diff options
Diffstat (limited to 'kernel/sched/fair.c')
| -rw-r--r-- | kernel/sched/fair.c | 1244 |
1 files changed, 1138 insertions, 106 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index c242944f5cbd..0771ad827e3b 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -30,10 +30,13 @@ #include <linux/mempolicy.h> #include <linux/migrate.h> #include <linux/task_work.h> +#include <linux/module.h> #include <trace/events/sched.h> #include "sched.h" +#include "tune.h" +#include "walt.h" /* * Targeted preemption latency for CPU-bound tasks: @@ -50,6 +53,17 @@ unsigned int sysctl_sched_latency = 6000000ULL; unsigned int normalized_sysctl_sched_latency = 6000000ULL; +unsigned int sysctl_sched_is_big_little = 0; +unsigned int sysctl_sched_sync_hint_enable = 1; +unsigned int sysctl_sched_initial_task_util = 0; +unsigned int sysctl_sched_cstate_aware = 1; + +#ifdef CONFIG_SCHED_WALT +unsigned int sysctl_sched_use_walt_cpu_util = 1; +unsigned int sysctl_sched_use_walt_task_util = 1; +__read_mostly unsigned int sysctl_sched_walt_cpu_high_irqload = + (10 * NSEC_PER_MSEC); +#endif /* * The initial- and re-scaling of tunables is configurable * (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus)) @@ -699,10 +713,13 @@ void init_entity_runnable_average(struct sched_entity *se) if (entity_is_task(se)) sa->load_avg = scale_load_down(se->load.weight); sa->load_sum = sa->load_avg * LOAD_AVG_MAX; + /* * At this point, util_avg won't be used in select_task_rq_fair anyway */ - sa->util_avg = 0; + sa->util_avg = sched_freq() ? + sysctl_sched_initial_task_util : + 0; sa->util_sum = 0; /* when this task enqueue'ed, it will contribute to its cfs_rq's load_avg */ } @@ -937,6 +954,7 @@ update_stats_enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) } trace_sched_stat_blocked(tsk, delta); + trace_sched_blocked_reason(tsk); /* * Blocking time is in units of nanosecs, so shift by @@ -2815,6 +2833,7 @@ __update_load_avg(u64 now, int cpu, struct sched_avg *sa, scale_freq = arch_scale_freq_capacity(NULL, cpu); scale_cpu = arch_scale_cpu_capacity(NULL, cpu); + trace_sched_contrib_scale_f(cpu, scale_freq, scale_cpu); /* delta_w is the amount already accumulated against our next period */ delta_w = sa->period_contrib; @@ -3082,6 +3101,10 @@ static inline void update_load_avg(struct sched_entity *se, int update_tg) if (update_cfs_rq_load_avg(now, cfs_rq, true) && update_tg) update_tg_load_avg(cfs_rq, 0); + + if (entity_is_task(se)) + trace_sched_load_avg_task(task_of(se), &se->avg); + trace_sched_load_avg_cpu(cpu, cfs_rq); } /** @@ -4527,6 +4550,30 @@ static inline void hrtick_update(struct rq *rq) } #endif +#ifdef CONFIG_SMP +static bool cpu_overutilized(int cpu); +static unsigned long capacity_orig_of(int cpu); +static unsigned long cpu_util(int cpu); +static inline unsigned long boosted_cpu_util(int cpu); +#else +#define boosted_cpu_util(cpu) cpu_util(cpu) +#endif + +#ifdef CONFIG_SMP +static void update_capacity_of(int cpu) +{ + unsigned long req_cap; + + if (!sched_freq()) + return; + + /* Convert scale-invariant capacity to cpu. */ + req_cap = boosted_cpu_util(cpu); + req_cap = req_cap * SCHED_CAPACITY_SCALE / capacity_orig_of(cpu); + set_cfs_cpu_capacity(cpu, true, req_cap); +} +#endif + /* * The enqueue_task method is called before nr_running is * increased. Here we update the fair scheduling stats and @@ -4537,6 +4584,10 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) { struct cfs_rq *cfs_rq; struct sched_entity *se = &p->se; +#ifdef CONFIG_SMP + int task_new = flags & ENQUEUE_WAKEUP_NEW; + int task_wakeup = flags & ENQUEUE_WAKEUP; +#endif /* * If in_iowait is set, the code below may not trigger any cpufreq @@ -4561,6 +4612,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) if (cfs_rq_throttled(cfs_rq)) break; cfs_rq->h_nr_running++; + walt_inc_cfs_cumulative_runnable_avg(cfs_rq, p); flags = ENQUEUE_WAKEUP; } @@ -4568,6 +4620,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) for_each_sched_entity(se) { cfs_rq = cfs_rq_of(se); cfs_rq->h_nr_running++; + walt_inc_cfs_cumulative_runnable_avg(cfs_rq, p); if (cfs_rq_throttled(cfs_rq)) break; @@ -4579,6 +4632,31 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) if (!se) add_nr_running(rq, 1); +#ifdef CONFIG_SMP + + if (!se) { + walt_inc_cumulative_runnable_avg(rq, p); + if (!task_new && !rq->rd->overutilized && + cpu_overutilized(rq->cpu)) { + rq->rd->overutilized = true; + trace_sched_overutilized(true); + } + + /* + * We want to potentially trigger a freq switch + * request only for tasks that are waking up; this is + * because we get here also during load balancing, but + * in these cases it seems wise to trigger as single + * request after load balancing is done. + */ + if (task_new || task_wakeup) + update_capacity_of(cpu_of(rq)); + } + + /* Update SchedTune accouting */ + schedtune_enqueue_task(p, cpu_of(rq)); + +#endif /* CONFIG_SMP */ hrtick_update(rq); } @@ -4608,6 +4686,7 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags) if (cfs_rq_throttled(cfs_rq)) break; cfs_rq->h_nr_running--; + walt_dec_cfs_cumulative_runnable_avg(cfs_rq, p); /* Don't dequeue parent if it has other entities besides us */ if (cfs_rq->load.weight) { @@ -4627,6 +4706,7 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags) for_each_sched_entity(se) { cfs_rq = cfs_rq_of(se); cfs_rq->h_nr_running--; + walt_dec_cfs_cumulative_runnable_avg(cfs_rq, p); if (cfs_rq_throttled(cfs_rq)) break; @@ -4638,6 +4718,32 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags) if (!se) sub_nr_running(rq, 1); +#ifdef CONFIG_SMP + + if (!se) { + walt_dec_cumulative_runnable_avg(rq, p); + + /* + * We want to potentially trigger a freq switch + * request only for tasks that are going to sleep; + * this is because we get here also during load + * balancing, but in these cases it seems wise to + * trigger as single request after load balancing is + * done. + */ + if (task_sleep) { + if (rq->cfs.nr_running) + update_capacity_of(cpu_of(rq)); + else if (sched_freq()) + set_cfs_cpu_capacity(cpu_of(rq), false, 0); + } + } + + /* Update SchedTune accouting */ + schedtune_dequeue_task(p, cpu_of(rq)); + +#endif /* CONFIG_SMP */ + hrtick_update(rq); } @@ -4944,15 +5050,6 @@ static unsigned long target_load(int cpu, int type) return max(rq->cpu_load[type-1], total); } -static unsigned long capacity_of(int cpu) -{ - return cpu_rq(cpu)->cpu_capacity; -} - -static unsigned long capacity_orig_of(int cpu) -{ - return cpu_rq(cpu)->cpu_capacity_orig; -} static unsigned long cpu_avg_load_per_task(int cpu) { @@ -5104,6 +5201,397 @@ static void record_wakee(struct task_struct *p) } /* + * Returns the current capacity of cpu after applying both + * cpu and freq scaling. + */ +unsigned long capacity_curr_of(int cpu) +{ + return cpu_rq(cpu)->cpu_capacity_orig * + arch_scale_freq_capacity(NULL, cpu) + >> SCHED_CAPACITY_SHIFT; +} + +static inline bool energy_aware(void) +{ + return sched_feat(ENERGY_AWARE); +} + +struct energy_env { + struct sched_group *sg_top; + struct sched_group *sg_cap; + int cap_idx; + int util_delta; + int src_cpu; + int dst_cpu; + int energy; + int payoff; + struct task_struct *task; + struct { + int before; + int after; + int delta; + int diff; + } nrg; + struct { + int before; + int after; + int delta; + } cap; +}; + +/* + * __cpu_norm_util() returns the cpu util relative to a specific capacity, + * i.e. it's busy ratio, in the range [0..SCHED_LOAD_SCALE] which is useful for + * energy calculations. Using the scale-invariant util returned by + * cpu_util() and approximating scale-invariant util by: + * + * util ~ (curr_freq/max_freq)*1024 * capacity_orig/1024 * running_time/time + * + * the normalized util can be found using the specific capacity. + * + * capacity = capacity_orig * curr_freq/max_freq + * + * norm_util = running_time/time ~ util/capacity + */ +static unsigned long __cpu_norm_util(int cpu, unsigned long capacity, int delta) +{ + int util = __cpu_util(cpu, delta); + + if (util >= capacity) + return SCHED_CAPACITY_SCALE; + + return (util << SCHED_CAPACITY_SHIFT)/capacity; +} + +static int calc_util_delta(struct energy_env *eenv, int cpu) +{ + if (cpu == eenv->src_cpu) + return -eenv->util_delta; + if (cpu == eenv->dst_cpu) + return eenv->util_delta; + return 0; +} + +static +unsigned long group_max_util(struct energy_env *eenv) +{ + int i, delta; + unsigned long max_util = 0; + + for_each_cpu(i, sched_group_cpus(eenv->sg_cap)) { + delta = calc_util_delta(eenv, i); + max_util = max(max_util, __cpu_util(i, delta)); + } + + return max_util; +} + +/* + * group_norm_util() returns the approximated group util relative to it's + * current capacity (busy ratio) in the range [0..SCHED_LOAD_SCALE] for use in + * energy calculations. Since task executions may or may not overlap in time in + * the group the true normalized util is between max(cpu_norm_util(i)) and + * sum(cpu_norm_util(i)) when iterating over all cpus in the group, i. The + * latter is used as the estimate as it leads to a more pessimistic energy + * estimate (more busy). + */ +static unsigned +long group_norm_util(struct energy_env *eenv, struct sched_group *sg) +{ + int i, delta; + unsigned long util_sum = 0; + unsigned long capacity = sg->sge->cap_states[eenv->cap_idx].cap; + + for_each_cpu(i, sched_group_cpus(sg)) { + delta = calc_util_delta(eenv, i); + util_sum += __cpu_norm_util(i, capacity, delta); + } + + if (util_sum > SCHED_CAPACITY_SCALE) + return SCHED_CAPACITY_SCALE; + return util_sum; +} + +static int find_new_capacity(struct energy_env *eenv, + const struct sched_group_energy const *sge) +{ + int idx; + unsigned long util = group_max_util(eenv); + + for (idx = 0; idx < sge->nr_cap_states; idx++) { + if (sge->cap_states[idx].cap >= util) + break; + } + + eenv->cap_idx = idx; + + return idx; +} + +static int group_idle_state(struct sched_group *sg) +{ + int i, state = INT_MAX; + + /* Find the shallowest idle state in the sched group. */ + for_each_cpu(i, sched_group_cpus(sg)) + state = min(state, idle_get_state_idx(cpu_rq(i))); + + /* Take non-cpuidle idling into account (active idle/arch_cpu_idle()) */ + state++; + + return state; +} + +/* + * sched_group_energy(): Computes the absolute energy consumption of cpus + * belonging to the sched_group including shared resources shared only by + * members of the group. Iterates over all cpus in the hierarchy below the + * sched_group starting from the bottom working it's way up before going to + * the next cpu until all cpus are covered at all levels. The current + * implementation is likely to gather the same util statistics multiple times. + * This can probably be done in a faster but more complex way. + * Note: sched_group_energy() may fail when racing with sched_domain updates. + */ +static int sched_group_energy(struct energy_env *eenv) +{ + struct sched_domain *sd; + int cpu, total_energy = 0; + struct cpumask visit_cpus; + struct sched_group *sg; + + WARN_ON(!eenv->sg_top->sge); + + cpumask_copy(&visit_cpus, sched_group_cpus(eenv->sg_top)); + + while (!cpumask_empty(&visit_cpus)) { + struct sched_group *sg_shared_cap = NULL; + + cpu = cpumask_first(&visit_cpus); + + /* + * Is the group utilization affected by cpus outside this + * sched_group? + */ + sd = rcu_dereference(per_cpu(sd_scs, cpu)); + + if (!sd) + /* + * We most probably raced with hotplug; returning a + * wrong energy estimation