isolate one core for mpd service


I want to isolate one core for the mpd.service on my Odroid C1. First I searched the cmdline.txt file I did not find it in /boot/ but in /var/www/_OS_SETTINGS/boot/. I added isolcpu=1 to the end of the line. I rebooted and via top saw that core 1 was not 100 % idle. I then copied the cmdline.txt also to the /boot/ directory and rebooted still core 1 was not 100 % idle. Anyone can help me where to isolate the core? If I was successful in isolating the core I would modify the mpd.service file:

ExecStart=/usr/bin/taskset -c 3 /usr/bin/mpd --no-daemon

That should assign mpd to core 1, which then would be the only process using this core.

Best Regards