atomic_sub_and_test(9)

💅 NAME — atomic_sub_and_test(9) 💅

okay bestie, welcome to the Kernel API Manual page for atomic_sub_and_test(9) — it’s literally atomic subtract and test if zero with full ordering, and it’s giving major kernel-core energy. ✨

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✨ SYNOPSIS ✨

bool atomic_sub_and_test (int i , atomic_t *v );

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🎀 ARGUMENTS 🎀

• i — int value to subtract.
• v — pointer to atomic_t.

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🦋 DESCRIPTION 🦋

okay so the whole serve: it atomically updates v to (v - i) with full ordering. no cap, that’s the entire description.

🚨 Unsafe to use in noinstr code; use raw_atomic_sub_and_test there. like, actually unsafe, bestie.

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👑 RETURN 👑

It returns true if the resulting value of v is zero, and false otherwise. ✅💖

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🌈 SEE ALSO 🌈

Kernel file: ./include/linux/atomic/atomic-instrumented.h. This is the reference-list moment, and we are not skipping a single one — here’s the whole exact list:

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(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_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), 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),
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)

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okay that’s the page, bestie 🫶 source/version: ./include/linux/atomic; date: October 2026. mwah 💋✨