Quoting Christian König (2019-08-21 13:31:45) > @@ -117,17 +120,10 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data, > busy_check_writer(rcu_dereference(obj->base.resv->fence_excl)); > > /* Translate shared fences to READ set of engines */ > - list = rcu_dereference(obj->base.resv->fence); > - if (list) { > - unsigned int shared_count = list->shared_count, i; > - > - for (i = 0; i < shared_count; ++i) { > - struct dma_fence *fence = > - rcu_dereference(list->shared[i]); > - > - args->busy |= busy_check_reader(fence); > - } > - } > + readers = dma_resv_fences_get_rcu(&obj->base.resv->readers); > + dma_fence_array_for_each(fence, cursor, readers) > + args->busy |= busy_check_reader(fence); > + dma_fence_put(readers); That's underwhelming, the full-mb shows up in scaling tests (I'll test the impact of this series later). Something like, do { read = 0; fences = dma_resv_fences_get_deref(&obj->base.resv->readers); dma_fence_array_for_each(fence, cursor, fences) read |= busy_check_reader(fence); smp_rmb(); } while (dma_resv_fences_get_deref(obj->readers) != fences) do { fences = dma_resv_fences_get_deref(&obj->base.resv->fences); write = busy_check_writer(fences); smp_rmb(); } while (dma_resv_fences_get_deref(obj->writes) != fences) args->busy = write | read; Perhaps? -Chris _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel