From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965061AbcDLPCL (ORCPT ); Tue, 12 Apr 2016 11:02:11 -0400 Received: from e19.ny.us.ibm.com ([129.33.205.209]:53236 "EHLO e19.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964932AbcDLPCI (ORCPT ); Tue, 12 Apr 2016 11:02:08 -0400 X-IBM-Helo: d01dlp01.pok.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 tip/core/rcu 2/6] rcu: Awaken grace-period kthread when stalled Date: Tue, 12 Apr 2016 08:02:18 -0700 Message-Id: <1460473342-20836-2-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 2.5.2 In-Reply-To: <20160412150157.GA19367@linux.vnet.ibm.com> References: <20160412150157.GA19367@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16041215-0057-0000-0000-00000403EF3A Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Recent kernels can fail to awaken the grace-period kthread for quiescent-state forcing. This commit is a crude hack that does a wakeup any time a stall is detected. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 531a328076bd..a327a253c178 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1224,8 +1224,10 @@ static void rcu_check_gp_kthread_starvation(struct rcu_state *rsp) rsp->gp_flags, gp_state_getname(rsp->gp_state), rsp->gp_state, rsp->gp_kthread ? rsp->gp_kthread->state : ~0); - if (rsp->gp_kthread) + if (rsp->gp_kthread) { sched_show_task(rsp->gp_kthread); + wake_up_process(rsp->gp_kthread); + } } } -- 2.5.2