Gpu memory monitoring (#15436)
Gpu memory monitoring (#15436)

* fix github issue 15267 test=develop

* fix github issue 15267 test=develop

* monitor the GPU usage during runtime

* revert allocator_facade.cc change

* comments update test=develop

luotao1/Paddle,chengduoZH/Paddle,baidu/Paddle,baidu/Paddle,PaddlePaddle/Paddle,PaddlePaddle/Paddle,chengduoZH/Paddle,tensor-tang/Paddle,baidu/Paddle,tensor-tang/Paddle,luotao1/Paddle,PaddlePaddle/Paddle,baidu/Paddle,PaddlePaddle/Paddle,luotao1/Paddle,luotao1/Paddle,luotao1/Paddle,chengduoZH/Paddle,luotao1/Paddle,PaddlePaddle/Paddle,chengduoZH/Paddle,tensor-tang/Paddle,tensor-tang/Paddle,baidu/Paddle,PaddlePaddle/Paddle,PaddlePaddle/Paddle,luotao1/Paddle,tensor-tang/Paddle,chengduoZH/Paddle