From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753861AbbLIX0f (ORCPT ); Wed, 9 Dec 2015 18:26:35 -0500 Received: from e35.co.us.ibm.com ([32.97.110.153]:35511 "EHLO e35.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754489AbbLIXXx (ORCPT ); Wed, 9 Dec 2015 18:23:53 -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 3/9] rcutorture: Dump stack when GP kthread stalls Date: Wed, 9 Dec 2015 15:23:40 -0800 Message-Id: <1449703426-4025-3-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 2.5.2 In-Reply-To: <20151209232318.GA3299@linux.vnet.ibm.com> References: <20151209232318.GA3299@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15120923-0013-0000-0000-00001AE92BA0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This commit increases debug information in the case where the grace-period kthread is being prevented from running by dumping that kthread's stack. Signed-off-by: Paul E. McKenney [ paulmck: Split into prior commit and this commit, as suggested by Josh Triplett. ] Reviewed-by: Josh Triplett --- kernel/rcu/tree.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index e2315fb57b23..7b78c88e19a3 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1196,12 +1196,15 @@ static void rcu_check_gp_kthread_starvation(struct rcu_state *rsp) j = jiffies; gpa = READ_ONCE(rsp->gp_activity); - if (j - gpa > 2 * HZ) + if (j - gpa > 2 * HZ) { pr_err("%s kthread starved for %ld jiffies! g%lu c%lu f%#x s%d ->state=%#lx\n", rsp->name, j - gpa, rsp->gpnum, rsp->completed, rsp->gp_flags, rsp->gp_state, rsp->gp_kthread ? rsp->gp_kthread->state : ~0); + if (rsp->gp_kthread) + sched_show_task(rsp->gp_kthread); + } } /* -- 2.5.2