Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20230703150859.6176-1-ubizjak@gmail.com> <87o7ks16gh.fsf@intel.com>
 <CAFULd4YDHqUud94Q1mbKyKqGHh==Gv7+FpNhgm5s1p=0ZwcAXg@mail.gmail.com> <87lefw139r.fsf@intel.com>
In-Reply-To: <87lefw139r.fsf@intel.com>
From:   Uros Bizjak <ubizjak@gmail.com>
Date:   Tue, 4 Jul 2023 11:25:15 +0200
Message-ID: <CAFULd4azR=ft9kEYN19WjxORcJNT_-v7q3sVs904Bf_td-VgEg@mail.gmail.com>
Subject: Re: [PATCH] drm/i915/pmu: Use local64_try_cmpxchg in i915_pmu_event_read
To:     Jani Nikula <jani.nikula@linux.intel.com>
Cc:     intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org,
        Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@intel.com>,
        Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Tue, Jul 4, 2023 at 10:37=E2=80=AFAM Jani Nikula <jani.nikula@linux.inte=
l.com> wrote:
>
> On Tue, 04 Jul 2023, Uros Bizjak <ubizjak@gmail.com> wrote:
> > On Tue, Jul 4, 2023 at 9:28=E2=80=AFAM Jani Nikula <jani.nikula@linux.i=
ntel.com> wrote:
> >> You could save everyone a lot of time by actually documenting what the=
se
> >> functions do. Assume you don't know what local64_try_cmpxchg() does, a=
nd
> >> see how many calls you have to go through to figure it out.
> >
> > These functions are documented in Documentation/atomic_t.txt (under
> > "RMW ops:" section), and the difference is explained in a separate
> > section "CMPXCHG vs TRY_CMPXCGS" in the same file.
>
> Thanks, but *sigh*.
>
> No kernel-doc above the functions, not even a regular comment
> referencing atomic_t.txt.
>
> $ git grep local.*_try -- Documentation
> [nothing]

Unfortunately, this was always the state w.r.t. local.* atomic
functions. There is an effort to improve the documentation of atomics,
perhaps it will be also extended to local variants.

Uros.