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

[Huang Rui]

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@xxxxxxx> wrote:
> >
> > [AMD Official Use Only]
> >
> > > -----Original Message-----
> > > From: Rafael J. Wysocki <rafael@xxxxxxxxxx>
> > > Sent: Tuesday, March 1, 2022 10:26 AM
> > > To: Su, Jinzhou (Joe) <Jinzhou.Su@xxxxxxx>
> > > Cc: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>; Linux PM <linux-
> > > pm@xxxxxxxxxxxxxxx>; Srinivas Pandruvada
> > > <srinivas.pandruvada@xxxxxxxxxxxxxxx>; Doug Smythies
> > > <dsmythies@xxxxxxxxx>; Huang, Ray <Ray.Huang@xxxxxxx>; Viresh Kumar
> > > <viresh.kumar@xxxxxxxxxx>; Todd Brandt <todd.e.brandt@xxxxxxxxxxxxxxx>;
> > > Linux Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx>; Sharma, Deepak
> > > <Deepak.Sharma@xxxxxxx>; Deucher, Alexander
> > > <Alexander.Deucher@xxxxxxx>; Du, Xiaojian <Xiaojian.Du@xxxxxxx>;
> > > Yuan, Perry <Perry.Yuan@xxxxxxx>; Meng, Li (Jassmine)
> > > <Li.Meng@xxxxxxx>
> > > 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@xxxxxxx>
> > > 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@xxxxxxx>
> > > > Signed-off-by: Huang Rui <ray.huang@xxxxxxx>
> > >
> > > 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@xxxxxxx>

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