Re: [patch 47/60] x86/ldt: Map LDT entries into fixmap

From: Andy Lutomirski
Date: Mon Dec 04 2017 - 17:33:32 EST

On Mon, Dec 4, 2017 at 6:07 AM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> LDT is not really commonly used on 64bit so the overhead of populating the
> fixmap entries on context switch for the rare LDT syscall users is a
> reasonable trade off vs. having extra dynamically managed mapping space per
> process.

Hmm, I wonder just how slow this is. It might be okay. It's
certainly not the way I imagined it working.