I'm observing a strange behavior and would like to know if it is Intel Xeon Phi related or not.
I observed, that the memory transfer times from host to the mic are extremely high. I have tracked the overhead for the memory transfers down to the memory allocation time on the accelerator which scales linear with the amount of requested memory (huge pages are used). The memory allocations take about twice the time for allocations form 2MB to 48MB. After this point the allocations overhead goes up to almost 7x.
I'm observing this behavior with LEO, OpenMP 4.0 and OpenCL. Is this a configuration problem of my MICs or is this somehow related to the OS running on the MIC? Is the overhead of allocating pages on the MIC realy that high?
If this is only my problem, how can I conquer it? Are there some environment variables to accelerate the allocation on the MIC?
Thanks in advance!