If you want to run a set of processes with as little preemption as possible, for example in HPC setting, your most powerful option is to reboot the system with a selection of cores (exact amount will differ on your needs) set as isolated cpus and manually put your task there with taskset - but then you need to really manually allocate tasks to CPUs, it's trivial to end up with all tasks on wrong CPU.
The standard way is to set interrupt masks so they don't go to "work" cpus and use cpusets to only allow specific cgroup to execute on given cpuset.