[PATCH 1/1] mm: Fix struct page layout on 32-bit systems

[Matthew Wilcox]

On Thu, Apr 15, 2021 at 09:11:56PM +0000, David Laight wrote:
> Isn't it possible to move the field down one long?
> This might require an explicit zero - but this is not a common
> code path - the extra write will be noise.

Then it overlaps page->mapping.  See emails passim.