Re: [PATCH] Optimize away pte_chains for single mappings

[Daniel Phillips <phillips@arcor.de>]

On Monday 15 July 2002 22:57, Andrew Morton wrote:
> Daniel Phillips wrote:
> > On Monday 15 July 2002 18:34, Rik van Riel wrote:
> > > On Mon, 15 Jul 2002, Daniel Phillips wrote:
> > >
> > > > None of these cases apply, the low bit is always masked off before being
> > > > used as a pointer.
> > >
> > > Too ugly to live.
> > 
> > That's a nonargument.  I presume you weren't able to think of a
> > substantive reason.
> 
> How about "Linus will roast our nuts if we do that"?

Unless someone can come up with a rational argument, I'd be forced to conclude
that Linus is superstitious.

> Plus accessing the same storage with both atomic and non-atomic
> ops may be a problem on some hardware.

Qu'est-ce que ca veux dire?  We're protected under the pte_chain lock are we
not?

> Let's wait until we run out of page flags first...

Sure, I intend to lay claim to six of them in due course, that would leave a
mere eight for posterity.

Then there is the method I proposed for saving 8 bytes per pte_chain with
the help of an overloaded pointer.  In what way does that not turn the ugly
duckling into a beautiful swan?

-- 
Daniel
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