On Mon, 11 Jan 2021 21:40:15 +0200 Mike Rapoport [off-list ref] wrote:

Commit 73a6e474cb37 ("mm: memmap_init: iterate over
memblock regions rather that check each PFN") exposed several issues with
the memory map initialization and these patches fix those issues.

Initially there were crashes during compaction that Qian Cai reported back
in April [1]. It seemed back then that the problem was fixed, but a few
weeks ago Andrea Arcangeli hit the same bug [2] and there was an additional
discussion at [3].

The earlier version of these fixes had cc:stable.  Was the omission
this time deliberate?