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.
v2: add the comment to the code as well.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/322916/
struct dma_fence {
struct kref refcount;
const struct dma_fence_ops *ops;
- struct rcu_head rcu;
- struct list_head cb_list;
+ /* 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.
+ */
+ union {
+ struct rcu_head rcu;
+ struct list_head cb_list;
+ };
spinlock_t *lock;
u64 context;
u64 seqno;