We clear the callback list on kref_put so that by the time we release the fence it is unused. No one should be adding to the cb_list that they don't themselves hold a reference for.

This small change is actually making the structure 16% smaller.

Signed-off-by: Christian König christian.koenig@amd.com Reviewed-by: Chris Wilson chris@chris-wilson.co.uk --- include/linux/dma-fence.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 05d29dbc7e62..3985c72cd0c2 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -65,8 +65,10 @@ struct dma_fence_cb; struct dma_fence { struct kref refcount; const struct dma_fence_ops *ops; - struct rcu_head rcu; - struct list_head cb_list; + union { + struct rcu_head rcu; + struct list_head cb_list; + }; spinlock_t *lock; u64 context; u64 seqno;