mm/zsmalloc: take obj index back from find_alloced_obj

the obj index value should be updated after return from
find_alloced_obj() to avoid CPU burning caused by unnecessary object
scanning.

Link: http://lkml.kernel.org/r/1467882338-4300-2-git-send-email-opensource.ganesh@gmail.com
Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 2 deletions

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 0b4790e81193..49143de9934c 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -1741,10 +1741,11 @@ static void zs_object_copy(struct size_class *class, unsigned long dst,
  * return handle.
  */
 static unsigned long find_alloced_obj(struct size_class *class,
-                                        struct page *page, int index)
+                                        struct page *page, int *obj_idx)
 {
         unsigned long head;
         int offset = 0;
+        int index = *obj_idx;
         unsigned long handle = 0;
         void *addr = kmap_atomic(page);
 
@@ -1765,6 +1766,9 @@ static unsigned long find_alloced_obj(struct size_class *class,
         }
 
         kunmap_atomic(addr);
+
+        *obj_idx = index;
+
         return handle;
 }
 
@@ -1790,7 +1794,7 @@ static int migrate_zspage(struct zs_pool *pool, struct size_class *class,
         int ret = 0;
 
         while (1) {
-                handle = find_alloced_obj(class, s_page, obj_idx);
+                handle = find_alloced_obj(class, s_page, &obj_idx);
                 if (!handle) {
                         s_page = get_next_page(s_page);
                         if (!s_page)