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authorAndrew Morton <akpm@linux-foundation.org>2016-05-19 17:10:58 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-19 19:12:14 -0700
commit0edaf86cf1a6a97d811fc34765ddbcbc310de564 (patch)
tree5ba3b435651e8d8459b577d74ce8bb3f24dd44a1 /lib/nodemask.c
parent48a270554a3251681ae11173f2fd6389d943e183 (diff)
downloadlinux-0edaf86cf1a6a97d811fc34765ddbcbc310de564.tar.bz2
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>
Diffstat (limited to 'lib/nodemask.c')
-rw-r--r--lib/nodemask.c30
1 files changed, 30 insertions, 0 deletions
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