[mpich-discuss] double free error after MPI run finished

[John Bray]

I've got some sample code that I'm using to test our debugger DDT. It
works on openmpi and intelmpi, but with all the MPICH series from
MPICH2 onwards to 3.1rc1, I get an error after MPI_FINALIZE. Our
memory debugging library claims its at

SendqFreePool (dbginit.c:386) trying to free previously freed pointer

with a stacktrrace
auditmpi
  pmpi_finalize__
    PMPI__finalize
      MPIR_Call_finalize_callbacks
        sendqFreePool (dbginit.c)

Run from a raw mpirun command outside DDT

*** glibc detected *** ./auditmpibad_f_debug.exe: double free or
corruption (fasttop): 0x1032a5c8 ***
*** glibc detected *** ./auditmpibad_f_debug.exe: double free or
corruption (fasttop): 0x104da5c8 ***
======= Backtrace: =========
======= Backtrace: =========
/lib/libc.so.6(+0xfe750e4)[0xf78e50e4]
/home/jbray/prog/mpich/mpich-3.1rc1/rhel-6-ppc64_ibm/install/lib/libmpich.so.11(+0x1a8b1c)[0xfec8b1c]
/lib/libc.so.6(+0xfe750e4)[0xf76c50e4]
/home/jbray/prog/mpich/mpich-3.1rc1/rhel-6-ppc64_ibm/install/lib/libmpich.so.11(+0x1a8b1c)[0xfec8b1c]
... and so on

I've configured with

./configure --prefix=$PWD/install --enable-shared --enable-fast=all
--enable-debuginfo

and compile with

mpif90 -o auditmpibad_f_debug.exe auditmpibad.F90 -O0 -g

Its works with the ALLTOALLV only called once.

Is this a bug or a misunderstanding on my part. The code is

program auditmpi

  use mpi, only :       &
    MPI_COMM_WORLD,     &
    MPI_REAL,           &
    MPI_STATUS_SIZE,    &
    MPI_BSEND_OVERHEAD, &
    MPI_SUM,            &
    MPI_UNDEFINED

  implicit none

  integer, parameter :: repeats=2

  integer :: rank, nproc,ierr,rpt
  real    :: input(100000),output(100000)
  integer :: status (MPI_STATUS_SIZE)
  integer :: statuses (MPI_STATUS_SIZE,repeats)
  integer :: request
  logical :: odd
  integer, allocatable :: recvcounts(:),sendcounts(:),displs(:)

  call MPI_INIT(ierr)

  call MPI_COMM_RANK(MPI_COMM_WORLD, rank, ierr)
  call MPI_COMM_SIZE(MPI_COMM_WORLD, nproc, ierr)

  if (rank == 0) print *,"auditmpi start"

  if (mod(rank,2) == 0) then
    odd=.false.
  else
    odd=.true.
  end if

  allocate (recvcounts(nproc))
  recvcounts(:) = 100000/nproc

  allocate (sendcounts(nproc))
  sendcounts(:) = 100000/nproc

  allocate (displs(nproc))
  displs(:)=0 ! don't care if we overlap

  if ( .NOT. odd) then
    call MPI_IRECV(output,size(output),MPI_REAL,rank+1,1,MPI_COMM_WORLD,
request, ierr)
  end if
  call MPI_BARRIER(MPI_COMM_WORLD,ierr)
  if (odd) then
    call MPI_IRSEND(input,size(input),MPI_REAL,rank-1,1,MPI_COMM_WORLD,request,ierr)
  end if
  call MPI_WAIT(request,status,ierr)

  do rpt=1,2
    call MPI_ALLTOALLV(input,sendcounts,displs,MPI_REAL,output,recvcounts,displs,MPI_REAL,MPI_COMM_WORLD,ierr)
  end do

  call MPI_BARRIER(MPI_COMM_WORLD,ierr)

  deallocate (recvcounts)
  deallocate (sendcounts)
  deallocate (displs)

  if (rank == 0) print *,"auditmpi finished"

  call MPI_FINALIZE(ierr)

end program auditmpi

John