atomic_sub(9)

🦋 atomic_sub(9) — Kernel API Manual 🦋

okay bestie, welcome to the atomic_sub(9) glow-up from the Kernel API Manual ✨ yes we are doing kernel atomics and yes we are making it cute 💅

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🎀 NAME 🎀

atomic_sub — atomic subtract with relaxed ordering. that's the vibe: subtract, atomically, relaxed ordering, periodt 💖

✨ SYNOPSIS ✨

void atomic_sub (int i , atomic_t *v );

🍓 ARGUMENTS 🍓

• i — an int value to subtract 🍓
• v — pointer to atomic_t 💖

🔥 DESCRIPTION 🔥

So basically, this function atomically updates v to (v - i) with relaxed ordering. That's the whole main-character move ✨

⚠️ important caution, no cap: it's unsafe to use in noinstr code. use raw_atomic_sub there instead 💀 don't make it weird.

👑 RETURN 👑

Nothing. literally nothing — void energy, empty hands, no return value 🫶

🌈 SEE ALSO 🌈

Kernel file ./include/linux/atomic/atomic-instrumented.h, plus the whole atomic extended universe, iykyk:

first up, the atomic_* set: atomic_read(9), atomic_read_acquire(9), atomic_set(9), atomic_set_release(9), atomic_add(9), atomic_add_return(9), atomic_add_return_acquire(9), atomic_add_return_release(9), atomic_add_return_relaxed(9), atomic_fetch_add(9), atomic_fetch_add_acquire(9), atomic_fetch_add_release(9), atomic_fetch_add_relaxed(9), atomic_sub_return(9), atomic_sub_return_acquire(9), atomic_sub_return_release(9), atomic_sub_return_relaxed(9), atomic_fetch_sub(9), atomic_fetch_sub_acquire(9), atomic_fetch_sub_release(9), atomic_fetch_sub_relaxed(9), atomic_inc(9), atomic_inc_return(9), atomic_inc_return_acquire(9), atomic_inc_return_release(9), atomic_inc_return_relaxed(9), atomic_fetch_inc(9), atomic_fetch_inc_acquire(9), atomic_fetch_inc_release(9), atomic_fetch_inc_relaxed(9), atomic_dec(9), atomic_dec_return(9), atomic_dec_return_acquire(9), atomic_dec_return_release(9), atomic_dec_return_relaxed(9), atomic_fetch_dec(9), atomic_fetch_dec_acquire(9), atomic_fetch_dec_release(9), atomic_fetch_dec_relaxed(9), atomic_and(9), atomic_fetch_and(9), atomic_fetch_and_acquire(9), atomic_fetch_and_release(9), atomic_fetch_and_relaxed(9), atomic_andnot(9), atomic_fetch_andnot(9), atomic_fetch_andnot_acquire(9), atomic_fetch_andnot_release(9), atomic_fetch_andnot_relaxed(9), atomic_or(9), atomic_fetch_or(9), atomic_fetch_or_acquire(9), atomic_fetch_or_release(9), atomic_fetch_or_relaxed(9), atomic_xor(9), atomic_fetch_xor(9), atomic_fetch_xor_acquire(9), atomic_fetch_xor_release(9), atomic_fetch_xor_relaxed(9), atomic_xchg(9), atomic_xchg_acquire(9), atomic_xchg_release(9), atomic_xchg_relaxed(9), atomic_cmpxchg(9), atomic_cmpxchg_acquire(9), atomic_cmpxchg_release(9), atomic_cmpxchg_relaxed(9), atomic_try_cmpxchg(9), atomic_try_cmpxchg_acquire(9), atomic_try_cmpxchg_release(9), atomic_try_cmpxchg_relaxed(9), atomic_sub_and_test(9), atomic_dec_and_test(9), atomic_inc_and_test(9), atomic_add_negative(9), atomic_add_negative_acquire(9), atomic_add_negative_release(9), atomic_add_negative_relaxed(9), atomic_fetch_add_unless(9), atomic_add_unless(9), atomic_inc_not_zero(9), atomic_inc_unless_negative(9), atomic_dec_unless_positive(9), atomic_dec_if_positive(9).

