linux-kernel - Re: [PATCH v6 4/5] devfreq_cooling: add trace information

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20151014115329.GA2998@e104805>
Date:	Wed, 14 Oct 2015 12:53:30 +0100
From:	Javi Merino <javi.merino@....com>
To:	Steven Rostedt <rostedt@...dmis.org>
Cc:	"linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"cw00.choi@...sung.com" <cw00.choi@...sung.com>,
	"edubezval@...il.com" <edubezval@...il.com>,
	Zhang Rui <rui.zhang@...el.com>, Ingo Molnar <mingo@...hat.com>
Subject: Re: [PATCH v6 4/5] devfreq_cooling: add trace information

Hi Steve,

On Thu, Sep 10, 2015 at 06:19:28PM +0100, Steven Rostedt wrote:
> On Thu, 10 Sep 2015 18:09:31 +0100
> Javi Merino <javi.merino@....com> wrote:
> 
> > Tracing is useful for debugging and performance tuning.  Add similar
> > traces to what's present in the cpu cooling device.
> > 
> > Cc: Zhang Rui <rui.zhang@...el.com>
> > Cc: Eduardo Valentin <edubezval@...il.com>
> > Cc: Steven Rostedt <rostedt@...dmis.org>
> > Cc: Ingo Molnar <mingo@...hat.com>
> > Signed-off-by: Javi Merino <javi.merino@....com>
> > ---
> >  drivers/thermal/devfreq_cooling.c |  6 +++++
> >  include/trace/events/thermal.h    | 53 +++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 59 insertions(+)
> > 
> > diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c
> > index a032c5d5c374..a27206815066 100644
> > --- a/drivers/thermal/devfreq_cooling.c
> > +++ b/drivers/thermal/devfreq_cooling.c
> > @@ -25,6 +25,8 @@
> >  #include <linux/pm_opp.h>
> >  #include <linux/thermal.h>
> >  
> > +#include <trace/events/thermal.h>
> > +
> >  static DEFINE_MUTEX(devfreq_lock);
> >  static DEFINE_IDR(devfreq_idr);
> >  
> > @@ -293,6 +295,9 @@ static int devfreq_cooling_get_requested_power(struct thermal_cooling_device *cd
> >  	/* Get static power */
> >  	static_power = get_static_power(dfc, freq);
> >  
> > +	trace_thermal_power_devfreq_get_power(cdev, status, freq, dyn_power,
> > +					      static_power);
> > +
> >  	*power = dyn_power + static_power;
> >  
> >  	return 0;
> > @@ -348,6 +353,7 @@ static int devfreq_cooling_power2state(struct thermal_cooling_device *cdev,
> >  			break;
> >  
> >  	*state = i;
> > +	trace_thermal_power_devfreq_limit(cdev, freq, *state, power);
> 
> I'm curious, does changing the above to:
> 
> 	trace_thermal_power_devfreq_limit(cdev, freq, i, power);
> 
> make the compiled code better?
> 
> A tracepoint does some whacky things, and gcc may not optimize this.
> 
> The rest looks fine to me.

Can I treat that last statement as an Acked-by?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/