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>
* enable bpftrace when using stress tests
update meson/stress test runner to enable
running bpftrace scripts while running
stress tests.
* disable layered stats output on ci
This change adds stress-ng as a load test for schedulers when running in
CI. It will run stress-ng while schedulers are being tested with a
reasonable amount of work. At the end of the run the stress-ng metrics
are collected for later analysis. However, since these results may be
running in a VM they may not be super robust.
