Commit 15dba1e3 authored Jul 04, 2016 by Thomas Gleixner Committed by Ingo Molnar Jul 07, 2016

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>

parent 2b1ecc3d

include/linux/list.h

+10 −0

Original line number	Diff line number	Diff line
		@@ -678,6 +678,16 @@ static inline bool hlist_fake(struct hlist_node *h)
		return h->pprev == &h->next;
		}

		/*
		* 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.