Question

这让我疯了 - 我不知道我做错了什么。我一遍又一遍地看着API。我知道MPI_Cart_create的签名：

int MPI_Cart_create(MPI_Comm comm_old, int ndims, int *dims, int *periods, 
               int reorder, MPI_Comm *comm_cart)

这是我的代码：

MPI_Init (&argc, &argv);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
MPI_Comm_size(MPI_COMM_WORLD, &processCount);
MPI_Comm cart_com, old_com;
int ndims = 2;
int reorder = 0;
int dim_size[2], periods[2];
dim_size[0] = processCount; 
dim_size[1] = processCount;
periods[0] = 1;
periods[1] = 1;
old_com = MPI_COMM_WORLD;
MPI_Cart_create(MPI_COMM_WORLD, ndims, dim_size, periods, reorder, &cart_com);

我收到错误：

[ubuntu:7975] *** An error occurred in MPI_Cart_create
[ubuntu:7975] *** on communicator MPI_COMM_WORLD
[ubuntu:7975] *** MPI_ERR_ARG: invalid argument of some other kind
[ubuntu:7975] *** MPI_ERRORS_ARE_FATAL (your MPI job will now abort)

即使只是一点点暗示也会很好...... 谢谢

Answer 1

您有processCount个进程，但是您正在尝试创建一个大小为processCount x processCount的通信器（总共产生processCount ^ 2个进程）。而且，正如documentation会告诉你的那样：

如果指定的网格大于组大小，则调用是错误的。

试试这个：

dim_size[0] = processCount; 
dim_size[1] = 1;

Answer 2

int * dims和int * period是指针。你正在发送阵列。

MPI_Cart_create(MPI_COMM_WORLD, ndims, dim_size, periods, reorder, &cart_com);

尝试发送指针。

MPI_Cart_create(MPI_COMM_WORLD, ndims, &dim_size, &periods, reorder, &cart_com);

MPI_Cart_create给出MPI_ERR_ARG

2 个答案: