From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755928Ab0DOSNy (ORCPT ); Thu, 15 Apr 2010 14:13:54 -0400 Received: from e6.ny.us.ibm.com ([32.97.182.146]:33070 "EHLO e6.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755202Ab0DOSNu (ORCPT ); Thu, 15 Apr 2010 14:13:50 -0400 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, dvhltc@us.ibm.com, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, "Paul E. McKenney" Subject: [PATCH RFC tip/core/rcu 15/16] rcu: permit discontiguous cpu_possible_mask CPU numbering Date: Thu, 15 Apr 2010 11:13:38 -0700 Message-Id: <1271355219-20714-15-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.0 In-Reply-To: <20100415181255.GA19588@linux.vnet.ibm.com> References: <20100415181255.GA19588@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org TREE_RCU assumes that CPU numbering is contiguous, but some users need large holes in the numbering to better map to hardware layout. This patch makes TREE_RCU (and TREE_PREEMPT_RCU) tolerate large holes in the CPU numbering. However, NR_CPUS must still be greater than the largest CPU number. Signed-off-by: Paul E. McKenney --- kernel/rcutree.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/kernel/rcutree.c b/kernel/rcutree.c index f391886..c60fd74 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1913,7 +1913,7 @@ static void __init rcu_init_one(struct rcu_state *rsp) rnp = rsp->level[NUM_RCU_LVLS - 1]; for_each_possible_cpu(i) { - if (i > rnp->grphi) + while (i > rnp->grphi) rnp++; rsp->rda[i]->mynode = rnp; rcu_boot_init_percpu_data(i, rsp); -- 1.7.0