Re: [PATCH 1/3] x86,mm/pat: Use generic interval trees

[Davidlohr Bueso]

> On Wed, 21 Aug 2019, Michel Lespinasse wrote:
> > As I had commented some time ago, I wish the interval trees used [start,end)
> > intervals instead of [start,last] - it would be a better fit for basically
> > all of the current interval tree users.

So the vma_interval_tree (which is a pretty important user) tends to break this
pattern, as most lookups are [a,a]. We would have to update most of the
vma_interval_tree_foreach calls, for example, to now do [a,a+1[ such that we
don't break things. Some cases for the anon_vma_tree as well (ie memory-failure).

I'm not sure anymore it's worth going down this path as we end up exchanging one
hack for another (and the vma_interval_tree is a pretty big user); but I'm sure
you're aware of this and thus disagree.

Thanks,
Davidlohr