Hi!
I tried to run trivial FORTRAN90 program (see below) on one physical
processor with:
$ mpirun -np 2 test_prog
Program execution shows that the data sent from rank 0 to rank 1 arrives
corrupted (or I'm missing something completely). It happens only after the
message size gets over 64KB. If I run this program with "-ssi rpi lamd" no
data corruption occurs. Can anyone explain me this behaviour?
LAM-MPI 7.0.6 and the program was compiled with Intel 8.0 compilers.
CC=icc
CXX=icc
FC=ifort
$ export CC CXX FC
$ ./configure --prefix=/usr/local/lam-7.0.6_intel --with-trillium \
--with-prefix-memcpy --with-debug --with-tv-debug --enable-tv-dll-force \
--enable-shared --with-purify --with-rsh="ssh -x"
$ mpif77 -u -o test_prog test_prog.f90
I also tried it with Sun's HPC 5.0 and Sun Fortran 95 6.2 compiler -
everything is OK for MPI_REAL and MPI_DOUBLE_PRECISION.
------------------------------------------------------------------
program test_prog
implicit none
include 'mpif.h'
integer, parameter :: rk = selected_real_kind(15,307)
!integer, parameter :: rk = selected_real_kind(6,37)
integer :: i
integer :: myrank, nprocs, ierr, request, status(MPI_STATUS_SIZE)
integer :: bufsize
integer :: bits
real(kind=rk), dimension(:), pointer :: bufs, bufr
real(kind=rk) :: chkval
integer :: MPI_kind
! define MPI_fkind
if (precision(1.0_rk) >= 15) then
MPI_kind = MPI_DOUBLE_PRECISION
bits = 64
bufsize = 8193 ! 8192=>8193 array elements; 65536=>65544 bytes
else
MPI_kind = MPI_REAL
bits = 32
bufsize = 8193*2 ! 8192*2=>8193*2 array elements; 65536=>65544 bytes
end if
call MPI_INIT(ierr)
call MPI_COMM_RANK(MPI_COMM_WORLD, myrank, ierr)
call MPI_COMM_SIZE(MPI_COMM_WORLD, nprocs, ierr)
if (nprocs /= 2) &
call MPI_ABORT(MPI_COMM_WORLD, ierr)
if (myrank == 0) then
write(*,'(a,i2,a,i6,a)') '<',myrank,'> size of send/recv buffers:',&
bits*bufsize/8,' bytes'
chkval = 1.1_rk
call MPI_ISEND(chkval, 1, MPI_kind, &
1, 11, MPI_COMM_WORLD, request, ierr)
allocate(bufs(bufsize))
bufs = chkval
call MPI_ISEND(bufs, bufsize, MPI_kind, &
1, 12, MPI_COMM_WORLD, request, ierr)
else
call MPI_RECV(chkval, 1, MPI_kind, &
0, 11, MPI_COMM_WORLD, status, ierr)
allocate(bufr(bufsize))
call MPI_RECV(bufr, bufsize, MPI_kind, &
0, 12, MPI_COMM_WORLD, status, ierr)
write(*,'(a,i2,a,f10.7)') '<',myrank,'> chkval=',chkval
if (any(bufr /= chkval)) &
write(*,'(a,i2,a)') '<',myrank,'> problems with ''bufr'''
do i = 1,bufsize
if (bufr(i) /= chkval) then
write(*,'(a,i2,a,i5,a,f10.7,a,f10.7)') &
'<',myrank,'> bufr(',i,')=',bufr(i), ':',bufr(i)-chkval
end if
end do
end if
if (myrank == 0) then
deallocate(bufs)
else
deallocate(bufr)
end if
call MPI_BARRIER(MPI_COMM_WORLD, ierr)
call MPI_FINALIZE(ierr)
end program test_prog
-----------------------------------------------------------------------
Regards,
Konstantin
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