Profile aiohttp server

[coolsuntraveler]

Hello, I am using yappi to profile my application server built with aiohttp.
This screenshot is from qcachegrind.

It indicates that my application spent a lot of time in RequestHandler.start (Note that the self time is almost as large as Incl.). Does anybody know what could cause this to happen? I would think a request handler should spend most of its time in the downstream functions and spend very little time in itself.