From: "Paul E. McKenney" <paulmck@kernel.org>
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com,
rostedt@goodmis.org,
Anna-Maria Behnsen <anna-maria@linutronix.de>,
Benedikt Spranger <b.spranger@linutronix.de>,
"Paul E . McKenney" <paulmck@kernel.org>
Subject: [PATCH rcu 02/12] rcu/torture: Change order of warning and trace dump
Date: Mon, 20 Jun 2022 15:58:07 -0700 [thread overview]
Message-ID: <20220620225817.3843106-2-paulmck@kernel.org> (raw)
In-Reply-To: <20220620225814.GA3842995@paulmck-ThinkPad-P17-Gen-1>
From: Anna-Maria Behnsen <anna-maria@linutronix.de>
Dumping a big ftrace buffer could lead to a RCU stall. So there is the
ftrace buffer and the stall information which needs to be printed. When
there is additionaly a WARN_ON() which describes the reason for the ftrace
buffer dump and the WARN_ON() is executed _after_ ftrace buffer dump, the
information get lost in the middle of the RCU stall information.
Therefore print WARN_ON() message before dumping the ftrace buffer in
rcu_torture_writer().
[ paulmck: Add tracing_off() to avoid cruft from WARN(). ]
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Reviewed-by: Benedikt Spranger <b.spranger@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
kernel/rcu/rcutorture.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 7120165a93426..3032dd7c7ad35 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1321,8 +1321,9 @@ rcu_torture_writer(void *arg)
if (list_empty(&rcu_tortures[i].rtort_free) &&
rcu_access_pointer(rcu_torture_current) !=
&rcu_tortures[i]) {
- rcu_ftrace_dump(DUMP_ALL);
+ tracing_off();
WARN(1, "%s: rtort_pipe_count: %d\n", __func__, rcu_tortures[i].rtort_pipe_count);
+ rcu_ftrace_dump(DUMP_ALL);
}
if (stutter_waited)
sched_set_normal(current, oldnice);
--
2.31.1.189.g2e36527f23
next prev parent reply other threads:[~2022-06-20 23:00 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-20 22:58 [PATCH rcu 0/12] Torture-test updates for v5.20 Paul E. McKenney
2022-06-20 22:58 ` [PATCH rcu 01/12] torture: Make kvm-remote.sh announce which system is being waited on Paul E. McKenney
2022-06-20 22:58 ` Paul E. McKenney [this message]
2022-06-20 22:58 ` [PATCH rcu 03/12] rcutorture: Simplify rcu_torture_read_exit_child() loop Paul E. McKenney
2022-06-20 22:58 ` [PATCH rcu 04/12] rcutorture: Fix memory leak in rcu_test_debug_objects() Paul E. McKenney
2022-06-20 22:58 ` [PATCH rcu 05/12] torture: Adjust to again produce debugging information Paul E. McKenney
2022-06-20 22:58 ` [PATCH rcu 06/12] rcutorture: Make failure indication note reader-batch overflow Paul E. McKenney
2022-06-20 22:58 ` [PATCH rcu 07/12] rcu/rcuscale: Fix smp_processor_id()-in-preemptible warnings Paul E. McKenney
2022-06-20 22:58 ` [PATCH rcu 08/12] torture: Create kvm-check-branches.sh output in proper location Paul E. McKenney
2022-06-20 22:58 ` [PATCH rcu 09/12] rcutorture: Fix ksoftirqd boosting timing and iteration Paul E. McKenney
2022-06-20 22:58 ` [PATCH rcu 10/12] rcutorture: Handle failure of memory allocation functions Paul E. McKenney
2022-06-20 22:58 ` [PATCH rcu 11/12] torture: Flush printk() buffers before powering off Paul E. McKenney
2022-06-20 23:23 ` John Ogness
2022-06-20 23:28 ` Paul E. McKenney
2022-06-21 8:09 ` John Ogness
2022-06-21 18:13 ` Paul E. McKenney
2022-06-21 20:52 ` John Ogness
2022-06-21 21:01 ` Paul E. McKenney
2022-06-20 22:58 ` [PATCH rcu 12/12] refscale: Convert test_lock spinlock to raw_spinlock Paul E. McKenney
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