Received-SPF: pass (google.com: domain of linux-kernel+bounces-9853-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1;
Precedence: bulk
MIME-Version: 1.0
References: <20231219092539.3655172-1-daniel.lezcano@linaro.org>
 <CAJZ5v0j+F2uLauRqGZ1nvX3CsoA3+JXyzXFp5VtzvVTQTg6Yvw@mail.gmail.com> <fa8628c7-f49a-4226-b26e-ada31316b130@linaro.org>
In-Reply-To: <fa8628c7-f49a-4226-b26e-ada31316b130@linaro.org>
From: "Rafael J. Wysocki" <rafael@kernel.org>
Date: Fri, 22 Dec 2023 16:48:05 +0100
Message-ID: <CAJZ5v0jXv1BHU_m_KebNfLt6ygPDZOnNp+aQk-cDESpDSdbSKQ@mail.gmail.com>
Subject: Re: [PATCH v3 1/2] thermal/debugfs: Add thermal cooling device
 debugfs information
To: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>, rjw@rjwysocki.net, lukasz.luba@arm.com, 
	rui.zhang@intel.com, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

On Fri, Dec 22, 2023 at 4:03=E2=80=AFPM Daniel Lezcano
<daniel.lezcano@linaro.org> wrote:
>
> On 21/12/2023 18:19, Rafael J. Wysocki wrote:
>
> [ ... ]
>
> >> +struct cdev_value {
> >
> > I'm not sure about the name here.  I would rather call it cdev_record,
> > because it consists of two items, the id and the value.
> >
> >> +       struct list_head node;
> >> +       int id;
> >> +       u64 value;
> >
> > This is kind of a union, but sort of in disguise.
> >
> > Why not make it a union proper, that is
> >
> > struct cdev_record {
> >          struct list_head node;
> >          int id;
> >          union {
> >                  krime_t residency; /* for duration records */
> >                  u64 count; /* for occurrences records */
> >          } data;
> > };
> >
> > which then would result in a bit cleaner code in some places below, if
> > I'm not mistaken?
>
> Can we stick to
>
> struct cdev_record {
>           struct list_head node;
>           int id;
>           union {
>                   u64 residency_ms;  <----- ?
>                   u64 count;
>           };
> };
>
> ?
>
> The usage of the ktime_t will have a more important impact in the code.

OK, but patch [2/2] uses ktime_t for duration computations regarding
trip points.  I'm not sure why this is different.