Re: MM patches against 2.5.31

[Linus Torvalds]

In article <[e-mail]>,
Andrew Morton  <[e-mail]> wrote:
>
>What I'm inclined to do there is to change __page_cache_release()
>to not attempt to free the page at all.  Just let it sit on the
>LRU until page reclaim encounters it.  With the anon-free-via-pagevec
>patch, very, very, very few pages actually get their final release in
>__page_cache_release() - zero on uniprocessor, I expect.

If you do this, then I would personally suggest a conceptually different
approach: make the LRU list count towards the page count.  That will
_automatically_ result in what you describe - if a page is on the LRU
list, then "freeing" it will always just decrement the count, and the
_real_ free comes from walking the LRU list and considering count==1 to
be trivially freeable. 

That way you don't have to have separate functions for releasing
different kinds of pages (we've seen how nasty that was from a
maintainance standpoint already with the "put_page vs
page_cache_release" thing). 

Ehh?

		Linus