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sched: rt-group: synchonised bandwidth period

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Various SMP balancing algorithms require that the bandwidth period
run in sync.

Possible improvements are moving the rt_bandwidth thing into root_domain
and keeping a span per rt_bandwidth which marks throttled cpus.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra
2008-04-19 19:44:57 +02:00
committed by Ingo Molnar
parent 57d3da2911
commit d0b27fa778
6 changed files with 320 additions and 88 deletions
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104
kernel/sched_rt.c
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@ -62,7 +62,7 @@ static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)
if (!rt_rq->tg)
return RUNTIME_INF;
return rt_rq->tg->rt_runtime;
return rt_rq->tg->rt_bandwidth.rt_runtime;
}
#define for_each_leaf_rt_rq(rt_rq, rq) \
@ -127,14 +127,29 @@ static int rt_se_boosted(struct sched_rt_entity *rt_se)
return p->prio != p->normal_prio;
}
#ifdef CONFIG_SMP
static inline cpumask_t sched_rt_period_mask(void)
{
return cpu_rq(smp_processor_id())->rd->span;
}
#else
static inline cpumask_t sched_rt_period_mask(void)
{
return cpu_online_map;
}
#endif
static inline
struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)
{
return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu];
}
#else
static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)
{
if (sysctl_sched_rt_runtime == -1)
return RUNTIME_INF;
return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
return def_rt_bandwidth.rt_runtime;
}
#define for_each_leaf_rt_rq(rt_rq, rq) \
@ -173,8 +188,55 @@ static inline int rt_rq_throttled(struct rt_rq *rt_rq)
{
return rt_rq->rt_throttled;
}
static inline cpumask_t sched_rt_period_mask(void)
{
return cpu_online_map;
}
static inline
struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)
{
return &cpu_rq(cpu)->rt;
}
#endif
static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
{
int i, idle = 1;
cpumask_t span;
if (rt_b->rt_runtime == RUNTIME_INF)
return 1;
span = sched_rt_period_mask();
for_each_cpu_mask(i, span) {
int enqueue = 0;
struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i);
struct rq *rq = rq_of_rt_rq(rt_rq);
spin_lock(&rq->lock);
if (rt_rq->rt_time) {
u64 runtime = rt_b->rt_runtime;
rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime);
if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) {
rt_rq->rt_throttled = 0;
enqueue = 1;
}
if (rt_rq->rt_time || rt_rq->rt_nr_running)
idle = 0;
}
if (enqueue)
sched_rt_rq_enqueue(rt_rq);
spin_unlock(&rq->lock);
}
return idle;
}
static inline int rt_se_prio(struct sched_rt_entity *rt_se)
{
#ifdef CONFIG_RT_GROUP_SCHED
@ -198,11 +260,7 @@ static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)
return rt_rq_throttled(rt_rq);
if (rt_rq->rt_time > runtime) {
struct rq *rq = rq_of_rt_rq(rt_rq);
rq->rt_throttled = 1;
rt_rq->rt_throttled = 1;
if (rt_rq_throttled(rt_rq)) {
sched_rt_rq_dequeue(rt_rq);
return 1;
@ -212,29 +270,6 @@ static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)
return 0;
}
static void update_sched_rt_period(struct rq *rq)
{
struct rt_rq *rt_rq;
u64 period;
while (rq->clock > rq->rt_period_expire) {
period = (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
rq->rt_period_expire += period;
for_each_leaf_rt_rq(rt_rq, rq) {
u64 runtime = sched_rt_runtime(rt_rq);
rt_rq->rt_time -= min(rt_rq->rt_time, runtime);
if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) {
rt_rq->rt_throttled = 0;
sched_rt_rq_enqueue(rt_rq);
}
}
rq->rt_throttled = 0;
}
}
/*
* Update the current task's runtime statistics. Skip current tasks that
* are not in our scheduling class.
@ -284,6 +319,11 @@ void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
#ifdef CONFIG_RT_GROUP_SCHED
if (rt_se_boosted(rt_se))
rt_rq->rt_nr_boosted++;
if (rt_rq->tg)
start_rt_bandwidth(&rt_rq->tg->rt_bandwidth);
#else
start_rt_bandwidth(&def_rt_bandwidth);
#endif
}