atomic_dec_and_lock(9)

💅 atomic_dec_and_lock (Kernel API Manual, section 9)

okay bestie, gather round, because this little function is genuinely iconic and also lowkey doing the most important job in the whole kernel 🎀

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✨ NAME ✨

atomic_dec_and_lock — lock on reaching reference count zero 🔥

like, that's it. that's the whole vibe. it counts down and then grabs the lock the moment things hit zero. no cap.

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🌸 SYNOPSIS 🌸

int atomic_dec_and_lock (atomic_t *atomic , spinlock_t *lock );

(no fr, copy it exactly like that, spaces and all, i don't make the rules 💅)

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🦋 ARGUMENTS 🦋

• atomic — the atomic counter. she's the one getting decremented, main character energy honestly 👑
• lock — the spinlock in question. the one that might get locked, depending on how the countdown goes 🎀

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💖 DESCRIPTION 💖

okay so here's the tea ☕

atomic_dec_and_lock decrements atomic by 1. that's the easy part.

if the result is 0, it returns true and locks lock. like — the moment the count hits zero, she snatches that spinlock. slay 💅✨

it returns false for all other cases. that's it, that's the whole story. no lock, no drama, just a polite false and she moves on 🙈

the way that this is literally the reference-count-hits-zero-and-we-lock pattern in one tidy call… obsessed 🫶

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🌈 SEE ALSO 🌈

• Kernel file ./include/linux/spinlock.h
• spin_is_locked(9)

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and that's the page, bestie! 🦋 this little beauty lives in ./include/linux and the manual's dated October 2026 — so go forth, decrement responsibly, and may your reference counts always land exactly on zero at the right moment 💜⭐🧚