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

From: Rafael J. Wysocki
Date: Tue Mar 01 2022 - 11:08:03 EST


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.