fix explanations for PCIERX/PCIETX (#1043)
Summary:
The previous explanations of `dcgm_fields.DCGM_FI_PROF_PCIE_TX_BYTES` and `dcgm_fields.DCGM_FI_PROF_PCIE_RX_BYTES` are wrong. Those two metrics refer CPU-GPU interactive memory traffic.
This PR also update the example code and add a readme file for TorchBench model analyzer.
Pull Request resolved: https://github.com/pytorch/benchmark/pull/1043
Reviewed By: xuzhao9
Differential Revision: D37966542
Pulled By: FindHao
fbshipit-source-id: ec219dadc6bc359238cd5c81050f4c6036f1f69d
