Question

我在Fortran中运行计算，我正在使用MPI来并行化 do 循环。有4个外部输入数组（X，Y，zeta_list和M_list），但为了便于测试，我使用调用random_number 来生成输入数组。我使用MPI_Scatter来分配循环运行的数组 zeta_list 中的元素。

PROGRAM TEST_MPI

use mpi

IMPLICIT NONE 

DOUBLE PRECISION,DIMENSION(1,10)::M_list
DOUBLE PRECISION,DIMENSION(11,11)::X,Y,z_m_z_x,z_m_z_y,dist_z_m_z,alpha_x, alpha_y, sub_alpha_x, sub_alpha_y
DOUBLE PRECISION,DIMENSION(2,10)::zeta_list
DOUBLE PRECISION,ALLOCATABLE,DIMENSION(:,:)::sub_zeta_list
INTEGER::i,myid,ntasks,ierror,n_elements,chunk 


call MPI_INIT(ierror)
call MPI_COMM_RANK(MPI_COMM_WORLD, myid, ierror)
call MPI_COMM_SIZE(MPI_COMM_WORLD, ntasks, ierror)


if (myid == 0) then 
    call random_number(X)
    call random_number(Y)
    call random_number(zeta_list)
    call random_number(M_list)
    alpha_x = 0
    alpha_y = 0 
    sub_alpha_x = 0 
    sub_alpha_y = 0 
    z_m_z_x = 0
    z_m_z_y = 0 
    dist_z_m_z = 0 
end if 
n_elements = size(zeta_list,1)*size(zeta_list,2)
chunk = n_elements/ntasks
allocate(sub_zeta_list(2,chunk/2))
sub_zeta_list = 0 

call MPI_Scatter(zeta_list,chunk,MPI_DOUBLE_PRECISION,sub_zeta_list,chunk,MPI_DOUBLE_PRECISION,0,MPI_COMM_WORLD)

do i=1,chunk/2,1
        z_m_z_x = X - sub_zeta_list(1,i)
        z_m_z_y = Y - sub_zeta_list(2,i)
        dist_z_m_z = z_m_z_x**2 + z_m_z_y**2
        sub_alpha_x = sub_alpha_x + (M_list(1,i)* z_m_z_x / dist_z_m_z)
end do

call MPI_REDUCE(sub_alpha_x,alpha_x,121,MPI_DOUBLE_PRECISION,MPI_SUM,0,MPI_COMM_WORLD,ierror)    

if (myid == 0) then
    write(*,*)alpha_x
end if 

call MPI_FINALIZE(ierror)
stop
END PROGRAM TEST_MPI

当我用mpif90 -g test.f90编译并执行mpirun -np 1 a.out时，我得到以下内容。第39行是我使用MPI_Scatter的地方，我检查了数组大小。我的Scatter功能可能出现什么问题？我想也许这种情况正在发生，因为输入数组zeta_list是2D，但我不完全确定。非常感谢任何帮助！

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

Backtrace for this error:
#0  0x7F1EC6382E08
#1  0x7F1EC6381F90
#2  0x7F1EC5FD24AF
#3  0x7F1EC66BC857
#4  0x401225 in MAIN__ at test9.f90:39

===================================================================================
=   BAD TERMINATION OF ONE OF YOUR APPLICATION PROCESSES
=   PID 9284 RUNNING AT juggernaut
=   EXIT CODE: 139
=   CLEANING UP REMAINING PROCESSES
=   YOU CAN IGNORE THE BELOW CLEANUP MESSAGES
===================================================================================
YOUR APPLICATION TERMINATED WITH THE EXIT STRING: Segmentation fault (signal 11)
This typically refers to a problem with your application.
Please see the FAQ page for debugging suggestions

Fortran MPI代码在使用MPI_Scatter时导致分段错误

0 个答案: