Re: [PATCH] for_each_zone / for_each_pgdat

Rik van Riel
2002-04-15T20:59:18Z

On Mon, 15 Apr 2002, Linus Torvalds wrote:
> On Mon, 15 Apr 2002, Rik van Riel wrote:
> > replace slightly obscure while loops with for_each_zone and
> > for_each_pgdat macros, this version has the added optimisation
> > of skipping empty zones (thanks to William Lee Irwin)
>
> I'd suggest against making this kind of complicated inlien functions, and
> I also don't see why the for_each_zone() isn't a simpler doubly nested
> for-loop instead of being forced into a less obvious iterative loop?

Because code that doesn't care about pgdats shouldn't have to
learn about them, IMHO. I used to have the doubly nested for
loop in -rmap, but William Irwin came up with a way to make
it a singly nested loop for code that only cares about zones.

> In short, this looks syntactically simple, but the syntactic simplicity
> comes at the expense of a unnecessarily complex implementation.

Since it was mostly done to clean up code I guess it makes
sense to simplify the thing a bit, if possible.

However, I really don't like the fact of teaching now-simple
VM code about pgdats again ;)

regards,

Rik
--
http://www.linuxsymposium.org/2002/
"You're one of those condescending OLS attendants"
"Here's a nickle kid. Go buy yourself a real t-shirt"

http://www.surriel.com/ http://distro.conectiva.com/