Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 42621697 authored by Alexander Gordeev's avatar Alexander Gordeev Committed by Paul E. McKenney
Browse files

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: default avatarAlexander Gordeev <agordeev@redhat.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
parent cb007102

kernel/rcu/tree.h

+4 −13
Original line number Diff line number Diff line
@@ -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;

kernel/rcu/tree_plugin.h

+2 −2
Original line number Diff line number Diff line
@@ -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);