remarkable-linux/include/linux/pagevec.h
Johannes Weiner 0cd6144aad mm + fs: prepare for non-page entries in page cache radix trees
shmem mappings already contain exceptional entries where swap slot
information is remembered.

To be able to store eviction information for regular page cache, prepare
every site dealing with the radix trees directly to handle entries other
than pages.

The common lookup functions will filter out non-page entries and return
NULL for page cache holes, just as before.  But provide a raw version of
the API which returns non-page entries as well, and switch shmem over to
use it.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Luigi Semenzato <semenzato@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Metin Doslu <metin@citusdata.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Ozgun Erdogan <ozgun@citusdata.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin <klamm@yandex-team.ru>
Cc: Ryan Mallon <rmallon@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03 16:21:00 -07:00

73 lines
1.7 KiB
C

/*
* include/linux/pagevec.h
*
* In many places it is efficient to batch an operation up against multiple
* pages. A pagevec is a multipage container which is used for that.
*/
#ifndef _LINUX_PAGEVEC_H
#define _LINUX_PAGEVEC_H
/* 14 pointers + two long's align the pagevec structure to a power of two */
#define PAGEVEC_SIZE 14
struct page;
struct address_space;
struct pagevec {
unsigned long nr;
unsigned long cold;
struct page *pages[PAGEVEC_SIZE];
};
void __pagevec_release(struct pagevec *pvec);
void __pagevec_lru_add(struct pagevec *pvec);
unsigned pagevec_lookup_entries(struct pagevec *pvec,
struct address_space *mapping,
pgoff_t start, unsigned nr_entries,
pgoff_t *indices);
void pagevec_remove_exceptionals(struct pagevec *pvec);
unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping,
pgoff_t start, unsigned nr_pages);
unsigned pagevec_lookup_tag(struct pagevec *pvec,
struct address_space *mapping, pgoff_t *index, int tag,
unsigned nr_pages);
static inline void pagevec_init(struct pagevec *pvec, int cold)
{
pvec->nr = 0;
pvec->cold = cold;
}
static inline void pagevec_reinit(struct pagevec *pvec)
{
pvec->nr = 0;
}
static inline unsigned pagevec_count(struct pagevec *pvec)
{
return pvec->nr;
}
static inline unsigned pagevec_space(struct pagevec *pvec)
{
return PAGEVEC_SIZE - pvec->nr;
}
/*
* Add a page to a pagevec. Returns the number of slots still available.
*/
static inline unsigned pagevec_add(struct pagevec *pvec, struct page *page)
{
pvec->pages[pvec->nr++] = page;
return pagevec_space(pvec);
}
static inline void pagevec_release(struct pagevec *pvec)
{
if (pagevec_count(pvec))
__pagevec_release(pvec);
}
#endif /* _LINUX_PAGEVEC_H */