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From: Peter Zijlstra <peterz@infradead.org>
To: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Ingo Molnar <mingo@kernel.org>,
	"Joel Fernandes (Google)" <joel@joelfernandes.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Josh Triplett <josh@joshtriplett.org>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Lai Jiangshan <jiangshanlai@gmail.com>
Subject: Re: [PATCH v2] tracing/perf: Move rcu_irq_enter/exit_irqson() to perf trace point hook
Date: Wed, 12 Feb 2020 09:05:22 +0100	[thread overview]
Message-ID: <20200212080522.GP14897@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20200211185457.GN2935@paulmck-ThinkPad-P72>

On Tue, Feb 11, 2020 at 10:54:57AM -0800, Paul E. McKenney wrote:
> On Tue, Feb 11, 2020 at 06:32:13PM +0100, Peter Zijlstra wrote:
> > On Tue, Feb 11, 2020 at 06:29:52PM +0100, Peter Zijlstra wrote:
> > > +#define trace_rcu_enter()					\
> > > +({								\
> > > +	unsigned long state = 0;				\
> > > +	if (!rcu_is_watching())	{				\
> > 
> > Also, afaict rcu_is_watching() itself needs more love, the functio has
> > notrace, but calls other stuff that does not have notrace or inline.
> 
> Good catch!  Like this?
> 
> 							Thanx, Paul
> 
> ------------------------------------------------------------------------
> 
> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> index 1f5fdf7..51616e72 100644
> --- a/kernel/rcu/tree.c
> +++ b/kernel/rcu/tree.c
> @@ -295,7 +295,7 @@ static void rcu_dynticks_eqs_online(void)
>   *
>   * No ordering, as we are sampling CPU-local information.
>   */
> -static bool rcu_dynticks_curr_cpu_in_eqs(void)
> +static bool notrace rcu_dynticks_curr_cpu_in_eqs(void)

Right, except that, given the size of the thing, I'd opt for 'inline'
over 'notrace'.

  reply	other threads:[~2020-02-12  8:06 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-11 14:50 [PATCH v2] tracing/perf: Move rcu_irq_enter/exit_irqson() to perf trace point hook Steven Rostedt
2020-02-11 15:34 ` Mathieu Desnoyers
2020-02-11 15:46   ` Peter Zijlstra
2020-02-11 16:02     ` Mathieu Desnoyers
2020-02-11 15:34 ` Peter Zijlstra
2020-02-11 16:18   ` Steven Rostedt
2020-02-11 16:27     ` Mathieu Desnoyers
2020-02-11 16:35       ` Steven Rostedt
2020-02-11 17:29     ` Peter Zijlstra
2020-02-11 17:32       ` Peter Zijlstra
2020-02-11 18:54         ` Paul E. McKenney
2020-02-12  8:05           ` Peter Zijlstra [this message]
2020-02-12  9:05             ` Paul E. McKenney
2020-02-11 17:35       ` Mathieu Desnoyers
2020-02-12  8:02         ` Peter Zijlstra
2020-02-12 15:14           ` Mathieu Desnoyers

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