atomic_notif..._unique_prio(9)

💅 atomic_notif..._unique_prio(9) — like, the Kernel API Manual page, bestie 🎀

okay so this is a page from the Kernel API Manual (atomic_notif..._unique_prio(9), yes the name is a whole mouthful, iykyk) and it's genuinely iconic once you get past the abbreviation situation ✨

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🌸 NAME 🌸

atomic_notifier_chain_register_unique_prio — Add notifier to an atomic notifier chain 🦋 that's it, that's the whole vibe.

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✨ SYNOPSIS ✨

int atomic_notifier_chain_register_unique_prio (struct
       atomic_notifier_head *nh , struct notifier_block *n );

literally just copy that exactly, no cap, do not retype it from memory 💀

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🫶 ARGUMENTS 🫶

• nh — Pointer to head of the atomic notifier chain 👑 this is the main character, the head of the whole chain.
• n — New entry in notifier chain 💖 the fresh new member you're adding to the group chat, basically.

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💅 DESCRIPTION 💅

So what this does: it adds a notifier to an atomic notifier chain — but only if there is no other notifier registered using the same priority 🙈 like, the priority slot is taken? then nope, nobody's squeezing in there. it's giving exclusive guest list, periodt.

And the returns, bestie, write these down:

• 0 on success ✅ slay
• -EEXIST or -EBUSY on error 😭 so if you see either of those, something already claimed that priority or things are busy — either way, not your moment.

fr fr the "unique prio" in the name is the entire plot twist — same priority = rejected 🎀

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🌈 SEE ALSO 🌈

Kernel file ./kernel/notifier.c — home of the source of truth 🧚, plus this whole friend group of notifier functions:

• notifier_call_chain(9)
• notifier_call_chain_robust(9)
• atomic_notifier_chain_register(9)
• atomic_notifier_chain_unregister(9)
• atomic_notifier_call_chain(9)
• atomic_notifier_call_chain_is_empty(9)
• blocking_notifier_chain_register(9)
• blocking_notifier_chain_register_unique_prio(9)
• blocking_notifier_chain_unregister(9)
• blocking_notifier_call_chain(9)
• raw_notifier_chain_register(9)
• raw_notifier_chain_unregister(9)
• raw_notifier_call_chain(9)
• srcu_notifier_chain_register(9)
• srcu_notifier_chain_unregister(9)
• srcu_notifier_call_chain(9)
• srcu_init_notifier_head(9)

the way that's a whole extended universe of notifier functions 😭 go read them, they're all linked, iykyk 💜

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okay that's the page!! 🍓 this came out of ./kernel, October 2026, and it's filed under atomic_notif..._unique_prio(9) — so like, screenshot it, memorize it, and go register some unique priorities responsibly 🌟 mwah 💋