Question about page count

[Dave Hylands]

Hey Mulyadi,

On Mon, Jun 20, 2011 at 10:15 PM, Mulyadi Santosa
<mulyadi.santosa at gmail.com> wrote:
...snip...
> looking at how page_count implemented, it checks whether the related
> page is gonna be reclaimed or a compound page (not sure what it is).
> If so, returns the first page of that "page".

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.

-- 
Dave Hylands
Shuswap, BC, Canada
http://www.davehylands.com