DEFINE_SCX_COMPAT_MARKER(9)

💅 DEFINE_SCX_COMPAT_MARKER 💅

ok so bestie, welcome to the Kernel API Manual entry for DEFINE_SCX_COMPAT_MARKER(9) — yes that trailing (9) means kernel API section, we stay fancy here ✨

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🌸 NAME 🌸

DEFINE_SCX_COMPAT_MARKER — define a userspace capability marker, no cap 🫶

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✨ SYNOPSIS ✨

DEFINE_SCX_COMPAT_MARKER (func );

that's it. that's the whole vibe. one argument, one macro, iconic behavior 👑

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🎀 ARGUMENTS 🎀

• func — the marker suffix, like the little name tag at the party 🏷️ the symbol you actually define ends up being scx_compat_marker_func, so yeah, it gets glued onto the end fr fr

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💖 DESCRIPTION 💖

okay so here's the tea 🍓 this macro emits an empty, callerless function — literally nobody calls it, it's giving main character who doesn't need an audience — and that function is retained in the kernel's BTF.

why tho? because its mere presence is part of the kernel↔userspace contract 🤝 userspace probes scx_compat_marker_func (like, via BTF, for example) to detect that this kernel supports the corresponding feature. it's basically a little "yes bestie, we have that" flag hiding in plain sight 💅

and the plumbing details, which are lowkey clever: the leading declaration suppresses the missing-prototype warning (thank u, we hate a nagging compiler 😭), and the trailing declaration consumes the semicolon at the use site — so you can drop it in with a ; and everything's chill 🧚

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🔥 SEE ALSO 🔥

all my mutuals in the same kernel file, ./kernel/sched/ext/internal.h:

• scx_add_event(9)
• __scx_add_event(9)
• struct scx_enable_args(9)
• struct sched_ext_ops(9)
• struct sched_ext_ops_cid(9)
• scx_arena_to_kaddr(9)
• scx_kaddr_to_arena(9)
• scx_root_protected_live(9)
• scx_root_protected(9)
• scx_bypass_dsp_enabled(9)
• scx_ops_sanitize_err(9)
• scx_has_subs(9)
• scx_task_sched(9)
• scx_task_sched_rcu(9)
• scx_task_on_sched(9)
• scx_prog_sched(9)
• scx_parent(9)

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ok that's the whole page bestie, go forth and probe responsibly 🌈

sign-off time 🎀 this one lives in ./kernel/sched/ext and it's dated October 2026 — slay, see u in the next release cycle, mwah 💜