From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751878AbbCGSDp (ORCPT ); Sat, 7 Mar 2015 13:03:45 -0500 Received: from e38.co.us.ibm.com ([32.97.110.159]:40223 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751692AbbCGSDn (ORCPT ); Sat, 7 Mar 2015 13:03:43 -0500 Date: Sat, 7 Mar 2015 10:03:37 -0800 From: "Paul E. McKenney" To: Alexander Gordeev Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/9] rcu: Remove superfluous local variable in rcu_init_geometry() Message-ID: <20150307180337.GM5236@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <64e1493699d370fa423c97e836b523650822ecd0.1425735920.git.agordeev@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <64e1493699d370fa423c97e836b523650822ecd0.1425735920.git.agordeev@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15030718-0029-0000-0000-00000867D192 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Mar 07, 2015 at 06:03:37PM +0100, Alexander Gordeev wrote: > 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" > Signed-off-by: Alexander Gordeev Good catch! Could you please port this to branch rcu/next of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git? Thanx, Paul > --- > 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 7588c7f..fb89630 100644 > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -3855,7 +3855,6 @@ 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]; > > /* > @@ -3898,7 +3897,7 @@ 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 < CONFIG_RCU_FANOUT_LEAF || > rcu_fanout_leaf > sizeof(unsigned long) * 8) { > @@ -3908,10 +3907,11 @@ 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; > @@ -3922,7 +3922,7 @@ 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; > } > > void __init rcu_init(void) > -- > 1.8.3.1 >