From: Steven Rostedt <rostedt@goodmis.org>
To: Matthias Kaehlcke <mka@chromium.org>
Cc: MyungJoo Ham <myungjoo.ham@samsung.com>,
Kyungmin Park <kyungmin.park@samsung.com>,
Chanwoo Choi <cw00.choi@samsung.com>,
Ingo Molnar <mingo@redhat.com>,
linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
Douglas Anderson <dianders@chromium.org>
Subject: Re: [PATCH] devfreq: Add tracepoint for frequency changes
Date: Thu, 19 Sep 2019 12:35:59 -0400 [thread overview]
Message-ID: <20190919123559.2931e0ef@gandalf.local.home> (raw)
In-Reply-To: <20190918191537.48837-1-mka@chromium.org>
On Wed, 18 Sep 2019 12:15:37 -0700
Matthias Kaehlcke <mka@chromium.org> wrote:
> Add a tracepoint for frequency changes of devfreq devices and
> use it.
>
> Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> ---
> drivers/devfreq/devfreq.c | 3 +++
> include/trace/events/devfreq.h | 18 ++++++++++++++++++
> 2 files changed, 21 insertions(+)
>
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index ab22bf8a12d6..32de1f6ac776 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -317,6 +317,9 @@ static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
>
> devfreq->previous_freq = new_freq;
>
> + if (new_freq != cur_freq)
I would make this:
if (trace_devfreq_frequency_enabled() && new_freq != cur_freq)
Because this would place the second check into the "nop" portion of the
code, keeping the test from being performed if the devfreq_frequency
trace point is not enabled. Slight micro optimization, but still enough
to add it.
-- Steve
> + trace_devfreq_frequency(devfreq, new_freq);
> +
> if (devfreq->suspend_freq)
> devfreq->resume_freq = cur_freq;
>
> diff --git a/include/trace/events/devfreq.h b/include/trace/events/devfreq.h
> index cf5b8772175d..a62d32fe3c33 100644
> --- a/include/trace/events/devfreq.h
> +++ b/include/trace/events/devfreq.h
> @@ -8,6 +8,24 @@
> #include <linux/devfreq.h>
> #include <linux/tracepoint.h>
>
> +TRACE_EVENT(devfreq_frequency,
> + TP_PROTO(struct devfreq *devfreq, unsigned long freq),
> +
> + TP_ARGS(devfreq, freq),
> +
> + TP_STRUCT__entry(
> + __string(dev_name, dev_name(&devfreq->dev))
> + __field(unsigned long, freq)
> + ),
> +
> + TP_fast_assign(
> + __assign_str(dev_name, dev_name(&devfreq->dev));
> + __entry->freq = freq;
> + ),
> +
> + TP_printk("dev_name=%s freq=%lu", __get_str(dev_name), __entry->freq)
> +);
> +
> TRACE_EVENT(devfreq_monitor,
> TP_PROTO(struct devfreq *devfreq),
>
next prev parent reply other threads:[~2019-09-19 16:36 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-18 19:15 [PATCH] devfreq: Add tracepoint for frequency changes Matthias Kaehlcke
2019-09-19 16:35 ` Steven Rostedt [this message]
2019-09-19 17:25 ` Matthias Kaehlcke
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190919123559.2931e0ef@gandalf.local.home \
--to=rostedt@goodmis.org \
--cc=cw00.choi@samsung.com \
--cc=dianders@chromium.org \
--cc=kyungmin.park@samsung.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=mka@chromium.org \
--cc=myungjoo.ham@samsung.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).