On Wed, 2013-10-16 at 23:43 +0800, Chuansheng Liu wrote: > Meet the case that on CPU2, there are just two tasks to be run, > one is one rt task A, another is idle task, but at this time, > and the rt_rq is throttled. > > CPU1 CPU2 > staying in idle task; > waking up rt task A on > target CPU 2; > > exiting from idle task; > DO schedule() > pick up RT next task > pick_next_task_rt() > _pick_next_task_rt() > rt_rq is throttled > return NULL rt task to be picked > > CPU2 then went into idle task AGAIN; > after 2s, CPU2 is waken up again; > rt task A is get running; > > Here rt task A is delayed for some time, even when CPU2 is in idle state. > > so in case there are just rt tasks running, we can pick up one of them > even rt_rq is throttled.
And shortly thereafter, a SCHED_NORMAL task wakes.. only to find that its alleged bodyguard slit its throat while it slept. Bad bodyguard. -Mike -- 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/
