Re: [PATCH 3/6] x86: Add support for the clwb instruction

Borislav Petkov
2014-11-11T19:54:45Z

On Tue, Nov 11, 2014 at 12:48:52PM -0700, Ross Zwisler wrote:
> Essentially we need one additional byte at the beginning of the clflush so
> that we can flip it into a clflushopt by changing that byte into a 0x66
> prefix. Two options are to either insert a 1 byte ASM_NOP1, or to add a 1
> byte NOP_DS_PREFIX. Both have no functional effect with the plain clflush,
> but I've been told that executing a clflush + prefix should be faster than
> executing a clflush + NOP.

I see. :)

Thanks.

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Regards/Gruss,
Boris.

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