summaryrefslogtreecommitdiffstats
path: root/mm/balloon_compaction.c
diff options
context:
space:
mode:
Diffstat (limited to 'mm/balloon_compaction.c')
-rw-r--r--mm/balloon_compaction.c26
1 files changed, 12 insertions, 14 deletions
diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c
index 6e45a5074bf0..52abeeb3cb9d 100644
--- a/mm/balloon_compaction.c
+++ b/mm/balloon_compaction.c
@@ -93,17 +93,12 @@ struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info)
* to be released by the balloon driver.
*/
if (trylock_page(page)) {
+ if (!PagePrivate(page)) {
+ /* raced with isolation */
+ unlock_page(page);
+ continue;
+ }
spin_lock_irqsave(&b_dev_info->pages_lock, flags);
- /*
- * Raise the page refcount here to prevent any wrong
- * attempt to isolate this page, in case of coliding
- * with balloon_page_isolate() just after we release
- * the page lock.
- *
- * balloon_page_free() will take care of dropping
- * this extra refcount later.
- */
- get_page(page);
balloon_page_delete(page);
spin_unlock_irqrestore(&b_dev_info->pages_lock, flags);
unlock_page(page);
@@ -187,7 +182,9 @@ static inline void __isolate_balloon_page(struct page *page)
{
struct balloon_dev_info *b_dev_info = page->mapping->private_data;
unsigned long flags;
+
spin_lock_irqsave(&b_dev_info->pages_lock, flags);
+ ClearPagePrivate(page);
list_del(&page->lru);
b_dev_info->isolated_pages++;
spin_unlock_irqrestore(&b_dev_info->pages_lock, flags);
@@ -197,7 +194,9 @@ static inline void __putback_balloon_page(struct page *page)
{
struct balloon_dev_info *b_dev_info = page->mapping->private_data;
unsigned long flags;
+
spin_lock_irqsave(&b_dev_info->pages_lock, flags);
+ SetPagePrivate(page);
list_add(&page->lru, &b_dev_info->pages);
b_dev_info->isolated_pages--;
spin_unlock_irqrestore(&b_dev_info->pages_lock, flags);
@@ -235,12 +234,11 @@ bool balloon_page_isolate(struct page *page)
*/
if (likely(trylock_page(page))) {
/*
- * A ballooned page, by default, has just one refcount.
+ * A ballooned page, by default, has PagePrivate set.
* Prevent concurrent compaction threads from isolating
- * an already isolated balloon page by refcount check.
+ * an already isolated balloon page by clearing it.
*/
- if (__is_movable_balloon_page(page) &&
- page_count(page) == 2) {
+ if (balloon_page_movable(page)) {
__isolate_balloon_page(page);
unlock_page(page);
return true;