raw_atomic_add_unless(9)

📦 version 7.3.1, in nixpkgs unstable

✨ raw_atomic_add_unless(9) ✨

okay so bestie, welcome to the Kernel API Manual 💖 this one's a lil kernel-page deep-cut, and honestly? it's giving "the friend who only shows up when the vibe check passes." let's get into it 🦋

🌸 NAME 🌸

raw_atomic_add_unless — atomic add unless value, with full ordering 💅

like, it adds... but only if you're not the value it's avoiding. conditional queen behavior 👑

⭐ SYNOPSIS ⭐

bool raw_atomic_add_unless (atomic_t *v , int a , int u );

that's it. that's the whole signature. short, sweet, and absolutely not to be messed with 🔥

🎀 ARGUMENTS 🎀

  • v — pointer to atomic_t ✨ (this is the thing getting updated, the main character of the operation)
  • a — int value to add 🍓 (the little gift you're adding in)
  • u — int value to compare with 🧚 (the "unless" part — if v is this, we don't do the thing)

💜 DESCRIPTION 💜

so here's the tea ☕ — if (v != u), it atomically updates v to (v + a) with full ordering. full ordering, bestie, we're not playing games here 🔥

otherwise (meaning v is u), v is not modified at all, and relaxed ordering is provided. so like, nothing happens, but it happens in a chill way 💅

it's safe to use in noinstr code 🫶 — but the manual says prefer atomic_add_unless elsewhere. so like, it's the special-occasion version, not your everyday grab-and-go. iykyk 🙈

🌈 RETURN 🌈

  • true if v was updated ✅
  • false otherwise ❌

that's the whole vibe check, no cap 💯

👑 SEE ALSO 👑

kernel file 📁 ./include/linux/atomic/atomic-arch-fallback.h

and now, the moment you've all been waiting for... the entire friend group 😭 (yes, all of them. i counted. there are SO many. not skipping a single one, that would be disrespectful 🙏):

like i said. HUGE friend group. every single one of them made the list 💀 but honestly? iconic. no notes. 👑

that's the whole page bestie, you ate it 💅✨

this lil beauty lives at ./include/linux/atomic — dated October 2026 — and goes by raw_atomic_add_unless(9). mwah, go forth and be atomic 🫶💖

📦 where this page comes from