Messages in this thread | | | From | Paul Turner <> | Date | Thu, 24 Feb 2011 19:11:29 -0800 | Subject | Re: [CFS Bandwidth Control v4 1/7] sched: introduce primitives to account for CFS bandwidth tracking |
| |
On Wed, Feb 23, 2011 at 5:32 AM, Peter Zijlstra <a.p.zijlstra@chello.nl> wrote: > On Tue, 2011-02-15 at 19:18 -0800, Paul Turner wrote: > >> @@ -245,6 +248,15 @@ struct cfs_rq; >> >> static LIST_HEAD(task_groups); >> >> +#ifdef CONFIG_CFS_BANDWIDTH >> +struct cfs_bandwidth { >> + raw_spinlock_t lock; >> + ktime_t period; >> + u64 runtime, quota; >> + struct hrtimer period_timer; >> +}; >> +#endif > > If you write that as: > > struct cfs_bandwidth { > #ifdef CONFIG_CFS_BANDWIDTH > ... > #endif > }; >
While I prefer (entirely subjectively) making the #ifdef's in cfs_rq explicit; I have no real objection and this lets us kill #ifdefs around init_cfs_bandwidth (since it does reference the member).
Done.
>> /* task group related information */ >> struct task_group { >> struct cgroup_subsys_state css; >> @@ -276,6 +288,10 @@ struct task_group { >> #ifdef CONFIG_SCHED_AUTOGROUP >> struct autogroup *autogroup; >> #endif >> + >> +#ifdef CONFIG_CFS_BANDWIDTH >> + struct cfs_bandwidth cfs_bandwidth; >> +#endif >> }; > > You can avoid the #ifdef'ery here >
Done
>> /* task_group_lock serializes the addition/removal of task groups */ >> @@ -370,9 +386,76 @@ struct cfs_rq { > >> +#ifdef CONFIG_CFS_BANDWIDTH >> +static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun); >> + >> +static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer) >> +{ >> + struct cfs_bandwidth *cfs_b = >> + container_of(timer, struct cfs_bandwidth, period_timer); >> + ktime_t now; >> + int overrun; >> + int idle = 0; >> + >> + for (;;) { >> + now = hrtimer_cb_get_time(timer); >> + overrun = hrtimer_forward(timer, now, cfs_b->period); >> + >> + if (!overrun) >> + break; >> + >> + idle = do_sched_cfs_period_timer(cfs_b, overrun); >> + } >> + >> + return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; >> +} >> + >> +static >> +void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b, u64 quota, u64 period) >> +{ >> + raw_spin_lock_init(&cfs_b->lock); >> + cfs_b->quota = cfs_b->runtime = quota; >> + cfs_b->period = ns_to_ktime(period); >> + >> + hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); >> + cfs_b->period_timer.function = sched_cfs_period_timer; >> +} >> + >> +static >> +void init_cfs_rq_quota(struct cfs_rq *cfs_rq) >> +{ >> + cfs_rq->quota_used = 0; >> + if (cfs_rq->tg->cfs_bandwidth.quota == RUNTIME_INF) >> + cfs_rq->quota_assigned = RUNTIME_INF; >> + else >> + cfs_rq->quota_assigned = 0; >> +} >> + >> +static void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b) >> +{ >> + if (cfs_b->quota == RUNTIME_INF) >> + return; >> + >> + if (hrtimer_active(&cfs_b->period_timer)) >> + return; >> + >> + raw_spin_lock(&cfs_b->lock); >> + start_bandwidth_timer(&cfs_b->period_timer, cfs_b->period); >> + raw_spin_unlock(&cfs_b->lock); >> +} >> + >> +static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) >> +{ >> + hrtimer_cancel(&cfs_b->period_timer); >> +} >> +#endif > > and #else > > stubs > #endif > >> /* Real-Time classes' related field in a runqueue: */ >> struct rt_rq { >> struct rt_prio_array active; >> @@ -8038,6 +8121,9 @@ static void init_tg_cfs_entry(struct tas >> tg->cfs_rq[cpu] = cfs_rq; >> init_cfs_rq(cfs_rq, rq); >> cfs_rq->tg = tg; >> +#ifdef CONFIG_CFS_BANDWIDTH >> + init_cfs_rq_quota(cfs_rq); >> +#endif > > also avoids #ifdef'ery here >
