Re: [PATCH 4/4] x86/cpu: Use SERIALIZE in sync_core() when available

[peterz]

On Sun, Jul 26, 2020 at 09:31:32PM -0700, Ricardo Neri wrote:
> @@ -75,6 +77,12 @@ static inline void sync_core(void)
>        * Like all of Linux's memory ordering operations, this is a
>        * compiler barrier as well.
>        */
> +
> +     if (boot_cpu_has(X86_FEATURE_SERIALIZE)) {
> +             serialize();
> +             return;
> +     }
> +
>       iret_to_self();

I was sorta expecting something like:

        alternative(IRET_TO_SELF, SERIALIZE, X86_FEATURE_SERIALIZE);

But instead you used boot_cpu_has() which is a dynamic test.