Re: [PATCH 1/6] mm/page_alloc: Add page->buddy_list and page->pcp_list

[Mel Gorman <mgorman@techsingularity.net>]

On Fri, May 13, 2022 at 04:41:20PM +0800, Muchun Song wrote:
> > @@ -94,6 +95,10 @@ struct page {
> >  					/* Count page's or folio's mlocks */
> >  					unsigned int mlock_count;
> >  				};
> > +
> > +				/* Or, free page */
> > +				struct list_head buddy_list;
> > +				struct list_head pcp_list;
> >  			};
> 
> Since you have clarified "lru" member, should we go further?
> Like union "index" to "pcp_migratetype" and "private" to "order"
> since buddy allocator reuses "index" and "private" as well.
> My initial idea is as follows, it is more clear for me, what
> do you think?
> 

I think it would be more appropriate to split it out as a separate type as
suggested by Matthew Wilcox. While I would not be opposed to your approach
as such, it's outside the context of the series which is modifying how
PCP works.

-- 
Mel Gorman
SUSE Labs