dma-buf: Expand reservation_list to fill allocation

Since kmalloc() will round up the allocation to the next slab size or
page, it will normally return a pointer to a memory block bigger than we
asked for. We can query for the actual size of the allocated block using
ksize() and expand our variable size reservation_list to take advantage
of that extra space.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Christian König <christian.koenig@amd.com>
Cc: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190712080314.21018-1-chris@chris-wilson.co.uk
This commit is contained in:
Chris Wilson 2019-07-12 09:03:13 +01:00
parent 913cafbb25
commit 94eb1e10a3

View File

@ -153,7 +153,9 @@ int reservation_object_reserve_shared(struct reservation_object *obj,
RCU_INIT_POINTER(new->shared[j++], fence);
}
new->shared_count = j;
new->shared_max = max;
new->shared_max =
(ksize(new) - offsetof(typeof(*new), shared)) /
sizeof(*new->shared);
preempt_disable();
write_seqcount_begin(&obj->seq);
@ -169,7 +171,7 @@ int reservation_object_reserve_shared(struct reservation_object *obj,
return 0;
/* Drop the references to the signaled fences */
for (i = k; i < new->shared_max; ++i) {
for (i = k; i < max; ++i) {
struct dma_fence *fence;
fence = rcu_dereference_protected(new->shared[i],