On 8 February 2013 15:46, Steven Rostedt <rost...@goodmis.org> wrote: > On Fri, 2013-02-08 at 12:11 +0100, Vincent Guittot wrote: >> When a RT task is scheduled on an idle CPU, the update of the rq's load is >> not done because CFS's functions are not called. Then, the idle_balance, >> which is called just before entering the idle function, updates the >> rq's load and makes the assumption that the elapsed time since the last >> update, was only running time. >> >> The rq's load of a CPU that only runs a periodic RT task, is close to >> LOAD_AVG_MAX whatever the running duration of the RT task is. >> >> A new idle_exit function is called when the prev task is the idle function >> so the elapsed time will be accounted as idle time in the rq's load. >> >> Signed-off-by: Vincent Guittot <vincent.guit...@linaro.org> >> --- >> kernel/sched/core.c | 3 +++ >> kernel/sched/fair.c | 10 ++++++++++ >> kernel/sched/sched.h | 5 +++++ >> 3 files changed, 18 insertions(+) >> >> diff --git a/kernel/sched/core.c b/kernel/sched/core.c >> index 26058d0..592e06c 100644 >> --- a/kernel/sched/core.c >> +++ b/kernel/sched/core.c >> @@ -2927,6 +2927,9 @@ need_resched: >> >> pre_schedule(rq, prev); >> >> + if (unlikely(prev == rq->idle)) >> + idle_exit(cpu, rq); >> + > > Let's get rid of the added junk in the core code that should be isolated > in the idle code. >
i agree > I posted these patches before, and I'm about to post again: > > https://lkml.org/lkml/2012/12/21/378 > https://lkml.org/lkml/2012/12/21/377 > > I'm working to clean these patches up today and post them again. Would > working on top of these work for you? yes for sure. I will move that code in pre_schedule Vincent > > -- Steve > > >> if (unlikely(!rq->nr_running)) >> idle_balance(cpu, rq); >> > > _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev
