raw_atomic_sub_and_test(9)

🎀 NAME 🎀

okay so bestie, this page is raw_atomic_sub_and_test(9) from the Kernel API Manual — she’s the atomic subtract-and-test-if-zero icon with full ordering, and she is literally here to tell you if v hits zero after the math. no cap. 💅

✨ SYNOPSIS ✨

bool raw_atomic_sub_and_test (int i , atomic_t *v );

🫶 ARGUMENTS 🫶

• i — the int value you’re subtracting. it’s giving “how much are we taking off?” 💖
• v — pointer to atomic_t. this is the atomic variable getting updated, main character energy only. ✨

💖 DESCRIPTION 💖

Atomically updates v to (v - i) with full ordering. so the subtract and the update happen as one atomic little moment, and the ordering is full — yes, that’s the whole vibe.

Safe to use in noinstr code; prefer atomic_sub_and_test elsewhere. like, if you’re in noinstr land she’s safe to use, but the rest of the time the preferred bestie is atomic_sub_and_test. 🫶

🌸 RETURN 🌸

• true if the resulting value of v is zero. 🎉
• false otherwise. 💀

literally that’s the whole answer, no extra plot twist.

🦋 SEE ALSO 🦋

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

🫶 the raw_atomic_* fam

• 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_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)

🫶 the raw_atomic64_* fam

• 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_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)

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xoxo, your kernel bestie 💖 — signed off with source ./include/linux/atomic, version/date October 2026, and the page is raw_atomic_sub_and_test(9). periodt. 🦋