JacobL wrote:Another thing that might impact real-time performance is that the Pi does not have a vectorized interrupt controller. Compared to other systems with such a controller then IRQ latencies will be higher, which could impact real-time performance, depending on the application. It is only really a problem if you use many different interrupts, and they are inside the critical path of your RT requirement.
This means that all IRQs on the Pi goes to the same handler function (with the exception of FIQ). This handler function would then need to determine which IRQ was triggered by polling status registers. This all takes time, though if only few interrupts are in use, then this time might be minimal. A vectorized controller will be able to resolve this in hardware, reducing the software latency of the interrupt.
Real time only defines that the system must process data for a given input within a specified time period, no one said that the time period had to be instantaneous. If the time period is half an hour, then the pi having a non vectorized interrupt controller really wont make a difference.