tick_nohz_retain_tick 830 kernel/time/tick-sched.c tick_nohz_retain_tick(ts); tick_nohz_retain_tick 966 kernel/time/tick-sched.c tick_nohz_retain_tick(ts); tick_nohz_retain_tick 982 kernel/time/tick-sched.c tick_nohz_retain_tick(this_cpu_ptr(&tick_cpu_sched));