Re: [PATCH] sched: Add missing memory barrier in switch_mm_cid

[Dave Hansen]

On 4/10/24 10:18, Mathieu Desnoyers wrote:
> --- a/arch/x86/include/asm/barrier.h
> +++ b/arch/x86/include/asm/barrier.h
> @@ -79,6 +79,9 @@ do {                                    \
>   #define __smp_mb__before_atomic()    do { } while (0)
>   #define __smp_mb__after_atomic()    do { } while (0)
> +/* Writing to CR3 provides a full memory barrier in switch_mm(). */
> +#define smp_mb__after_switch_mm()    do { } while (0)

I haven't gone through this in detail, but the CR3 certainly is a full
barrier and the x86 code _looks_ correct, so:

Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> # for x86