Commit 10331795 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
Browse files

pagevec: Add folio_batch 



The folio_batch is the same as the pagevec, except that it is typed
to contain folios and not pages.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarWilliam Kucharski <william.kucharski@oracle.com>
parent a229a4f0

include/linux/pagevec.h

+69 −0
Original line number Original line Diff line number Diff line
@@ -15,8 +15,10 @@ 
#define PAGEVEC_SIZE	15

#define PAGEVEC_SIZE	15





struct page;

struct page;

struct folio;

struct address_space;

struct address_space;





/* Layout must match folio_batch */

struct pagevec {

struct pagevec {

	unsigned char nr;

	unsigned char nr;

	bool percpu_pvec_drained;

	bool percpu_pvec_drained;
@@ -81,4 +83,71 @@ static inline void pagevec_release(struct pagevec *pvec) 
		__pagevec_release(pvec);

		__pagevec_release(pvec);

}

}





/**

 * struct folio_batch - A collection of folios.

 *

 * The folio_batch is used to amortise the cost of retrieving and

 * operating on a set of folios.  The order of folios in the batch may be

 * significant (eg delete_from_page_cache_batch()).  Some users of the

 * folio_batch store "exceptional" entries in it which can be removed

 * by calling folio_batch_remove_exceptionals().

 */

struct folio_batch {

	unsigned char nr;

	bool percpu_pvec_drained;

	struct folio *folios[PAGEVEC_SIZE];

};



/* Layout must match pagevec */

static_assert(sizeof(struct pagevec) == sizeof(struct folio_batch));

static_assert(offsetof(struct pagevec, pages) ==

		offsetof(struct folio_batch, folios));



/**

 * folio_batch_init() - Initialise a batch of folios

 * @fbatch: The folio batch.

 *

 * A freshly initialised folio_batch contains zero folios.

 */

static inline void folio_batch_init(struct folio_batch *fbatch)

{

	fbatch->nr = 0;

}



static inline unsigned int folio_batch_count(struct folio_batch *fbatch)

{

	return fbatch->nr;

}



static inline unsigned int fbatch_space(struct folio_batch *fbatch)

{

	return PAGEVEC_SIZE - fbatch->nr;

}



/**

 * folio_batch_add() - Add a folio to a batch.

 * @fbatch: The folio batch.

 * @folio: The folio to add.

 *

 * The folio is added to the end of the batch.

 * The batch must have previously been initialised using folio_batch_init().

 *

 * Return: The number of slots still available.

 */

static inline unsigned folio_batch_add(struct folio_batch *fbatch,

		struct folio *folio)

{

	fbatch->folios[fbatch->nr++] = folio;

	return fbatch_space(fbatch);

}



static inline void folio_batch_release(struct folio_batch *fbatch)

{

	pagevec_release((struct pagevec *)fbatch);

}



static inline void folio_batch_remove_exceptionals(struct folio_batch *fbatch)

{

	pagevec_remove_exceptionals((struct pagevec *)fbatch);

}

#endif /* _LINUX_PAGEVEC_H */
 
#endif /* _LINUX_PAGEVEC_H */