We are running Linux on core 0 and FreeRTOS on core 1.

We have a high priority FreeRTOS task that needs to run with a 100 µs interval. When the system is up and running, no cross core communication takes place.

If I login with a ssh session into the Linux core, this will cause a performance hit on the FreeRTOS core and cause the high priority task to miss its deadline.

I can see that even an ISR on FreeRTOS core that normally takes 4.5 µs to execute, temporarily will take 7.6 µs to execute just when I open a ssh session into Linux core. So everything will temporarily run slower on FreeRTOS core before it goes back to normal.

What can cause this, and how can we prevent activity on Linux core affecting performance on FreeRTOS core?

-Gaute Nilsson

We are running Linux on core 0 and FreeRTOS on core 1.

We have a high priority FreeRTOS task that needs to run with a 100 µs interval. When the system is up and running, no cross core communication takes place.

If I login with a ssh session into the Linux core, this will cause a performance hit on the FreeRTOS core and cause the high priority task to miss its deadline.

I can see that even an ISR on FreeRTOS core that normally takes 4.5 µs to execute, temporarily will take 7.6 µs to execute just when I open a ssh session into Linux core. So everything will temporarily run slower on FreeRTOS core before it goes back to normal.

What can cause this, and how can we prevent activity on Linux core affecting performance on FreeRTOS core?

-Gaute Nilsson