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From: Andy Lutomirski <luto@kernel.org>
Date: Mon, 4 Dec 2017 14:33:06 -0800
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Subject: Re: [patch 47/60] x86/ldt: Map LDT entries into fixmap
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>, X86 ML <x86@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
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On Mon, Dec 4, 2017 at 6:07 AM, Thomas Gleixner <tglx@linutronix.de> wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
>
> 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.

--Andy