Linux and interrupt latency (Axel)

Info Box Applies to Axel Ultra Applies to Axel Lite Applies to AXEL ESATTA

Introduction

Generally speaking Linux is not a real-time operating system. As such it can't guarantee that interrupt latency is always smaller than a determined limit.

When developing applications base on embedded platforms, this can cause unacceptable behaviors. For this reason system integrators have to be aware of it and, if necessary, have to implement specific strategies to prevent or limit them.

Numerous solutions exist (see for example AN-XELK-001:_Asymmetric_Multiprocessing_.28AMP.29_on_Axel_.E2.80.93_Linux_.2B_FreeRTOS, BRX-WP001:_Real-timeness,_system_integrity_and_TrustZone®_technology_on_AMP_configuration, https://rt.wiki.kernel.org/index.php/Main_Page). An exhaustive dissertation of these is beyond the scope of this document. Instead