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-rw-r--r--mm/swap.c52
-rw-r--r--mm/vmscan.c18
2 files changed, 38 insertions, 32 deletions
diff --git a/mm/swap.c b/mm/swap.c
index b524ea90bddb..3045a0f4c451 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -209,19 +209,18 @@ int lru_add_drain_all(void)
*/
void fastcall __page_cache_release(struct page *page)
{
- unsigned long flags;
- struct zone *zone = page_zone(page);
+ if (PageLRU(page)) {
+ unsigned long flags;
+ struct zone *zone = page_zone(page);
- spin_lock_irqsave(&zone->lru_lock, flags);
- if (TestClearPageLRU(page))
+ spin_lock_irqsave(&zone->lru_lock, flags);
+ if (!TestClearPageLRU(page))
+ BUG();
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);
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
+ }
+ free_hot_page(page);
}
-
EXPORT_SYMBOL(__page_cache_release);
/*
@@ -245,7 +244,6 @@ void release_pages(struct page **pages, int nr, int cold)
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) {
@@ -259,23 +257,27 @@ void release_pages(struct page **pages, int nr, int cold)
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))
+ if (PageLRU(page)) {
+ struct zone *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))
+ BUG();
del_page_from_lru(zone, page);
- if (page_count(page) == 0) {
- if (!pagevec_add(&pages_to_free, page)) {
+ }
+
+ if (!pagevec_add(&pages_to_free, page)) {
+ if (zone) {
spin_unlock_irq(&zone->lru_lock);
- __pagevec_free(&pages_to_free);
- pagevec_reinit(&pages_to_free);
- zone = NULL; /* No lock is held */
+ zone = NULL;
}
- }
+ __pagevec_free(&pages_to_free);
+ pagevec_reinit(&pages_to_free);
+ }
}
if (zone)
spin_unlock_irq(&zone->lru_lock);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 4fe7e3aa02e2..acb7611cd525 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1085,21 +1085,25 @@ static int isolate_lru_pages(int nr_to_scan, struct list_head *src,
page = lru_to_page(src);
prefetchw_prev_lru_page(page, src, flags);
- if (!TestClearPageLRU(page))
- BUG();
list_del(&page->lru);
- if (get_page_testone(page)) {
+ if (unlikely(get_page_testone(page))) {
/*
* It is being freed elsewhere
*/
__put_page(page);
- SetPageLRU(page);
list_add(&page->lru, src);
continue;
- } else {
- list_add(&page->lru, dst);
- nr_taken++;
}
+
+ /*
+ * Be careful not to clear PageLRU until after we're sure
+ * the page is not being freed elsewhere -- the page release
+ * code relies on it.
+ */
+ if (!TestClearPageLRU(page))
+ BUG();
+ list_add(&page->lru, dst);
+ nr_taken++;
}
*scanned = scan;