MU kernel module / M4 core communication

[dav1]

Ran across this patch + demo that exposes four MU's in linux (/dev/mu1) that opens a communication bridge to the M4 core (in the example, running Zephyr)

imx-mu - Unnamed repository; edit this file 'description' to name the repository. 

Anyone here with expertise around the MessageUnit and performance?

would like to understand what would be a reasonable max throughput to/from the A53 and the M4 or vice versa.

[b36401]

Usually MU is not used to send data directly, but just the notification.
In our current Linux BSP, the MU is used for RPMSG.
The data exchange happens in the shared DDR memory which is reseved for RPMSG
and MU is used to send notice from one processor to another about when to access the memory and get the data.
Therefore it's hard to evaluated the performance of MU alone since it's just a messenger.