}
/*
+ * isolated_balloon_page - identify an isolated balloon page on private
+ * compaction/migration page lists.
+ *
+ * After a compaction thread isolates a balloon page for migration, it raises
+ * the page refcount to prevent concurrent compaction threads from re-isolating
+ * the same page. For that reason putback_movable_pages(), or other routines
+ * that need to identify isolated balloon pages on private pagelists, cannot
+ * rely on balloon_page_movable() to accomplish the task.
+ */
+static inline bool isolated_balloon_page(struct page *page)
+{
+ /* Already isolated balloon pages, by default, have a raised refcount */
+ if (page_flags_cleared(page) && !page_mapped(page) &&
+ page_count(page) >= 2)
+ return __is_movable_balloon_page(page);
+
+ return false;
+}
+
+/*
* balloon_page_insert - insert a page into the balloon's page list and make
* the page->mapping assignment accordingly.
* @page : page to be assigned as a 'balloon page'
return false;
}
+static inline bool isolated_balloon_page(struct page *page)
+{
+ return false;
+}
+
static inline bool balloon_page_isolate(struct page *page)
{
return false;
list_del(&page->lru);
dec_zone_page_state(page, NR_ISOLATED_ANON +
page_is_file_cache(page));
- if (unlikely(balloon_page_movable(page)))
+ if (unlikely(isolated_balloon_page(page)))
balloon_page_putback(page);
else
putback_lru_page(page);
#include <asm/div64.h>
#include <linux/swapops.h>
+#include <linux/balloon_compaction.h>
#include "internal.h"
LIST_HEAD(clean_pages);
list_for_each_entry_safe(page, next, page_list, lru) {
- if (page_is_file_cache(page) && !PageDirty(page)) {
+ if (page_is_file_cache(page) && !PageDirty(page) &&
+ !isolated_balloon_page(page)) {
ClearPageActive(page);
list_move(&page->lru, &clean_pages);
}