[Intel-gfx] [PATCH 2/2] drm/i915: Make GPU pages movable

[Chris Wilson]

Best if we send these as a new series to unconfuse CI.

On Fri, Nov 04, 2016 at 06:18:26PM +0530, akash.goel at intel.com wrote:
> +static int do_migrate_page(struct drm_i915_gem_object *obj)
> +{
> +	struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
> +	int ret = 0;
> +
> +	if (!can_migrate_page(obj))
> +		return -EBUSY;
> +
> +	/* HW access would be required for a GGTT bound object, for which
> +	 * device has to be kept awake. But a deadlock scenario can arise if
> +	 * the attempt is made to resume the device, when either a suspend
> +	 * or a resume operation is already happening concurrently from some
> +	 * other path and that only also triggers compaction. So only unbind
> +	 * if the device is currently awake.
> +	 */
> +	if (!intel_runtime_pm_get_if_in_use(dev_priv))
> +		return -EBUSY;
> +
> +	i915_gem_object_get(obj);
> +	if (!unsafe_drop_pages(obj))
> +		ret = -EBUSY;
> +	i915_gem_object_put(obj);

Since the object release changes, we can now do this without the
i915_gem_object_get / i915_gem_object_put (as we are guarded by the BKL
struct_mutex).
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre