On Fri, Aug 22, 2008 at 11:48 PM, Daniel J Blueman <daniel.blueman@gmail.com> wrote:
That's quite funny :-)
It seems to be a similar problem as before, except that this is the free path, and not alloc.
You might try the appended patch -- but it's completely untested on my end!
What it does is to move the actual freeing until after we've released the hash-entry lock. In the cases of multiple objects freed, we enqueue all the objects on a local list.
Also added Thomas to Cc.
Vegard
PS: Why are you the only one seeing these things? Does debug_objects=1 need to be passed to activate this code, or can a CONFIG also be used?
diff --git a/lib/debugobjects.c b/lib/debugobjects.c
index 45a6bde..9d8161f 100644
--- a/lib/debugobjects.c
+++ b/lib/debugobjects.c
@@ -171,19 +171,28 @@ static void debug_objects_oom(void)
{
struct debug_bucket *db = obj_hash;
struct hlist_node *node, *tmp;
+ HLIST_HEAD(freelist);
struct debug_obj *obj;
unsigned long flags;
int i;
printk(KERN_WARNING "ODEBUG: Out of memory. ODEBUG disabled\n");
+ /* XXX: Could probably be optimized by transplantation of more than
+ * one entry at a time. */
for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
spin_lock_irqsave(&db->lock, flags);
hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) {
hlist_del(&obj->node);
- free_object(obj);
+ hlist_add_head(&obj->node, &freelist);
}
spin_unlock_irqrestore(&db->lock, flags);
+
+ /* Now free them */
+ hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) {
+ hlist_del(&obj->node);
+ free_object(obj);
+ }
}
}
@@ -498,8 +507,9 @@ void debug_object_free(void *addr, struct debug_obj_descr *descr)
return;
default:
hlist_del(&obj->node);
+ spin_unlock_irqrestore(&db->lock, flags);
free_object(obj);
- break;
+ return;
}
out_unlock:
spin_unlock_irqrestore(&db->lock, flags);
@@ -510,6 +520,7 @@ static void __debug_check_no_obj_freed(const void *address, unsigned long size)
{
unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
struct hlist_node *node, *tmp;
+ HLIST_HEAD(freelist);
struct debug_obj_descr *descr;
enum debug_obj_state state;
struct debug_bucket *db;
@@ -545,11 +556,18 @@ repeat:
goto repeat;
default:
hlist_del(&obj->node);
- free_object(obj);
+ hlist_add_head(&obj->node, &freelist);
break;
}
}
spin_unlock_irqrestore(&db->lock, flags);
+
+ /* Now free them */
+ hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) {
+ hlist_del(&obj->node);
+ free_object(obj);
+ }
+
if (cnt > debug_objects_maxchain)
debug_objects_maxchain = cnt;
}
--
