From: Chris Wilson Date: Tue, 6 Aug 2013 08:59:46 +0000 (+0100) Subject: drm: Apply kref_put_mutex() optimisations to drm_gem_object_unreference_unlocked() X-Git-Tag: v3.12-rc2~3^2~152 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7fc65eb731cda8304865669166fb9a4c519bee69;p=platform%2Fkernel%2Flinux-stable.git drm: Apply kref_put_mutex() optimisations to drm_gem_object_unreference_unlocked() We can apply the same optimisation tricks as kref_put_mutex() in our local equivalent function. However, we have a different locking semantic (we unlock ourselves, in kref_put_mutex() the callee unlocks) so that we can use the same callbacks for both locked and unlocked kref_put()s and so can not simply convert to using kref_put_mutex() directly. Signed-off-by: Chris Wilson Reviewed-by: Daniel Vetter Signed-off-by: Dave Airlie --- diff --git a/include/drm/drmP.h b/include/drm/drmP.h index a029dea..3b7fda5 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -1629,10 +1629,12 @@ drm_gem_object_unreference(struct drm_gem_object *obj) static inline void drm_gem_object_unreference_unlocked(struct drm_gem_object *obj) { - if (obj != NULL) { + if (obj && !atomic_add_unless(&obj->refcount.refcount, -1, 1)) { struct drm_device *dev = obj->dev; + mutex_lock(&dev->struct_mutex); - kref_put(&obj->refcount, drm_gem_object_free); + if (likely(atomic_dec_and_test(&obj->refcount.refcount))) + drm_gem_object_free(&obj->refcount); mutex_unlock(&dev->struct_mutex); } }