Re: [PATCH v5 02/12] mm: migrate: support non-lru movable page migration

Minchan Kim
2016-05-17T01:18:57Z

On Mon, May 16, 2016 at 04:17:51PM +0900, Sergey Senozhatsky wrote:
> On (05/09/16 11:20), Minchan Kim wrote:
> [..]
> > +++ b/include/linux/migrate.h
> > @@ -32,11 +32,16 @@ extern char *migrate_reason_names[MR_TYPES];
> >
> > #ifdef CONFIG_MIGRATION
> >
> > +extern int PageMovable(struct page *page);
> > +extern void __SetPageMovable(struct page *page, struct address_space *mapping);
> > +extern void __ClearPageMovable(struct page *page);
> > extern void putback_movable_pages(struct list_head *l);
> > extern int migrate_page(struct address_space *,
> > struct page *, struct page *, enum migrate_mode);
> > extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
> > unsigned long private, enum migrate_mode mode, int reason);
> > +extern bool isolate_movable_page(struct page *page, isolate_mode_t mode);
> > +extern void putback_movable_page(struct page *page);
> >
> > extern int migrate_prep(void);
> > extern int migrate_prep_local(void);
>
> given that some of Movable users can be built as modules, shouldn't
> at least some of those symbols be exported via EXPORT_SYMBOL?

Those functions aim for VM compaction so driver shouldn't use it.
Only driver should be aware of are __SetPageMovable and __CleraPageMovable.
I will export them.

Thanks for the review, Sergey!
>
> -ss