Re: [RFC 00/13] x86/mm: PCID and INVPCID

[Linus Torvalds]

On Fri, Jan 8, 2016 at 3:36 PM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
>>
>> Either things have changed (newer hardware with more pcids perhaps?)
>> or you did a better job at it.
>
> On my Skylake laptop, all of the PCID bits appear to have at least
> some effect.  Whether this means it gets hashed or whether this means
> that all of the bits are real, I don't know.

They have always gotten hashed, and no the bits aren't real - hardware
doesn't actually have as many bits in the pcid as there are in cr3.

              Linus