Question about the speed of using PCIE with DMA

Autonomous Machines Jetson & Embedded Systems Jetson AGX Xavier
1

Hi,

I am trying to use the PCIe to communicate two Xavier boards. I thought the maximum speed I can get is around 15.76GB/s with PCIe x8. But I found in NVIDIA doc,

https://docs.nvidia.com/jetson/archives/l4t-archived/l4t-3231/index.html#page/Tegra%2520Linux%2520Driver%2520Package%2520Development%2520Guide%2Fxavier_PCIe_endpoint_mode.html%23

It shows that with DMA, I can only get 150Mbps speed as shown below.

I was wondering whether there is a way to have 15.67GB/s speed with the use of PCIe.

Thanks!

2

We are working on improving speed. Currently, we are able to get around 5 Gbps. Some more performance improvement tasks are in the queue. We can share patches to get 5 Gbps if you are ok with that to start with.

3

Hi,

I’m working with Ruiying.
Could you share the patched to get 5 Gbps?
If you improve more performance, please let us know we can apply more.

Jetson AGX Xavier
tag: tegra-l4t-r32.3.1
kernel version: 4.9.140-tegra

Thank you.

4

Please apply the attached patches
T2T_VETH_PATCH.zip (18.6 KB)

5

Hi Vidyas,

Thank you for your reply.
I’ll try to apply the patches and check.

Thank you.

6

Hi vidyas,

I want to try the patches but I don’t know how to do this.

Please, can you give me the steps for applying these patches?

Thanks

7

Kernel build & flash details are provided at
https://devtalk.nvidia.com/default/topic/1050616/jetson-agx-xavier/the-bandwidth-of-of-virtual-ethernet-over-pcie-between-two-xaviers-is-low/post/5434432/#5434432

Marking comment #4 as the answer.