Hello Jaeyong,
It results in calling l4_task_unmap multiple times with the same parameters. I'm just concern that this may not cause anything harmful.
your observation is spot-on. There are indeed redundant unmap operations. Even though they are producing no harm, it would be worthwhile to eliminate them nevertheless. I have just created the following topic at our issue tracker and added my thoughts:
https://github.com/genodelabs/genode/issues/595
Thank you very much for sharing your findings!
Cheers Norman