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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>,
	Steven Rostedt <rostedt@goodmis.org>
Subject: [PATCH v2 2/9] rcu: Remove superfluous local variable in rcu_init_geometry()
Date: Fri, 29 May 2015 11:53:38 +0200	[thread overview]
Message-ID: <d58e26ab843a42d54a4e729b7394848bbb1c2c45.1432889921.git.agordeev@redhat.com> (raw)
In-Reply-To: <cover.1432889921.git.agordeev@redhat.com>

Local variable 'n' mimics 'nr_cpu_ids' while the both are
used within one function. There is no reason for 'n' to
exist whatsoever.

Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
---
 kernel/rcu/tree.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 66a4230..6a418be 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -4083,7 +4083,6 @@ static void __init rcu_init_geometry(void)
 	ulong d;
 	int i;
 	int j;
-	int n = nr_cpu_ids;
 	int rcu_capacity[MAX_RCU_LVLS + 1];
 
 	/*
@@ -4126,7 +4125,7 @@ static void __init rcu_init_geometry(void)
 	 * the rcu_node masks.  Complain and fall back to the compile-
 	 * time values if these limits are exceeded.
 	 */
-	if (n > rcu_capacity[MAX_RCU_LVLS])
+	if (nr_cpu_ids > rcu_capacity[MAX_RCU_LVLS])
 		panic("rcu_init_geometry: rcu_capacity[] is too small");
 	else if (rcu_fanout_leaf < RCU_FANOUT_LEAF ||
 		 rcu_fanout_leaf > sizeof(unsigned long) * 8) {
@@ -4136,10 +4135,11 @@ static void __init rcu_init_geometry(void)
 
 	/* Calculate the number of rcu_nodes at each level of the tree. */
 	for (i = 1; i <= MAX_RCU_LVLS; i++)
-		if (n <= rcu_capacity[i]) {
-			for (j = 0; j <= i; j++)
-				num_rcu_lvl[j] =
-					DIV_ROUND_UP(n, rcu_capacity[i - j]);
+		if (nr_cpu_ids <= rcu_capacity[i]) {
+			for (j = 0; j <= i; j++) {
+				int cap = rcu_capacity[i - j];
+				num_rcu_lvl[j] = DIV_ROUND_UP(nr_cpu_ids, cap);
+			}
 			rcu_num_lvls = i;
 			for (j = i + 1; j <= MAX_RCU_LVLS; j++)
 				num_rcu_lvl[j] = 0;
@@ -4150,7 +4150,7 @@ static void __init rcu_init_geometry(void)
 	rcu_num_nodes = 0;
 	for (i = 0; i <= MAX_RCU_LVLS; i++)
 		rcu_num_nodes += num_rcu_lvl[i];
-	rcu_num_nodes -= n;
+	rcu_num_nodes -= nr_cpu_ids;
 }
 
 /*
-- 
1.8.3.1


  parent reply	other threads:[~2015-05-29  9:54 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-05-29  9:53 [PATCH v2 0/9] rcu: Cleanup RCU tree initialization Alexander Gordeev
2015-05-29  9:53 ` [PATCH v2 1/9] rcu: Panic if RCU tree can not accommodate all CPUs Alexander Gordeev
2015-06-01 18:37   ` Paul E. McKenney
2015-06-02  6:45     ` Alexander Gordeev
2015-06-02 12:37       ` Paul E. McKenney
2015-05-29  9:53 ` Alexander Gordeev [this message]
2015-05-29  9:53 ` [PATCH v2 3/9] rcu: Cleanup rcu_init_geometry() code and arithmetics Alexander Gordeev
2015-05-29  9:53 ` [PATCH v2 4/9] rcu: Simplify rcu_init_geometry() capacity arithmetics Alexander Gordeev
2015-05-29  9:53 ` [PATCH v2 5/9] rcu: Limit rcu_state::levelcnt[] to RCU_NUM_LVLS items Alexander Gordeev
2015-05-29  9:53 ` [PATCH v2 6/9] rcu: Limit rcu_capacity[] size " Alexander Gordeev
2015-05-29  9:53 ` [PATCH v2 7/9] rcu: Remove unnecessary fields from rcu_state structure Alexander Gordeev
2015-05-29  9:53 ` [PATCH v2 8/9] rcu: Limit count of static data to the number of RCU levels Alexander Gordeev
2015-05-29  9:53 ` [PATCH v2 9/9] rcu: Simplify arithmetic to calculate number of RCU nodes Alexander Gordeev
2015-06-01 18:58 ` [PATCH v2 0/9] rcu: Cleanup RCU tree initialization Paul E. McKenney

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