rcu: Limit count of static data to the number of RCU levels

Although a number of RCU levels may be less than the current
maximum of four, some static data associated with each level
are allocated for all four levels. As result, the extra data
never get accessed and just wast memory. This update limits
count of allocated items to the number of used RCU levels.

Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

1 files changed, 4 insertions, 17 deletions

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 7226e25ba97f..e53bbc53bcd5 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -124,13 +124,8 @@ module_param(rcu_fanout_exact, bool, 0444);
 static int rcu_fanout_leaf = RCU_FANOUT_LEAF;
 module_param(rcu_fanout_leaf, int, 0444);
 int rcu_num_lvls __read_mostly = RCU_NUM_LVLS;
-static int num_rcu_lvl[] = {  /* Number of rcu_nodes at specified level. */
-        NUM_RCU_LVL_0,
-        NUM_RCU_LVL_1,
-        NUM_RCU_LVL_2,
-        NUM_RCU_LVL_3,
-        NUM_RCU_LVL_4,
-};
+/* Number of rcu_nodes at specified level. */
+static int num_rcu_lvl[] = NUM_RCU_LVL_INIT;
 int rcu_num_nodes __read_mostly = NUM_RCU_NODES; /* Total # rcu_nodes in use. */
 
 /*
@@ -3994,16 +3989,8 @@ static void __init rcu_init_levelspread(int *levelspread, const int *levelcnt)
 static void __init rcu_init_one(struct rcu_state *rsp,
                 struct rcu_data __percpu *rda)
 {
-        static const char * const buf[] = {
-                "rcu_node_0",
-                "rcu_node_1",
-                "rcu_node_2",
-                "rcu_node_3" };
-        static const char * const fqs[] = {
-                "rcu_node_fqs_0",
-                "rcu_node_fqs_1",
-                "rcu_node_fqs_2",
-                "rcu_node_fqs_3" };
+        static const char * const buf[] = RCU_NODE_NAME_INIT;
+        static const char * const fqs[] = RCU_FQS_NAME_INIT;
         static u8 fl_mask = 0x1;
 
         int levelcnt[RCU_NUM_LVLS];             /* # nodes in each level. */