From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754245AbbLIXD1 (ORCPT ); Wed, 9 Dec 2015 18:03:27 -0500 Received: from e31.co.us.ibm.com ([32.97.110.149]:47961 "EHLO e31.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753834AbbLIXDY (ORCPT ); Wed, 9 Dec 2015 18:03:24 -0500 X-IBM-Helo: d03dlp02.boulder.ibm.com X-IBM-MailFrom: paulmck@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@kernel.org, jiangshanlai@gmail.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 v2 tip/core/rcu 06/11] rcu: Make expedited grace periods resolve stall-warning ties Date: Wed, 9 Dec 2015 15:03:03 -0800 Message-Id: <1449702188-493-6-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 2.5.2 In-Reply-To: <20151209230243.GA32518@linux.vnet.ibm.com> References: <20151209230243.GA32518@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15120923-8236-0000-0000-00001437AB75 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently, if a grace period ends just as the stall-warning timeout fires, an empty stall warning will be printed. This is not helpful, so this commit avoids these useless warnings by rechecking completion after awakening in synchronize_sched_expedited_wait(). Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 33d7e2551165..bc6b79716a86 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3757,7 +3757,7 @@ static void synchronize_sched_expedited_wait(struct rcu_state *rsp) rsp->expedited_wq, sync_rcu_preempt_exp_done(rnp_root), jiffies_stall); - if (ret > 0) + if (ret > 0 || sync_rcu_preempt_exp_done(rnp_root)) return; if (ret < 0) { /* Hit a signal, disable CPU stall warnings. */ -- 2.5.2