Short update: The polled file descriptor is related to a socket, which I identified to be the local tcp btl connection ... On a Lustre file system the problem does not show up.
Best Christoph ----- Mensaje original ----- De: "niethammer" <nietham...@hlrs.de> Para: "Open MPI Users" <users@lists.open-mpi.org> Enviados: Sábado, 30 de Marzo 2019 10:25:49 Asunto: [OMPI users] Using strace with Open MPI on Cray Hello, I was trying to investigate some processes with strace under Open MPI. However I have some issues when MPI I/O functionality is included writing data to a NFS file system. mpirun -np 2 strace -f ./hello-world mpi-io does not return and strace is stuck reporting infinite "poll" calls. However, the program works fine without strace. I tried with Open MPI 3.x and 4.0.1 switching between ompi and romio on different operating systems (CentOS 7.6, SLES 12). I'd appreciate any hints which help me to understand what is going on. Best Christoph -- Christoph Niethammer High Performance Computing Center Stuttgart (HLRS) Nobelstrasse 19 70569 Stuttgart Tel: ++49(0)711-685-87203 email: nietham...@hlrs.de http://www.hlrs.de/people/niethammer _______________________________________________ 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
