From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com,
akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org,
rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com,
dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com,
bobby.prani@gmail.com, Alexander Gordeev <agordeev@redhat.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: [PATCH tip/core/rcu 03/12] rcu: Remove superfluous local variable in rcu_init_geometry()
Date: Fri, 17 Jul 2015 15:30:54 -0700 [thread overview]
Message-ID: <1437172263-15466-3-git-send-email-paulmck@linux.vnet.ibm.com> (raw)
In-Reply-To: <1437172263-15466-1-git-send-email-paulmck@linux.vnet.ibm.com>
From: Alexander Gordeev <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>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.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 fe8d92987dfa..ad49dbed44fb 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];
/*
@@ -4133,15 +4132,16 @@ static void __init rcu_init_geometry(void)
* The tree must be able to accommodate the configured number of CPUs.
* If this limit is exceeded than we have a serious problem elsewhere.
*/
- 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");
/* 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;
@@ -4152,7 +4152,7 @@ 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;
}
/*
--
1.8.1.5
next prev parent reply other threads:[~2015-07-17 22:33 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-17 22:30 [PATCH tip/core/rcu 0/12] Tree geometry-initialization simplifications for 4.3 Paul E. McKenney
2015-07-17 22:30 ` [PATCH tip/core/rcu 01/12] rcu: Provide more diagnostics for stalled GP kthread Paul E. McKenney
2015-07-17 22:30 ` [PATCH tip/core/rcu 02/12] rcu: Panic if RCU tree can not accommodate all CPUs Paul E. McKenney
2015-07-30 12:28 ` Peter Zijlstra
2015-07-30 15:25 ` Paul E. McKenney
2015-07-30 15:32 ` Peter Zijlstra
2015-07-30 15:34 ` Peter Zijlstra
2015-07-30 16:01 ` Paul E. McKenney
2015-07-30 15:54 ` Paul E. McKenney
2015-07-30 16:22 ` Peter Zijlstra
2015-07-31 15:53 ` Paul E. McKenney
2015-07-17 22:30 ` Paul E. McKenney [this message]
2015-07-17 22:30 ` [PATCH tip/core/rcu 04/12] rcu: Cleanup rcu_init_geometry() code and arithmetics Paul E. McKenney
2015-07-17 22:30 ` [PATCH tip/core/rcu 05/12] rcu: Simplify rcu_init_geometry() capacity arithmetics Paul E. McKenney
2015-07-17 22:30 ` [PATCH tip/core/rcu 06/12] rcu: Limit rcu_state::levelcnt[] to RCU_NUM_LVLS items Paul E. McKenney
2015-07-17 22:30 ` [PATCH tip/core/rcu 07/12] rcu: Limit rcu_capacity[] size " Paul E. McKenney
2015-07-17 22:30 ` [PATCH tip/core/rcu 08/12] rcu: Remove unnecessary fields from rcu_state structure Paul E. McKenney
2015-07-17 22:31 ` [PATCH tip/core/rcu 09/12] rcu: Limit count of static data to the number of RCU levels Paul E. McKenney
2015-07-17 22:31 ` [PATCH tip/core/rcu 10/12] rcu: Simplify arithmetic to calculate number of RCU nodes Paul E. McKenney
2015-07-17 22:31 ` [PATCH tip/core/rcu 11/12] rcu: Shut up bogus gcc array bounds warning Paul E. McKenney
2015-07-17 22:31 ` [PATCH tip/core/rcu 12/12] rcu: Reset rcu_fanout_leaf if out of bounds Paul E. McKenney
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1437172263-15466-3-git-send-email-paulmck@linux.vnet.ibm.com \
--to=paulmck@linux.vnet.ibm.com \
--cc=agordeev@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=bobby.prani@gmail.com \
--cc=dhowells@redhat.com \
--cc=dipankar@in.ibm.com \
--cc=dvhart@linux.intel.com \
--cc=edumazet@google.com \
--cc=fweisbec@gmail.com \
--cc=jiangshanlai@gmail.com \
--cc=josh@joshtriplett.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mathieu.desnoyers@efficios.com \
--cc=mingo@kernel.org \
--cc=oleg@redhat.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®