linux-kernel - Re: Assignment of GDT entries

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Message-ID: <45086553.4090804@goop.org>
Date:	Wed, 13 Sep 2006 13:08:51 -0700
From:	Jeremy Fitzhardinge <jeremy@...p.org>
To:	"linux-os (Dick Johnson)" <linux-os@...logic.com>
CC:	Linus Torvalds <torvalds@...l.org>, Ingo Molnar <mingo@...e.hu>,
	Andi Kleen <ak@...e.de>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Arjan van de Ven <arjan@...radead.org>,
	Zachary Amsden <zach@...are.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Michael A Fetterman <Michael.Fetterman@...cam.ac.uk>
Subject: Re: Assignment of GDT entries

linux-os (Dick Johnson) wrote:
> The entries 1 through 3 are used during the boot sequence, see
> setup.S, search for "gdt" around line 983.
>   

OK, but that's an early GDT used during boot, which shouldn't have any 
bearing on the GDT of the running kernel.

> I can't imagine a reason why you'd want to do this.
>   

I'm looking at packing all the descriptors together so they share a 
cache line, and therefore reduce the likelihood of a cache miss when 
loading a segment register.

    J
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