linux.git/rust/kernel/sync/barrier.rs, branch v6.18.21 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git rust: sync: Add memory barriers 2025-09-15T07:38:34+00:00 Boqun Feng boqun.feng@gmail.com 2025-09-05T04:41:36+00:00 d9ea5a41cef80dc8103f4114b072b27364f2e06a Memory barriers are building blocks for concurrent code, hence provide a minimal set of them. The compiler barrier, barrier(), is implemented in inline asm instead of using core::sync::atomic::compiler_fence() because memory models are different: kernel's atomics are implemented in inline asm therefore the compiler barrier should be implemented in inline asm as well. Also it's currently only public to the kernel crate until there's a reasonable driver usage. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev> Link: https://lore.kernel.org/all/20250719030827.61357-10-boqun.feng@gmail.com/ 
Memory barriers are building blocks for concurrent code, hence provide
a minimal set of them.

The compiler barrier, barrier(), is implemented in inline asm instead of
using core::sync::atomic::compiler_fence() because memory models are
different: kernel's atomics are implemented in inline asm therefore the
compiler barrier should be implemented in inline asm as well. Also it's
currently only public to the kernel crate until there's a reasonable
driver usage.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://lore.kernel.org/all/20250719030827.61357-10-boqun.feng@gmail.com/