Re: [GIT pull] x86/urgent for v5.9-rc2

[Linus Torvalds]

On Sun, Aug 23, 2020 at 1:26 AM Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
>
> Remove the RDPID optimization, which is not even
> backed by numbers from the paranoid entry path instead.

Ugh, that's sad. I'd expect the LSL to be quite a bit slower than the
RDPID on raw hardware, since LSL has to go out to the GDT.

And I don't think we need the GDT for anything else normally, so it's
not even going to be cached.

Oh well.

                   Linus