From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756894Ab3CRVR3 (ORCPT ); Mon, 18 Mar 2013 17:17:29 -0400 Received: from e37.co.us.ibm.com ([32.97.110.158]:40057 "EHLO e37.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756879Ab3CRVRZ (ORCPT ); Mon, 18 Mar 2013 17:17:25 -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, 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, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 7/7] rcu: Tone down debugging during boot-up and shutdown. Date: Mon, 18 Mar 2013 14:16:56 -0700 Message-Id: <1363641416-18642-7-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.1.5 In-Reply-To: <1363641416-18642-1-git-send-email-paulmck@linux.vnet.ibm.com> References: <20130318211615.GA15814@linux.vnet.ibm.com> <1363641416-18642-1-git-send-email-paulmck@linux.vnet.ibm.com> X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13031821-7408-0000-0000-00000DEE5C8B Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Paul E. McKenney" In some situations, randomly delaying RCU grace-period initialization can cause more trouble than help. This commit therefore restricts this type of RCU self-torture to runtime, giving it a rest during boot and shutdown. Reported-by: Sasha Levin Signed-off-by: Paul E. McKenney --- kernel/rcutree.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 71df6f9..0e52250 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1319,7 +1319,8 @@ static int rcu_gp_init(struct rcu_state *rsp) rnp->grphi, rnp->qsmask); raw_spin_unlock_irq(&rnp->lock); #ifdef CONFIG_PROVE_RCU_DELAY - if ((random32() % (rcu_num_nodes * 8)) == 0) + if ((random32() % (rcu_num_nodes * 8)) == 0 && + system_state == SYSTEM_RUNNING) schedule_timeout_uninterruptible(2); #endif /* #ifdef CONFIG_PROVE_RCU_DELAY */ cond_resched(); -- 1.8.1.5