Rik van Riel wrote:
> The special cases in the use-once code have annoyed me for a while,
> and I'd like to see if replacing them with something simpler could
> be worthwhile.
> 
> I haven't actually benchmarked (or even tested) this code yet, but
> the basic idea is that we want to ignore multiple references to the
> same page if they happen really close to each other, and only keep
> a page on the active list if it got accessed again on a time scale
> that matters to the pageout code.  In other words, filtering out
> correlated references in a simpler way.
> 
> Opinions ?
> 

I've had some patches around that do basically exactly the same thing.
I'll attach them just for reference, but they're pretty messy and
depend on other private patches I have here.

I think the biggest problem with our twine and duct tape page reclaim
scheme is that somehow *works* (for some value of works).

And intermediate steps like this are likely to upset its fragile workings
even though they really should be better solutions.

I think we branch a new tree for all interested VM developers to work
on and try to get performing well. Probably try to restrict it to page
reclaim and related fundamentals so it stays as small as possible and
worth testing.

I would be interested in helping to maintain such a tree (we would have
it track 2.6, of course). I have a whole load of patches and things here
that I need to do something with some day (many of them are probabably
crap!).

Any thoughts? If positive, any ideas about what sort of format? Maybe an
akpm style tree (although probably not tracking Linus' head quite so fast)?
Names? Same style as -mm trees? -vm?

Nick

-- 
SUSE Labs, Novell Inc.