drm/i915: Retire requests from i915_gem_busy_ioctl.

This ensures that the user gets the latest information from the hardware
on whether the buffer is busy, potentially reducing the working set of objects
that the user chooses.

Signed-off-by: Eric Anholt <[e-mail]>
Signed-off-by: Dave Airlie <[e-mail]>

drivers/gpu/drm/i915/i915_gem.c

···
 		return -EBADF;
 	}
 
+	/* Update the active list for the hardware's current position.
+	 * Otherwise this only updates on a delayed timer or when irqs are
+	 * actually unmasked, and our working set ends up being larger than
+	 * required.
+	 */
+	i915_gem_retire_requests(dev);
+
 	obj_priv = obj->driver_private;
 	/* Don't count being on the flushing list against the object being
 	 * done.  Otherwise, a buffer left on the flushing list but not getting