SYSDATA_CPU_NR
curr = !!(nt->sysdata_fields & SYSDATA_CPU_NR);
nt->sysdata_fields |= SYSDATA_CPU_NR;
disable_sysdata_feature(nt, SYSDATA_CPU_NR);
if (nt->sysdata_fields & SYSDATA_CPU_NR)
cpu_nr_enabled = !!(nt->sysdata_fields & SYSDATA_CPU_NR);