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>

5 files changed, 10 insertions, 44 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 19d0d08b396f..5856093f9062 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -937,9 +937,7 @@ err:
  */
 static int next_node_allowed(int nid, nodemask_t *nodes_allowed)
 {
-	nid = next_node(nid, *nodes_allowed);
-	if (nid == MAX_NUMNODES)
-		nid = first_node(*nodes_allowed);
+	nid = next_node_in(nid, *nodes_allowed);
 	VM_BUG_ON(nid >= MAX_NUMNODES);
 
 	return nid;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index fe787f5c41bd..6740c4c2b550 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1389,9 +1389,7 @@ int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
 	mem_cgroup_may_update_nodemask(memcg);
 	node = memcg->last_scanned_node;
 
-	node = next_node(node, memcg->scan_nodes);
-	if (node == MAX_NUMNODES)
-		node = first_node(memcg->scan_nodes);
+	node = next_node_in(node, memcg->scan_nodes);
 	/*
 	 * We call this when we hit limit, not when pages are added to LRU.
 	 * No LRU may hold pages because all pages are UNEVICTABLE or
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 36cc01bc950a..8d369cee0cd6 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -97,7 +97,6 @@
 
 #include <asm/tlbflush.h>
 #include <asm/uaccess.h>
-#include <linux/random.h>
 
 #include "internal.h"
 
@@ -347,9 +346,7 @@ static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes,
 		BUG();
 
 	if (!node_isset(current->il_next, tmp)) {
-		current->il_next = next_node(current->il_next, tmp);
-		if (current->il_next >= MAX_NUMNODES)
-			current->il_next = first_node(tmp);
+		current->il_next = next_node_in(current->il_next, tmp);
 		if (current->il_next >= MAX_NUMNODES)
 			current->il_next = numa_node_id();
 	}
@@ -1709,9 +1706,7 @@ static unsigned interleave_nodes(struct mempolicy *policy)
 	struct task_struct *me = current;
 
 	nid = me->il_next;
-	next = next_node(nid, policy->v.nodes);
-	if (next >= MAX_NUMNODES)
-		next = first_node(policy->v.nodes);
+	next = next_node_in(nid, policy->v.nodes);
 	if (next < MAX_NUMNODES)
 		me->il_next = next;
 	return nid;
@@ -1805,21 +1800,6 @@ static inline unsigned interleave_nid(struct mempolicy *pol,
 		return interleave_nodes(pol);
 }
 
-/*
- * 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;
-}
-
 #ifdef CONFIG_HUGETLBFS
 /*
  * huge_zonelist(@vma, @addr, @gfp_flags, @mpol)
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index c4f568206544..67bedd18429c 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -288,13 +288,10 @@ struct page *alloc_migrate_target(struct page *page, unsigned long private,
 	 * accordance with memory policy of the user process if possible. For
 	 * now as a simple work-around, we use the next node for destination.
 	 */
-	if (PageHuge(page)) {
-		int node = next_online_node(page_to_nid(page));
-		if (node == MAX_NUMNODES)
-			node = first_online_node;
+	if (PageHuge(page))
 		return alloc_huge_page_node(page_hstate(compound_head(page)),
-					    node);
-	}
+					    next_node_in(page_to_nid(page),
+							 node_online_map));
 
 	if (PageHighMem(page))
 		gfp_mask |= __GFP_HIGHMEM;
diff --git a/mm/slab.c b/mm/slab.c
index d81565a92864..c11bf5007952 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -522,22 +522,15 @@ static DEFINE_PER_CPU(unsigned long, slab_reap_node);
 
 static void init_reap_node(int cpu)
 {
-	int node;
-
-	node = next_node(cpu_to_mem(cpu), node_online_map);
-	if (node == MAX_NUMNODES)
-		node = first_node(node_online_map);
-
-	per_cpu(slab_reap_node, cpu) = node;
+	per_cpu(slab_reap_node, cpu) = next_node_in(cpu_to_mem(cpu),
+						    node_online_map);
 }
 
 static void next_reap_node(void)
 {
 	int node = __this_cpu_read(slab_reap_node);
 
-	node = next_node(node, node_online_map);
-	if (unlikely(node >= MAX_NUMNODES))
-		node = first_node(node_online_map);
+	node = next_node_in(node, node_online_map);
 	__this_cpu_write(slab_reap_node, node);
 }