[PATCH] drm/amdgpu/ttm: Fix memory leak userptr pages

[Daniel Gomez]

On Thu, 18 Mar 2021 at 08:49, Christian König <christian.koenig at amd.com> wrote:
>
> Am 17.03.21 um 17:08 schrieb Daniel Gomez:
> > If userptr pages have been pinned but not bounded,
> > they remain uncleared.
> >
> > Signed-off-by: Daniel Gomez <daniel at qtec.com>
>
> Good catch, not sure if that can ever happen in practice but better save
> than sorry.
Thanks! We actually had a case with clEnqueueWriteBuffer where the
driver was leaking.
I can see the problem also affects to the radeon driver so, I'll send
a patch for that one as
well.
>
> Reviewed-by: Christian König <christian.koenig at amd.com>
>
> > ---
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 6 +++---
> >   1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> > index 9fd2157b133a..50c2b4827c13 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> > @@ -1162,13 +1162,13 @@ static void amdgpu_ttm_backend_unbind(struct ttm_bo_device *bdev,
> >       struct amdgpu_ttm_tt *gtt = (void *)ttm;
> >       int r;
> >
> > -     if (!gtt->bound)
> > -             return;
> > -
> >       /* if the pages have userptr pinning then clear that first */
> >       if (gtt->userptr)
> >               amdgpu_ttm_tt_unpin_userptr(bdev, ttm);
> >
> > +     if (!gtt->bound)
> > +             return;
> > +
> >       if (gtt->offset == AMDGPU_BO_INVALID_OFFSET)
> >               return;
> >
>