| Date | Thu, 7 Jul 2016 01:44:25 -0700 | From | tip-bot for Thomas Gleixner <> | Subject | [tip:timers/core] hlist: Add hlist_is_singular_node() helper |
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Commit-ID: 15dba1e37b5cfd7fab9bc84e0f05f35c918f4eef Gitweb: http://git.kernel.org/tip/15dba1e37b5cfd7fab9bc84e0f05f35c918f4eef Author: Thomas Gleixner <tglx@linutronix.de> AuthorDate: Mon, 4 Jul 2016 09:50:27 +0000 Committer: Ingo Molnar <mingo@kernel.org> 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 <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Chris Mason <clm@fb.com> Cc: Eric Dumazet <edumazet@google.com> Cc: George Spelvin <linux@sciencehorizons.net> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160704094341.867631372@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org> --- 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. */
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