NVML-how can i get the total physical memory occupied by the process, including the page fault triggered physical memory occupation

How can i get the total physical memory occupied by the process when i use the unified virtual memory mechanism, including the page fault triggered physical memory occupation?

When i use nvidia-smi which derived from nvml, there are some gap between the process occupy memory and the total allocated memory. I think the gap is because of the unified virtual memory is not counted when i count the process occupy gpu memory.

For example, total occupy memory is 10979MiB, but the sum of memory occupy by all processes is 4461MiB.

P.S.: i use Unified Virtual Memory in the processes which marked as python. Even when i use nvmlDeviceGetComputeRunningProcesses, i saw the memory used by the process is always 707MB, it seems that the physical memory occupy by the page fault mechanism is not included.

Mon Jun 1 12:03:21 2020
±----------------------------------------------------------------------------+
| NVIDIA-SMI 410.129 Driver Version: 410.129 CUDA Version: 10.0 |
|-------------------------------±---------------------±---------------------+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute M. |
|===============================+======================+======================|
| 0 GeForce RTX 208… On | 00000000:65:00.0 Off | N/A |
| 34% 71C P2 150W / 250W | 10979MiB / 10986MiB | 100% Default |
±------------------------------±---------------------±---------------------+

±----------------------------------------------------------------------------+
| Processes: GPU Memory |
| GPU PID Type Process name Usage |
|=============================================================================|
| 0 2173 G /usr/bin/gnome-shell 59MiB |
| 0 3182 G /usr/lib/xorg/Xorg 11MiB |
| 0 3338 G /usr/bin/gnome-shell 61MiB |
| 0 28881 C /opt/conda/envs/CI/bin/python 1305MiB |
| 0 29381 C …y/install_package/jdk1.8.0_231/bin/java 197MiB |
| 0 31078 C python 707MiB |
| 0 31229 C python 707MiB |
| 0 32093 C python 707MiB |
| 0 32435 C python 707MiB |