Hi I know nearly nothing about fortran but it looks to me as the pointer 'temp' in
> call MPI_FILE_WRITE(FH, temp, COUNT, MPI_REAL8, STATUS, IERR) is not defined (or perhaps NULL?) for all processors except processor 0 : > if ( myid == 0 ) then > count = 1 > else > count = 0 > end if > > if (count .gt. 0) then > allocate(temp(count)) > temp(1) = 2122010.0d0 > end if In C/C++ something like this would almost certainly lead to a crash, but i don't know if this would be the case in Fortran... jody On Wed, Feb 24, 2010 at 4:38 AM, w k <thuw...@gmail.com> wrote: > Hello everyone, > > > I'm trying to implement some functions in my code using parallel writing. > Each processor has an array, say q, whose length is single_no(could be zero > on some processors). I want to write q down to a common file, but the > elements of q would be scattered to their locations in this file. The > locations of the elements are described by a map. I wrote my testing code > according to an example in a MPI-2 tutorial which can be found here: > www.npaci.edu/ahm2002/ahm_ppt/Parallel_IO_MPI_2.ppt. This way of writing is > called "Accessing Irregularly Distributed Arrays" in this tutorial and the > example is given in page 42. > > I tested my code with mvapich and got the result as expected. But when I > tested it with openmpi, it didn't work. I tried the version 1.2.8 and 1.4 > and both didn't work. I tried two clusters. Both of them are intel chips > (woodcrest and nehalem), DDR infiniband with Linux system. I got some error > message like > > +++++++++++++++++++++++++++++++++++++++++++++++++++ > [n0883:08251] *** Process received signal *** > [n0883:08249] *** Process received signal *** > [n0883:08249] Signal: Segmentation fault (11) > [n0883:08249] Signal code: Address not mapped (1) > [n0883:08249] Failing at address: (nil) > [n0883:08251] Signal: Segmentation fault (11) > [n0883:08251] Signal code: Address not mapped (1) > [n0883:08251] Failing at address: (nil) > [n0883:08248] *** Process received signal *** > [n0883:08250] *** Process received signal *** > [n0883:08248] Signal: Segmentation fault (11) > [n0883:08248] Signal code: Address not mapped (1) > [n0883:08248] Failing at address: (nil) > [n0883:08250] Signal: Segmentation fault (11) > [n0883:08250] Signal code: Address not mapped (1) > [n0883:08250] Failing at address: (nil) > [n0883:08251] [ 0] /lib64/libpthread.so.0 [0x2b4f0a2f0d60] > +++++++++++++++++++++++++++++++++++++++++++++++++++ > > > > My testing code is here: > > =========================================================================================================== > program test_MPI_write_adv2 > > > !-- Template for any mpi program > > implicit none > > !--Include the mpi header file > include 'mpif.h' ! --> Required statement > > !--Declare all variables and arrays. > integer :: fh, ierr, myid, numprocs, itag, etype, filetype, info > integer :: status(MPI_STATUS_SIZE) > integer :: irc, ip > integer(kind=mpi_offset_kind) :: offset, disp > integer :: i, j, k > > integer :: num > > character(len=64) :: filename > > real(8), pointer :: q(:), temp(:) > integer, pointer :: map(:) > integer :: single_no, count > > > !--Initialize MPI > call MPI_INIT( ierr ) ! --> Required statement > > !--Who am I? --- get my rank=myid > call MPI_COMM_RANK( MPI_COMM_WORLD, myid, ierr ) > > !--How many processes in the global group? > call MPI_COMM_SIZE( MPI_COMM_WORLD, numprocs, ierr ) > > if ( myid == 0 ) then > single_no = 4 > elseif ( myid == 1 ) then > single_no = 2 > elseif ( myid == 2 ) then > single_no = 2 > elseif ( myid == 3 ) then > single_no = 3 > else > single_no = 0 > end if > > if (single_no .gt. 0) allocate(map(single_no)) > > if ( myid == 0 ) then > map = (/ 0, 2, 5, 6 /) > elseif ( myid == 1 ) then > map = (/ 1, 4 /) > elseif ( myid == 2 ) then > map = (/ 3, 9 /) > elseif ( myid == 3 ) then > map = (/ 7, 8, 10 /) > end if > > if (single_no .gt. 0) allocate(q(single_no)) > > if (single_no .gt. 0) then > do i = 1,single_no > q(i) = dble(myid+1)*100.0d0 + dble(map(i)+1) > end do > end if > > if (single_no .gt. 0) map = map + 1 > > if ( myid == 0 ) then > count = 1 > else > count = 0 > end if > > if (count .gt. 0) then > allocate(temp(count)) > temp(1) = 2122010.0d0 > end if > > write(filename,'(a)') 'test_write.bin' > > call MPI_FILE_OPEN(MPI_COMM_WORLD, filename, > MPI_MODE_RDWR+MPI_MODE_CREATE, MPI_INFO_NULL, fh, ierr) > > call MPI_FILE_WRITE(FH, temp, COUNT, MPI_REAL8, STATUS, IERR) > > call MPI_TYPE_CREATE_INDEXED_BLOCK(single_no, 1, map, > MPI_DOUBLE_PRECISION, filetype, ierr) > call MPI_TYPE_COMMIT(filetype, ierr) > disp = 0 > call MPI_FILE_SET_VIEW(fh, disp, MPI_DOUBLE_PRECISION, filetype, 'native', > MPI_INFO_NULL, ierr) > call MPI_FILE_WRITE_ALL(fh, q, single_no, MPI_DOUBLE_PRECISION, status, > ierr) > call MPI_FILE_CLOSE(fh, ierr) > > > if (single_no .gt. 0) deallocate(map) > > if (single_no .gt. 0) deallocate(q) > > if (count .gt. 0) deallocate(temp) > > !--Finilize MPI > call MPI_FINALIZE(irc) ! ---> Required statement > > stop > > > end program test_MPI_write_adv2 > =========================================================================================================== > > > The expected result is (should be in binary but the values are as follows) : > > 2122010.00000000 > 101.000000000000 > 202.000000000000 > 103.000000000000 > 304.000000000000 > 205.000000000000 > 106.000000000000 > 107.000000000000 > 408.000000000000 > 409.000000000000 > 310.000000000000 > 411.000000000000 > > > Can anyone help me on this problem? > > > Thanks a lot, > Kan > > > > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users >
