Commit-ID: 15dba1e37b5cfd7fab9bc84e0f05f35c918f4eef Gitweb: http://git.kernel.org/tip/15dba1e37b5cfd7fab9bc84e0f05f35c918f4eef Author: Thomas Gleixner <[email protected]> AuthorDate: Mon, 4 Jul 2016 09:50:27 +0000 Committer: Ingo Molnar <[email protected]> CommitDate: Thu, 7 Jul 2016 10:35:07 +0200
hlist: Add hlist_is_singular_node() helper Required to figure out whether the entry is the only one in the hlist. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Frederic Weisbecker <[email protected]> Cc: Arjan van de Ven <[email protected]> Cc: Chris Mason <[email protected]> Cc: Eric Dumazet <[email protected]> Cc: George Spelvin <[email protected]> Cc: Josh Triplett <[email protected]> Cc: Len Brown <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Rik van Riel <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- include/linux/list.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/include/linux/list.h b/include/linux/list.h index 5356f4d..5183138 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -679,6 +679,16 @@ static inline bool hlist_fake(struct hlist_node *h) } /* + * Check whether the node is the only node of the head without + * accessing head: + */ +static inline bool +hlist_is_singular_node(struct hlist_node *n, struct hlist_head *h) +{ + return !n->next && n->pprev == &h->first; +} + +/* * Move a list from one list head to another. Fixup the pprev * reference of the first entry if it exists. */
