raw_atomic64_add_unless(9)

💅 NAME 💅

okay so bestie, welcome to the Kernel API Manual page for raw_atomic64_add_unless(9) — it’s literally the “atomic add unless value with full ordering” one ✨. no cap, that’s the whole vibe.

✨ SYNOPSIS ✨

bool raw_atomic64_add_unless (atomic64_t *v , s64 a , s64 u );

🎀 ARGUMENTS 🎀

• v — pointer to atomic64_t 🫶
• a — s64 value to add 💖
• u — s64 value to compare with 🌸

🦋 DESCRIPTION 🦋

so the condition is (v != u) — if that’s true, it atomically updates v to (v + a) with full ordering 🔥.

otherwise? v is not modified, and relaxed ordering is provided 🧚. that’s it, that’s the tea.

it’s safe to use in noinstr code; the original also says to prefer atomic64_add_unless elsewhere 💅.

🌸 RETURN 🌸

true if v was updated, false otherwise 😌. boolean queen behavior.

💅 SEE ALSO 💅

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

and here’s the whole extended raw-atomic friend group, every single one, no gatekeeping 🫶:

raw_atomic_read(9), raw_atomic_read_acquire(9), raw_atomic_set(9),
raw_atomic_set_release(9), raw_atomic_add(9), raw_atomic_add_return(9),
raw_atomic_add_return_acquire(9), raw_atomic_add_return_release(9),
raw_atomic_add_return_relaxed(9), raw_atomic_fetch_add(9),
raw_atomic_fetch_add_acquire(9), raw_atomic_fetch_add_release(9),
raw_atomic_fetch_add_relaxed(9), raw_atomic_sub(9),
raw_atomic_sub_return(9), raw_atomic_sub_return_acquire(9),
raw_atomic_sub_return_release(9), raw_atomic_sub_return_relaxed(9),
raw_atomic_fetch_sub(9), raw_atomic_fetch_sub_acquire(9),
raw_atomic_fetch_sub_release(9), raw_atomic_fetch_sub_relaxed(9),
raw_atomic_inc(9), raw_atomic_inc_return(9),
raw_atomic_inc_return_acquire(9), raw_atomic_inc_return_release(9),
raw_atomic_inc_return_relaxed(9), raw_atomic_fetch_inc(9),
raw_atomic_fetch_inc_acquire(9), raw_atomic_fetch_inc_release(9),
raw_atomic_fetch_inc_relaxed(9), raw_atomic_dec(9),
raw_atomic_dec_return(9), raw_atomic_dec_return_acquire(9),
raw_atomic_dec_return_release(9), raw_atomic_dec_return_relaxed(9),
raw_atomic_fetch_dec(9), raw_atomic_fetch_dec_acquire(9),
raw_atomic_fetch_dec_release(9), raw_atomic_fetch_dec_relaxed(9),
raw_atomic_and(9), raw_atomic_fetch_and(9),
raw_atomic_fetch_and_acquire(9), raw_atomic_fetch_and_release(9),
raw_atomic_fetch_and_relaxed(9), raw_atomic_andnot(9),
raw_atomic_fetch_andnot(9), raw_atomic_fetch_andnot_acquire(9),
raw_atomic_fetch_andnot_release(9), raw_atomic_fetch_andnot_relaxed(9),
raw_atomic_or(9), raw_atomic_fetch_or(9),
raw_atomic_fetch_or_acquire(9), raw_atomic_fetch_or_release(9),
raw_atomic_fetch_or_relaxed(9), raw_atomic_xor(9),
raw_atomic_fetch_xor(9), raw_atomic_fetch_xor_acquire(9),
raw_atomic_fetch_xor_release(9), raw_atomic_fetch_xor_relaxed(9),
raw_atomic_xchg(9), raw_atomic_xchg_acquire(9),
raw_atomic_xchg_release(9), raw_atomic_xchg_relaxed(9),
raw_atomic_cmpxchg(9), raw_atomic_cmpxchg_acquire(9),
raw_atomic_cmpxchg_release(9), raw_atomic_cmpxchg_relaxed(9),
raw_atomic_try_cmpxchg(9), raw_atomic_try_cmpxchg_acquire(9),
raw_atomic_try_cmpxchg_release(9), raw_atomic_try_cmpxchg_relaxed(9),
raw_atomic_sub_and_test(9), raw_atomic_dec_and_test(9),
