mm/vmalloc.c: get rid of one single unlink_va() when merge

It does not make sense to try to "unlink" the node that is definitely not
linked with a list nor tree.  On the first merge step VA just points to
the previously disconnected busy area.

On the second step, check if the node has been merged and do "unlink" if
so, because now it points to an object that must be linked.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Uladzislau Rezki (Sony) <[email protected]>
Acked-by: Hillf Danton <[email protected]>
Reviewed-by: Roman Gushchin <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Oleksiy Avramchenko <[email protected]>
Cc: Steven Rostedt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 45e0dc0e09f80b632c0c0203815ed2486fffb18a..857dd8415a2e0a06e0d2dd2bf58d376cef4e7da1 100644 (file)
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -719,9 +719,6 @@ merge_or_add_vmap_area(struct vmap_area *va,
                        /* Check and update the tree if needed. */
                        augment_tree_propagate_from(sibling);
 
-                       /* Remove this VA, it has been merged. */
-                       unlink_va(va, root);
-
                        /* Free vmap_area object. */
                        kmem_cache_free(vmap_area_cachep, va);
 
@@ -746,12 +743,11 @@ merge_or_add_vmap_area(struct vmap_area *va,
                        /* Check and update the tree if needed. */
                        augment_tree_propagate_from(sibling);
 
-                       /* Remove this VA, it has been merged. */
-                       unlink_va(va, root);
+                       if (merged)
+                               unlink_va(va, root);
 
                        /* Free vmap_area object. */
                        kmem_cache_free(vmap_area_cachep, va);
-
                        return;
                }
        }