/*
* This moves pages from the active list to
* the inactive list.
*
* We move them the other way when we see the
* reference bit on the page.
*/
static void refill_inactive(int nr_pages, zone_t * classzone)
{
struct list_head * entry;
unsigned long ratio;
ratio = (unsigned long) nr_pages * classzone->nr_active_pages / (((unsigned long) classzone->nr_inactive_pages * vm_lru_balance_ratio) + 1);
entry = active_list.prev;
while (ratio && entry != &active_list) {
struct page * page;
page = list_entry(entry, struct page, lru);
entry = entry->prev;
if (PageTestandClearReferenced(page)) {
list_del(&page->lru);
list_add(&page->lru, &active_list);
continue;
}
ratio--;
del_page_from_active_list(page);
add_page_to_inactive_list(page);
SetPageReferenced(page);
}
if (entry != &active_list) {
list_del(&active_list);
list_add(&active_list, entry);
}
}
/*
* This moves pages from the active list to
* the inactive list.
*
* We move them the other way when we see the
* reference bit on the page.
*/
static void refill_inactive(int nr_pages)
{
struct list_head * entry;
spin_lock(&pagemap_lru_lock);
entry = active_list.prev;
while (nr_pages && entry != &active_list) {
struct page * page;
page = list_entry(entry, struct page, lru);
entry = entry->prev;
if (PageTestandClearReferenced(page)) {
list_del(&page->lru);
list_add(&page->lru, &active_list);
continue;
}
nr_pages--;
del_page_from_active_list(page);
add_page_to_inactive_list(page);
SetPageReferenced(page);
}
spin_unlock(&pagemap_lru_lock);
}
/*
* Isolate one page from the LRU lists. If successful put it onto
* the indicated list with elevated page count.
*
* Result:
* -EBUSY: page not on LRU list
* 0: page removed from LRU list and added to the specified list.
*/
int isolate_lru_page(struct page *page, struct list_head *pagelist)
{
int ret = -EBUSY;
if (PageLRU(page)) {
struct zone *zone = page_zone(page);
spin_lock_irq(&zone->lru_lock);
if (PageLRU(page) && get_page_unless_zero(page)) {
ret = 0;
ClearPageLRU(page);
if (PageActive(page))
del_page_from_active_list(zone, page);
else
del_page_from_inactive_list(zone, page);
list_add_tail(&page->lru, pagelist);
}
spin_unlock_irq(&zone->lru_lock);
}
return ret;
}