is better than entering an + * infinite loop. + */ + return -EINVAL; + + if (sd->parent) + sg_shared_cap = sd->parent->groups; + + for_each_domain(cpu, sd) { + sg = sd->groups; + + /* Has this sched_domain already been visited? */ + if (sd->child && group_first_cpu(sg) != cpu) + break; + + do { + unsigned long group_util; + int sg_busy_energy, sg_idle_energy; + int cap_idx, idle_idx; + + if (sg_shared_cap && sg_shared_cap->group_weight >= sg->group_weight) + eenv->sg_cap = sg_shared_cap; + else + eenv->sg_cap = sg; + + cap_idx = find_new_capacity(eenv, sg->sge); + + if (sg->group_weight == 1) { + /* Remove capacity of src CPU (before task move) */ + if (eenv->util_delta == 0 && + cpumask_test_cpu(eenv->src_cpu, sched_group_cpus(sg))) { + eenv->cap.before = sg->sge->cap_states[cap_idx].cap; + eenv->cap.delta -= eenv->cap.before; + } + /* Add capacity of dst CPU (after task move) */ + if (eenv->util_delta != 0 && + cpumask_test_cpu(eenv->dst_cpu, sched_group_cpus(sg))) { + eenv->cap.after = sg->sge->cap_states[cap_idx].cap; + eenv->cap.delta += eenv->cap.after; + } + } + + idle_idx = group_idle_state(sg); + group_util = group_norm_util(eenv, sg); + sg_busy_energy = (group_util * sg->sge->cap_states[cap_idx].power) + >> SCHED_CAPACITY_SHIFT; + sg_idle_energy = ((SCHED_CAPACITY_SCALE-group_util) + * sg->sge->idle_states[idle_idx].power) + >> SCHED_CAPACITY_SHIFT; + + total_energy += sg_busy_energy + sg_idle_energy; + + if (!sd->child) + cpumask_xor(&visit_cpus, &visit_cpus, sched_group_cpus(sg)); + + if (cpumask_equal(sched_group_cpus(sg), sched_group_cpus(eenv->sg_top))) + goto next_cpu; + + } while (sg = sg->next, sg != sd->groups); + } +next_cpu: + cpumask_clear_cpu(cpu, &visit_cpus); + continue; + } + + eenv->energy = total_energy; + return 0; +} + +static inline bool cpu_in_sg(struct sched_group *sg, int cpu) +{ + return cpu != -1 && cpumask_test_cpu(cpu, sched_group_cpus(sg)); +} + +/* + * energy_diff(): Estimate the energy impact of changing the utilization + * distribution. eenv specifies the change: utilisation amount, source, and + * destination cpu. Source or destination cpu may be -1 in which case the + * utilization is removed from or added to the system (e.g. task wake-up). If + * both are specified, the utilization is migrated. + */ +static inline int __energy_diff(struct energy_env *eenv) +{ + struct sched_domain *sd; + struct sched_group *sg; + int sd_cpu = -1, energy_before = 0, energy_after = 0; + + struct energy_env eenv_before = { + .util_delta = 0, + .src_cpu = eenv->src_cpu, + .dst_cpu = eenv->dst_cpu, + .nrg = { 0, 0, 0, 0}, + .cap = { 0, 0, 0 }, + }; + + if (eenv->src_cpu == eenv->dst_cpu) + return 0; + + sd_cpu = (eenv->src_cpu != -1) ? eenv->src_cpu : eenv->dst_cpu; + sd = rcu_dereference(per_cpu(sd_ea, sd_cpu)); + + if (!sd) + return 0; /* Error */ + + sg = sd->groups; + + do { + if (cpu_in_sg(sg, eenv->src_cpu) || cpu_in_sg(sg, eenv->dst_cpu)) { + eenv_before.sg_top = eenv->sg_top = sg; + + if (sched_group_energy(&eenv_before)) + return 0; /* Invalid result abort */ + energy_before += eenv_before.energy; + + /* Keep track of SRC cpu (before) capacity */ + eenv->cap.before = eenv_before.cap.before; + eenv->cap.delta = eenv_before.cap.delta; + + if (sched_group_energy(eenv)) + return 0; /* Invalid result abort */ + energy_after += eenv->energy; + } + } while (sg = sg->next, sg != sd->groups); + + eenv->nrg.before = energy_before; + eenv->nrg.after = energy_after; + eenv->nrg.diff = eenv->nrg.after - eenv->nrg.before; + eenv->payoff = 0; + + trace_sched_energy_diff(eenv->task, + eenv->src_cpu, eenv->dst_cpu, eenv->util_delta, + eenv->nrg.before, eenv->nrg.after, eenv->nrg.diff, + eenv->cap.before, eenv->cap.after, eenv->cap.delta, + eenv->nrg.delta, eenv->payoff); + + return eenv->nrg.diff; +} + +#ifdef CONFIG_SCHED_TUNE + +struct target_nrg schedtune_target_nrg; + +/* + * System energy normalization + * Returns the normalized value, in the range [0..SCHED_LOAD_SCALE], + * corresponding to the specified energy variation. + */ +static inline int +normalize_energy(int energy_diff) +{ + u32 normalized_nrg; +#ifdef CONFIG_SCHED_DEBUG + int max_delta; + + /* Check for boundaries */ + max_delta = schedtune_target_nrg.max_power; + max_delta -= schedtune_target_nrg.min_power; + WARN_ON(abs(energy_diff) >= max_delta); +#endif + + /* Do scaling using positive numbers to increase the range */ + normalized_nrg = (energy_diff < 0) ? -energy_diff : energy_diff; + + /* Scale by energy magnitude */ + normalized_nrg <<= SCHED_CAPACITY_SHIFT; + + /* Normalize on max energy for target platform */ + normalized_nrg = reciprocal_divide( + normalized_nrg, schedtune_target_nrg.rdiv); + + return (energy_diff < 0) ? -normalized_nrg : normalized_nrg; +} + +static inline int +energy_diff(struct energy_env *eenv) +{ + unsigned int boost; + int nrg_delta; + + /* Conpute "absolute" energy diff */ + __energy_diff(eenv); + + /* Return energy diff when boost margin is 0 */ +#ifdef CONFIG_CGROUP_SCHEDTUNE + boost = schedtune_task_boost(eenv->task); +#else + boost = get_sysctl_sched_cfs_boost(); +#endif + if (boost == 0) + return eenv->nrg.diff; + + /* Compute normalized energy diff */ + nrg_delta = normalize_energy(eenv->nrg.diff); + eenv->nrg.delta = nrg_delta; + + eenv->payoff = schedtune_accept_deltas( + eenv->nrg.delta, + eenv->cap.delta, + eenv->task); + + /* + * When SchedTune is enabled, the energy_diff() function will return + * the computed energy payoff value. Since the energy_diff() return + * value is expected to be negative by its callers, this evaluation + * function return a negative value each time the evaluation return a + * positive payoff, which is the condition for the acceptance of + * a scheduling decision + */ + return -eenv->payoff; +} +#else /* CONFIG_SCHED_TUNE */ +#define energy_diff(eenv) __energy_diff(eenv) +#endif + +/* * Detect M:N waker/wakee relationships via a switching-frequency heuristic. * * A waker of many should wake a different task than the one last awakened @@ -5199,6 +5687,169 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, return 1; } +static inline int task_util(struct task_struct *p) +{ +#ifdef CONFIG_SCHED_WALT + if (!walt_disabled && sysctl_sched_use_walt_task_util) { + unsigned long demand = p->ravg.demand; + return (demand << 10) / walt_ravg_window; + } +#endif + return p->se.avg.util_avg; +} + +static inline unsigned long boosted_task_util(struct task_struct *task); + +static inline bool __task_fits(struct task_struct *p, int cpu, int util) +{ + unsigned long capacity = capacity_of(cpu); + + util += boosted_task_util(p); + + return (capacity * 1024) > (util * capacity_margin); +} + +static inline bool task_fits_max(struct task_struct *p, int cpu) +{ + unsigned long capacity = capacity_of(cpu); + unsigned long max_capacity = cpu_rq(cpu)->rd->max_cpu_capacity.val; + + if (capacity == max_capacity) + return true; + + if (capacity * capacity_margin > max_capacity * 1024) + return true; + + return __task_fits(p, cpu, 0); +} + +static inline bool task_fits_spare(struct task_struct *p, int cpu) +{ + return __task_fits(p, cpu, cpu_util(cpu)); +} + +static bool cpu_overutilized(int cpu) +{ + return (capacity_of(cpu) * 1024) < (cpu_util(cpu) * capacity_margin); +} + +#ifdef CONFIG_SCHED_TUNE + +static long +schedtune_margin(unsigned long signal, long boost) +{ + long long margin = 0; + + /* + * Signal proportional compensation (SPC) + * + * The Boost (B) value is used to compute a Margin (M) which is + * proportional to the complement of the original Signal (S): + * M = B * (SCHED_LOAD_SCALE - S), if B is positive + * M = B * S, if B is negative + * The obtained M could be used by the caller to "boost" S. + */ + + if (boost >= 0) { + margin = SCHED_CAPACITY_SCALE - signal; + margin *= boost; + } else + margin = -signal * boost; + /* + * Fast integer division by constant: + * Constant : (C) = 100 + * Precision : 0.1% (P) = 0.1 + * Reference : C * 100 / P (R) = 100000 + * + * Thus: + * Shift bits : ceil(log(R,2)) (S) = 17 + * Mult const : round(2^S/C) (M) = 1311 + * + * + */ + margin *= 1311; + margin >>= 17; + + if (boost < 0) + margin *= -1; + return margin; +} + +static inline int +schedtune_cpu_margin(unsigned long util, int cpu) +{ + int boost; + +#ifdef CONFIG_CGROUP_SCHEDTUNE + boost = schedtune_cpu_boost(cpu); +#else + boost = get_sysctl_sched_cfs_boost(); +#endif + if (boost == 0) + return 0; + + return schedtune_margin(util, boost); +} + +static inline long +schedtune_task_margin(struct task_struct *task) +{ + int boost; + unsigned long util; + long margin; + +#ifdef CONFIG_CGROUP_SCHEDTUNE + boost = schedtune_task_boost(task); +#else + boost = get_sysctl_sched_cfs_boost(); +#endif + if (boost == 0) + return 0; + + util = task_util(task); + margin = schedtune_margin(util, boost); + + return margin; +} + +#else /* CONFIG_SCHED_TUNE */ + +static inline int +schedtune_cpu_margin(unsigned long util, int cpu) +{ + return 0; +} + +static inline int +schedtune_task_margin(struct task_struct *task) +{ + return 0; +} + +#endif /* CONFIG_SCHED_TUNE */ + +static inline unsigned long +boosted_cpu_util(int cpu) +{ + unsigned long util = cpu_util(cpu); + long margin = schedtune_cpu_margin(util, cpu); + + trace_sched_boost_cpu(cpu, util, margin); + + return util + margin; +} + +static inline unsigned long +boosted_task_util(struct task_struct *task) +{ + unsigned long util = task_util(task); + long margin = schedtune_task_margin(task); + + trace_sched_boost_task(task, util, margin); + + return util + margin; +} + /* * find_idlest_group finds and returns the least busy CPU group within the * domain. @@ -5208,7 +5859,10 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu, int sd_flag) { struct sched_group *idlest = NULL, *group = sd->groups; + struct sched_group *fit_group = NULL, *spare_group = NULL; unsigned long min_load = ULONG_MAX, this_load = 0; + unsigned long fit_capacity = ULONG_MAX; + unsigned long max_spare_capacity = capacity_margin - SCHED_CAPACITY_SCALE; int load_idx = sd->forkexec_idx; int imbalance = 100 + (sd->imbalance_pct-100)/2; @@ -5216,7 +5870,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, load_idx = sd->wake_idx; do { - unsigned long load, avg_load; + unsigned long load, avg_load, spare_capacity; int local_group; int i; @@ -5239,6 +5893,25 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, load = target_load(i, load_idx); avg_load += load; + + /* + * Look for most energy-efficient group that can fit + * that can fit the task. + */ + if (capacity_of(i) < fit_capacity && task_fits_spare(p, i)) { + fit_capacity = capacity_of(i); + fit_group = group; + } + + /* + * Look for group which has most spare capacity on a + * single cpu. + */ + spare_capacity = capacity_of(i) - cpu_util(i); + if (spare_capacity > max_spare_capacity) { + max_spare_capacity = spare_capacity; + spare_group = group; + } } /* Adjust by relative CPU capacity of the group */ @@ -5252,6 +5925,12 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, } } while (group = group->next, group != sd->groups); + if (fit_group) + return fit_group; + + if (spare_group) + return spare_group; + if (!idlest || 100*this_load < imbalance*min_load) return NULL; return idlest; @@ -5276,7 +5955,7 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) /* Traverse only the allowed CPUs */ for_each_cpu_and(i, sched_group_cpus(group), tsk_cpus_allowed(p)) { - if (idle_cpu(i)) { + if (task_fits_spare(p, i)) { struct rq *rq = cpu_rq(i); struct cpuidle_state *idle = idle_get_state(rq); if (idle && idle->exit_latency < min_exit_latency) { @@ -5288,7 +5967,8 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) min_exit_latency = idle->exit_latency; latest_idle_timestamp = rq->idle_stamp; shallowest_idle_cpu = i; - } else if ((!idle || idle->exit_latency == min_exit_latency) && + } else if (idle_cpu(i) && + (!idle || idle->exit_latency == min_exit_latency) && rq->idle_stamp > latest_idle_timestamp) { /* * If equal or no active idle state, then @@ -5297,6 +5977,13 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) */ latest_idle_timestamp = rq->idle_stamp; shallowest_idle_cpu = i; + } else if (shallowest_idle_cpu == -1) { + /* + * If we haven't found an idle CPU yet + * pick a non-idle one that can fit the task as + * fallback. + */ + shallowest_idle_cpu = i; } } else if (shallowest_idle_cpu == -1) { load = weighted_cpuload(i); @@ -5520,94 +6207,305 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t static int select_idle_sibling(struct task_struct *p, int prev, int target) { struct sched_domain *sd; - int i; + struct sched_group *sg; + int i = task_cpu(p); + int best_idle = -1; + int best_idle_cstate = -1; + int best_idle_capacity = INT_MAX; - if (idle_cpu(target)) - return target; + if (!sysctl_sched_cstate_aware) { + if (idle_cpu(target)) + return target; - /* - * If the previous cpu is cache affine and idle, don't be stupid. - */ - if (prev != target && cpus_share_cache(prev, target) && idle_cpu(prev)) - return prev; + /* + * If the prevous cpu is cache affine and idle, don't be stupid. + */ + if (i != target && cpus_share_cache(i, target) && idle_cpu(i)) + return i; - sd = rcu_dereference(per_cpu(sd_llc, target)); - if (!sd) - return target; + sd = rcu_dereference(per_cpu(sd_llc, target)); + if (!sd) + return target; - i = select_idle_core(p, sd, target); - if ((unsigned)i < nr_cpumask_bits) - return i; + i = select_idle_core(p, sd, target); + if ((unsigned)i < nr_cpumask_bits) + return i; - i = select_idle_cpu(p, sd, target); - if ((unsigned)i < nr_cpumask_bits) - return i; + i = select_idle_cpu(p, sd, target); + if ((unsigned)i < nr_cpumask_bits) + return i; - i = select_idle_smt(p, sd, target); - if ((unsigned)i < nr_cpumask_bits) - return i; + i = select_idle_smt(p, sd, target); + if ((unsigned)i < nr_cpumask_bits) + return i; + } - return target; -} + /* + * Otherwise, iterate the domains and find an elegible idle cpu. + */ + sd = rcu_dereference(per_cpu(sd_llc, target)); + for_each_lower_domain(sd) { + sg = sd->groups; + do { + if (!cpumask_intersects(sched_group_cpus(sg), + tsk_cpus_allowed(p))) + goto next; + + + if (sysctl_sched_cstate_aware) { + for_each_cpu_and(i, tsk_cpus_allowed(p), sched_group_cpus(sg)) { + struct rq *rq = cpu_rq(i); + int idle_idx = idle_get_state_idx(rq); + unsigned long new_usage = boosted_task_util(p); + unsigned long capacity_orig = capacity_orig_of(i); + if (new_usage > capacity_orig || !idle_cpu(i)) + goto next; + + if (i == target && new_usage <= capacity_curr_of(target)) + return target; + + if (best_idle < 0 || (idle_idx < best_idle_cstate && capacity_orig <= best_idle_capacity)) { + best_idle = i; + best_idle_cstate = idle_idx; + best_idle_capacity = capacity_orig; + } + } + } else { + for_each_cpu(i, sched_group_cpus(sg)) { + if (i == target || !idle_cpu(i)) + goto next; + } -/* - * cpu_util returns the amount of capacity of a CPU that is used by CFS - * tasks. The unit of the return value must be the one of capacity so we can - * compare the utilization with the capacity of the CPU that is available for - * CFS task (ie cpu_capacity). - * - * cfs_rq.avg.util_avg is the sum of running time of runnable tasks plus the - * recent utilization of currently non-runnable tasks on a CPU. It represents - * the amount of utilization of a CPU in the range [0..capacity_orig] where - * capacity_orig is the cpu_capacity available at the highest frequency - * (arch_scale_freq_capacity()). - * The utilization of a CPU converges towards a sum equal to or less than the - * current capacity (capacity_curr <= capacity_orig) of the CPU because it is - * the running time on this CPU scaled by capacity_curr. - * - * Nevertheless, cfs_rq.avg.util_avg can be higher than capacity_curr or even - * higher than capacity_orig because of unfortunate rounding in - * cfs.avg.util_avg or just after migrating tasks and new task wakeups until - * the average stabilizes with the new running time. We need to check that the - * utilization stays within the range of [0..capacity_orig] and cap it if - * necessary. Without utilization capping, a group could be seen as overloaded - * (CPU0 utilization at 121% + CPU1 utilization at 80%) whereas CPU1 has 20% of - * available capacity. We allow utilization to overshoot capacity_curr (but not - * capacity_orig) as it useful for predicting the capacity required after task - * migrations (scheduler-driven DVFS). - */ -static int cpu_util(int cpu) -{ - unsigned long util = cpu_rq(cpu)->cfs.avg.util_avg; - unsigned long capacity = capacity_orig_of(cpu); - - return (util >= capacity) ? capacity : util; + target = cpumask_first_and(sched_group_cpus(sg), + tsk_cpus_allowed(p)); + goto done; + } +next: + sg = sg->next; + } while (sg != sd->groups); + } + if (best_idle > 0) + target = best_idle; + +done: + return target; } -static inline int task_util(struct task_struct *p) +static inline int find_best_target(struct task_struct *p, bool boosted, bool prefer_idle) { - return p->se.avg.util_avg; + int iter_cpu; + int target_cpu = -1; + int target_util = 0; + int