include/linux/nodemask.h: create next_node_in() helper

Lots of code does

	node = next_node(node, XXX);
	if (node == MAX_NUMNODES)
		node = first_node(XXX);

so create next_node_in() to do this and use it in various places.

[mhocko@suse.com: use next_node_in() helper]
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Hui Zhu <zhuhui@xiaomi.com>
Cc: Wang Xiaoqiang <wangxq10@lzu.edu.cn>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 1 deletions

diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index 6e85889cf9ab..f746e44d4046 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -43,8 +43,10 @@
  *
  * int first_node(mask)			Number lowest set bit, or MAX_NUMNODES
  * int next_node(node, mask)		Next node past 'node', or MAX_NUMNODES
+ * int next_node_in(node, mask)		Next node past 'node', or wrap to first,
+ *					or MAX_NUMNODES
  * int first_unset_node(mask)		First node not set in mask, or 
- *					MAX_NUMNODES.
+ *					MAX_NUMNODES
  *
  * nodemask_t nodemask_of_node(node)	Return nodemask with bit 'node' set
  * NODE_MASK_ALL			Initializer - all bits set
@@ -259,6 +261,13 @@ static inline int __next_node(int n, const nodemask_t *srcp)
 	return min_t(int,MAX_NUMNODES,find_next_bit(srcp->bits, MAX_NUMNODES, n+1));
 }
 
+/*
+ * Find the next present node in src, starting after node n, wrapping around to
+ * the first node in src if needed.  Returns MAX_NUMNODES if src is empty.
+ */
+#define next_node_in(n, src) __next_node_in((n), &(src))
+int __next_node_in(int node, const nodemask_t *srcp);
+
 static inline void init_nodemask_of_node(nodemask_t *mask, int node)
 {
 	nodes_clear(*mask);