I can confirm this issue is already fixed in the 1.8 nightly. -Nathan
________________________________________ From: users on behalf of Thibaud Kloczko Sent: Friday, February 13, 2015 3:09:03 AM To: Open MPI Users Subject: [OMPI users] Weird behavior using MPI_Lock Hi all, I observed non-consistent behaviors for the lock functions when applied to windows either created using MPI_Win_create or using MPI_Win_allocate/MPI_Win_allocate_shared. I am using openmpi 1.8.4. A sample of the code is joined to this mail. 1- Locking a window created using allocate functions. As explained by Nathan Hjelm, the MPI_MODE_NOCHECK assert had a bug in its path, so I use 0 instead. In my tests, each process use the lock functions as follows, first a lock/unlock for read then a lock/unlock for write, nothing is done between lock/unlock but it does not change the behavior: ----- // Lock for read (local rank) MPI_Win_lock(MPI_LOCK_SHARED, rank, 0, win_shared); MPI_Win_unlock(rank, win_shared); // Lock for write (local rank) MPI_Win_lock(MPI_LOCK_EXCLUSIVE, rank, 0, win_shared); MPI_Win_unlock(rank, win_shared); ----- This works fine. 2- Locking a window created using MPI_Win_create. In this case, the same code ... ----- // Lock for read (local rank) MPI_Win_lock(MPI_LOCK_SHARED, rank, 0, win); MPI_Win_unlock(rank, win); // Lock for write (local rank) MPI_Win_lock(MPI_LOCK_EXCLUSIVE, rank, 0, win); MPI_Win_unlock(rank, win); ----- ... freezes when entering the lock for write (it happens for all processes) Further tests show that it works fine when: - the MPI_MODE_NOCHECK assert is used - the locks are applied to non-local rank - the exclusive lock is done before the shared lock In this last case, if I call a third lock with MPI_LOCK_EXCLUSIVE option, it works also. Maybe, I misunderstand something :-/ ! Thanks for your help :-) ! Cheers, Thibaud. ------------------------------------------------- Ingénieur d'Expérimentation et de Développement Inria CRISAM 2004, route des lucioles 06902 Sophia Antipolis FRANCE +33 4 92 38 50 03