then the atomic64_* set: atomic64_read(9), atomic64_read_acquire(9), atomic64_set(9), atomic64_set_release(9), atomic64_add(9), atomic64_add_return(9), atomic64_add_return_acquire(9), atomic64_add_return_release(9), atomic64_add_return_relaxed(9), atomic64_fetch_add(9), atomic64_fetch_add_acquire(9), atomic64_fetch_add_release(9), atomic64_fetch_add_relaxed(9), atomic64_sub(9), atomic64_sub_return(9), atomic64_sub_return_acquire(9), atomic64_sub_return_release(9), atomic64_sub_return_relaxed(9), atomic64_fetch_sub(9), atomic64_fetch_sub_acquire(9), atomic64_fetch_sub_release(9), atomic64_fetch_sub_relaxed(9), atomic64_inc(9), atomic64_inc_return(9), atomic64_inc_return_acquire(9), atomic64_inc_return_release(9), atomic64_inc_return_relaxed(9), atomic64_fetch_inc(9), atomic64_fetch_inc_acquire(9), atomic64_fetch_inc_release(9), atomic64_fetch_inc_relaxed(9), atomic64_dec(9), atomic64_dec_return(9), atomic64_dec_return_acquire(9), atomic64_dec_return_release(9), atomic64_dec_return_relaxed(9), atomic64_fetch_dec(9), atomic64_fetch_dec_acquire(9), atomic64_fetch_dec_release(9), atomic64_fetch_dec_relaxed(9), atomic64_and(9), atomic64_fetch_and(9), atomic64_fetch_and_acquire(9), atomic64_fetch_and_release(9), atomic64_fetch_and_relaxed(9), atomic64_andnot(9), atomic64_fetch_andnot(9), atomic64_fetch_andnot_acquire(9), atomic64_fetch_andnot_release(9), atomic64_fetch_andnot_relaxed(9), atomic64_or(9), atomic64_fetch_or(9), atomic64_fetch_or_acquire(9), atomic64_fetch_or_release(9), atomic64_fetch_or_relaxed(9), atomic64_xor(9), atomic64_fetch_xor(9), atomic64_fetch_xor_acquire(9), atomic64_fetch_xor_release(9), atomic64_fetch_xor_relaxed(9), atomic64_xchg(9), atomic64_xchg_acquire(9), atomic64_xchg_release(9), atomic64_xchg_relaxed(9), atomic64_cmpxchg(9), atomic64_cmpxchg_acquire(9), atomic64_cmpxchg_release(9), atomic64_cmpxchg_relaxed(9), atomic64_try_cmpxchg(9), atomic64_try_cmpxchg_acquire(9), atomic64_try_cmpxchg_release(9), atomic64_try_cmpxchg_relaxed(9), atomic64_sub_and_test(9), atomic64_dec_and_test(9), atomic64_inc_and_test(9), atomic64_add_negative(9), atomic64_add_negative_acquire(9), atomic64_add_negative_release(9), atomic64_add_negative_relaxed(9), atomic64_fetch_add_unless(9), atomic64_add_unless(9), atomic64_inc_not_zero(9), atomic64_inc_unless_negative(9), atomic64_dec_unless_positive(9), atomic64_dec_if_positive(9).

and the atomic_long_* set: atomic_long_read(9), atomic_long_read_acquire(9), atomic_long_set(9), atomic_long_set_release(9), atomic_long_add(9), atomic_long_add_return(9), atomic_long_add_return_acquire(9), atomic_long_add_return_release(9), atomic_long_add_return_relaxed(9), atomic_long_fetch_add(9), atomic_long_fetch_add_acquire(9), atomic_long_fetch_add_release(9), atomic_long_fetch_add_relaxed(9), atomic_long_sub(9), atomic_long_sub_return(9), atomic_long_sub_return_acquire(9), atomic_long_sub_return_release(9), atomic_long_sub_return_relaxed(9), atomic_long_fetch_sub(9), atomic_long_fetch_sub_acquire(9), atomic_long_fetch_sub_release(9), atomic_long_fetch_sub_relaxed(9), atomic_long_inc(9), atomic_long_inc_return(9), atomic_long_inc_return_acquire(9), atomic_long_inc_return_release(9), atomic_long_inc_return_relaxed(9), atomic_long_fetch_inc(9), atomic_long_fetch_inc_acquire(9), atomic_long_fetch_inc_release(9), atomic_long_fetch_inc_relaxed(9), atomic_long_dec(9), atomic_long_dec_return(9), atomic_long_dec_return_acquire(9), atomic_long_dec_return_release(9), atomic_long_dec_return_relaxed(9), atomic_long_fetch_dec(9), atomic_long_fetch_dec_acquire(9), atomic_long_fetch_dec_release(9), atomic_long_fetch_dec_relaxed(9), atomic_long_and(9), atomic_long_fetch_and(9), atomic_long_fetch_and_acquire(9), atomic_long_fetch_and_release(9), atomic_long_fetch_and_relaxed(9), atomic_long_andnot(9), atomic_long_fetch_andnot(9), atomic_long_fetch_andnot_acquire(9), atomic_long_fetch_andnot_release(9), atomic_long_fetch_andnot_relaxed(9), atomic_long_or(9), atomic_long_fetch_or(9), atomic_long_fetch_or_acquire(9), atomic_long_fetch_or_release(9), atomic_long_fetch_or_relaxed(9), atomic_long_xor(9), atomic_long_fetch_xor(9), atomic_long_fetch_xor_acquire(9), atomic_long_fetch_xor_release(9), atomic_long_fetch_xor_relaxed(9), atomic_long_xchg(9), atomic_long_xchg_acquire(9), atomic_long_xchg_release(9), atomic_long_xchg_relaxed(9), atomic_long_cmpxchg(9), atomic_long_cmpxchg_acquire(9), atomic_long_cmpxchg_release(9), atomic_long_cmpxchg_relaxed(9), atomic_long_try_cmpxchg(9), atomic_long_try_cmpxchg_acquire(9), atomic_long_try_cmpxchg_release(9), atomic_long_try_cmpxchg_relaxed(9), atomic_long_sub_and_test(9), atomic_long_dec_and_test(9), atomic_long_inc_and_test(9), atomic_long_add_negative(9), atomic_long_add_negative_acquire(9), atomic_long_add_negative_release(9), atomic_long_add_negative_relaxed(9), atomic_long_fetch_add_unless(9), atomic_long_add_unless(9), atomic_long_inc_not_zero(9), atomic_long_inc_unless_negative(9), atomic_long_dec_unless_positive(9), atomic_long_dec_if_positive(9).

mwah 💋 source/version: ./include/linux/atomic; date: October 2026 — bye bestie, go be atomic 🫶✨