[Intel-gfx] [PATCH v5 4/5] drm: Add library for shmem backed GEM objects

[Daniel Vetter]

On Tue, Nov 27, 2018 at 12:38:44PM -0800, Eric Anholt wrote:
> Daniel Vetter <daniel at ffwll.ch> writes:
> 
> > On Mon, Nov 26, 2018 at 04:36:21PM -0800, Eric Anholt wrote:
> >> Noralf Trønnes <noralf at tronnes.org> writes:
> >> > +static void drm_gem_shmem_vm_close(struct vm_area_struct *vma)
> >> > +{
> >> > +	struct drm_gem_object *obj = vma->vm_private_data;
> >> > +	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
> >> > +
> >> > +	drm_gem_shmem_put_pages(shmem);
> >> > +	drm_gem_vm_close(vma);
> >> > +}
> >> > +
> >> > +const struct vm_operations_struct drm_gem_shmem_vm_ops = {
> >> > +	.fault = drm_gem_shmem_fault,
> >> > +	.open = drm_gem_vm_open,
> >> > +	.close = drm_gem_shmem_vm_close,
> >> > +};
> >> > +EXPORT_SYMBOL_GPL(drm_gem_shmem_vm_ops);
> >> 
> >> I just saw a warning from drm_gem_shmem_put_pages() for
> >> !shmem->pages_use_count -- I think drm_gem_vm_open() needs to
> >> drm_gem_shmem_get_pages().
> >
> > Yeah we need a drm_gem_shmem_vm_open here.
> 
> Adding one of those fixed my refcounting issues, so I've sent out a v6
> with it.

Just realized that I've reviewed this patch already, spotted that vma
management issue there too. Plus a pile of other things. From reading that
other thread discussion with Noralf concluded with "not yet ready for
prime time" unfortunately :-/
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch