Took Mark's suggestion on dropping _NOWAIT suffix on allocation macro.
Left the macro for symmetry with the FREE macros in the file.

I'd have to get the machine back to go drill down, but there's some caching allocations in there -- I don't think that's out of the norm.

With D24757:

Yeah, that makes sense given what we're seeing. I'll try it out and let you know.

Since I assume the latency split may be related, I booted "-v" and pulled the SRAT lines relevant to memory (you don't need all the CPU and table stuff, I assume). Left out all the 0 addr, 0 len disabled ones as well:

Hopefully everything you need/asked for in this attachment.

No custom calls that I know of (or can find on a quick double check of the code). May end up being one I missed, of course.
The domain 1 ranges I see with the problem are avail and contiguous, just split into separate ranges -- I'll get you the output you requested.

So -- just to run this by you, because obviously I want to get something you'll like for upstream -- assuming you agree, is there a reason we don't coalesce the phys_avail array as well? I'm thinking that would be the simplest solution as it would restore the assumption in the segment walk loop.
The other obvious possibility is to try to adjust the end of the avail range being considered if the next avail range is adjacent. I've prototyped that, and got something that mostly works (an earlier small segment in Domain 0 still wasn't added right, and I'd need to chase that down), but figured it makes much more sense to ping you at this point and see what you'd be thinking.
Thanks again.

Mark -- first, apologies for going off on the wrong track on this originally. I got the idea of the order being wrong from other triage comments and ran with that. Mea culpa.

In D27546#615650, @markj wrote:

which it isn't as that is at (SI_SUB_VM - 1) which is after CPU

I don't quite follow. SI_SUB_VM is before SI_SUB_CPU.

LGTM.

Moved new local variable n to appropriate spot in multiple declarations.

Looks like a straightforward copy of what we reviewed, yeah.

Updated per review comments -- did I miss anything?

Uploaded file for diff instead of cut/paste that was introducing a whitespace issue.