Re: [PATCH 1/3] cpufreq: amd-pstate: Add more tracepoint for AMD P-State module

From: Huang Rui <ray.huang@amd.com>
To: "Rafael J. Wysocki" <rafael@kernel.org>,
	"Su, Jinzhou (Joe)" <Jinzhou.Su@amd.com>
Cc: "Deucher, Alexander" <Alexander.Deucher@amd.com>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Linux PM <linux-pm@vger.kernel.org>,
	Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
	Doug Smythies <dsmythies@telus.net>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Todd Brandt <todd.e.brandt@linux.intel.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"Sharma, Deepak" <Deepak.Sharma@amd.com>,
	"Du, Xiaojian" <Xiaojian.Du@amd.com>,
	"Yuan, Perry" <Perry.Yuan@amd.com>,
	"Meng, Li (Jassmine)" <Li.Meng@amd.com>
Subject: Re: [PATCH 1/3] cpufreq: amd-pstate: Add more tracepoint for AMD P-State module
Date: Wed, 2 Mar 2022 17:09:07 +0800	[thread overview]
Message-ID: <Yh80MwmHqAXK+PbD@amd.com> (raw)
In-Reply-To: <CAJZ5v0jDbNVEtRiaiUXembZB2r4uxVy3iKO0aTqOJsB0rLpV=A@mail.gmail.com>

On Wed, Mar 02, 2022 at 12:07:45AM +0800, Rafael J. Wysocki wrote:
> On Tue, Mar 1, 2022 at 5:05 PM Deucher, Alexander
> <Alexander.Deucher@amd.com> wrote:
> >
> > [AMD Official Use Only]
> >
> > > -----Original Message-----
> > > From: Rafael J. Wysocki <rafael@kernel.org>
> > > Sent: Tuesday, March 1, 2022 10:26 AM
> > > To: Su, Jinzhou (Joe) <Jinzhou.Su@amd.com>
> > > Cc: Rafael J. Wysocki <rjw@rjwysocki.net>; Linux PM <linux-
> > > pm@vger.kernel.org>; Srinivas Pandruvada
> > > <srinivas.pandruvada@linux.intel.com>; Doug Smythies
> > > <dsmythies@telus.net>; Huang, Ray <Ray.Huang@amd.com>; Viresh Kumar
> > > <viresh.kumar@linaro.org>; Todd Brandt <todd.e.brandt@linux.intel.com>;
> > > Linux Kernel Mailing List <linux-kernel@vger.kernel.org>; Sharma, Deepak
> > > <Deepak.Sharma@amd.com>; Deucher, Alexander
> > > <Alexander.Deucher@amd.com>; Du, Xiaojian <Xiaojian.Du@amd.com>;
> > > Yuan, Perry <Perry.Yuan@amd.com>; Meng, Li (Jassmine)
> > > <Li.Meng@amd.com>
> > > Subject: Re: [PATCH 1/3] cpufreq: amd-pstate: Add more tracepoint for AMD
> > > P-State module
> > >
> > > On Wed, Feb 23, 2022 at 11:04 AM Jinzhou Su <Jinzhou.Su@amd.com>
> > > wrote:
> > > >
> > > > Add frequency, mperf, aperf and tsc in the trace. This can be used to
> > > > debug and tune the performance of AMD P-state driver.
> > > >
> > > > Use the time difference between amd_pstate_update to calculate CPU
> > > > frequency. There could be sleep in arch_freq_get_on_cpu, so do not use
> > > > it here.
> > > >
> > > > Signed-off-by: Jinzhou Su <Jinzhou.Su@amd.com>
> > > > Signed-off-by: Huang Rui <ray.huang@amd.com>
> > >
> > > I'm not sure what the second sign-off is for.
> > >
> > > If this is a maintainer's sign-off, it should be added by the maintainer himself
> > > and you should not add it when submitting the patch.
> >
> > Both developers co-worked on the patch.  Isn't that pretty standard when you rework someone else's patch?
> 
> It is, but that's when Co-developed-by should be used.  Otherwise the
> meaning of the second s-o-b is unclear.

Yes.

Joe, can you add below in next V2:

Co-developed-by: Huang Rui <ray.huang@amd.com>

Patch looks good for me, could you please add new patch to describe how to
use the tracer script in Documentation/admin-guide/pm/amd-pstate.rst?

Thanks,
Ray