Re: [PATCH] sched_ext:SCX is preemptible by the Fair scheduler

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The autogenerated header enum_defs.autogen.h was not updated to include HAVE_SCX_CPU_PREEMPT_FAIR.
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commit 6eebc3231d63fa92ff2758fc84fe12b421fbde6c
Author: Cui Jian <cjian720@163.com>

sched_ext:SCX is preemptible by the Fair scheduler

This commit adds a new SCX_CPU_PREEMPT_FAIR preempt reason for the sched_ext
subsystem. It updates the internal enum and preempt reason mapping to make it
easier to observe when a task is preempted by the Fair scheduler.

[ ... ]

> diff --git a/kernel/sched/ext_internal.h b/kernel/sched/ext_internal.h
> --- a/kernel/sched/ext_internal.h
> +++ b/kernel/sched/ext_internal.h
> @@ -241,6 +241,8 @@ enum scx_cpu_preempt_reason {
>  	SCX_CPU_PREEMPT_DL,
>  	/* next task is being scheduled by &sched_class_stop */
>  	SCX_CPU_PREEMPT_STOP,
> +	/* next task is being scheduled by &sched_class_fair*/
> +	SCX_CPU_PREEMPT_FAIR,

[Severity: Medium]
Should tools/sched_ext/include/scx/enum_defs.autogen.h also be updated in
this patch to include HAVE_SCX_CPU_PREEMPT_FAIR?

Without adding this to the autogenerated header, external BPF schedulers
cannot use #ifdef HAVE_SCX_CPU_PREEMPT_FAIR to safely compile and support
both old and new kernels.

>  	/* unknown reason for SCX being preempted */
>  	SCX_CPU_PREEMPT_UNKNOWN,
>  };

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Sashiko AI review · https://sashiko.dev/#/patchset/20260612152304.94821-1-cjian720@163.com?part=1