_status_list,MPIdata%iErr)
CALL MPI_Finalize(MPIdata%iErr)
ENDPROGRAM
