Re: XArray documentation

[Matthew Wilcox]

On Fri, Nov 24, 2017 at 11:48:49AM -0800, Shakeel Butt wrote:
> Adding on to Martin's questions. Basically what is the motivation
> behind it? It seems like a replacement for radix tree, so, it would be
> good to write why radix tree was not good enough or which use cases
> radix tree could not solve. Also how XArray solves those
> issues/use-cases? And if you know which scenarios or use-cases where
> XArray will not be an optimal solution.

I strongly disagree that there should be any mention of the radix tree
in this document.  In the Glorious Future, there will be no more radix
tree and so talking about it will only confuse people (because Linux's
radix tree is not in fact a radix tree).

Talking about why the radix tree isn't good enough is for the cover letter.
I did it quite well here:

https://lwn.net/Articles/715948/