Does myelin of Tensorrt synchronize the multi-streams?

Description

I try to utilize multi-streams (e.g 4 stream) to overlap the H2D, compute and D2H time.
However, there are gaps between each multi-streams as shown in profile.
It seems that the myelin graph synchronize the streams of the D2H stage or something else,
and thus degrade the pipeline of the multi-streams.
PS: We user Gather op in the graph, dose this op make the difference？

Specifically, there are 4 meylinGraphExecute in different streams, but it seems that the meylinGraphUnload are done in the same stream, which synchronize the 4 streams. As there are not document of myelin, could you please provide some information of the mechanism of the myelinGraphExecute in multi-stream, with Gathrer op. Thanks very much!!!

Environment

TensorRT Version: 8.4.3
NVIDIA GPU: Tesla T4
NVIDIA Driver Version: 460.73.01
CUDA Version: 11.6
CUDNN Version:
Operating System: Ubuntu 20.04
ONNX opset: 13
Python Version (if applicable):
Tensorflow Version (if applicable):
PyTorch Version (if applicable):
Baremetal or Container (if so, version):

Relevant Files

Steps To Reproduce