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authorIngo Molnar <mingo@elte.hu>2009-08-15 18:55:58 +0200
committerIngo Molnar <mingo@elte.hu>2009-08-15 18:56:13 +0200
commitfa08661af834875c9bd6f7f0b1b9388dc72a6585 (patch)
treec381fcfcfeb38515bfa93445c80ad9231343414d /Documentation/RCU
parent240ebbf81f149b11a31e060ebe5ee51a3c775360 (diff)
parent64f1607ffbbc772685733ea63e6f7f4183df1b16 (diff)
Merge commit 'v2.6.31-rc6' into core/rcu
Merge reason: the branch was on pre-rc1 .30, update to latest. Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'Documentation/RCU')
-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)