atd, batch // Setting the load limiting factor

I am launching non interactive jobs using batch, and I would like to increase the load limiting factor in order to use all 8 of my cores. I am on Ubuntu 16.04 LTS. From what I understand, batch uses atd to do the jobs. Jobs start when the load factor goes under a threshold, called the *load limiting factor*. It is said in the man of atd that we can change this factor using the -l option. My question: how can I use this atd -l XX option? When I type, for instance, atd -l 7.2 before batch, it doesn't seem to be changing anything. What I have found so far: - In this question https://unix.stackexchange.com/questions/292555/how-to-run-bash-script-via-multithreading/292598#292598 , one contributor proposes to do this in the 'atd service starting script'. I guess that it refers to the /etc/init.d/atd, but I do not know what to change there, cf next bullet point. - I have found pages, such as this one http://searchitchannel.techtarget.com/feature/Understanding-run-level-scripts-in-Fedora-11-and-RHEL , where they propose to: "modify the following line (in the start section) of the /etc/init.d/atd script: daemon /usr/sbin/atd. Replace it with this line, using the -l argument to specify the new minimum system load value: daemon /usr/sbin/atd -l 1.6". However, there is no such a line in /etc/init.d/atd. It seems that it can be introduced in the /etc/init.d/atd, but I do not know where. I have never changed such files. So, how can I change the load limiting factor used by the batch command?