On Fri, Jun 28, 2019 at 3:34 AM Gerd Hoffmann <kra...@redhat.com> wrote:
>
> Hi,
>
> > > --- a/drivers/gpu/drm/virtio/virtgpu_drv.h
> > > +++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
> > > @@ -120,9 +120,9 @@ struct virtio_gpu_vbuffer {
> > >
> > > char *resp_buf;
> > > int resp_size;
> > > -
> > > virtio_gpu_resp_cb resp_cb;
> > >
> > > + struct virtio_gpu_object_array *objs;
> > This can use a comment (e.g., objects referenced by the vbuffer)
>
> IMHO this is obvious ...
>
> > > void virtio_gpu_cmd_submit(struct virtio_gpu_device *vgdev,
> > > void *data, uint32_t data_size,
> > > - uint32_t ctx_id, struct virtio_gpu_fence
> > > *fence);
> > > + uint32_t ctx_id, struct virtio_gpu_fence
> > > *fence,
> > > + struct virtio_gpu_object_array *objs);
> > Can we keep fence, which is updated, as the last parameter?
>
> Fixed.
>
> > > + if (buflist) {
> > > + for (i = 0; i < exbuf->num_bo_handles; i++)
> > > +
> > > reservation_object_add_excl_fence(buflist->objs[i]->resv,
> > > + &out_fence->f);
> > > + drm_gem_unlock_reservations(buflist->objs, buflist->nents,
> > > + &ticket);
> > > + }
> > We used to unlock after virtio_gpu_cmd_submit.
> >
> > I guess, the fence is considered signaled (because its seqno is still
> > 0) until after virtio_gpu_cmd_submit. We probably don't want other
> > processes to see the semi-initialized fence.
>
> Good point. Fixed.
>
> > > out_memdup:
> > > kfree(buf);
> > > out_unresv:
> > > - ttm_eu_backoff_reservation(&ticket, &validate_list);
> > > -out_free:
> > > - virtio_gpu_unref_list(&validate_list);
> > Keeping out_free to free buflist seems just fine.
>
> We don't need the separate label though ...
>
> > > + drm_gem_unlock_reservations(buflist->objs, buflist->nents,
> > > &ticket);
> > > out_unused_fd:
> > > kvfree(bo_handles);
> > > - kvfree(buflist);
> > > + if (buflist)
> > > + virtio_gpu_array_put_free(buflist);
>
> ... and the buflist is released here if needed.
>
> But we need if (buflist) for drm_gem_unlock_reservations too. Fixed.
>
> > > -
> > > - list_del(&entry->list);
> > > - free_vbuf(vgdev, entry);
> > > }
> > > wake_up(&vgdev->ctrlq.ack_queue);
> > >
> > > if (fence_id)
> > > virtio_gpu_fence_event_process(vgdev, fence_id);
> > > +
> > > + list_for_each_entry_safe(entry, tmp, &reclaim_list, list) {
> > > + if (entry->objs)
> > > + virtio_gpu_array_put_free(entry->objs);
> > > + list_del(&entry->list);
> > We are clearing the list. I guess list_del is not needed.
> > > + free_vbuf(vgdev, entry);
>
> This just shuffles around the code. Dropping list_del() is unrelated
> and should be a separate patch.
Fair point. We now loop the list twice and I was just looking for
chances for micro-optimizations.
>
> Beside that I'm not sure it actually can be dropped. free_vbuf() will
> not kfree() the vbuf but keep it cached in a freelist instead.
vbuf is created with kmem_cache_zalloc which always zeros the struct.
>
> cheers,
> Gerd
>
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