Re: [PATCH 8/9] mm: Rearrange page flags

[Yosry Ahmed <yosryahmed@xxxxxxxxxx>]

On Mon, Aug 14, 2023 at 8:27 PM Matthew Wilcox (Oracle)
<willy@xxxxxxxxxxxxx> wrote:
>
> Move PG_writeback into bottom byte so that it can use PG_waiters in a
> later patch.  Move PG_head into bottom byte as well to match with where
> 'order' is moving next.

Sorry if that's obvious, but why do we want to move PG_head to where
'order' is moving? I thought we would want to avoid an overlap to
avoid mistaking the first tail page of a high-order compound page as a
head page?