raw_atomic_l...h_add_unless(9)

📦 version 7.3.1, in nixpkgs unstable

💅 raw_atomic_l...h_add_unless(9) — from the Kernel API Manual, bestie

okay so picture this: you're deep in kernel land, the manual's literally called the Kernel API Manual, and you need one very specific little long atomic to do exactly one very specific little thing. that's this page. welcome 🫶

✨ NAME ✨

raw_atomic_long_fetch_add_unless — atomic add unless value, with full ordering. yes the name is a whole sentence, we don't make the rules 💀

🌸 SYNOPSIS 🌸

long raw_atomic_long_fetch_add_unless (atomic_long_t *v , long a , long
u );

🎀 ARGUMENTS 🎀

  • v — pointer to atomic_long_t. it's the thing we're being all atomic about ✨
  • a — a long value to add. the "add" part of the show 💖
  • u — a long value to compare with. the "unless" part, our little vibe check 🦋

💜 DESCRIPTION 💜

so here's the plot: if (v != u), we atomically update v to (v + a) with full ordering. slay. iconic. the whole package 🌈

otherwise — like, if v is u — nothing happens to v at all, and you get relaxed ordering instead. not me giving you a different ordering depending on the answer 😭 that's just how it is.

🫶 important bestie note: this one is safe to use in noinstr code; prefer atomic_long_fetch_add_unless everywhere else. that's literally in the manual, no cap.

⭐ RETURN ⭐

the original value of v. not the new one, the original one — read it, remember it, it's yours 👑

🦋 SEE ALSO 🦋

the kernel file is ./include/linux/atomic/atomic-long.h — go say hi to it for me 💅

and now, the friend group. every single one. i'm not skipping a single member of this family, they all get their moment ✨

anyway that's the whole page, you ate that 💅 ok bye love u, stay atomic 🧚💖

this came from ./include/linux/atomic, October 2026 edition — signed, sealed, delivered, periodt 👑
📦 where this page comes from