Hi I can't answer your question about the array q offhand, but i will try to translate your program to C and see if it fails the same way.
Jody On Wed, Feb 24, 2010 at 7:40 PM, w k <thuw...@gmail.com> wrote: > Hi Jordy, > > I don't think this part caused the problem. For fortran, it doesn't matter > if the pointer is NULL as long as the count requested from the processor is > 0. Actually I tested the code and it passed this part without problem. I > believe it aborted at MPI_FILE_SET_VIEW part. > > Just curious, how does C handle the case that we need to collect data in > array q but only part of the processors has q with a length greater than 0? > > Thanks for your reply, > Kan > > > > > On Wed, Feb 24, 2010 at 2:29 AM, jody <jody....@gmail.com> wrote: >> >> 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 >> > >> >> _______________________________________________ >> users mailing list >> us...@open-mpi.org >> http://www.open-mpi.org/mailman/listinfo.cgi/users > > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users >
