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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Tue, 27 Jun 2023 14:01:34 +0200
Message-ID: <CAMuHMdV924gJs1X1nMUbQ5LEbFe8hrrXgxxvgZ_dXf95O0bK5Q@mail.gmail.com>
Subject: Re: [PATCH v6 3/3] drm/virtio: Support sync objects
To:     Dmitry Osipenko <dmitry.osipenko@collabora.com>
Cc:     David Airlie <airlied@redhat.com>,
        Gerd Hoffmann <kraxel@redhat.com>,
        Gurchetan Singh <gurchetansingh@chromium.org>,
        Chia-I Wu <olvaffe@gmail.com>, Daniel Vetter <daniel@ffwll.ch>,
        Rob Clark <robdclark@gmail.com>,
        =?UTF-8?B?TWFyZWsgT2zFocOhaw==?= <maraeo@gmail.com>,
        Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>,
        Emil Velikov <emil.velikov@collabora.com>,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        kernel@collabora.com, virtualization@lists.linux-foundation.org
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Hi Dmitry,

On Mon, Jun 26, 2023 at 6:11 PM Dmitry Osipenko
<dmitry.osipenko@collabora.com> wrote:
> On 6/25/23 18:36, Geert Uytterhoeven wrote:
> > On Sun, Jun 25, 2023 at 2:41 PM Dmitry Osipenko
> > <dmitry.osipenko@collabora.com> wrote:
> >> On 6/25/23 11:47, Geert Uytterhoeven wrote:
> >>> On Sun, Apr 16, 2023 at 1:55 PM Dmitry Osipenko
> >>> <dmitry.osipenko@collabora.com> wrote:
> >>>> Add sync object DRM UAPI support to VirtIO-GPU driver. Sync objects
> >>>> support is needed by native context VirtIO-GPU Mesa drivers, it also will
> >>>> be used by Venus and Virgl contexts.
> >>>>
> >>>> Reviewed-by; Emil Velikov <emil.velikov@collabora.com>
> >>>> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
> >>>
> >>> Thanks for your patch!
> >>>
> >>>> --- a/drivers/gpu/drm/virtio/virtgpu_submit.c
> >>>> +++ b/drivers/gpu/drm/virtio/virtgpu_submit.c
> >>>
> >>>> +static int
> >>>> +virtio_gpu_parse_deps(struct virtio_gpu_submit *submit)
> >>>> +{
> >>>> +       struct drm_virtgpu_execbuffer *exbuf = submit->exbuf;
> >>>> +       struct drm_virtgpu_execbuffer_syncobj syncobj_desc;
> >>>> +       size_t syncobj_stride = exbuf->syncobj_stride;
> >>>> +       u32 num_in_syncobjs = exbuf->num_in_syncobjs;
> >>>> +       struct drm_syncobj **syncobjs;
> >>>> +       int ret = 0, i;
> >>>> +
> >>>> +       if (!num_in_syncobjs)
> >>>> +               return 0;
> >>>> +
> >>>> +       /*
> >>>> +        * kvalloc at first tries to allocate memory using kmalloc and
> >>>> +        * falls back to vmalloc only on failure. It also uses GFP_NOWARN
> >>>
> >>> GFP_NOWARN does not exist.
> >>
> >> https://elixir.bootlin.com/linux/v6.4-rc7/source/include/linux/gfp_types.h#L38
> >
> > That line defines "__GFP_NOWARN", not "GFP_NOWARN".
> > C is case- and underscore-sensitive. as is "git grep -w" ;-)
>
> The removal of underscores was done intentionally for improving
> readability of the comment

Please don't do that, as IMHO it actually hampers readability:
  1. For some xxx, both GFP_xxx and __GFP_xxx are defined,
     so it does matter which one you are referring to,
  2. After dropping the underscores, "git grep -w" can no longer find
     the definition, nor its users.

Thanks!

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds