From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754483Ab3KPA0Q (ORCPT ); Fri, 15 Nov 2013 19:26:16 -0500 Received: from e31.co.us.ibm.com ([32.97.110.149]:43663 "EHLO e31.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753780Ab3KPAXr (ORCPT ); Fri, 15 Nov 2013 19:23:47 -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, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, darren@dvhart.com, fweisbec@gmail.com, sbw@mit.edu, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 04/16] rcu: Allow task-level idle entry/exit nesting Date: Fri, 15 Nov 2013 16:23:26 -0800 Message-Id: <1384561418-30575-4-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.1.5 In-Reply-To: <1384561418-30575-1-git-send-email-paulmck@linux.vnet.ibm.com> References: <20131116002316.GA29049@linux.vnet.ibm.com> <1384561418-30575-1-git-send-email-paulmck@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13111600-8236-0000-0000-000003D80E2A Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Paul E. McKenney" The current task-level idle entry/exit code forces an entry/exit on each call, regardless of the nesting level. This commit therefore properly accounts for nesting. Signed-off-by: Paul E. McKenney Reviewed-by: Frederic Weisbecker --- kernel/rcu/tree.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index c01213b19dee..acbfead2eb82 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -418,11 +418,12 @@ static void rcu_eqs_enter(bool user) rdtp = this_cpu_ptr(&rcu_dynticks); oldval = rdtp->dynticks_nesting; WARN_ON_ONCE((oldval & DYNTICK_TASK_NEST_MASK) == 0); - if ((oldval & DYNTICK_TASK_NEST_MASK) == DYNTICK_TASK_NEST_VALUE) + if ((oldval & DYNTICK_TASK_NEST_MASK) == DYNTICK_TASK_NEST_VALUE) { rdtp->dynticks_nesting = 0; - else + rcu_eqs_enter_common(rdtp, oldval, user); + } else { rdtp->dynticks_nesting -= DYNTICK_TASK_NEST_VALUE; - rcu_eqs_enter_common(rdtp, oldval, user); + } } /** @@ -540,11 +541,12 @@ static void rcu_eqs_exit(bool user) rdtp = this_cpu_ptr(&rcu_dynticks); oldval = rdtp->dynticks_nesting; WARN_ON_ONCE(oldval < 0); - if (oldval & DYNTICK_TASK_NEST_MASK) + if (oldval & DYNTICK_TASK_NEST_MASK) { rdtp->dynticks_nesting += DYNTICK_TASK_NEST_VALUE; - else + } else { rdtp->dynticks_nesting = DYNTICK_TASK_EXIT_IDLE; - rcu_eqs_exit_common(rdtp, oldval, user); + rcu_eqs_exit_common(rdtp, oldval, user); + } } /** -- 1.8.1.5