Messages in this thread | | | Date | Wed, 18 May 2016 23:57:10 +0100 | From | Chris Wilson <> | Subject | Re: [PATCH 1/2] dma-buf/fence: add fence_collection fences |
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On Wed, May 18, 2016 at 05:59:52PM -0300, Gustavo Padovan wrote: > +static void collection_check_cb_func(struct fence *fence, struct fence_cb *cb) > +{ > + struct fence_collection_cb *f_cb; > + struct fence_collection *collection; > + > + f_cb = container_of(cb, struct fence_collection_cb, cb); > + collection = f_cb->collection; > + > + if (atomic_dec_and_test(&collection->num_pending_fences)) > + fence_signal(&collection->base); > +} > + > +static bool fence_collection_enable_signaling(struct fence *fence) > +{ > + struct fence_collection *collection = to_fence_collection(fence); > + int i; > + > + for (i = 0 ; i < collection->num_fences ; i++) { > + if (fence_add_callback(collection->fences[i].fence, > + &collection->fences[i].cb, > + collection_check_cb_func)) { > + atomic_dec(&collection->num_pending_fences); > + } > + }
We don't always have a convenient means to preallocate an array of fences to use. Keeping a list of fences in addition to the array would be easier to user in many circumstances.
Just means we need a
struct fence_collection_entry { struct fence *fence; struct list_head link; };
int fence_collection_add(struct fence *_collection, struct fence *fence) { struct fence_collection *collection = to_fence_collection(_collection); struct fence_collection_entry *entry;
entry = kmalloc(sizeof(*entry), GFP_KERNEL); if (!entry) return -ENOMEM;
entry->fence = fence_get(fence); list_add_tail(&entry->link, &collection->fence_list); atomic_inc(&collection->num_pending_fences);
return 0; }
and a couple of list iterations as well as walking the arrays.
(This fence_collection_add() needs to be documented to only be valid from the constructing thread before the fence is sealed for export/use.) -Chris
-- Chris Wilson, Intel Open Source Technology Centre
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