Re: [patch 0/4] mm: de-skew page refcount

[Linus Torvalds <torvalds@osdl.org>]

On Thu, 19 Jan 2006, Nick Piggin wrote:
> 
> Hmm... this is what the de-skew patch _did_ (although it was wrapped
> in a function called get_page_unless_zero), in fact the main aim was
> to prevent this twiddling and the de-skewing was just a nice side effect
> (I guess the patch title is misleading).
> 
> So I'm confused...

The thing I minded was the _other_ changes, namely the de-skewing itself. 
It seemed totally unnecessary to what you claimed was the point of the 
patch.

So I objected to the patch on the grounds that it did what you claimed 
badly. All the _optimization_ was totally independent of that de-skewing, 
and the de-skewing was a potential un-optimization.

But if you do the optimizations as one independent set of patches, and 
_then_ do the counter thing as a "simplify logic" patch, I don't see that 
as a problem.

Side note: I may be crazy, but for me when merging, one of the biggest 
things is "does this pass my 'makes sense' detector". I look less at the 
end result, than I actually look at the _change_. See?

That's why two separate patches that do the same thing as one combined 
patch may make sense, even if the _combined_ one does not (it could go the 
other way too, obviously).

		Linus