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

[Boqun Feng]

On Tue, Jan 06, 2026 at 03:20:43PM +0100, Richard Weinberger wrote:
> ----- Ursprüngliche Mail -----
> > Von: "Boqun Feng" <boqun.feng@xxxxxxxxx>
> > An: "linux-um" <linux-um@xxxxxxxxxxxxxxxxxxx>, "x86" <x86@xxxxxxxxxx>
> > CC: "richard" <richard@xxxxxx>, "anton ivanov" <anton.ivanov@xxxxxxxxxxxxxxxxxx>, "Johannes Berg"
> > <johannes@xxxxxxxxxxxxxxxx>, "tglx" <tglx@xxxxxxxxxxxxx>, "mingo" <mingo@xxxxxxxxxx>, "bp" <bp@xxxxxxxxx>, "dave
> > hansen" <dave.hansen@xxxxxxxxxxxxxxx>, "hpa" <hpa@xxxxxxxxx>, "Miguel Ojeda" <ojeda@xxxxxxxxxx>, "Boqun Feng"
> > <boqun.feng@xxxxxxxxx>, "Gary Guo" <gary@xxxxxxxxxxx>, "Björn Roy Baron" <bjorn3_gh@xxxxxxxxxxxxxx>, "Benno Lossin"
> > <lossin@xxxxxxxxxx>, "Andreas Hindborg" <a.hindborg@xxxxxxxxxx>, "Alice Ryhl" <aliceryhl@xxxxxxxxxx>, "Trevor Gross"
> > <tmgross@xxxxxxxxx>, "dakr" <dakr@xxxxxxxxxx>, "linux-kernel" <linux-kernel@xxxxxxxxxxxxxxx>, "Rust for Linux Kernel"
> > <rust-for-linux@xxxxxxxxxxxxxxx>, "FUJITA Tomonori" <fujita.tomonori@xxxxxxxxx>
> > 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@xxxxxxxxx>
> > ---
> > 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@xxxxxx>
> 

Queued with both tags applied, thank you both!

Regards,
Boqun

> Thanks,
> //richard