/*
* This path almost never happens for VM activity - pages are normally
* freed via pagevecs. But it gets used by networking.
*/
void fastcall __page_cache_release(struct page *page)
{
unsigned long flags;
struct zone *zone = page_zone(page);
spin_lock_irqsave(&zone->lru_lock, flags);
if (TestClearPageLRU(page))
del_page_from_lru(zone, page);
if (page_count(page) != 0)
page = NULL;
spin_unlock_irqrestore(&zone->lru_lock, flags);
if (page)
free_hot_page(page);
}
/*
* Batched page_cache_release(). Decrement the reference count on all the
* passed pages. If it fell to zero then remove the page from the LRU and
* free it.
*
* Avoid taking zone->lru_lock if possible, but if it is taken, retain it
* for the remainder of the operation.
*
* The locking in this function is against shrink_cache(): we recheck the
* page count inside the lock to see whether shrink_cache grabbed the page
* via the LRU. If it did, give up: shrink_cache will free it.
*/
void release_pages(struct page **pages, int nr, int cold)
{
int i;
struct pagevec pages_to_free;
struct zone *zone = NULL;
pagevec_init(&pages_to_free, cold);
for (i = 0; i < nr; i++) {
struct page *page = pages[i];
struct zone *pagezone;
if (unlikely(PageCompound(page))) {
if (zone) {
spin_unlock_irq(&zone->lru_lock);
zone = NULL;
}
put_compound_page(page);
continue;
}
if (!put_page_testzero(page))
continue;
pagezone = page_zone(page);
if (pagezone != zone) {
if (zone)
spin_unlock_irq(&zone->lru_lock);
zone = pagezone;
spin_lock_irq(&zone->lru_lock);
}
if (TestClearPageLRU(page))
del_page_from_lru(zone, page);
if (page_count(page) == 0) {
if (!pagevec_add(&pages_to_free, page)) {
spin_unlock_irq(&zone->lru_lock);
__pagevec_free(&pages_to_free);
pagevec_reinit(&pages_to_free);
zone = NULL; /* No lock is held */
}
}
}
if (zone)
spin_unlock_irq(&zone->lru_lock);
pagevec_free(&pages_to_free);
}
