Comment 52 for bug 1674838

the only big mm changes pulled in from 4.11.x that I could find with a quick look through the history are related to KSM, but those are missing a later fixup (from 4.11.x as well):

d75450ff40df0199bf13dfb19f435519ff947138 which fixes ace71a19cec5 ("mm: introduce page_vma_mapped_walk()")

ace71a19cec5 was first contained in Ubuntu-4.10.0-14.16, which AFAICT fits nicely into the working/non-working kernels reported by various users here?

there are also a few other commits by the same upstream author, which do not explicitly contain any followup/fixes tags but touch similar code, some of which were picked.

since I cannot reproduce the problem at hand, I cannot tell whether including that fixup helps, but it might be worth a shot.