atomic_dec_return(9)

📦 version 7.3.1, in nixpkgs unstable

🎀 atomic_dec_return(9) 🎀

okay bestie, welcome to the atomic_dec_return(9) page — it lives in the Kernel API Manual and it's lowkey one of the most useful little functions in the atomic family. it's giving "shrink the counter, but make it thread-safe" energy. let's get into it 💅

✨ NAME ✨

atomic_dec_return — atomic decrement with full ordering. that's it, that's the whole vibe: minus one, done atomically, and everything around it properly ordered. no cap 🔥

🌸 SYNOPSIS 🌸

int atomic_dec_return (atomic_t *v );

(yes, there's a space before that closing paren. that's just how the man page prints it, don't @ me 🫶)

🦋 ARGUMENTS 🦋

  • v — pointer to atomic_t. you're handing over a pointer to the little atomic counter, and it's gonna get decremented. main character energy for v, honestly 👑

💖 DESCRIPTION 💖

Atomically updates v to (v - 1) with full ordering.

so like. the decrement happens all at once, nobody can catch it mid-subtraction, and the full ordering means the memory barriers are doing their thing around it. iconic behavior ✨

⚠️ Unsafe to use in noinstr code — use raw_atomic_dec_return there instead. not me warning you twice: do NOT use this one in noinstr code, bestie. it's literally unsafe there. use raw_atomic_dec_return and everyone stays happy 💀

🌈 RETURN 🌈

The updated value of v — i.e. the value after the decrement. so you get the fresh new number back, not the old one. obsessed 🍓

👑 SEE ALSO 👑

buckle up, this list is a whole mood board of atomic operations. every single one of these is a real page, fr fr 🧚

iykyk, that's the whole atomic cinematic universe right there 😭🔥

okayyy so that's the page!! this gem came out of ./include/linux/atomic and it's dated October 2026 — so it's fresh, it's documented, and it's decrementing with full ordering. go forth and atomic_dec_return responsibly, bestie 🫶💖✨

📦 where this page comes from