this_cpu_time = per_cpu(cpu_time, cpu);
update_count = this_cpu_time->update_count;
current_time = this_cpu_time->time_sel[update_count&1];
walltime = current_time->walltime +
(get_cycles() - current_time->tsc) /
current_time->freq;
this_cpu_time = per_cpu(cpu_time, cpu);
update_count = this_cpu_time->update_count;
current_time = this_cpu_time->time_sel[update_count&1];
walltime = current_time->walltime +
(get_cycles() - current_time->tsc) /
current_time->freq;