raw_atomic_t...xchg_acquire(9)

πŸ“¦ version 7.3.1, in nixpkgs unstable

πŸŽ€ NAME πŸŽ€

raw_atomic_try_cmpxchg_acquire β€” atomic compare and exchange with acquire ordering

okay so real talk, bestie β€” you're in the Kernel API Manual right now, and this page is all about one very specific little atomic function. no cap, she's a baddie. let's get into it πŸ’…


✨ SYNOPSIS ✨

bool raw_atomic_try_cmpxchg_acquire (atomic_t *v , int *old , int new );

πŸ¦‹ ARGUMENTS πŸ¦‹

  • v β€” pointer to atomic_t. this is the main character, the value we're lowkey trying to swap 🫢
  • old β€” pointer to int value to compare with. she's the vibe check β€” if v matches her, the exchange goes through ✨
  • new β€” int value to assign. the glow-up we're applying if everything lines up πŸ’–

🌸 DESCRIPTION 🌸

If (v == old), then she atomically updates v to new with acquire ordering. slay. the swap happened, everyone clapped πŸ‘‘

Otherwise β€” and this is the part people miss β€” v is not modified, old gets updated to the current value of v, and relaxed ordering is provided. so it's giving "no exchange, but here's the tea on what v actually is right now" πŸ“

Safe to use in noinstr code; prefer atomic_try_cmpxchg_acquire elsewhere. fr fr, that's the rule β€” like, this one works in noinstr if you need it, but everywhere else, go use the normal one. iykyk 🧚

πŸ’œ RETURN πŸ’œ

true if the exchange occurred, false otherwise. that's it, that's the whole vibe check β€” boolean girlie, no grey area πŸ’€


🌈 SEE ALSO 🌈

first off, the kernel source file you want to peek at:

./include/linux/atomic/atomic-arch-fallback.h

and then... okay bestie, buckle up, because the friend group is extensive. literally everyone showed up to this party 😭:

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_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_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)

that's the whole group chat, go say hi πŸ‘‹


πŸ’– and that's the page, bestie! πŸ’– brought to you by the source at ./include/linux/atomic, dated October 2026, filed under raw_atomic_t...xchg_acquire(9). go forth and atomically exchange, you absolute icon πŸŽ€βœ¨

πŸ“¦ where this page comes from