Question about page count

[Mulyadi Santosa]

Hi Dave :)

On Tue, Jun 21, 2011 at 20:23, Dave Hylands <dhylands at gmail.com> wrote:
> On the ARM, you can setup the MMU to map 1Mb regions or 4Kb regions. A
> 1 Mb region only goes through the top level of the MMU, whereas a 4K
> page has to go through 2 levesl, so accessing pages through the 1 Mb
> mapping is faster.
>
> I believe (I'm not 100% sure) that the 256 x 4K pages that make up the
> 1Mb region are a compound page.

Oh, very valuable info...thanks for sharing that...yes, quite make
sense to me. Anyway, I also found this info in
Documentation/vm/pagemap.txt inside kernel tree. I paste here so
everybody could take a quick peek:

"The major consumers of compound
    pages are hugeTLB pages (Documentation/vm/hugetlbpage.txt), the SLUB etc.
    memory allocators and various device drivers. However in this interface,
    only huge/giga pages are made visible to end users."

-- 
regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com