Subject: Re: sync i386 pmap with amd64
To: YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>
From: Bang Jun-Young <junyoung@mogua.com>
List: port-i386
Date: 07/26/2004 09:19:47
YAMAMOTO Takashi wrote:
> hi,
> 
> > > actually, there's some benefits.
> > > 	- low cost to maintain.  (by sharing code with amd64 eventually)
> > > 	- a step to support PAE.
> > 
> > Even with AMD64, "PD" and "PT" are still officially used. Only "PDP" is
> > added for PAE and 64-bit virtual-physical address translation. Why do you
> > want to replace the official terms with non-official ones? In other words,
> > why can't amd64 pmap changed so it shares more code with i386 and better
> > meets the techdocs?
> 
> the point is designating pte levels by numbers, not by names.
> in this way we can more easily deal with arbitrary numbers of pte levels.

I'm wondering
- how your patch can make arbitrary numbers of pte levels easier to deal
  with
- why it is a benefit to support arbitrary numbers of pte levels, if
  considering the current 3-level, 52-bit address space on amd64 seems to
  be enough for the next 20 years.

Jun-Young