From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755241AbbAGRcs (ORCPT ); Wed, 7 Jan 2015 12:32:48 -0500 Received: from e35.co.us.ibm.com ([32.97.110.153]:41842 "EHLO e35.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754422AbbAGRcq (ORCPT ); Wed, 7 Jan 2015 12:32:46 -0500 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: 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, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 06/14] rcu: Shorten irq-disable region in rcu_cleanup_dead_cpu() Date: Wed, 7 Jan 2015 09:32:25 -0800 Message-Id: <1420651953-2651-6-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.1.5 In-Reply-To: <1420651953-2651-1-git-send-email-paulmck@linux.vnet.ibm.com> References: <20150107173215.GA897@linux.vnet.ibm.com> <1420651953-2651-1-git-send-email-paulmck@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15010717-0013-0000-0000-000007B5066F Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Paul E. McKenney" Now that we are not migrating callbacks, there is no need to hold the ->orphan_lock across the the ->qsmaskinit bit-clearing process. This commit therefore releases ->orphan_lock immediately after adopting the orphaned RCU callbacks. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 84f16cf05991..990b406faf4e 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2289,14 +2289,14 @@ static void rcu_cleanup_dead_cpu(int cpu, struct rcu_state *rsp) /* Orphan the dead CPU's callbacks, and adopt them if appropriate. */ rcu_send_cbs_to_orphanage(cpu, rsp, rnp, rdp); rcu_adopt_orphan_cbs(rsp, flags); + raw_spin_unlock_irqrestore(&rsp->orphan_lock, flags); /* Remove outgoing CPU from mask in the leaf rcu_node structure. */ - raw_spin_lock(&rnp->lock); /* irqs already disabled. */ + raw_spin_lock_irqsave(&rnp->lock, flags); smp_mb__after_unlock_lock(); /* Enforce GP memory-order guarantee. */ rnp->qsmaskinit &= ~rdp->grpmask; if (rnp->qsmaskinit == 0 && !rcu_preempt_has_tasks(rnp)) rcu_cleanup_dead_rnp(rnp); - raw_spin_unlock(&rsp->orphan_lock); /* irqs remain disabled. */ raw_spin_unlock_irqrestore(&rnp->lock, flags); WARN_ONCE(rdp->qlen != 0 || rdp->nxtlist != NULL, "rcu_cleanup_dead_cpu: Callbacks on offline CPU %d: qlen=%lu, nxtlist=%p\n", -- 1.8.1.5