drm/ttm: Optimize vm locking using kref_get_unless_zero v3
Removes the need for a write lock each time we call ttm_bo_unref().
v2: Remove an unused variable.
v3: Really remove the unused variable.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 7426fe5..2c54c3d 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -696,6 +696,7 @@
struct ttm_bo_device *bdev = bo->bdev;
struct ttm_mem_type_manager *man = &bdev->man[bo->mem.mem_type];
+ write_lock(&bdev->vm_lock);
if (likely(bo->vm_node != NULL)) {
rb_erase(&bo->vm_rb, &bdev->addr_space_rb);
drm_mm_put_block(bo->vm_node);
@@ -707,18 +708,14 @@
ttm_mem_io_unlock(man);
ttm_bo_cleanup_refs_or_queue(bo);
kref_put(&bo->list_kref, ttm_bo_release_list);
- write_lock(&bdev->vm_lock);
}
void ttm_bo_unref(struct ttm_buffer_object **p_bo)
{
struct ttm_buffer_object *bo = *p_bo;
- struct ttm_bo_device *bdev = bo->bdev;
*p_bo = NULL;
- write_lock(&bdev->vm_lock);
kref_put(&bo->kref, ttm_bo_release);
- write_unlock(&bdev->vm_lock);
}
EXPORT_SYMBOL(ttm_bo_unref);