This is a known issue when using osc/pt2pt. The only way to get progress is to enable (it is not on by default) it at the network level (btl). How this is done depends on the underlying transport.
-Nathan > On Nov 1, 2017, at 9:49 PM, Joseph Schuchart <schuch...@hlrs.de> wrote: > > All, > > I came across what I consider another issue regarding progress in Open MPI: > consider one process (P1) polling locally on a regular window (W1) for a > local value to change (using MPI_Win_lock+MPI_Get+MPI_Win_unlock) while a > second process (P2) tries to read from a memory location in a dynamic window > (W2) on process P1 (using MPI_Rget+MPI_Wait, other combinations affected as > well). P2 will later update the memory location waited on by P1. However, the > read on the dynamic window stalls as the (local) read on W1 on P1 does not > trigger progress on the dynamic window W2, causing the application to > deadlock. > > It is my understanding that process P1 should guarantee progress on any > communication it is involved in, irregardless of the window or window type, > and thus the communication should succeed. Is this assumption correct? Or is > P1 required to access W2 as well to ensure progress? I can trigger progress > on W2 on P1 by adding a call to MPI_Iprobe but that seems like a hack to me. > Also, if both W1 and W2 are regular (allocated) windows the communication > succeeds. > > I am attaching a small reproducer, tested with Open MPI release 3.0.0 on a > single GNU/Linux node (Linux Mint 18.2, gcc 5.4.1, Linux 4.10.0-38-generic). > > Many thanks in advance! > > Joseph > -- > Dipl.-Inf. Joseph Schuchart > High Performance Computing Center Stuttgart (HLRS) > Nobelstr. 19 > D-70569 Stuttgart > > Tel.: +49(0)711-68565890 > Fax: +49(0)711-6856832 > E-Mail: schuch...@hlrs.de > <ompi_dynamicwin_hang.c>_______________________________________________ > users mailing list > users@lists.open-mpi.org > https://lists.open-mpi.org/mailman/listinfo/users _______________________________________________ users mailing list users@lists.open-mpi.org https://lists.open-mpi.org/mailman/listinfo/users
