rcu: Simplify arithmetic to calculate number of RCU nodes

This update makes arithmetic to calculate number of RCU nodes
more straight and easy to read.

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>

diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index d44856b6170afaf04cd82a0e1de712c4276102c9..581f8d3c5b289b66920ddf8af62913d245abe093 100644 (file)
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -64,10 +64,7 @@
 #if NR_CPUS <= RCU_FANOUT_1
 #  define RCU_NUM_LVLS       1
 #  define NUM_RCU_LVL_0              1
-#  define NUM_RCU_LVL_1              (NR_CPUS)
-#  define NUM_RCU_LVL_2              0
-#  define NUM_RCU_LVL_3              0
-#  define NUM_RCU_LVL_4              0
+#  define NUM_RCU_NODES              NUM_RCU_LVL_0
 #  define NUM_RCU_LVL_INIT    { NUM_RCU_LVL_0 }
 #  define RCU_NODE_NAME_INIT  { "rcu_node_0" }
 #  define RCU_FQS_NAME_INIT   { "rcu_node_fqs_0" }
@@ -75,9 +72,7 @@
 #  define RCU_NUM_LVLS       2
 #  define NUM_RCU_LVL_0              1
 #  define NUM_RCU_LVL_1              DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_1)
-#  define NUM_RCU_LVL_2              (NR_CPUS)
-#  define NUM_RCU_LVL_3              0
-#  define NUM_RCU_LVL_4              0
+#  define NUM_RCU_NODES              (NUM_RCU_LVL_0 + NUM_RCU_LVL_1)
 #  define NUM_RCU_LVL_INIT    { NUM_RCU_LVL_0, NUM_RCU_LVL_1 }
 #  define RCU_NODE_NAME_INIT  { "rcu_node_0", "rcu_node_1" }
 #  define RCU_FQS_NAME_INIT   { "rcu_node_fqs_0", "rcu_node_fqs_1" }
@@ -86,8 +81,7 @@
 #  define NUM_RCU_LVL_0              1
 #  define NUM_RCU_LVL_1              DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_2)
 #  define NUM_RCU_LVL_2              DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_1)
-#  define NUM_RCU_LVL_3              (NR_CPUS)
-#  define NUM_RCU_LVL_4              0
+#  define NUM_RCU_NODES              (NUM_RCU_LVL_0 + NUM_RCU_LVL_1 + NUM_RCU_LVL_2)
 #  define NUM_RCU_LVL_INIT    { NUM_RCU_LVL_0, NUM_RCU_LVL_1, NUM_RCU_LVL_2 }
 #  define RCU_NODE_NAME_INIT  { "rcu_node_0", "rcu_node_1", "rcu_node_2" }
 #  define RCU_FQS_NAME_INIT   { "rcu_node_fqs_0", "rcu_node_fqs_1", "rcu_node_fqs_2" }
@@ -97,7 +91,7 @@
 #  define NUM_RCU_LVL_1              DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_3)
 #  define NUM_RCU_LVL_2              DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_2)
 #  define NUM_RCU_LVL_3              DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_1)
-#  define NUM_RCU_LVL_4              (NR_CPUS)
+#  define NUM_RCU_NODES              (NUM_RCU_LVL_0 + NUM_RCU_LVL_1 + NUM_RCU_LVL_2 + NUM_RCU_LVL_3)
 #  define NUM_RCU_LVL_INIT    { NUM_RCU_LVL_0, NUM_RCU_LVL_1, NUM_RCU_LVL_2, NUM_RCU_LVL_3 }
 #  define RCU_NODE_NAME_INIT  { "rcu_node_0", "rcu_node_1", "rcu_node_2", "rcu_node_3" }
 #  define RCU_FQS_NAME_INIT   { "rcu_node_fqs_0", "rcu_node_fqs_1", "rcu_node_fqs_2", "rcu_node_fqs_3" }
@@ -105,9 +99,6 @@
 # error "CONFIG_RCU_FANOUT insufficient for NR_CPUS"
 #endif /* #if (NR_CPUS) <= RCU_FANOUT_1 */
 
-#define RCU_SUM (NUM_RCU_LVL_0 + NUM_RCU_LVL_1 + NUM_RCU_LVL_2 + NUM_RCU_LVL_3 + NUM_RCU_LVL_4)
-#define NUM_RCU_NODES (RCU_SUM - NR_CPUS)
-
 extern int rcu_num_lvls;
 extern int rcu_num_nodes;
 

diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 013485fb2b06b9f499d0673a36bf8f62d5e72607..5dac0a10a985fb6c0869d08ed9e26709b1a39771 100644 (file)
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -84,8 +84,8 @@ static void __init rcu_bootup_announce_oddness(void)
                pr_info("\tRCU torture testing starts during boot.\n");
        if (IS_ENABLED(CONFIG_RCU_CPU_STALL_INFO))
                pr_info("\tAdditional per-CPU info printed with stalls.\n");
-       if (NUM_RCU_LVL_4 != 0)
-               pr_info("\tFour-level hierarchy is enabled.\n");
+       if (RCU_NUM_LVLS >= 4)
+               pr_info("\tFour(or more)-level hierarchy is enabled.\n");
        if (RCU_FANOUT_LEAF != 16)
                pr_info("\tBuild-time adjustment of leaf fanout to %d.\n",
                        RCU_FANOUT_LEAF);