Re: [PATCH 1/2] sched_ext: Initialize idle masks before ops.init()

Kuba Piecuch <[email protected]> Fri, 31 Jul 2026 10:47:30 +0000
Newsgroups dev.linux.lists.sched-ext,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
Hi Andrea,

On Fri Jul 31, 2026 at 8:59 AM UTC, Andrea Righi wrote:
> @@ -59,11 +59,13 @@ static inline void init_sched_ext_class(void) {}
>  #endif	/* CONFIG_SCHED_CLASS_EXT */
>  
>  #ifdef CONFIG_SCHED_CLASS_EXT
> +DECLARE_STATIC_KEY_FALSE(scx_idle_tracking_enabled);
> +

I was originally thinking about reusing scx_builtin_idle_enabled here,
apologies if I wasn't clear enough.

My reasoning is: If the user is doing their own idle CPU tracking,
in which case scx_builtin_idle_enable will be disabled, what's the point
of SCX tracking idle CPUs?

Do you see a scenario where using one static branch is problematic?

Thanks,
Kuba