21.02.2014, 15:39, "Kirill Tkhai" <tk...@yandex.ru>: > 21.02.2014, 14:37, "Peter Zijlstra" <pet...@infradead.org>: > >> On Thu, Feb 20, 2014 at 02:16:00AM +0400, Kirill Tkhai wrote: >>> Since deadline tasks share rt bandwidth, we must care about >>> bandwidth timer set. Otherwise rt_time may grow up to infinity >>> in update_curr_dl(), if there are no other available RT tasks >>> on top level bandwidth. >>> >>> I'm going to decide the problem the way below. Almost untested >>> because of I skipped almost all of recent patches which haveto be applied >>> from lkml. >>> >>> Please say, if I skipped anything in idea. Maybe better put >>> start_top_rt_bandwidth() into set_curr_task_dl()? >> How about we only increment rt_time when there's an RT bandwidth timer >> active? > > This case RT and DL may eat all the time: > > -------------- time ------------------> > |RT's working |DL's working| > ---------------------------- > |rt_runtime | | > ---------------------------- > | rt_period | > > Or at least more, than it's allowed. > > It looks like, if we want to limit time of high priority classes > execution, we have to set the timer anyway.
Oh, above is confusing. Sorry. I mean one RT task and ----------------- time --------------------------> |DL's working |RT's working| |DL's working | -------------------------------------------------- | |rt_runtime | | | -------------------------------------------------- | | rt_period | | In this case FAIR receives less ratio, than (rt_period-rt_runtime)/rt_period. >> --- >> --- a/kernel/sched/rt.c >> +++ b/kernel/sched/rt.c >> @@ -568,6 +568,12 @@ static inline struct rt_bandwidth *sched > > [snipped by dumb mail client] > -- > 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/ -- 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/
