Comment 2 for bug 1635674

Stephen's suggested is not quite right because NUMACell.siblings field is often used to check does host has HyperThreading or not. If we will add single siblings into this field it will disrupt the logic in other files. Better solution is call pin_cpus_with_siblings() only if cell has siblings (i.e. has HyperThreading). In this case CPU isolation will be guaranteed by 'dedicated' CPU allocation policy. Remember that 'isolate' CPU thread allocation policy can be used only combined with 'dedicated' CPU allocation policy'.