This is a single user-defined scheduler used within sched_ext, which is a Linux kernel feature which enables implementing kernel thread schedulers in BPF and dynamically loading them. Read more about sched_ext.
scx_rlfifo is a simple FIFO scheduler runs in user-space, based on the scx_rustland_core framework.
This scheduler is provided as a simple template that can be used as a baseline to test more complex scheduling policies.
Definitely not. Using this scheduler in a production environment is not recommended, unless there are specific requirements that necessitate a basic FIFO scheduling approach. Even then, it's still recommended to use the kernel's SCHED_FIFO real-time class.