raw_atomic_inc_and_test(9), raw_atomic_add_negative(9),
raw_atomic_add_negative_acquire(9), raw_atomic_add_negative_release(9),
raw_atomic_add_negative_relaxed(9), raw_atomic_fetch_add_unless(9),
raw_atomic_add_unless(9), raw_atomic_inc_not_zero(9),
raw_atomic_inc_unless_negative(9), raw_atomic_dec_unless_positive(9),
raw_atomic_dec_if_positive(9), raw_atomic64_read(9),
raw_atomic64_read_acquire(9), raw_atomic64_set(9),
raw_atomic64_set_release(9), raw_atomic64_add(9),
raw_atomic64_add_return(9), raw_atomic64_add_return_acquire(9),
raw_atomic64_add_return_release(9), raw_atomic64_add_return_relaxed(9),
raw_atomic64_fetch_add(9), raw_atomic64_fetch_add_acquire(9),
raw_atomic64_fetch_add_release(9), raw_atomic64_fetch_add_relaxed(9),
raw_atomic64_sub(9), raw_atomic64_sub_return(9),
raw_atomic64_sub_return_acquire(9), raw_atomic64_sub_return_release(9),
raw_atomic64_sub_return_relaxed(9), raw_atomic64_fetch_sub(9),
raw_atomic64_fetch_sub_acquire(9), raw_atomic64_fetch_sub_release(9),
raw_atomic64_fetch_sub_relaxed(9), raw_atomic64_inc(9),
raw_atomic64_inc_return(9), raw_atomic64_inc_return_acquire(9),
raw_atomic64_inc_return_release(9), raw_atomic64_inc_return_relaxed(9),
raw_atomic64_fetch_inc(9), raw_atomic64_fetch_inc_acquire(9),
raw_atomic64_fetch_inc_release(9), raw_atomic64_fetch_inc_relaxed(9),
raw_atomic64_dec(9), raw_atomic64_dec_return(9),
raw_atomic64_dec_return_acquire(9), raw_atomic64_dec_return_release(9),
raw_atomic64_dec_return_relaxed(9), raw_atomic64_fetch_dec(9),
raw_atomic64_fetch_dec_acquire(9), raw_atomic64_fetch_dec_release(9),
raw_atomic64_fetch_dec_relaxed(9), raw_atomic64_and(9),
raw_atomic64_fetch_and(9), raw_atomic64_fetch_and_acquire(9),
raw_atomic64_fetch_and_release(9), raw_atomic64_fetch_and_relaxed(9),
raw_atomic64_andnot(9), raw_atomic64_fetch_andnot(9),
raw_atomic64_fetch_andnot_acquire(9),
raw_atomic64_fetch_andnot_release(9),
raw_atomic64_fetch_andnot_relaxed(9), raw_atomic64_or(9),
raw_atomic64_fetch_or(9), raw_atomic64_fetch_or_acquire(9),
raw_atomic64_fetch_or_release(9), raw_atomic64_fetch_or_relaxed(9),
raw_atomic64_xor(9), raw_atomic64_fetch_xor(9),
raw_atomic64_fetch_xor_acquire(9), raw_atomic64_fetch_xor_release(9),
raw_atomic64_fetch_xor_relaxed(9), raw_atomic64_xchg(9),
raw_atomic64_xchg_acquire(9), raw_atomic64_xchg_release(9),
raw_atomic64_xchg_relaxed(9), raw_atomic64_cmpxchg(9),
raw_atomic64_cmpxchg_acquire(9), raw_atomic64_cmpxchg_release(9),
raw_atomic64_cmpxchg_relaxed(9), raw_atomic64_try_cmpxchg(9),
raw_atomic64_try_cmpxchg_acquire(9),
raw_atomic64_try_cmpxchg_release(9),
raw_atomic64_try_cmpxchg_relaxed(9), raw_atomic64_sub_and_test(9),
raw_atomic64_dec_and_test(9), raw_atomic64_inc_and_test(9),
raw_atomic64_add_negative(9), raw_atomic64_add_negative_acquire(9),
raw_atomic64_add_negative_release(9),
raw_atomic64_add_negative_relaxed(9), raw_atomic64_fetch_add_unless(9),
raw_atomic64_inc_not_zero(9), raw_atomic64_inc_unless_negative(9),
raw_atomic64_dec_unless_positive(9), raw_atomic64_dec_if_positive(9)

mwah 💋 — this page lives in ./include/linux/atomic, dated October 2026, and it’s the raw_atomic64_add_unless(9) manual, periodt. 🎀