On 13/09/2021 14:16, Christian König wrote:
This is maybe even a fix since the RCU usage here looks incorrect.
What you think is incorrect? Pointless extra rcu locking?
Also, FWIW, I submitted a patch to remove this function altogether since
its IMO pretty useless, just failed in getting anyone to ack it so far.
Regards,
Tvrtko
Signed-off-by: Christian König <christian.koenig@xxxxxxx>
---
drivers/gpu/drm/i915/gem/i915_gem_object.h | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
index e9eecebf5c9d..3343922af4d6 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
@@ -500,16 +500,15 @@ static inline struct intel_engine_cs *
i915_gem_object_last_write_engine(struct drm_i915_gem_object *obj)
{
struct intel_engine_cs *engine = NULL;
+ struct dma_resv_cursor cursor;
struct dma_fence *fence;
- rcu_read_lock();
- fence = dma_resv_get_excl_unlocked(obj->base.resv);
- rcu_read_unlock();
-
- if (fence && dma_fence_is_i915(fence) && !dma_fence_is_signaled(fence))
- engine = to_request(fence)->engine;
- dma_fence_put(fence);
-
+ dma_resv_for_each_fence_unlocked(obj->base.resv, &cursor, false,
+ fence) {
+ if (fence && dma_fence_is_i915(fence) &&
+ !dma_fence_is_signaled(fence))
+ engine = to_request(fence)->engine;
+ }
return engine;
}
