confine user(s) to a core with systemd + gcgroup

[lejeczek]

hi everybody

I thought I could easily (as easily as I could do that with 
libcgroup) permanently restric a user to a specific cpu core.

I thought it would be CPUAffinity responsible for it either 
in systemd-user-sessions or(and) in systemd-logind

but it does not work,
is it possible to have user(s) sessions permanently 
restricted in this way? so his/her processes would be 
executed only on given core?
if yes then how would you do this? please shed some light

thanks
P