Hi Juri, On Tue, Nov 18, 2014 at 06:00:20PM +0000, Juri Lelli wrote: >Hi, > >On 13/11/14 08:47, Wanpeng Li wrote: >> Dl class will refuse the bandwidth being set to some value smaller >> than the currently allocated bandwidth in any of the root_domains >> through sched_rt_runtime_us and sched_rt_period_us. RT runtime will >> be set according to sched_rt_runtime_us before dl class verify if >> the new bandwidth is suitable in the case of !CONFIG_RT_GROUP_SCHED. >> >> However, rt runtime will be corrupt if dl refuse the new bandwidth >> since there is no undo to reset the rt runtime to the old value. >> > >Can't we just move sched_dl_global_constraints() before >sched_rt_global_constraints(), and change the name of the >former to sched_dl_global_validate() ?
Good idea, I will send out the next version later. ;-) Regards, Wanpeng Li > >Thanks, > >- Juri > >> This patch fix it by setting rt runtime after all kinds of rational >> checking in the case of !CONFIG_RT_GROUP_SCHED. >> >> Signed-off-by: Wanpeng Li <[email protected]> >> --- >> kernel/sched/core.c | 30 ++++++++++++++++-------------- >> 1 file changed, 16 insertions(+), 14 deletions(-) >> >> diff --git a/kernel/sched/core.c b/kernel/sched/core.c >> index 2e7578a..355dde3 100644 >> --- a/kernel/sched/core.c >> +++ b/kernel/sched/core.c >> @@ -7795,20 +7795,7 @@ static int sched_rt_can_attach(struct task_group *tg, >> struct task_struct *tsk) >> #else /* !CONFIG_RT_GROUP_SCHED */ >> static int sched_rt_global_constraints(void) >> { >> - unsigned long flags; >> - int i, ret = 0; >> - >> - raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); >> - for_each_possible_cpu(i) { >> - struct rt_rq *rt_rq = &cpu_rq(i)->rt; >> - >> - raw_spin_lock(&rt_rq->rt_runtime_lock); >> - rt_rq->rt_runtime = global_rt_runtime(); >> - raw_spin_unlock(&rt_rq->rt_runtime_lock); >> - } >> - raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); >> - >> - return ret; >> + return 0; >> } >> #endif /* CONFIG_RT_GROUP_SCHED */ >> >> @@ -7890,6 +7877,21 @@ static int sched_rt_global_validate(void) >> >> static void sched_rt_do_global(void) >> { >> +#ifndef CONFIG_RT_GROUP_SCHED >> + unsigned long flags; >> + int i; >> + >> + raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); >> + for_each_possible_cpu(i) { >> + struct rt_rq *rt_rq = &cpu_rq(i)->rt; >> + >> + raw_spin_lock(&rt_rq->rt_runtime_lock); >> + rt_rq->rt_runtime = global_rt_runtime(); >> + raw_spin_unlock(&rt_rq->rt_runtime_lock); >> + } >> + raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); >> +#endif >> + >> def_rt_bandwidth.rt_runtime = global_rt_runtime(); >> def_rt_bandwidth.rt_period = ns_to_ktime(global_rt_period()); >> } >> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
