diff options
| author | Ingo Molnar <mingo@kernel.org> | 2016-09-16 09:08:43 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-09-16 09:08:43 +0200 |
| commit | 2d8fbcd13ea1d0be3a7ea5f20c3a5b44b592e79c (patch) | |
| tree | 5a88bad802e3c2e4f5d241b9596f9102db04f78e /include/linux/list.h | |
| parent | 024c7e3756d8a42fc41fe8a9488488b9b09d1dcc (diff) | |
| parent | d74b62bc3241af8ebf5141f5b12e89d9d7f341e1 (diff) | |
Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU changes from Paul E. McKenney:
- Expedited grace-period changes, most notably avoiding having
user threads drive expedited grace periods, using a workqueue
instead.
- Miscellaneous fixes, including a performance fix for lists
that was sent with the lists modifications (second URL below).
- CPU hotplug updates, most notably providing exact CPU-online
tracking for RCU. This will in turn allow removal of the
checks supporting RCU's prior heuristic that was based on the
assumption that CPUs would take no longer than one jiffy to
come online.
- Torture-test updates.
- Documentation updates.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/list.h')
| -rw-r--r-- | include/linux/list.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/include/linux/list.h b/include/linux/list.h index 5183138aa932..5809e9a2de5b 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -381,8 +381,11 @@ static inline void list_splice_tail_init(struct list_head *list, * * Note that if the list is empty, it returns NULL. */ -#define list_first_entry_or_null(ptr, type, member) \ - (!list_empty(ptr) ? list_first_entry(ptr, type, member) : NULL) +#define list_first_entry_or_null(ptr, type, member) ({ \ + struct list_head *head__ = (ptr); \ + struct list_head *pos__ = READ_ONCE(head__->next); \ + pos__ != head__ ? list_entry(pos__, type, member) : NULL; \ +}) /** * list_next_entry - get the next element in list |