Done
>> tg->se[cpu] = se; >> /* se could be NULL for root_task_group */ >> @@ -8173,6 +8259,10 @@ void __init sched_init(void) >> * We achieve this by letting root_task_group's tasks sit >> * directly in rq->cfs (i.e root_task_group->se[] = NULL). >> */ >> +#ifdef CONFIG_CFS_BANDWIDTH >> + init_cfs_bandwidth(&root_task_group.cfs_bandwidth, >> + RUNTIME_INF, sched_cfs_bandwidth_period); >> +#endif > > and here >
Done
>> init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, NULL); >> #endif /* CONFIG_FAIR_GROUP_SCHED */ >> >> @@ -8415,6 +8505,10 @@ static void free_fair_sched_group(struct >> { >> int i; >> >> +#ifdef CONFIG_CFS_BANDWIDTH >> + destroy_cfs_bandwidth(&tg->cfs_bandwidth); >> +#endif > > and here >
Done
>> for_each_possible_cpu(i) { >> if (tg->cfs_rq) >> kfree(tg->cfs_rq[i]); >> @@ -8442,7 +8536,10 @@ int alloc_fair_sched_group(struct task_g >> goto err; >> >> tg->shares = NICE_0_LOAD; >> - >> +#ifdef CONFIG_CFS_BANDWIDTH >> + init_cfs_bandwidth(&tg->cfs_bandwidth, RUNTIME_INF, >> + sched_cfs_bandwidth_period); >> +#endif > > and here >
Done
>> for_each_possible_cpu(i) { >> rq = cpu_rq(i); >> > >> @@ -9107,6 +9204,116 @@ static u64 cpu_shares_read_u64(struct cg >> >> return (u64) tg->shares; >> } >> + >> +#ifdef CONFIG_CFS_BANDWIDTH >> +static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota) >> +{ >> + int i; >> + static DEFINE_MUTEX(mutex); >> + >> + if (tg == &root_task_group) >> + return -EINVAL; >> + >> + if (!period) >> + return -EINVAL; >> + >> + /* >> + * Ensure we have at least one tick of bandwidth every period. This is >> + * to prevent reaching a state of large arrears when throttled via >> + * entity_tick() resulting in prolonged exit starvation. >> + */ >> + if (NS_TO_JIFFIES(quota) < 1) >> + return -EINVAL; >> + >> + mutex_lock(&mutex); >> + raw_spin_lock_irq(&tg->cfs_bandwidth.lock); >> + tg->cfs_bandwidth.period = ns_to_ktime(period); >> + tg->cfs_bandwidth.runtime = tg->cfs_bandwidth.quota = quota; >> + raw_spin_unlock_irq(&tg->cfs_bandwidth.lock); >> + >> + for_each_possible_cpu(i) { >> + struct cfs_rq *cfs_rq = tg->cfs_rq[i]; >> + struct rq *rq = rq_of(cfs_rq); >> + >> + raw_spin_lock_irq(&rq->lock); >> + init_cfs_rq_quota(cfs_rq); >> + raw_spin_unlock_irq(&rq->lock); > > Any particular reason you didn't mirror rt_rq->rt_runtime_lock? > >> + } >> + mutex_unlock(&mutex); >> + >> + return 0; >> +} > > >> Index: tip/kernel/sched_fair.c >> =================================================================== >> --- tip.orig/kernel/sched_fair.c >> +++ tip/kernel/sched_fair.c >> @@ -88,6 +88,15 @@ const_debug unsigned int sysctl_sched_mi >> */ >> unsigned int __read_mostly sysctl_sched_shares_window = 10000000UL; >> >> + >> +#ifdef CONFIG_CFS_BANDWIDTH >> +/* >> + * default period for cfs group bandwidth. >> + * default: 0.5s, units: nanoseconds >> + */ >> +static u64 sched_cfs_bandwidth_period = 500000000ULL; >> +#endif >> + >> static const struct sched_class fair_sched_class; >> >> /************************************************************** >> @@ -397,6 +406,9 @@ static void __enqueue_entity(struct cfs_ >> >> rb_link_node(&se->run_node, parent, link); >> rb_insert_color(&se->run_node, &cfs_rq->tasks_timeline); >> +#ifdef CONFIG_CFS_BANDWIDTH >> + start_cfs_bandwidth(&cfs_rq->tg->cfs_bandwidth); >> +#endif >> } > > This really needs to life elsewhere, __*_entity() functions are for > rb-tree muck. >
Moved to enqueue_entity
>> static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |