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() ? 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 <wanpeng...@linux.intel.com> > --- > 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 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/