Parallella Community

I'm not sure why you have errors. I believe the threaded MPI COPRTHR beta download should be used rather than the COPRTHR source on github.

The kernel already has e_dma_copy in it for off-chip DMAs (bringing data in and writing out results). The on-chip MPI_Sendrecv_replace routine in the n-body code uses the DMA engine on the back end, although that's an implementation detail the application developer doesn't need to know. Regardless of the copy method, the n-body algorithm is not communication bound for large problems so that even if a more efficient copy method were written, it would not increase performance significantly (less than 5%).

I see you have some OpenMPI stuff installed. OpenMPI is different than COPRTHR threaded MPI. OpenMPI is strictly for the ARM host cores, not the Epiphany cores.

Thanks jar. That's actually very frustrating. I spent hours trying to figure out how to get the COPRTHR MPI interface and the best i could find was the README.md from the para-para example. I also downloaded a tiny compressed file from browdeer that included the coprthr_mpi.h file but that seemed too small to be anything of substance. Clearly not the good stuff.

Would you be so kind as to post a link to the coprthr beta version that includes the mpi extensions. I'll get rid of openmpi and that might get the e_dma_copy and mutex_lock problems sorted as well.

nick

Hi JAR,

Thanks for that. I followed the log file through and everything was going fine until there was a reference to /opt/adapteva/esdk/tools/e-gnu/epiphany-elf/sys-include. I don't have such a directory. I've got /opt/adapteva/esdk/tools/e-gnu/epiphany-elf/include which has the e_mutex.h and e_dma.h in it.

When I created a soft link on ...-elf/include to give myself a ...elf/sys-include directory everything was happy.

I'm happy with this work around but is there a setting somewhere that causes the script to use ...elf/sys-include rather than ...elf/include?

nick

It's probably set in the configure process while building the COPRTHR SDK.

Thanks. I'll live with it for now. Hopefully version 2 will have it fixed.

nick