diff options
Diffstat (limited to 'kernel/sched_fair.c')
| -rw-r--r-- | kernel/sched_fair.c | 62 |
1 files changed, 40 insertions, 22 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index f604dae71316..9573c33688b8 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -73,6 +73,8 @@ unsigned int sysctl_sched_wakeup_granularity = 5000000UL; const_debug unsigned int sysctl_sched_migration_cost = 500000UL; +static const struct sched_class fair_sched_class; + /************************************************************** * CFS operations on generic schedulable entities: */ @@ -334,7 +336,7 @@ int sched_nr_latency_handler(struct ctl_table *table, int write, #endif /* - * delta *= w / rw + * delta *= P[w / rw] */ static inline unsigned long calc_delta_weight(unsigned long delta, struct sched_entity *se) @@ -348,15 +350,13 @@ calc_delta_weight(unsigned long delta, struct sched_entity *se) } /* - * delta *= rw / w + * delta /= w */ static inline unsigned long calc_delta_fair(unsigned long delta, struct sched_entity *se) { - for_each_sched_entity(se) { - delta = calc_delta_mine(delta, - cfs_rq_of(se)->load.weight, &se->load); - } + if (unlikely(se->load.weight != NICE_0_LOAD)) + delta = calc_delta_mine(delta, NICE_0_LOAD, &se->load); return delta; } @@ -386,26 +386,26 @@ static u64 __sched_period(unsigned long nr_running) * We calculate the wall-time slice from the period by taking a part * proportional to the weight. * - * s = p*w/rw + * s = p*P[w/rw] */ static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se) { - return calc_delta_weight(__sched_period(cfs_rq->nr_running), se); + unsigned long nr_running = cfs_rq->nr_running; + + if (unlikely(!se->on_rq)) + nr_running++; + + return calc_delta_weight(__sched_period(nr_running), se); } /* * We calculate the vruntime slice of a to be inserted task * - * vs = s*rw/w = p + * vs = s/w */ -static u64 sched_vslice_add(struct cfs_rq *cfs_rq, struct sched_entity *se) +static u64 sched_vslice(struct cfs_rq *cfs_rq, struct sched_entity *se) { - unsigned long nr_running = cfs_rq->nr_running; - - if (!se->on_rq) - nr_running++; - - return __sched_period(nr_running); + return calc_delta_fair(sched_slice(cfs_rq, se), se); } /* @@ -628,7 +628,7 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) * stays open at the end. */ if (initial && sched_feat(START_DEBIT)) - vruntime += sched_vslice_add(cfs_rq, se); + vruntime += sched_vslice(cfs_rq, se); if (!initial) { /* sleeps upto a single latency don't count. */ @@ -748,7 +748,7 @@ pick_next(struct cfs_rq *cfs_rq, struct sched_entity *se) struct rq *rq = rq_of(cfs_rq); u64 pair_slice = rq->clock - cfs_rq->pair_start; - if (!cfs_rq->next || pair_slice > sched_slice(cfs_rq, cfs_rq->next)) { + if (!cfs_rq->next || pair_slice > sysctl_sched_min_granularity) { cfs_rq->pair_start = rq->clock; return se; } @@ -849,11 +849,31 @@ static void hrtick_start_fair(struct rq *rq, struct task_struct *p) hrtick_start(rq, delta); } } + +/* + * called from enqueue/dequeue and updates the hrtick when the + * current task is from our class and nr_running is low enough + * to matter. + */ +static void hrtick_update(struct rq *rq) +{ + struct task_struct *curr = rq->curr; + + if (curr->sched_class != &fair_sched_class) + return; + + if (cfs_rq_of(&curr->se)->nr_running < sched_nr_latency) + hrtick_start_fair(rq, curr); +} #else /* !CONFIG_SCHED_HRTICK */ static inline void hrtick_start_fair(struct rq *rq, struct task_struct *p) { } + +static inline void hrtick_update(struct rq *rq) +{ +} #endif /* @@ -874,7 +894,7 @@ static void enqueue_task_fair(struct rq *rq, struct task_struct *p, int wakeup) wakeup = 1; } - hrtick_start_fair(rq, rq->curr); + hrtick_update(rq); } /* @@ -896,7 +916,7 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int sleep) sleep = 1; } - hrtick_start_fair(rq, rq->curr); + hrtick_update(rq); } /* @@ -1002,8 +1022,6 @@ static inline int wake_idle(int cpu, struct task_struct *p) #ifdef CONFIG_SMP -static const struct sched_class fair_sched_class; - #ifdef CONFIG_FAIR_GROUP_SCHED /* * effective_load() calculates the load change as seen from the root_task_group |