atomic64_dec...ess_positive(9)

📦 version 7.3.1, in nixpkgs unstable

💅 atomic64_dec_unless_positive(9) — the Kernel API Manual, but make it make sense

okay so bestie, welcome to the Kernel API Manual 🎀 this is page atomic64_dec...ess_positive(9) (yes the header truncates it, the real name is atomic64_dec_unless_positive, we're slaying regardless) and it's literally the "decrement but only if you're being nice about it" function. let's go 🌸

✨ NAME ✨

atomic64_dec_unless_positive — atomic decrement unless positive, with full ordering. that's the whole vibe. 🦋

🌈 SYNOPSIS 🌈

bool atomic64_dec_unless_positive (atomic64_t *v );

💖 ARGUMENTS 💖

  • v — pointer to atomic64_t. that's it. that's the argument. she's a pointer to an atomic64_t and she knows it 👑

🫶 DESCRIPTION 🫶

okay so here's the tea ☕ if (v <= 0), it atomically updates v to (v - 1) with full ordering. like, atomic atomic. no one's sneaking in between. 🔥

otherwise — meaning if it's not the case that v <= 0 — then v is not modified, and relaxed ordering is provided. so she looked at your number, went "nope, not touching that", and gave you relaxed ordering instead. respectful. 😌

⚠️ not me telling you this is unsafe in noinstr code — it literally is! use raw_atomic64_dec_unless_positive there instead. do not come for me if you ignore this, i warned you 🙈

⭐ RETURN ⭐

  • true — if v was updated 💖
  • false — otherwise 🥲

that's it. boolean. clean. iconic.

🦋 SEE ALSO 🦋

so the kernel file is ./include/linux/atomic/atomic-instrumented.h and bestie. bestie. the see-also list is long. like genuinely enormous. but i'm not skipping a single one because every single function deserves her moment ✨ here we go:

🌸 the atomic_* girlies

💜 the atomic64_* squad (yes, our main character lives here)

🧚 the atomic_long_* besties

okay that's genuinely everyone, i counted, we're done, nobody got left out 💅

and that's the page bestie!! 🎀 her home is ./include/linux/atomic, she's dated October 2026, and the header/footer both call her atomic64_dec...ess_positive(9) because even manpage headers get truncated. go forth and decrement responsibly — only when v <= 0, and never in noinstr code. mwah 🫶✨

📦 where this page comes from