Kernel Configuration
The RISC-V architecture has been supported by the Linux kernel since version 4.15, dating back to 2017. StarFive VisionFive 2 BSP now uses the 5.15.0 version of kernel. So the BSP kernel 5.15.0 is chosen to apply RT-Linux patches. Due to RT-Linux not supporting the RISC-V architecture on kernel 5.15, kernel has multiple custom changes that allow PREEMPT_RT to function on RISC-V. These changes are described thoroughly in PREEMPT_RT For RISC-V. This customized kernel codebase was used for all measurements and latency analysis.
The final measurements featured two differently configured kernels. The only difference between the kernels was the preemption setting, but otherwise, the used configurations were the same. In the real-time kernel configuration, the preemption setting was set to the real-time mode. Whereas in the mainline kernel configuration, this same setting was instead set to low-latency desktop.