Re: [PATCH] arch: um/x86: Select ARCH_SUPPORTS_ATOMIC_RMW for UML_X86

Richard Weinberger
2026-01-06T14:21:00Z

----- Ursprüngliche Mail -----
> Von: "Boqun Feng" <boqun.feng@gmail.com>
> An: "linux-um" <linux-um@lists.infradead.org>, "x86" <x86@kernel.org>
> CC: "richard" <richard@nod.at>, "anton ivanov" <anton.ivanov@cambridgegreys.com>, "Johannes Berg"
> <johannes@sipsolutions.net>, "tglx" <tglx@linutronix.de>, "mingo" <mingo@redhat.com>, "bp" <bp@alien8.de>, "dave
> hansen" <dave.hansen@linux.intel.com>, "hpa" <hpa@zytor.com>, "Miguel Ojeda" <ojeda@kernel.org>, "Boqun Feng"
> <boqun.feng@gmail.com>, "Gary Guo" <gary@garyguo.net>, "Björn Roy Baron" <bjorn3_gh@protonmail.com>, "Benno Lossin"
> <lossin@kernel.org>, "Andreas Hindborg" <a.hindborg@kernel.org>, "Alice Ryhl" <aliceryhl@google.com>, "Trevor Gross"
> <tmgross@umich.edu>, "dakr" <dakr@kernel.org>, "linux-kernel" <linux-kernel@vger.kernel.org>, "Rust for Linux Kernel"
> <rust-for-linux@vger.kernel.org>, "FUJITA Tomonori" <fujita.tomonori@gmail.com>
> Gesendet: Dienstag, 6. Januar 2026 04:40:34
> Betreff: [PATCH] arch: um/x86: Select ARCH_SUPPORTS_ATOMIC_RMW for UML_X86

> x86 atomic instructions are used for um on UML_X86, therefore atomics
> on UML_X86 support native atomic RmW as x86 does, hence select
> ARCH_SUPPORTS_ATOMIC_RMW.
>
> Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
> ---
> UM & x86 maintainers,
>
> I need this to avoid a build error for Rust atomics since Rust currently
> only support Atomic<i8/i16> on ARCH_SUPPORTS_ATOMIC_RMW archs. I will
> add it to my upcoming PR if I get some Acked-by, thanks!
>
> arch/x86/um/Kconfig | 1 +
> 1 file changed, 1 insertion(+)

Acked-by: Richard Weinberger <richard@nod.at>

Thanks,
//richard