linux-kernel - Re: [PATCH v2] drm/amdgpu: fix double reference dropping

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Date:   Wed, 6 Nov 2019 12:23:14 -0500
From:   Alex Deucher <alexdeucher@...il.com>
To:     "Koenig, Christian" <Christian.Koenig@....com>
Cc:     Pan Bian <bianpan2016@....com>,
        "Deucher, Alexander" <Alexander.Deucher@....com>,
        "Zhou, David(ChunMing)" <David1.Zhou@....com>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        Sam Ravnborg <sam@...nborg.org>,
        "dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
        "amd-gfx@...ts.freedesktop.org" <amd-gfx@...ts.freedesktop.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2] drm/amdgpu: fix double reference dropping

On Wed, Nov 6, 2019 at 7:48 AM Koenig, Christian
<Christian.Koenig@....com> wrote:
>
> Am 06.11.19 um 12:35 schrieb Pan Bian:
> > The reference to object fence is dropped at the end of the loop.
> > However, it is dropped again outside the loop. The reference can be
> > dropped immediately after calling dma_fence_wait() in the loop and
> > thus the dropping operation outside the loop can be removed.
> >
> > Signed-off-by: Pan Bian <bianpan2016@....com>
>
> Reviewed-by: Christian König <christian.koenig@....com>
>

Applied.  thanks!

Alex

> > ---
> > v2: fix the bug in a more concise way
> > ---
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c | 6 ++----
> >   1 file changed, 2 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c
> > index 649e68c4479b..d1495e1c9289 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c
> > @@ -33,7 +33,7 @@ static int amdgpu_benchmark_do_move(struct amdgpu_device *adev, unsigned size,
> >   {
> >       unsigned long start_jiffies;
> >       unsigned long end_jiffies;
> > -     struct dma_fence *fence = NULL;
> > +     struct dma_fence *fence;
> >       int i, r;
> >
> >       start_jiffies = jiffies;
> > @@ -44,16 +44,14 @@ static int amdgpu_benchmark_do_move(struct amdgpu_device *adev, unsigned size,
> >               if (r)
> >                       goto exit_do_move;
> >               r = dma_fence_wait(fence, false);
> > +             dma_fence_put(fence);
> >               if (r)
> >                       goto exit_do_move;
> > -             dma_fence_put(fence);
> >       }
> >       end_jiffies = jiffies;
> >       r = jiffies_to_msecs(end_jiffies - start_jiffies);
> >
> >   exit_do_move:
> > -     if (fence)
> > -             dma_fence_put(fence);
> >       return r;
> >   }
> >
>
> _______________________________________________
> amd-gfx mailing list
> amd-gfx@...ts.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx

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