[Intel-gfx] [PATCH 2/4 v3] drm/i915: mark a newly-created GEM object dirty when filled with data

[Daniel Vetter]

On Thu, Dec 10, 2015 at 09:06:25PM +0000, Chris Wilson wrote:
> On Thu, Dec 10, 2015 at 06:51:24PM +0000, Dave Gordon wrote:
> > When creating a new (pageable) GEM object and filling it with data, we
> > must mark it as 'dirty', i.e. backing store is out-of-date w.r.t. the
> > newly-written content. This ensures that if the object is evicted under
> > memory pressure, its pages in the pagecache will be written to backing
> > store rather than discarded.
> > 
> > Based on an original version by Alex Dai.
> > 
> > Signed-off-by: Alex Dai <yu.dai at intel.com>
> > Signed-off-by: Dave Gordon <david.s.gordon at intel.com>
> > Cc: Chris Wilson <chris at chris-wilson.co.uk>
> 
> I've made my peace with this patch finally.
> Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
> 
> > ---
> >  drivers/gpu/drm/i915/i915_gem.c | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> > index 06a5f39..936f0a9 100644
> > --- a/drivers/gpu/drm/i915/i915_gem.c
> > +++ b/drivers/gpu/drm/i915/i915_gem.c
> > @@ -5224,6 +5224,7 @@ i915_gem_object_create_from_data(struct drm_device *dev,
> >  	i915_gem_object_pin_pages(obj);
> >  	sg = obj->pages;
> >  	bytes = sg_copy_from_buffer(sg->sgl, sg->nents, (void *)data, size);
> > +	obj->dirty = 1;		/* Backing store is now out of date */
> 
> That seems like it would be better served as an improvement to the
> existing obj->dirty /** doc */

Yeah doc polish at the end would be stellar. Merged the first 2 patches
from this series meanwhile.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch