1 files changed, 26 insertions, 0 deletions

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 1227f8323e93..4b39e5eaf34f 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -1676,6 +1676,29 @@ static struct page *isolate_source_page(struct size_class *class)
         return page;
 }
 
+/*
+ *
+ * Based on the number of unused allocated objects calculate
+ * and return the number of pages that we can free.
+ *
+ * Should be called under class->lock.
+ */
+static unsigned long zs_can_compact(struct size_class *class)
+{
+        unsigned long obj_wasted;
+
+        if (!zs_stat_get(class, CLASS_ALMOST_EMPTY))
+                return 0;
+
+        obj_wasted = zs_stat_get(class, OBJ_ALLOCATED) -
+                zs_stat_get(class, OBJ_USED);
+
+        obj_wasted /= get_maxobj_per_zspage(class->size,
+                        class->pages_per_zspage);
+
+        return obj_wasted * get_pages_per_zspage(class->size);
+}
+
 static unsigned long __zs_compact(struct zs_pool *pool,
                                 struct size_class *class)
 {
@@ -1689,6 +1712,9 @@ static unsigned long __zs_compact(struct zs_pool *pool,
 
                 BUG_ON(!is_first_page(src_page));
 
+                if (!zs_can_compact(class))
+                        break;
+
                 cc.index = 0;
                 cc.s_page = src_page;