Re: [RFC PATCH v6 01/26] Documentation/x86: Add CET description

Ingo Molnar
2018-11-21T07:24:33Z

* Yu-cheng Yu <yu-cheng.yu@intel.com> wrote:

> On Tue, 2018-11-20 at 10:52 +0100, Ingo Molnar wrote:
> > * Yu-cheng Yu <yu-cheng.yu@intel.com> wrote:
> >
> > > +X86 Documentation
> > > [...]
> > > +
> > > +At run time, /proc/cpuinfo shows the availability of SHSTK and IBT.
> >
> > What is the rough expected performance impact of CET on average function
> > call frequency user applications and the kernel itself?
>
> I don't have any conclusive numbers yet; but since currently only user-mode
> protection is implemented, I suspect any impact would be most likely to the
> application. The kernel would spend some small amount of time on the setup of
> CET.

This is horribly vague.

Thanks,

Ingo