From: Steven Rostedt <rostedt@goodmis.org>
To: "Paul E. McKenney" <paulmck@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Linux Trace Kernel <linux-trace-kernel@vger.kernel.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Joel Fernandes <joel@joelfernandes.org>,
Tom Zanussi <zanussi@kernel.org>
Subject: Re: [PATCH] tracing: Add trace_trigger kernel command line option
Date: Thu, 20 Oct 2022 13:05:28 -0400 [thread overview]
Message-ID: <20221020130528.5f7436c3@gandalf.local.home> (raw)
In-Reply-To: <20221020123357.0f90e823@gandalf.local.home>
On Thu, 20 Oct 2022 12:33:57 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index c03fd7037add..79ac31a6a87b 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -2748,9 +2748,12 @@ void trace_buffered_event_disable(void)
> disable_trace_buffered_event, NULL, 1);
> preempt_enable();
>
> + if (!irqs_disabled())
> + printk("IRQS DISABLED!! before %s:%d\n", __func__, __LINE__);
> /* Wait for all current users to finish */
> - if (!early_boot_irqs_disabled)
> - synchronize_rcu();
> + synchronize_rcu();
> + if (!irqs_disabled())
> + printk("IRQS DISABLED!! after %s:%d\n", __func__, __LINE__);
>
> for_each_tracing_cpu(cpu) {
> free_page((unsigned long)per_cpu(trace_buffered_event, cpu));
Continuing the above printk()s I found the culprit.
synchronize_rcu() {
rcu_poll_gp_seq_start_unlocked() {
struct rcu_node *rnp = rcu_get_root();
if (rcu_init_invoked()) {
lockdep_assert_irqs_enabled();
raw_spin_lock_irq_rcu_node(rnp);
}
rcu_poll_gp_seq_start(snap);
if (rcu_init_invoked())
raw_spin_unlock_irq_rcu_node(rnp); <<-- Interrupts enabled here
}
-- Steve
next prev parent reply other threads:[~2022-10-20 17:05 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-20 0:01 [PATCH] tracing: Add trace_trigger kernel command line option Steven Rostedt
2022-10-20 0:07 ` Steven Rostedt
2022-10-20 15:59 ` Paul E. McKenney
2022-10-20 16:33 ` Steven Rostedt
2022-10-20 16:44 ` Joel Fernandes
2022-10-20 17:05 ` Steven Rostedt [this message]
2022-10-20 17:55 ` Paul E. McKenney
2022-10-20 18:53 ` Steven Rostedt
2022-10-20 22:21 ` Paul E. McKenney
2022-10-20 22:23 ` Steven Rostedt
2022-10-20 17:54 ` Paul E. McKenney
2022-10-20 7:49 ` kernel test robot
2022-10-20 8:50 ` kernel test robot
2022-10-20 14:33 ` Masami Hiramatsu
2022-10-20 15:20 ` Steven Rostedt
2022-10-20 14:43 ` Joel Fernandes
2022-10-20 14:52 ` Joel Fernandes
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