kernel-ark/include/linux/mm_inline.h
Johannes Weiner 6c0b13519d mm: return boolean from page_is_file_cache()
page_is_file_cache() has been used for both boolean checks and LRU
arithmetic, which was always a bit weird.

Now that page_lru_base_type() exists for LRU arithmetic, make
page_is_file_cache() a real predicate function and adjust the
boolean-using callsites to drop those pesky double negations.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:37 -07:00

96 lines
2.3 KiB
C

#ifndef LINUX_MM_INLINE_H
#define LINUX_MM_INLINE_H
/**
* page_is_file_cache - should the page be on a file LRU or anon LRU?
* @page: the page to test
*
* Returns 1 if @page is page cache page backed by a regular filesystem,
* or 0 if @page is anonymous, tmpfs or otherwise ram or swap backed.
* Used by functions that manipulate the LRU lists, to sort a page
* onto the right LRU list.
*
* We would like to get this info without a page flag, but the state
* needs to survive until the page is last deleted from the LRU, which
* could be as far down as __page_cache_release.
*/
static inline int page_is_file_cache(struct page *page)
{
return !PageSwapBacked(page);
}
static inline void
add_page_to_lru_list(struct zone *zone, struct page *page, enum lru_list l)
{
list_add(&page->lru, &zone->lru[l].list);
__inc_zone_state(zone, NR_LRU_BASE + l);
mem_cgroup_add_lru_list(page, l);
}
static inline void
del_page_from_lru_list(struct zone *zone, struct page *page, enum lru_list l)
{
list_del(&page->lru);
__dec_zone_state(zone, NR_LRU_BASE + l);
mem_cgroup_del_lru_list(page, l);
}
/**
* page_lru_base_type - which LRU list type should a page be on?
* @page: the page to test
*
* Used for LRU list index arithmetic.
*
* Returns the base LRU type - file or anon - @page should be on.
*/
static inline enum lru_list page_lru_base_type(struct page *page)
{
if (page_is_file_cache(page))
return LRU_INACTIVE_FILE;
return LRU_INACTIVE_ANON;
}
static inline void
del_page_from_lru(struct zone *zone, struct page *page)
{
enum lru_list l;
list_del(&page->lru);
if (PageUnevictable(page)) {
__ClearPageUnevictable(page);
l = LRU_UNEVICTABLE;
} else {
l = page_lru_base_type(page);
if (PageActive(page)) {
__ClearPageActive(page);
l += LRU_ACTIVE;
}
}
__dec_zone_state(zone, NR_LRU_BASE + l);
mem_cgroup_del_lru_list(page, l);
}
/**
* page_lru - which LRU list should a page be on?
* @page: the page to test
*
* Returns the LRU list a page should be on, as an index
* into the array of LRU lists.
*/
static inline enum lru_list page_lru(struct page *page)
{
enum lru_list lru;
if (PageUnevictable(page))
lru = LRU_UNEVICTABLE;
else {
lru = page_lru_base_type(page);
if (PageActive(page))
lru += LRU_ACTIVE;
}
return lru;
}
#endif