Re: [PATCH 4/4] x86/asm: Change sync_core() to use MOV to CR2 to serialize

[Borislav Petkov]

On Wed, Nov 30, 2016 at 12:34:55PM -0800, Andy Lutomirski wrote:
> Aside from being excessively slow, CPUID is problematic: Linux runs
> on a handful of CPUs that don't have CPUID.  MOV to CR2 is always
> available, so use it instead.
> 
> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
> ---
>  arch/x86/include/asm/processor.h | 31 ++++++++-----------------------
>  1 file changed, 8 insertions(+), 23 deletions(-)

Looks nice.

I'm wondering if we should leave this one in tip for an additional cycle
to have it tested on more hw. I know, it is architectural and so on but
who knows what every implementation actually does...

-- 
Regards/Gruss,
    Boris.

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