Re: [PATCH v2 05/36] x86/entry/64/compat: Fix SYSENTER's NT flag before user memory access

[Borislav Petkov]

On Wed, Oct 07, 2015 at 10:33:10AM -0400, Brian Gerst wrote:
> This is an optimization, since NT is unlikely to be set.  The forward
> branch is usually predicted as not taken, and it keeps these rarely
> used instructions out of the hot cache.

Ah, slick. Because branch predictors mark new branches as not taken and
this particular one will remain non-taken in the majority of the cases.
I think this warrants a mention in the comment above it though...

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
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