Introduce scx_flash (Fair Latency-Aware ScHeduler), a scheduler that
focuses on ensuring fairness among tasks and performance predictability.
This scheduler is introduced as a replacement of the "lowlatency" mode
in scx_bpfland, that has been dropped in commit 78101e4 ("scx_bpfland:
drop lowlatency mode and the priority DSQ").
scx_flash operates based on an EDF (Earliest Deadline First) policy,
where each task is assigned a latency weight. This weight is adjusted
dynamically, influenced by the task's static weight and how often it
releases the CPU before its full assigned time slice is used: tasks that
release the CPU early receive a higher latency weight, granting them
a higher priority over tasks that fully use their time slice.
The combination of dynamic latency weights and EDF scheduling ensures
responsive and stable performance, even in overcommitted systems, making
the scheduler particularly well-suited for latency-sensitive workloads,
such as multimedia or real-time audio processing.
Tested-by: Peter Jung <ptr1337@cachyos.org>
Tested-by: Piotr Gorski <piotrgorski@cachyos.org>
Signed-off-by: Andrea Righi <arighi@nvidia.com>
678b10133d