From: Alexander Gordeev <agordeev@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: Alexander Gordeev <agordeev@redhat.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: [PATCH 09/10] rcu: Simplify arithmetic to calculate number of RCU nodes
Date: Mon, 9 Mar 2015 09:34:13 +0100 [thread overview]
Message-ID: <6eabdcacc2871b726f5ed82a8b7220390fa02646.1425889432.git.agordeev@redhat.com> (raw)
In-Reply-To: <cover.1425889432.git.agordeev@redhat.com>
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>
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
---
kernel/rcu/tree.h | 17 ++++-------------
kernel/rcu/tree_plugin.h | 4 ++--
2 files changed, 6 insertions(+), 15 deletions(-)
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index cdb98e5..f12fe83 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -43,10 +43,7 @@
#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" }
@@ -54,9 +51,7 @@
# 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" }
@@ -65,8 +60,7 @@
# 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" }
@@ -76,7 +70,7 @@
# 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" }
@@ -84,9 +78,6 @@
# 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 2549f4b..cf1410f 100644
--- 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 (CONFIG_RCU_FANOUT_LEAF != 16)
pr_info("\tBuild-time adjustment of leaf fanout to %d.\n",
CONFIG_RCU_FANOUT_LEAF);
--
1.8.3.1
next prev parent reply other threads:[~2015-03-09 8:34 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-09 8:34 [PATCH 00/10] rcu: Cleanup RCU tree initialization Alexander Gordeev
2015-03-09 8:34 ` [PATCH 01/10] rcu: Panic if RCU tree can not accommodate all CPUs Alexander Gordeev
2015-03-09 8:34 ` [PATCH 02/10] rcu: Remove superfluous local variable in rcu_init_geometry() Alexander Gordeev
2015-03-09 8:34 ` [PATCH 03/10] rcu: Cleanup rcu_init_geometry() code and arithmetics Alexander Gordeev
2015-03-09 8:34 ` [PATCH 04/10] rcu: Simplify rcu_init_geometry() capacity arithmetics Alexander Gordeev
2015-03-09 8:34 ` [PATCH 05/10] rcu: Limit rcu_state::levelcnt[] to RCU_NUM_LVLS items Alexander Gordeev
2015-03-09 8:34 ` [PATCH 06/10] rcu: Limit rcu_capacity[] size " Alexander Gordeev
2015-03-09 8:34 ` [PATCH 07/10] rcu: Remove unnecessary fields from rcu_state structure Alexander Gordeev
2015-03-09 8:34 ` [PATCH 08/10] rcu: Limit count of static data to the number of RCU levels Alexander Gordeev
2015-03-09 8:34 ` Alexander Gordeev [this message]
2015-03-09 8:34 ` [PATCH 10/10] rcu: Remove unnecessary grpnum field from rcu_node structure Alexander Gordeev
2015-03-09 9:36 ` [PATCH 00/10] rcu: Cleanup RCU tree initialization Alexander Gordeev
2015-03-09 21:35 ` Paul E. McKenney
2015-03-10 14:33 ` Alexander Gordeev
2015-03-10 14:57 ` Paul E. McKenney
2015-03-09 21:40 ` Paul E. McKenney
2015-03-09 23:39 ` Paul E. McKenney
2015-03-09 23:49 ` Paul E. McKenney
2015-03-10 4:43 ` Paul E. McKenney
2015-03-10 14:39 ` Alexander Gordeev
2015-03-10 14:52 ` Paul E. McKenney
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