slub: Dump list of objects not freed on kmem_cache_close()

Dump a list of unfreed objects if a slab cache is closed but
objects still remain.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

diff --git a/mm/slub.c b/mm/slub.c
index c937233127e2db963690a3dc0e978daa5ed38769..64c2b2bfbd7993f4e03e3bd4d3c99c5e0eebeffa 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2371,6 +2371,32 @@ const char *kmem_cache_name(struct kmem_cache *s)
 }
 EXPORT_SYMBOL(kmem_cache_name);
 
+static void list_slab_objects(struct kmem_cache *s, struct page *page,
+                                                       const char *text)
+{
+#ifdef CONFIG_SLUB_DEBUG
+       void *addr = page_address(page);
+       void *p;
+       DECLARE_BITMAP(map, page->objects);
+
+       bitmap_zero(map, page->objects);
+       slab_err(s, page, "%s", text);
+       slab_lock(page);
+       for_each_free_object(p, s, page->freelist)
+               set_bit(slab_index(p, s, addr), map);
+
+       for_each_object(p, s, addr, page->objects) {
+
+               if (!test_bit(slab_index(p, s, addr), map)) {
+                       printk(KERN_ERR "INFO: Object 0x%p @offset=%tu\n",
+                                                       p, p - addr);
+                       print_tracking(s, p);
+               }
+       }
+       slab_unlock(page);
+#endif
+}
+
 /*
  * Attempt to free all partial slabs on a node.
  */
@@ -2380,12 +2406,16 @@ static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
        struct page *page, *h;
 
        spin_lock_irqsave(&n->list_lock, flags);
-       list_for_each_entry_safe(page, h, &n->partial, lru)
+       list_for_each_entry_safe(page, h, &n->partial, lru) {
                if (!page->inuse) {
                        list_del(&page->lru);
                        discard_slab(s, page);
                        n->nr_partial--;
+               } else {
+                       list_slab_objects(s, page,
+                               "Objects remaining on kmem_cache_close()");
                }
+       }
        spin_unlock_irqrestore(&n->list_lock, flags);
 }