fix for tf-directml

Author: iperov

core/leras/device.py

@@ -161,6 +161,7 @@ def initialize_main_env():
         if 'CUDA_VISIBLE_DEVICES' in os.environ.keys():
             os.environ.pop('CUDA_VISIBLE_DEVICES')
 
+        os.environ['TF_DIRECTML_KERNEL_CACHE_SIZE'] = '2500'
         os.environ['CUDA_​CACHE_​MAXSIZE'] = '2147483647'
         os.environ['TF_MIN_GPU_MULTIPROCESSOR_COUNT'] = '2'
         os.environ['TF_CPP_MIN_LOG_LEVEL'] = '3' # tf log errors only