On Fri, Mar 04, 2005 at 10:59:45AM +0900, YAMAMOTO Takashi wrote:
> > however, as far as I can tell, linux does not track clean and dirty pages
> > separately such that one can find the dirty pages without looking through
> > the clean ones, and last I heard, solaris didn't either.  yet both of them
> > had even better performance than freebsd in the article.
> 
> iirc, linux does.
> depending on the version, via separated lists or radix tree tags.

I was looking at 2.6.9.  it looked to me that the radix tree tags
were how dirty pages were identified, but it had to look at the tag
for every page to find the dirty ones.  granted, this is a lot faster
than what we do, but it doesn't let you find the dirty pages without
examining the state for every page.

-Chuck