MPI相关我用MPI中的MPI_Isend发送很多数据，然后再接受发现只有256个数据收到了，请问有人知道原因吗？

本文链接：https://blog.youkuaiyun.com/guibihujvgbyui/article/details/122078437

在MPI程序中，使用MPI_Isend发送多个数据到邻居进程，但只接收到256个数据。代码展示了如何遍历接口并发送数据，然后通过MPI_Irecv接收并检查停止标志。问题可能是由于缓冲区大小限制或通信同步问题导致。

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MPI问题

for(interfaceMCiter = interfaceMCs.begin () ; interfaceMCiter != interfaceMCs.end () ; interfaceMCiter++)
{
MathCover* nd = (*interfaceMCiter) ;

        double *coord = nd->getCentrixCoord ();
       sbuf[0] =static_cast<double> (nd->_boundary .size ());
       sbuf[1] = coord[0];
       sbuf[2] = coord[1];
       sbuf[3] = coord[2];
       delete[] coord;

       for(i=0;i<_numOfNeighborSubdm ;i++)
       {
           p2 = (*_neigborsubdms)(i);

           ierr = MPI_Isend(sbuf, nn, MPI_DOUBLE, p2, _myRank ,MPI_COMM_WORLD, &reqs);
       }

   }

   //terminate signal
   sbuf[0] =-11;
   for(i=0;i<_numOfNeighborSubdm ;i++)
   {
       p2 = (*_neigborsubdms)(i);

       ierr = MPI_Isend(sbuf, nn, MPI_DOUBLE, p2, _myRank ,MPI_COMM_WORLD, &reqs);
       printf("%d send to %d\n",_myRank,p2);

   }

   int stop=0;
   do {
       ierr = MPI_Irecv(rbuf, nn, MPI_DOUBLE, MPI_ANY_SOURCE, MPI_ANY_TAG,MPI_COMM_WORLD, &reqr);
       ierr=MPI_Wait(&reqr,&status);
       nVtxLoop = static_cast<int> (rbuf[0]) ;
       if(nVtxLoop==-11)
       {

           stop++;
       }

       MathCover* nd=0;
       for(interfaceMCiter = interfaceMCs.begin () ; interfaceMCiter != interfaceMCs.end () ; interfaceMCiter++)
       {
           if(nVtxLoop == (*interfaceMCiter)->_boundary.size ())
           {
               double * coord = (*interfaceMCiter)->getCentrixCoord ();
               if( fabs(rbuf[1] - coord[0])<1.0e-5 &&
                   fabs(rbuf[2] - coord[1])<1.0e-5 &&
                   fabs(rbuf[3] - coord[2])<1.0e-5 )
               {
                   nd = (*interfaceMCiter);
                   delete[] coord ;
                   break;
               }
               delete[] coord ;
           }

       }
       if(nd)
       {
           nd->set_parallelType (INTERFACE_Node);
       }