Re: [OMPI users] MPI_Win_allocate: Memory alignment

2017-05-17 Thread Joseph Schuchart
Gilles, all, I can confirm that the fix has landed in OpenMPI 2.1.1. Unfortunately, 1.10.7 still provides 4-Byte-aligned memory. Will this be fixed in the 1.x branch at some point? We are selectively enabling the use of shared memory windows when using OpenMPI so it would be interesting to kno

Re: [OMPI users] MPI_Win_allocate: Memory alignment

2017-02-15 Thread Joseph Schuchart
Gilles, Thanks for the quick reply and the immediate fix. I can confirm that allocations from both MPI_Win_allocate_shared and MPI_Win_allocate are now consistently aligned at 8-byte boundaries and the application runs fine now. For the records, allocations from malloc and MPI_Mem_alloc are

Re: [OMPI users] MPI_Win_allocate: Memory alignment

2017-02-14 Thread Gilles Gouaillardet
Joseph, thanks for the report and the test program. the memory allocated by MPI_Win_allocate_shared() is indeed aligned on (4*communicator_size). i could not reproduce such a thing with MPI_Win_allocate(), but will investigate it. i fixed MPI_Win_allocate_shared() in https://github.com

[OMPI users] MPI_Win_allocate: Memory alignment

2017-02-14 Thread Joseph Schuchart
Hi, We have been experiencing strange crashes in our application that mostly works on memory allocated through MPI_Win_allocate and MPI_Win_allocate_shared. We eventually realized that the application crashes if it is compiled with -O3 or -Ofast and run with an odd number of processors on our