[OMPI users] Large send problem: Error when send buf size =2^28 in a simple code

Dear All, I write a simple test code to use MPI_Allgatherv function. The problem comes when the send buf size becomes relatively big. When Bufsize = 2^28 – 1, run on 4 processors. OK When Bufsize = 2^28, run on 4 processors. Error [btl_tcp_frag.c:209:mca_btl_tcp_frag_recv] mca_btl_tcp_frag_recv:

[OMPI users] MPI_Allgatherv error for relative large data on distributed machine, same machine is ok. Narrow down the prob.

Dear All, I meet a strange problem using MPI_Allgatherv when the send buf size becomes bigger but not that big. The following simple testing code of MPI_Allgatherv runs fine when I use processors on same machine. However, when I use processors on different machine, I see following problems on