Thx Ivan for your support. I got an eye on the logs and everything around.
ps: updated to 2.9.9 some hours ago... looks like ok for now.
Ivan Markin :
There is nothing wrong at your side. You're probably experiencing the same issue as in ticket I've mentioned earlier. "a memory leakage somewhere" means that this "somewhere" is a place in tor code and probably triggered remotely. This definitely ought to be fixed since it may be a DoS vulnerability (process crash). So if you have some details on this issue please report them to the mentioned ticket.
Thanks,