diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2016-01-04 13:11:00 +0300 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2016-01-05 10:59:48 +0300 |
| commit | 98a8883ad419128493b8cfab3982d58785deabda (patch) | |
| tree | cfb8d888c0957c543090829e4b9eabad758ba90e /drivers/gpu/drm/drm_gem.c | |
| parent | 6984128d01cf935820a0563f3a00c6623ba58109 (diff) | |
| download | linux-98a8883ad419128493b8cfab3982d58785deabda.tar.xz | |
drm: Only bump object-reference count when adding first handle
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>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1451902261-25380-2-git-send-email-chris@chris-wilson.co.uk
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm/drm_gem.c')
| -rw-r--r-- | drivers/gpu/drm/drm_gem.c | 17 |
1 files 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); /* * 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; |