Closed adrianjhpc closed 3 years ago
Hi @adrianjhpc,
Thank you for the question. This is most likely due to the fact that the latest IMB uses MPI_Alloc_mem / MPI_Free_mem instead of system's malloc / free, and perhaps the SGI MPT library has some features in the MPI_Alloc_mem / MPI_Free_mem implementation that lead to the difference.
I have a performance regression for some of the benchmarks between commits c3ef058515b0f1c4d1d26d031243cade7f174bf1 and ebb564671ce52fc208b591f291714798daa35447.
When running benchmarks between two processes on the same node but on different sockets, like this:
mpiexec_mpt -ppn 2 -n 2 omplace -nt 32 ./IMB-MPI1 biband -npmin 2
I get this performance for the old source code:
And this performance for the newer version of IMB:
I'm using the same compilers between both source codes and the network setup isn't changed. Is this expected with the latest IMB?
thanks