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>

1 files changed, 31 insertions, 1 deletions

diff --git a/mm/slub.c b/mm/slub.c
index c937233127e2..64c2b2bfbd79 100644
--- 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);
 }