From: Steven Rostedt <rostedt@goodmis.org>
To: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: mingo@redhat.com, linux-kernel@vger.kernel.org, rostedt@goodmis.org
Subject: Re: [RFC] trace_irqsoff: remove redundant reset per-CPU buff
Date: Thu, 4 Feb 2016 21:40:45 -0500 [thread overview]
Message-ID: <20160204214045.1d6c2893@grimm.local.home> (raw)
In-Reply-To: <1445278226-16187-1-git-send-email-0x7f454c46@gmail.com>
On Mon, 19 Oct 2015 21:10:26 +0300
Dmitry Safonov <0x7f454c46@gmail.com> wrote:
> There is no reason to do it twice: from commit b6f11df26fdc28
> ("trace: Call tracing_reset_online_cpus before tracer->init()")
> resetting of per-CPU buffers done before tracer->init() call.
>
> tracer->init() calls {irqs,preempt,preemptirqs}off_tracer_init() and it
> calls __irqsoff_tracer_init(), which resets per-CPU ringbuffer second
> time.
> It's slowpath, but anyway.
Bah, I said I'd look at this and I did. But never added it to my queue.
It's not a big deal as this is the slow path but it makes sense. I knew
there was a patch from you to get but saw the TP_ARGS redefining patch
and thought that was it.
I Cc'd myself on this to make sure I see it again.
-- Steve
>
> Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
> ---
> kernel/trace/trace_irqsoff.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
> index 8523ea345f2b1a..4ebcb8bfaced24 100644
> --- a/kernel/trace/trace_irqsoff.c
> +++ b/kernel/trace/trace_irqsoff.c
> @@ -612,7 +612,6 @@ static int __irqsoff_tracer_init(struct trace_array *tr)
> irqsoff_trace = tr;
> /* make sure that the tracer is visible */
> smp_wmb();
> - tracing_reset_online_cpus(&tr->trace_buffer);
>
> ftrace_init_array_ops(tr, irqsoff_tracer_call);
>
next prev parent reply other threads:[~2016-02-05 2:40 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-19 18:10 [RFC] trace_irqsoff: remove redundant reset per-CPU buff Dmitry Safonov
2015-11-03 18:25 ` Dmitry Safonov
2015-11-03 18:37 ` Steven Rostedt
2016-02-05 2:40 ` Steven Rostedt [this message]
2016-02-05 11:52 ` Dmitry Safonov
2016-02-05 14:40 ` Steven Rostedt
2016-02-05 15:04 ` Steven Rostedt
2016-02-05 15:56 ` Dmitry Safonov
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