How to Allow tensorflow to utilize all of my GPU memory ?, my GPU utilizes only 9083 MB out of 16GB of my GPU

I have a GPU setup of 16GB of tesla V100 , 4 GPU is available like that. but only 1 GPU is being utilized that too only 9083 MB out of 16GB. enter image description here

if i config my code to os.environ['CUDA_VISIBLE_DEVICES'] = '0,1,2,3' to utilize all 4 GPU only 1 GPU will be utilized to 9083MB and other GPU utilizes 453 MB

I am following this github for tensorflow object detection

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