drm/ttm, drm/vmwgfx: Use RCU locking for object lookups v3
The mostly used lookup+get put+potential_destroy path of TTM objects
is converted to use RCU locks. This will substantially decrease the amount
of locked bus cycles during normal operation.
Since we use kfree_rcu to free the objects, no rcu synchronization is needed
at module unload time.
v2: Don't touch include/linux/kref.h
v3: Adapt to kref_get_unless_zero return value change
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/include/drm/ttm/ttm_object.h b/include/drm/ttm/ttm_object.h
index b01c563..fc0cf06 100644
--- a/include/drm/ttm/ttm_object.h
+++ b/include/drm/ttm/ttm_object.h
@@ -40,6 +40,7 @@
#include <linux/list.h>
#include <drm/drm_hashtab.h>
#include <linux/kref.h>
+#include <linux/rcupdate.h>
#include <ttm/ttm_memory.h>
/**
@@ -120,6 +121,7 @@
*/
struct ttm_base_object {
+ struct rcu_head rhead;
struct drm_hash_item hash;
enum ttm_object_type object_type;
bool shareable;
@@ -268,4 +270,6 @@
extern void ttm_object_device_release(struct ttm_object_device **p_tdev);
+#define ttm_base_object_kfree(__object, __base)\
+ kfree_rcu(__object, __base.rhead)
#endif