From 323e4bfcbe2dc6c6cac6e007dded0ba4f89a6458 Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Tue, 30 Dec 2025 18:37:17 +0900 Subject: [PATCH] rust: list: Switch to kernel::sync atomic primitives Convert uses of `AtomicBool` to `Atomic`. Note that the compare_exchange migration simplifies to `try_cmpxchg()`, since `try_cmpxchg()` provides relaxed ordering on failure, making the explicit failure ordering unnecessary. Signed-off-by: FUJITA Tomonori Reviewed-by: Alice Ryhl Signed-off-by: Boqun Feng Link: https://patch.msgid.link/20251230093718.1852322-3-fujita.tomonori@gmail.com --- rust/kernel/list/arc.rs | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/rust/kernel/list/arc.rs b/rust/kernel/list/arc.rs index d92bcf665c891..2282f33913ee9 100644 --- a/rust/kernel/list/arc.rs +++ b/rust/kernel/list/arc.rs @@ -6,11 +6,11 @@ use crate::alloc::{AllocError, Flags}; use crate::prelude::*; +use crate::sync::atomic::{ordering, Atomic}; use crate::sync::{Arc, ArcBorrow, UniqueArc}; use core::marker::PhantomPinned; use core::ops::Deref; use core::pin::Pin; -use core::sync::atomic::{AtomicBool, Ordering}; /// Declares that this type has some way to ensure that there is exactly one `ListArc` instance for /// this id. @@ -469,7 +469,7 @@ where /// If the boolean is `false`, then there is no [`ListArc`] for this value. #[repr(transparent)] pub struct AtomicTracker { - inner: AtomicBool, + inner: Atomic, // This value needs to be pinned to justify the INVARIANT: comment in `AtomicTracker::new`. _pin: PhantomPinned, } @@ -480,12 +480,12 @@ impl AtomicTracker { // INVARIANT: Pin-init initializers can't be used on an existing `Arc`, so this value will // not be constructed in an `Arc` that already has a `ListArc`. Self { - inner: AtomicBool::new(false), + inner: Atomic::new(false), _pin: PhantomPinned, } } - fn project_inner(self: Pin<&mut Self>) -> &mut AtomicBool { + fn project_inner(self: Pin<&mut Self>) -> &mut Atomic { // SAFETY: The `inner` field is not structurally pinned, so we may obtain a mutable // reference to it even if we only have a pinned reference to `self`. unsafe { &mut Pin::into_inner_unchecked(self).inner } @@ -500,7 +500,7 @@ impl ListArcSafe for AtomicTracker { unsafe fn on_drop_list_arc(&self) { // INVARIANT: We just dropped a ListArc, so the boolean should be false. - self.inner.store(false, Ordering::Release); + self.inner.store(false, ordering::Release); } } @@ -514,8 +514,6 @@ unsafe impl TryNewListArc for AtomicTracker { fn try_new_list_arc(&self) -> bool { // INVARIANT: If this method returns true, then the boolean used to be false, and is no // longer false, so it is okay for the caller to create a new [`ListArc`]. - self.inner - .compare_exchange(false, true, Ordering::Acquire, Ordering::Relaxed) - .is_ok() + self.inner.cmpxchg(false, true, ordering::Acquire).is_ok() } } -- 2.47.3