| Message ID | 1451902261-25380-2-git-send-email-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Jan 04, 2016 at 10:11:00AM +0000, Chris Wilson wrote: > We only need a single reference count for all handles (i.e. non-zero > obj->handle_count) and so can trim a few atomic operations by only > taking the reference on the first handle and dropping it after the last. > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > --- > drivers/gpu/drm/drm_gem.c | 17 ++++++++++++----- > 1 file changed, 12 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c > index a08176debc0e..ad955d7c99fd 100644 > --- a/drivers/gpu/drm/drm_gem.c > +++ b/drivers/gpu/drm/drm_gem.c > @@ -220,6 +220,9 @@ static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj) > static void > drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj) > { > + struct drm_device *dev = obj->dev; > + bool final = false; > + > if (WARN_ON(obj->handle_count == 0)) > return; > > @@ -229,14 +232,16 @@ drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj) > * checked for a name > */ > > - mutex_lock(&obj->dev->object_name_lock); > + mutex_lock(&dev->object_name_lock); > if (--obj->handle_count == 0) { > drm_gem_object_handle_free(obj); > drm_gem_object_exported_dma_buf_free(obj); > + final = true; > } > - mutex_unlock(&obj->dev->object_name_lock); > + mutex_unlock(&dev->object_name_lock); > > - drm_gem_object_unreference_unlocked(obj); > + if (final) > + drm_gem_object_unreference_unlocked(obj); > } > > /** > @@ -329,6 +334,8 @@ drm_gem_handle_create_tail(struct drm_file *file_priv, > int ret; > > WARN_ON(!mutex_is_locked(&dev->object_name_lock)); > + if (obj->handle_count++ == 0) > + drm_gem_object_reference(obj); Hmm. Yeah, handle_count is protected by object_name_lock, so this looks better here rather than within the spinlocked section. Patch looks sane: Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > > /* > * Get the user-visible handle using idr. Preload and perform > @@ -338,10 +345,10 @@ drm_gem_handle_create_tail(struct drm_file *file_priv, > spin_lock(&file_priv->table_lock); > > ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT); > - drm_gem_object_reference(obj); > - obj->handle_count++; > + > spin_unlock(&file_priv->table_lock); > idr_preload_end(); > + > mutex_unlock(&dev->object_name_lock); > if (ret < 0) > goto err_unref; > -- > 2.6.4 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/dri-devel
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index a08176debc0e..ad955d7c99fd 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -220,6 +220,9 @@ static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj) static void drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj) { + struct drm_device *dev = obj->dev; + bool final = false; + if (WARN_ON(obj->handle_count == 0)) return; @@ -229,14 +232,16 @@ drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj) * checked for a name */ - mutex_lock(&obj->dev->object_name_lock); + mutex_lock(&dev->object_name_lock); if (--obj->handle_count == 0) { drm_gem_object_handle_free(obj); drm_gem_object_exported_dma_buf_free(obj); + final = true; } - mutex_unlock(&obj->dev->object_name_lock); + mutex_unlock(&dev->object_name_lock); - drm_gem_object_unreference_unlocked(obj); + if (final) + drm_gem_object_unreference_unlocked(obj); } /** @@ -329,6 +334,8 @@ drm_gem_handle_create_tail(struct drm_file *file_priv, int ret; WARN_ON(!mutex_is_locked(&dev->object_name_lock)); + if (obj->handle_count++ == 0) + drm_gem_object_reference(obj); /* * Get the user-visible handle using idr. Preload and perform @@ -338,10 +345,10 @@ drm_gem_handle_create_tail(struct drm_file *file_priv, spin_lock(&file_priv->table_lock); ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT); - drm_gem_object_reference(obj); - obj->handle_count++; + spin_unlock(&file_priv->table_lock); idr_preload_end(); + mutex_unlock(&dev->object_name_lock); if (ret < 0) goto err_unref;
We only need a single reference count for all handles (i.e. non-zero obj->handle_count) and so can trim a few atomic operations by only taking the reference on the first handle and dropping it after the last. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> --- drivers/gpu/drm/drm_gem.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-)