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| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-06-08 22:34:53 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-06-08 22:34:53 -0700 |
| commit | 38a4671cad3f0d277cf48445b49e42a475ebfb6a (patch) | |
| tree | 7348f3dd5f4e1bec39758dcff748a9dcbbf3430c /include/linux/rculist_nulls.h | |
| parent | d652f7022b359afd5d34fc9fffd71df118521ead (diff) | |
| parent | 317ddd256b9c24b0d78fa8018f80f1e495481a10 (diff) | |
Merge 3.10-rc5 into char-misc-next
Diffstat (limited to 'include/linux/rculist_nulls.h')
| -rw-r--r-- | include/linux/rculist_nulls.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/include/linux/rculist_nulls.h b/include/linux/rculist_nulls.h index 2ae13714828b..1c33dd7da4a7 100644 --- a/include/linux/rculist_nulls.h +++ b/include/linux/rculist_nulls.h @@ -105,9 +105,14 @@ static inline void hlist_nulls_add_head_rcu(struct hlist_nulls_node *n, * @head: the head for your list. * @member: the name of the hlist_nulls_node within the struct. * + * The barrier() is needed to make sure compiler doesn't cache first element [1], + * as this loop can be restarted [2] + * [1] Documentation/atomic_ops.txt around line 114 + * [2] Documentation/RCU/rculist_nulls.txt around line 146 */ #define hlist_nulls_for_each_entry_rcu(tpos, pos, head, member) \ - for (pos = rcu_dereference_raw(hlist_nulls_first_rcu(head)); \ + for (({barrier();}), \ + pos = rcu_dereference_raw(hlist_nulls_first_rcu(head)); \ (!is_a_nulls(pos)) && \ ({ tpos = hlist_nulls_entry(pos, typeof(*tpos), member); 1; }); \ pos = rcu_dereference_raw(hlist_nulls_next_rcu(pos))) |