[petsc-users] MPI Derived Data Type and Non Blocking MPI Send/Recieve

[Zhenglun (Alan) Wei]

Dear All,
      I hope you're having a nice day.
      I met a memory problem for MPI data communication. I guess here is 
a good place to ask this question since you guys are experts and may 
experienced the same problem before.
      I used the MPI derived data type (MPI_Type_contiguous, 
MPI_Type_vector and MPI_Type_indexed) to communicate data for a 
simulation of 3D problem. The communication is fine, as I checked every 
single data it sent and received. However, the problem is that the 
memory keeps increasing while communication. Therefore, I tested each of 
these three types. MPI_Type_contiguous does not have any problem; while 
MPI_Type_vector and MPI_Type_indexed have problem of memory 
accumulation. I tried to use MPI_Type_free, but it does not help. Have 
anyone experienced this problem before?
      Would this be related to the non-blocking MPI communication 
(MPI_Isend and MPI_Irecv). I have to use this non-blocking communication 
since the blocking communication is extremely slow when it has a lot of 
data involved in the communication.
      Is there any alternative way in PETSc that could do the similar 
work of MPI derived types?

thanks,
Alan