raw_atomic64_add_negative(9)

📦 version 7.3.1, in nixpkgs unstable

💅 raw_atomic64_add_negative ✨

so this is a page from the Kernel API Manual and bestie, it's lowkey iconic — it's giving "one job, full ordering, no notes" 🎀

🌸 NAME 🌸

raw_atomic64_add_negative — the atomic add that ALSO tells you if the result went negative, and it does it with full ordering 💖

🦋 SYNOPSIS 🦋

bool raw_atomic64_add_negative (s64 i , atomic64_t *v );

🎀 ARGUMENTS 🎀

  • i — an s64, aka the value you're adding in. that's it, that's the number 💫
  • v — a pointer to an atomic64_t. this is the thing getting updated, she's the main character here 👑

💜 DESCRIPTION 💜

okay so here's the tea: this bad boy atomically updates v to (v + i), and it does it with full ordering. like, all the ordering. not relaxed, not acquire, not release — full. slay ✨

and ngl, the cute part: it's safe to use in noinstr code 🫶 literally built different for that context.

but bestie, listen — prefer atomic64_add_negative elsewhere. this raw version is the specialist; she's here for the noinstr moments. iykyk 💅

🔥 RETURN 🔥

returns true if the resulting value of v is negative 😭 and false otherwise 🌈

👑 SEE ALSO 👑

first up, the actual kernel file this lives in, no cap:

  • Kernel file ./include/linux/atomic/atomic-arch-fallback.h

and now, the whole entire friend group 🫶 (yes, all of them, i'm not skipping a single one):

and that's the whole page bestie, we ate and left zero crumbs 🍓

source file: ./include/linux/atomic — dated: October 2026 — mwah, see u in the next manpage 💋 ✨ periodt ✨

📦 where this page comes from