From 0edaf86cf1a6a97d811fc34765ddbcbc310de564 Mon Sep 17 00:00:00 2001
From: Andrew Morton <akpm@linux-foundation.org>
Date: Thu, 19 May 2016 17:10:58 -0700
Subject: 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>
---
 lib/Makefile   |  2 +-
 lib/nodemask.c | 30 ++++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)
 create mode 100644 lib/nodemask.c

(limited to 'lib')

diff --git a/lib/Makefile b/lib/Makefile
index 931396ada5eb..42b69185f963 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -25,7 +25,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
 	 sha1.o md5.o irq_regs.o argv_split.o \
 	 flex_proportions.o ratelimit.o show_mem.o \
 	 is_single_threaded.o plist.o decompress.o kobject_uevent.o \
-	 earlycpio.o seq_buf.o nmi_backtrace.o
+	 earlycpio.o seq_buf.o nmi_backtrace.o nodemask.o
 
 obj-$(CONFIG_ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS) += usercopy.o
 lib-$(CONFIG_MMU) += ioremap.o
diff --git a/lib/nodemask.c b/lib/nodemask.c
new file mode 100644
index 000000000000..e42a5bf44d33
--- /dev/null
+++ b/lib/nodemask.c
@@ -0,0 +1,30 @@
+#include <linux/nodemask.h>
+#include <linux/module.h>
+#include <linux/random.h>
+
+int __next_node_in(int node, const nodemask_t *srcp)
+{
+	int ret = __next_node(node, srcp);
+
+	if (ret == MAX_NUMNODES)
+		ret = __first_node(srcp);
+	return ret;
+}
+EXPORT_SYMBOL(__next_node_in);
+
+#ifdef CONFIG_NUMA
+/*
+ * Return the bit number of a random bit set in the nodemask.
+ * (returns NUMA_NO_NODE if nodemask is empty)
+ */
+int node_random(const nodemask_t *maskp)
+{
+	int w, bit = NUMA_NO_NODE;
+
+	w = nodes_weight(*maskp);
+	if (w)
+		bit = bitmap_ord_to_pos(maskp->bits,
+			get_random_int() % w, MAX_NUMNODES);
+	return bit;
+}
+#endif
-- 
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