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

[Minchan Kim]

On Mon, May 16, 2016 at 04:04:55PM +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);
> 
> __ClearPageMovable() is under CONFIG_MIGRATION in include/linux/migrate.h,
> but zsmalloc checks for CONFIG_COMPACTION.

Thanks!

PageMovable check function should be in compact.c, I think.
I will fix it.


> 
> can we have stub declarations of movable functions for !CONFIG_MIGRATION builds?
> otherwise the users (zsmalloc, for example) have to do things like
> 
> static void reset_page(struct page *page)
> {
> #ifdef CONFIG_COMPACTION
>         __ClearPageMovable(page);
> #endif
>         clear_bit(PG_private, &page->flags);
>         clear_bit(PG_private_2, &page->flags);
>         set_page_private(page, 0);
>         ClearPageHugeObject(page);
>         page->freelist = NULL;
> }
> 
> 	-ss