用fortran MPI_Barrier分割故障

Question

我见过有人使用MPI_Barrier (libpmpi.12.dylib)和C++ (Barrier cause a segmentation fault in C++)产生分割错误。然而，我并没有复制他们所犯的错误。

然而，现在我得到了相同的错误fortran MPI_Barrier。我的代码很简单，比如：

program main

implicit none

include 'mpif.h'


! local variables
!
character(len=80) :: filename, input
character(len=4) :: command
integer :: ierror, i, l, cmdunit
logical :: terminate
integer :: num_procs, my_id, impi_error
real :: program_start, program_end
call MPI_INIT(impi_error)
call MPI_COMM_RANK(MPI_COMM_WORLD,my_id,impi_error)
call MPI_COMM_SIZE(MPI_COMM_WORLD,num_procs,impi_error)
call MPI_Barrier(MPI_COMM_WORLD)
program_start = MPI_Wtime()
filename='sc.cmd'
cmdunit=8
print *, my_id, cmdunit
call MPI_Barrier(MPI_COMM_WORLD)
call MPI_Barrier(MPI_COMM_WORLD)
call MPI_Barrier(MPI_COMM_WORLD)
call MPI_Barrier(MPI_COMM_WORLD)
call MPI_Barrier(MPI_COMM_WORLD)
program_end = MPI_Wtime()
if (my_id == 0) then
    write(*,'(a,F25.16,a)') "MDStressLab runs in ", program_end -             program_start, " s."
endif
call MPI_FINALIZE(impi_error)
end program

密码没什么特别的。但是，当我使用命令mpif90 tmp.f90编译代码，然后使用命令mpirun -n 2 ./a.out运行时。它给了我：

           0           8
           1           8

Program received signal SIGSEGV: Segmentation fault - invalid memory     reference.

Backtrace for this error:

Program received signal SIGSEGV: Segmentation fault - invalid memory reference.

Backtrace for this error:
#0  0x7FBF2C700E08
#1  0x7FBF2C6FFF90
#0  0x7F2EDF972E08
#2  0x7FBF2C3514AF
#1  0x7F2EDF971F90
#2  0x7F2EDF5C34AF
#3  0x7FBF2CA4F808
#4  0x400EB4 in MAIN__ at tmp.f90:?
#3  0x7F2EDFCC1808
#4  0x400EB4 in MAIN__ at tmp.f90:?
--------------------------------------------------------------------------
mpirun noticed that process rank 1 with PID 35660 on node min-virtual-machine exited on signal 11 (Segmentation fault).
--------------------------------------------------------------------------

有趣的是，它只有两个节点崩溃。它在1~10个节点上运行很好，除了2个节点。因为这也是在C和C++中随机发生的，所以我认为在MPI库中可能有一些隐藏的bug。这只是我的猜测。有人能帮忙吗？

Answer 1

只需替换

call MPI_Barrier(MPI_COMM_WORLD)

使用

call MPI_Barrier(MPI_COMM_WORLD, impi_error)

注意，如果您的Fortran编译器和MPI库支持Fortran 2008，您也可以选择替换

include mpif.h

使用

use mpi_f08

而且您不再需要impi_error参数了，因为Fortran 2008绑定使这个参数成为可选的