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authorDavid S. Miller <davem@davemloft.net>2009-07-16 17:34:50 -0700
committerDavid S. Miller <davem@davemloft.net>2009-07-16 17:34:50 -0700
commit95aa1fe4abfc8d75dcd110bb285b09740214d053 (patch)
tree668998047f77fe5d7f76ecbceec73a4f4c8311a6 /Documentation
parentb13bb2e9933b9dfa25c81d959d847c843481111e (diff)
parent941297f443f871b8c3372feccf27a8733f6ce9e9 (diff)
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/kaber/nf-2.6
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/RCU/rculist_nulls.txt7
1 files changed, 6 insertions, 1 deletions
diff --git a/Documentation/RCU/rculist_nulls.txt b/Documentation/RCU/rculist_nulls.txt
index 93cb28d05dcd..18f9651ff23d 100644
--- a/Documentation/RCU/rculist_nulls.txt
+++ b/Documentation/RCU/rculist_nulls.txt
@@ -83,11 +83,12 @@ not detect it missed following items in original chain.
obj = kmem_cache_alloc(...);
lock_chain(); // typically a spin_lock()
obj->key = key;
-atomic_inc(&obj->refcnt);
/*
* we need to make sure obj->key is updated before obj->next
+ * or obj->refcnt
*/
smp_wmb();
+atomic_set(&obj->refcnt, 1);
hlist_add_head_rcu(&obj->obj_node, list);
unlock_chain(); // typically a spin_unlock()
@@ -159,6 +160,10 @@ out:
obj = kmem_cache_alloc(cachep);
lock_chain(); // typically a spin_lock()
obj->key = key;
+/*
+ * changes to obj->key must be visible before refcnt one
+ */
+smp_wmb();
atomic_set(&obj->refcnt, 1);
/*
* insert obj in RCU way (readers might be traversing chain)