Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934414AbbEMDWT (ORCPT ); Tue, 12 May 2015 23:22:19 -0400 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.228]:30764 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933961AbbEMDWR (ORCPT ); Tue, 12 May 2015 23:22:17 -0400 Date: Tue, 12 May 2015 23:22:32 -0400 From: Steven Rostedt To: "Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, dhowells@redhat.com, edumazet@google.com, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com, Alexander Gordeev Subject: Re: [PATCH tip/core/rcu 06/24] rcu: Cleanup rcu_init_geometry() code and arithmetics Message-ID: <20150512232232.3f3b23c6@grimm.local.home> In-Reply-To: <1431469854-3826-6-git-send-email-paulmck@linux.vnet.ibm.com> References: <20150512223034.GA1396@linux.vnet.ibm.com> <1431469854-3826-1-git-send-email-paulmck@linux.vnet.ibm.com> <1431469854-3826-6-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.25; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-RR-Connecting-IP: 107.14.168.118:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1713 Lines: 62 On Tue, 12 May 2015 15:30:36 -0700 "Paul E. McKenney" wrote: > @@ -4103,24 +4102,21 @@ static void __init rcu_init_geometry(void) > return; > } > > + /* Calculate the number of levels in the tree. */ > + for (i = 0; nr_cpu_ids > rcu_capacity[i]; i++) { Should this start at i = 1 as it use to? Also, should there be a safety check too: for (i = 1; i <= MAX_RCU_LVLS && nr_cpu_ids > rcu_capacity[i]; i++) { > + } > + rcu_num_lvls = i; > + > /* Calculate the number of rcu_nodes at each level of the tree. */ > - for (i = 1; i <= MAX_RCU_LVLS; i++) > - 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; > - break; > - } > + for (i = 0; i < rcu_num_lvls; i++) { Hmm, up above we have: for (j = 0; j <= i; j++) and now we have rcu_num_lvls = i, so shouldn't this be; for (i = 0; i <= rcu_num_lvls; i++) ? -- Steve > + int cap = rcu_capacity[rcu_num_lvls - i]; > + num_rcu_lvl[i] = DIV_ROUND_UP(nr_cpu_ids, cap); > + } > > /* Calculate the total number of rcu_node structures. */ > rcu_num_nodes = 0; > - for (i = 0; i <= MAX_RCU_LVLS; i++) > + for (i = 0; i < rcu_num_lvls; i++) > rcu_num_nodes += num_rcu_lvl[i]; > - rcu_num_nodes -= nr_cpu_ids; > } > > void __init rcu_init(void) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/