Re: [PATCH v2 1/2] sched/doc: add a preemption model overview
From: Jonathan Corbet
Date: Sat Sep 26 2026 - 11:45:37 EST
Quchaosheng <quchaosheng000406@xxxxxxx> writes:
> The scheduler documentation describes the individual scheduling classes
> and various tuning knobs, but there is nothing that describes the
> preemption models themselves. The only place where they are documented
> is the kernel-parameters entry for "preempt=", which explains the boot
> time parameter but not the models it selects.
>
> Add Documentation/scheduler/sched-preemption.rst, covering the four
> models, how a scheduling request is honoured under each of them, and
> which of them can be selected at runtime.
>
> The overview follows the scheduling request: a wakeup makes a task
> runnable, the scheduler decides what has to leave the CPU and sets
> TIF_NEED_RESCHED or TIF_NEED_RESCHED_LAZY on it, and the preemption model
> decides where that request is honoured.
>
> Assisted-by: LLM
> Suggested-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> Signed-off-by: Quchaosheng <quchaosheng000406@xxxxxxx>
> ---
I have applied these two patches. However: can you please send a
followup with a suitable SPDX line for your new sched-preemption.rst
file?
Thanks,
jon