Re: [PATCH 1/3] mm,hugetlb: use folio fields in second tail page

From: Hugh Dickins
Date: Wed Nov 09 2022 - 21:10:22 EST


On Wed, 9 Nov 2022, Sidhartha Kumar wrote:
> On 11/3/22 9:29 PM, Hugh Dickins wrote:
> >
> >> Should the usage of page_1 and page_2 also be documented here?
> > You must have something interesting in mind to document about them,
> > but I cannot guess what! They are for field alignment, not for use.
> > (page_2 to help when/if someone needs to add another pageful.)
> >
> > Do you mean that I should copy the
> > /* private: the union with struct page is transitional */
> > comment from above the original "struct page page;" line I copied?
> > Or give all three of them a few underscores to imply not for use?
>
> I think the underscores with a comment about not for use could be helpful.

I've given them two underscores (but not to the original "struct page page",
since a build showed that used as "page" elsewhere, not just for alignment).

I'm sorry, but I've not given them any comment: I don't think they
belong in the commented fields section (_flags_1 etc), "page" is not
there; and I'm, let's be honest, terrified of dabbling in this kerneldoc
area - feel very fortunate to have escaped attack by a robot for my
additions so far. I'll leave adding comment to you or other cognoscenti.

Hugh