atomic_long...ess_positive(9)
π¦ atomic_long_dec_unless_positive β Kernel API Manual β¨
okay so bestie, welcome to the atomic_long...ess_positive(9) page π
(yes the title gets truncated, that's just how the kernel rolls, it's giving "my name is a long function and the man page header simply cannot"). This is a page from the Kernel API Manual and we're gonna get into it together π«Ά
πΈ NAME πΈ
atomic_long_dec_unless_positive β atomic decrement unless positive with full ordering π₯
β SYNOPSIS β
bool atomic_long_dec_unless_positive (atomic_long_t *v );
literally one function, one argument, returns a bool. clean. iconic. no notes π
π ARGUMENTS π
vβ pointer toatomic_long_t. that's it, that's the whole argument list π
π DESCRIPTION π
okay here's the tea β If (v <= 0), it atomically updates v to (v - 1) with full ordering. otherwise, v is not modified and relaxed ordering is provided.
so yeah β it only decrements when the value is already zero or below, and it does the whole thing atomically so nobody else can slide in mid-update π
β οΈ bestie listen to me: it is unsafe to use in noinstr code. use raw_atomic_long_dec_unless_positive there instead. no cap, don't do the wrong one π
π¦ RETURN π¦
true if v was updated, false otherwise β¨ (so like, did the decrement actually happen or nah)
π SEE ALSO π
Kernel file ./include/linux/atomic/atomic-instrumented.h β and here is the entire extended friend group, no one left behind π
πΈ plain atomic_* β read & set πΈ
atomic_read(9), atomic_read_acquire(9), atomic_set(9), atomic_set_release(9)
π atomic_* β add πΈ
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)
π atomic_* β sub π
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)
β atomic_* β inc β
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)
π¦ atomic_* β dec π¦
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)
π atomic_* β bitwise besties π
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)
π
atomic_* β exchange & compare πΈ
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)
π₯ atomic_* β the conditional girlies π₯
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)
π§ the whole atomic64_* cinematic universe π§
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)
π the atomic_long_* fam (yes, our girl's whole bloodline) π
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_if_positive(9)
and that's the whole page bestie, you ate that π β¨
little sign-off from the source files: this came from the ./include/linux/atomic corner of the kernel tree, dated October 2026, and the manual it lives in is atomic_long...ess_positive(9) β okay love you, bye ππ¦π
π¦ where this page comes from
- nixpkgs unstable: linux-manual 7.3.1
- π girlified by deepseek-ai/DeepSeek-V4.1-Flash-1017 on : a language model's rewrite of the original, under its terms