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Glance performances when uploading snapshots to a ceph backend

I noticed some performance irregularities regarding when Glance uploads a snapshot to a ceph backend. Basically, the upload process will throttle itself at about 30% of one core's cpu usage and will not upload faster than 80 MB/sec no matter the actual link speed. Additionally, if I start a second simultaneous snapshot upload, the new process will also throttle itself at the same values (which means I reach a total speed of 160 MB/sec). The same happens with additional snapshots, until the network link speed is reached.

This is definitely caused by either inefficient code or a throttling mechanism inside glance itself. If this is a throttling mechanism, is there a way to modify it so that the upload speed and resource usage may increase per glance process?

I also understand that my question will become moot once copy-on-write cloning is available for snapshots, but that's not even close to be ready yet.