[OMPI users] How to know if SM collective is being used?

Hi, I see in *mca_coll_sm_comm_query()* of *ompi/mca/coll/sm/coll_sm_module.c* that al allreduce and bcast have shared memory implementations. Is there a way to know if this implementation is being used when running my program that calls these collectives? Thank you, Saliya -- Saliya Ekanayake

Re: [OMPI users] MPI Spawn functionality and core allocation questions

You may want to look at the —oversubscribe mpirun option. If you want more control, you can consider making a rankfile where you place explicitly processes. Aurélien > Le 29 juin 2016 à 11:50, Jason Maldonis a écrit : > > Hi everyone, > > I am having trouble developing a complicated paral

[OMPI users] MPI Spawn functionality and core allocation questions

Hi everyone, I am having trouble developing a complicated parallelization algorithm with MPI and I'm hoping for some tips (I am using OpenMPI 1.10.2). I posted the latest problem I ran into on Stack Overflow and got a response from someone saying they don't think it is possible to do the spawn all

Re: [OMPI users] OpenMP explicit thread affinity with MPI

The OMP_PROC_BIND=CLOSE approach works, except it will bind threads to 1 hardware thread only (when HT is present). For example, doing the following to run 2 procs per node each with 4 threads, the thread affinity info (queried through sched_getaffinity()) comes out as below. mpirun -np 2 --map-by

Re: [OMPI users] OpenMP explicit thread affinity with MPI

Thank you, Ralph and Gilles. I didn't know about the OMPI_COMM_WORLD_LOCAL_RANK variable. Essentially, this means I should be able to wrap my application call in a shell script and have mpirun invoke that. Then within the script I can query this variable and set correct OMP env variable, correct?