Created by: pzelazko-intel

Problem: When we set environment variable FLAGS_use_mkldnn to true, there is an exception thrown, telling that there is no MKLDNN kernel for e.g. sigmoid activation OP. It happens this way, because all activation functions have one GetExpectedKernel method and only few have MKLDNN implementation.

Workaround: If no MKLDNN kernel can be found, try again with plain CPU one.

Can you see better solutions for this problem?