[PATCH v2 12/46] mm/memcg: Use the node id in mem_cgroup_update_tree()

["Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>]

Hoist the page_to_nid() call from mem_cgroup_page_nodeinfo() into
mem_cgroup_update_tree().  That lets us call soft_limit_tree_node()
and delete soft_limit_tree_from_page() altogether.  Saves 42
bytes of kernel text on my config.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
 mm/memcontrol.c | 17 ++++-------------
 1 file changed, 4 insertions(+), 13 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 1204c6a0c671..7423cb11eb88 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -453,10 +453,8 @@ ino_t page_cgroup_ino(struct page *page)
 }
 
 static struct mem_cgroup_per_node *
-mem_cgroup_page_nodeinfo(struct mem_cgroup *memcg, struct page *page)
+mem_cgroup_nodeinfo(struct mem_cgroup *memcg, int nid)
 {
-	int nid = page_to_nid(page);
-
 	return memcg->nodeinfo[nid];
 }
 
@@ -466,14 +464,6 @@ soft_limit_tree_node(int nid)
 	return soft_limit_tree.rb_tree_per_node[nid];
 }
 
-static struct mem_cgroup_tree_per_node *
-soft_limit_tree_from_page(struct page *page)
-{
-	int nid = page_to_nid(page);
-
-	return soft_limit_tree.rb_tree_per_node[nid];
-}
-
 static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_node *mz,
 					 struct mem_cgroup_tree_per_node *mctz,
 					 unsigned long new_usage_in_excess)
@@ -549,8 +539,9 @@ static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page)
 	unsigned long excess;
 	struct mem_cgroup_per_node *mz;
 	struct mem_cgroup_tree_per_node *mctz;
+	int nid = page_to_nid(page);
 
-	mctz = soft_limit_tree_from_page(page);
+	mctz = soft_limit_tree_node(nid);
 	if (!mctz)
 		return;
 	/*
@@ -558,7 +549,7 @@ static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page)
 	 * because their event counter is not touched.
 	 */
 	for (; memcg; memcg = parent_mem_cgroup(memcg)) {
-		mz = mem_cgroup_page_nodeinfo(memcg, page);
+		mz = mem_cgroup_nodeinfo(memcg, nid);
 		excess = soft_limit_excess(memcg);
 		/*
 		 * We have to update the tree if mz is on RB-tree or
-- 
2.30.2