From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755843Ab3AEQ7Q (ORCPT ); Sat, 5 Jan 2013 11:59:16 -0500 Received: from e32.co.us.ibm.com ([32.97.110.150]:47123 "EHLO e32.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755768Ab3AEQ7O (ORCPT ); Sat, 5 Jan 2013 11:59:14 -0500 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, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, edumazet@google.com, darren@dvhart.com, fweisbec@gmail.com, sbw@mit.edu, patches@linaro.org, Paul Gortmaker , "Paul E. McKenney" Subject: [PATCH tip/core/urgent 1/2] rcu: Prevent soft-lockup complaints about no-CBs CPUs Date: Sat, 5 Jan 2013 08:58:50 -0800 Message-Id: <1357405131-13421-1-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.8 In-Reply-To: <20130105165817.GA13260@linux.vnet.ibm.com> References: <20130105165817.GA13260@linux.vnet.ibm.com> X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13010516-5406-0000-0000-000003E570DE Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paul Gortmaker The wait_event() at the head of the rcu_nocb_kthread() can result in soft-lockup complaints if the CPU in question does not register RCU callbacks for an extended period. This commit therefore changes the wait_event() to a wait_event_interruptible(). Reported-by: Frederic Weisbecker Signed-off-by: Paul Gortmaker Signed-off-by: Paul E. McKenney --- kernel/rcutree_plugin.h | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index f6e5ec2..43dba2d 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -2366,10 +2366,11 @@ static int rcu_nocb_kthread(void *arg) for (;;) { /* If not polling, wait for next batch of callbacks. */ if (!rcu_nocb_poll) - wait_event(rdp->nocb_wq, rdp->nocb_head); + wait_event_interruptible(rdp->nocb_wq, rdp->nocb_head); list = ACCESS_ONCE(rdp->nocb_head); if (!list) { schedule_timeout_interruptible(1); + flush_signals(current); continue; } -- 1.7.8