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 --- include/linux/dma-fence.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 05d29dbc7e62..bea1d05cf51e 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -65,8 +65,14 @@ 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; + /* 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;
Daniel any more comments on this one?
If not I'm going to push it.
Christian.
Am 08.08.19 um 15:22 schrieb Christian König:
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
include/linux/dma-fence.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 05d29dbc7e62..bea1d05cf51e 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -65,8 +65,14 @@ 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;
- /* 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;
On Thu, Aug 08, 2019 at 04:41:39PM +0200, Christian König wrote:
Daniel any more comments on this one?
It's not kerneldoc, but then all the dma-* docs need some serious love anyway, so all good with me. -Daniel
If not I'm going to push it.
Christian.
Am 08.08.19 um 15:22 schrieb Christian König:
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
include/linux/dma-fence.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 05d29dbc7e62..bea1d05cf51e 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -65,8 +65,14 @@ 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;
- /* 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;
dri-devel@lists.freedesktop.org
-
Christian König -
Daniel Vetter