On Fri, 13 Nov 2015, Jacob Pan wrote: > <idle>-0 [000] 30.093473: bprint: > __tick_nohz_idle_enter: JPAN: __tick_nohz_idle_enter 803 > <idle>-0 [000] 30.093473: bprint: > __tick_nohz_idle_enter: JPAN: can_stop_idle_tick 743 > [JP] can_stop_idle_tick() checks ok to stop tick > > <idle>-0 [000] 30.093474: bprint: > __tick_nohz_idle_enter: JPAN: tick_nohz_stop_sched_tick 609 delta 1000000 > [JP] but sees delta is exactly 1 tick away. didn't stop tick.
If the delta is 1 tick then it is not supposed to stop it. Did you ever try to figure out WHY it is 1 tick? There are two code pathes which can set it to basemono + TICK_NSEC: if (rcu_needs_cpu(basemono, &next_rcu) || arch_needs_cpu() || irq_work_needs_cpu()) { next_tick = basemono + TICK_NSEC; } else { next_tmr = get_next_timer_interrupt(basejiff, basemono); ts->next_timer = next_tmr; /* Take the next rcu event into account */ next_tick = next_rcu < next_tmr ? next_rcu : next_tmr; } Can you please figure out WHY the tick is requested to continue instead of blindly wreckaging the logic in that code? Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/