backup_capacity = 0; + int best_idle_cpu = -1; + int best_idle_cstate = INT_MAX; + int backup_cpu = -1; + unsigned long task_util_boosted, new_util; + + task_util_boosted = boosted_task_util(p); + for (iter_cpu = 0; iter_cpu < NR_CPUS; iter_cpu++) { + int cur_capacity; + struct rq *rq; + int idle_idx; + + /* + * Iterate from higher cpus for boosted tasks. + */ + int i = boosted ? NR_CPUS-iter_cpu-1 : iter_cpu; + + if (!cpu_online(i) || !cpumask_test_cpu(i, tsk_cpus_allowed(p))) + continue; + + /* + * p's blocked utilization is still accounted for on prev_cpu + * so prev_cpu will receive a negative bias due to the double + * accounting. However, the blocked utilization may be zero. + */ + new_util = cpu_util(i) + task_util_boosted; + + /* + * Ensure minimum capacity to grant the required boost. + * The target CPU can be already at a capacity level higher + * than the one required to boost the task. + */ + if (new_util > capacity_orig_of(i)) + continue; + +#ifdef CONFIG_SCHED_WALT + if (walt_cpu_high_irqload(i)) + continue; +#endif + /* + * Unconditionally favoring tasks that prefer idle cpus to + * improve latency. + */ + if (idle_cpu(i) && prefer_idle) { + if (best_idle_cpu < 0) + best_idle_cpu = i; + continue; + } + + cur_capacity = capacity_curr_of(i); + rq = cpu_rq(i); + idle_idx = idle_get_state_idx(rq); + + if (new_util < cur_capacity) { + if (cpu_rq(i)->nr_running) { + if(prefer_idle) { + // Find a target cpu with lowest + // utilization. + if (target_util == 0 || + target_util < new_util) { + target_cpu = i; + target_util = new_util; + } + } else { + // Find a target cpu with highest + // utilization. + if (target_util == 0 || + target_util > new_util) { + target_cpu = i; + target_util = new_util; + } + } + } else if (!prefer_idle) { + if (best_idle_cpu < 0 || + (sysctl_sched_cstate_aware && + best_idle_cstate > idle_idx)) { + best_idle_cstate = idle_idx; + best_idle_cpu = i; + } + } + } else if (backup_capacity == 0 || + backup_capacity > cur_capacity) { + // Find a backup cpu with least capacity. + backup_capacity = cur_capacity; + backup_cpu = i; + } + } + + if (prefer_idle && best_idle_cpu >= 0) + target_cpu = best_idle_cpu; + else if (target_cpu < 0) + target_cpu = best_idle_cpu >= 0 ? best_idle_cpu : backup_cpu; + + return target_cpu; } -/* - * Disable WAKE_AFFINE in the case where task @p doesn't fit in the - * capacity of either the waking CPU @cpu or the previous CPU @prev_cpu. - * - * In that case WAKE_AFFINE doesn't make sense and we'll let - * BALANCE_WAKE sort things out. - */ -static int wake_cap(struct task_struct *p, int cpu, int prev_cpu) +static int energy_aware_wake_cpu(struct task_struct *p, int target, int sync) { - long min_cap, max_cap; + struct sched_domain *sd; + struct sched_group *sg, *sg_target; + int target_max_cap = INT_MAX; + int target_cpu = task_cpu(p); + unsigned long task_util_boosted, new_util; + int i; - min_cap = min(capacity_orig_of(prev_cpu), capacity_orig_of(cpu)); - max_cap = cpu_rq(cpu)->rd->max_cpu_capacity; + if (sysctl_sched_sync_hint_enable && sync) { + int cpu = smp_processor_id(); + cpumask_t search_cpus; + cpumask_and(&search_cpus, tsk_cpus_allowed(p), cpu_online_mask); + if (cpumask_test_cpu(cpu, &search_cpus)) + return cpu; + } - /* Minimum capacity is close to max, no need to abort wake_affine */ - if (max_cap - min_cap < max_cap >> 3) - return 0; + sd = rcu_dereference(per_cpu(sd_ea, task_cpu(p))); + + if (!sd) + return target; + + sg = sd->groups; + sg_target = sg; - return min_cap * 1024 < task_util(p) * capacity_margin; + if (sysctl_sched_is_big_little) { + + /* + * Find group with sufficient capacity. We only get here if no cpu is + * overutilized. We may end up overutilizing a cpu by adding the task, + * but that should not be any worse than select_idle_sibling(). + * load_balance() should sort it out later as we get above the tipping + * point. + */ + do { + /* Assuming all cpus are the same in group */ + int max_cap_cpu = group_first_cpu(sg); + + /* + * Assume smaller max capacity means more energy-efficient. + * Ideally we should query the energy model for the right + * answer but it easily ends up in an exhaustive search. + */ + if (capacity_of(max_cap_cpu) < target_max_cap && + task_fits_max(p, max_cap_cpu)) { + sg_target = sg; + target_max_cap = capacity_of(max_cap_cpu); + } + } while (sg = sg->next, sg != sd->groups); + + task_util_boosted = boosted_task_util(p); + /* Find cpu with sufficient capacity */ + for_each_cpu_and(i, tsk_cpus_allowed(p), sched_group_cpus(sg_target)) { + /* + * p's blocked utilization is still accounted for on prev_cpu + * so prev_cpu will receive a negative bias due to the double + * accounting. However, the blocked utilization may be zero. + */ + new_util = cpu_util(i) + task_util_boosted; + + /* + * Ensure minimum capacity to grant the required boost. + * The target CPU can be already at a capacity level higher + * than the one required to boost the task. + */ + if (new_util > capacity_orig_of(i)) + continue; + + if (new_util < capacity_curr_of(i)) { + target_cpu = i; + if (cpu_rq(i)->nr_running) + break; + } + + /* cpu has capacity at higher OPP, keep it as fallback */ + if (target_cpu == task_cpu(p)) + target_cpu = i; + } + } else { + /* + * Find a cpu with sufficient capacity + */ +#ifdef CONFIG_CGROUP_SCHEDTUNE + bool boosted = schedtune_task_boost(p) > 0; + bool prefer_idle = schedtune_prefer_idle(p) > 0; +#else + bool boosted = 0; + bool prefer_idle = 0; +#endif + int tmp_target = find_best_target(p, boosted, prefer_idle); + if (tmp_target >= 0) { + target_cpu = tmp_target; + if ((boosted || prefer_idle) && idle_cpu(target_cpu)) + return target_cpu; + } + } + + if (target_cpu != task_cpu(p)) { + struct energy_env eenv = { + .util_delta = task_util(p), + .src_cpu = task_cpu(p), + .dst_cpu = target_cpu, + .task = p, + }; + + /* Not enough spare capacity on previous cpu */ + if (cpu_overutilized(task_cpu(p))) + return target_cpu; + + if (energy_diff(&eenv) >= 0) + return task_cpu(p); + } + + return target_cpu; } /* @@ -5633,8 +6531,9 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f if (sd_flag & SD_BALANCE_WAKE) { record_wakee(p); - want_affine = !wake_wide(p) && !wake_cap(p, cpu, prev_cpu) - && cpumask_test_cpu(cpu, tsk_cpus_allowed(p)); + want_affine = (!wake_wide(p) && task_fits_max(p, cpu) && + cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) || + energy_aware(); } rcu_read_lock(); @@ -5665,7 +6564,9 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f } if (!sd) { - if (sd_flag & SD_BALANCE_WAKE) /* XXX always ? */ + if (energy_aware() && !cpu_rq(cpu)->rd->overutilized) + new_cpu = energy_aware_wake_cpu(p, prev_cpu, sync); + else if (sd_flag & SD_BALANCE_WAKE) /* XXX always ? */ new_cpu = select_idle_sibling(p, prev_cpu, new_cpu); } else while (sd) { @@ -5760,6 +6661,8 @@ static void task_dead_fair(struct task_struct *p) { remove_entity_load_avg(&p->se); } +#else +#define task_fits_max(p, cpu) true #endif /* CONFIG_SMP */ static unsigned long @@ -6006,6 +6909,8 @@ again: if (hrtick_enabled(rq)) hrtick_start_fair(rq, p); + rq->misfit_task = !task_fits_max(p, rq->cpu); + return p; simple: cfs_rq = &rq->cfs; @@ -6027,9 +6932,12 @@ simple: if (hrtick_enabled(rq)) hrtick_start_fair(rq, p); + rq->misfit_task = !task_fits_max(p, rq->cpu); + return p; idle: + rq->misfit_task = 0; /* * This is OK, because current is on_cpu, which avoids it being picked * for load-balance and preemption/IRQs are still disabled avoiding @@ -6242,6 +7150,13 @@ static unsigned long __read_mostly max_load_balance_interval = HZ/10; enum fbq_type { regular, remote, all }; +enum group_type { + group_other = 0, + group_misfit_task, + group_imbalanced, + group_overloaded, +}; + #define LBF_ALL_PINNED 0x01 #define LBF_NEED_BREAK 0x02 #define LBF_DST_PINNED 0x04 @@ -6260,6 +7175,7 @@ struct lb_env { int new_dst_cpu; enum cpu_idle_type idle; long imbalance; + unsigned int src_grp_nr_running; /* The set of CPUs under consideration for load-balancing */ struct cpumask *cpus; @@ -6596,6 +7512,10 @@ static void attach_one_task(struct rq *rq, struct task_struct *p) { raw_spin_lock(&rq->lock); attach_task(rq, p); + /* + * We want to potentially raise target_cpu's OPP. + */ + update_capacity_of(cpu_of(rq)); raw_spin_unlock(&rq->lock); } @@ -6617,6 +7537,11 @@ static void attach_tasks(struct lb_env *env) attach_task(env->dst_rq, p); } + /* + * We want to potentially raise env.dst_cpu's OPP. + */ + update_capacity_of(env->dst_cpu); + raw_spin_unlock(&env->dst_rq->lock); } @@ -6712,12 +7637,6 @@ static unsigned long task_h_load(struct task_struct *p) /********** Helpers for find_busiest_group ************************/ -enum group_type { - group_other = 0, - group_imbalanced, - group_overloaded, -}; - /* * sg_lb_stats - stats of a sched_group required for load_balancing */ @@ -6733,6 +7652,7 @@ struct sg_lb_stats { unsigned int group_weight; enum group_type group_type; int group_no_capacity; + int group_misfit_task; /* A cpu has a task too big for its capacity */ #ifdef CONFIG_NUMA_BALANCING unsigned int nr_numa_running; unsigned int nr_preferred_running; @@ -6830,13 +7750,43 @@ static unsigned long scale_rt_capacity(int cpu) return 1; } +void init_max_cpu_capacity(struct max_cpu_capacity *mcc) +{ + raw_spin_lock_init(&mcc->lock); + mcc->val = 0; + mcc->cpu = -1; +} + static void update_cpu_capacity(struct sched_domain *sd, int cpu) { unsigned long capacity = arch_scale_cpu_capacity(sd, cpu); struct sched_group *sdg = sd->groups; + struct max_cpu_capacity *mcc; + unsigned long max_capacity; + int max_cap_cpu; + unsigned long flags; cpu_rq(cpu)->cpu_capacity_orig = capacity; + mcc = &cpu_rq(cpu)->rd->max_cpu_capacity; + + raw_spin_lock_irqsave(&mcc->lock, flags); + max_capacity = mcc->val; + max_cap_cpu = mcc->cpu; + + if ((max_capacity > capacity && max_cap_cpu == cpu) || + (max_capacity < capacity)) { + mcc->val = capacity; + mcc->cpu = cpu; +#ifdef CONFIG_SCHED_DEBUG + raw_spin_unlock_irqrestore(&mcc->lock, flags); + pr_info("CPU%d: update max cpu_capacity %lu\n", cpu, capacity); + goto skip_unlock; +#endif + } + raw_spin_unlock_irqrestore(&mcc->lock, flags); + +skip_unlock: __attribute__ ((unused)); capacity *= scale_rt_capacity(cpu); capacity >>= SCHED_CAPACITY_SHIFT; @@ -6845,13 +7795,14 @@ static void update_cpu_capacity(struct sched_domain *sd, int cpu) cpu_rq(cpu)->cpu_capacity = capacity; sdg->sgc->capacity = capacity; + sdg->sgc->max_capacity = capacity; } void update_group_capacity(struct sched_domain *sd, int cpu) { struct sched_domain *child = sd->child; struct sched_group *group, *sdg = sd->groups; - unsigned long capacity; + unsigned long capacity, max_capacity; unsigned long interval; interval = msecs_to_jiffies(sd->balance_interval); @@ -6864,6 +7815,7 @@ void update_group_capacity(struct sched_domain *sd, int cpu) } capacity = 0; + max_capacity = 0; if (child->flags & SD_OVERLAP) { /* @@ -6888,11 +7840,12 @@ void update_group_capacity(struct sched_domain *sd, int cpu) */ if (unlikely(!rq->sd)) { capacity += capacity_of(cpu); - continue; + } else { + sgc = rq->sd->groups->sgc; + capacity += sgc->capacity; } - sgc = rq->sd->groups->sgc; - capacity += sgc->capacity; + max_capacity = max(capacity, max_capacity); } } else { /* @@ -6902,12 +7855,16 @@ void update_group_capacity(struct sched_domain *sd, int cpu) group = child->groups; do { - capacity += group->sgc->capacity; + struct sched_group_capacity *sgc = group->sgc; + + capacity += sgc->capacity; + max_capacity = max(sgc->max_capacity, max_capacity); group = group->next; } while (group != child->groups); } sdg->sgc->capacity = capacity; + sdg->sgc->max_capacity = max_capacity; } /* @@ -7012,6 +7969,9 @@ group_type group_classify(struct sched_group *group, if (sg_imbalanced(group)) return group_imbalanced; + if (sgs->group_misfit_task) + return group_misfit_task; + return group_other; } @@ -7023,11 +7983,12 @@ group_type group_classify(struct sched_group *group, * @local_group: Does group contain this_cpu. * @sgs: variable to hold the statistics for this group. * @overload: Indicate more than one runnable task for any CPU. + * @overutilized: Indicate overutilization for any CPU. */ static inline void update_sg_lb_stats(struct lb_env *env, struct sched_group *group, int load_idx, int local_group, struct sg_lb_stats *sgs, - bool *overload) + bool *overload, bool *overutilized) { unsigned long load; int i, nr_running; @@ -7061,6 +8022,12 @@ static inline void update_sg_lb_stats(struct lb_env *env, */ if (!nr_running && idle_cpu(i)) sgs->idle_cpus++; + + if (cpu_overutilized(i)) { + *overutilized = true; + if (!sgs->group_misfit_task && rq->misfit_task) + sgs->group_misfit_task = capacity_of(i); + } } /* Adjust by relative CPU capacity of the group */ @@ -7170,7 +8137,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd struct sched_group *sg = env->sd->groups; struct sg_lb_stats tmp_sgs; int load_idx, prefer_sibling = 0; - bool overload = false; + bool overload = false, overutilized = false; if (child && child->flags & SD_PREFER_SIBLING) prefer_sibling = 1; @@ -7192,7 +8159,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd } update_sg_lb_stats(env, sg, load_idx, local_group, sgs, - &overload); + &overload, &overutilized); if (local_group) goto next_group; @@ -7230,10 +8197,23 @@ next_group: if (env->sd->flags & SD_NUMA) env->fbq_type = fbq_classify_group(&sds->busiest_stat); + env->src_grp_nr_running = sds->busiest_stat.sum_nr_running; + if (!env->sd->parent) { /* update overload indicator if we are at root domain */ if (env->dst_rq->rd->overload != overload) env->dst_rq->rd->overload = overload; + + /* Update over-utilization (tipping point, U >= 0) indicator */ + if (env->dst_rq->rd->overutilized != overutilized) { + env->dst_rq->rd->overutilized = overutilized; + trace_sched_overutilized(overutilized); + } + } else { + if (!env->dst_rq->rd->overutilized && overutilized) { + env->dst_rq->rd->overutilized = true; + trace_sched_overutilized(true); + } } } @@ -7454,6 +8434,10 @@ static struct sched_group *find_busiest_group(struct lb_env *env) * this level. */ update_sd_lb_stats(env, &sds); + + if (energy_aware() && !env->dst_rq->rd->overutilized) + goto out_balanced; + local = &sds.local_stat; busiest = &sds.busiest_stat; @@ -7633,6 +8617,13 @@ static int need_active_balance(struct lb_env *env) return 1; } + if ((capacity_of(env->src_cpu) < capacity_of(env->dst_cpu)) && + env->src_rq->cfs.h_nr_running == 1 && + cpu_overutilized(env->src_cpu) && + !cpu_overutilized(env->dst_cpu)) { + return 1; + } + return unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2); } @@ -7754,6 +8745,11 @@ more_balance: * ld_moved - cumulative load moved across iterations */ cur_ld_moved = detach_tasks(&env); + /* + * We want to potentially lower env.src_cpu's OPP. + */ + if (cur_ld_moved) + update_capacity_of(env.src_cpu); /* * We've detached some tasks from busiest_rq. Every @@ -7845,7 +8841,8 @@ more_balance: * excessive cache_hot migrations and active balances. */ if (idle != CPU_NEWLY_IDLE) - sd->nr_balance_failed++; + if (env.src_grp_nr_running > 1) + sd->nr_balance_failed++; if (need_active_balance(&env)) { raw_spin_lock_irqsave(&busiest->lock, flags); @@ -7975,6 +8972,7 @@ static int idle_balance(struct rq *this_rq) struct sched_domain *sd; int pulled_task = 0; u64 curr_cost = 0; + long removed_util=0; /* * We must set idle_stamp _before_ calling idle_balance(), such that we @@ -7982,8 +8980,9 @@ static int idle_balance(struct rq *this_rq) */ this_rq->idle_stamp = rq_clock(this_rq); - if (this_rq->avg_idle < sysctl_sched_migration_cost || - !this_rq->rd->overload) { + if (!energy_aware() && + (this_rq->avg_idle < sysctl_sched_migration_cost || + !this_rq->rd->overload)) { rcu_read_lock(); sd = rcu_dereference_check_sched_domain(this_rq->sd); if (sd) @@ -7995,6 +8994,17 @@ static int idle_balance(struct rq *this_rq) raw_spin_unlock(&this_rq->lock); + /* + * If removed_util_avg is !0 we most probably migrated some task away + * from this_cpu. In this case we might be willing to trigger an OPP + * update, but we want to do so if we don't find anybody else to pull + * here (we will trigger an OPP update with the pulled task's enqueue + * anyway). + * + * Record removed_util before calling update_blocked_averages, and use + * it below (before returning) to see if an OPP update is required. + */ + removed_util = atomic_long_read(&(this_rq->cfs).removed_util_avg); update_blocked_averages(this_cpu); rcu_read_lock(); for_each_domain(this_cpu, sd) { @@ -8058,6 +9068,13 @@ out: if (pulled_task) this_rq->idle_stamp = 0; + else if (removed_util) { + /* + * No task pulled and someone has been migrated away. + * Good case to trigger an OPP update. + */ + update_capacity_of(this_cpu); + } return pulled_task; } @@ -8118,6 +9135,10 @@ static int active_load_balance_cpu_stop(void *data) p = detach_one_task(&env); if (p) { schedstat_inc(sd->alb_pushed); + /* + * We want to potentially lower env.src_cpu's OPP. + */ + update_capacity_of(env.src_cpu); /* Active balancing done, reset the failure counter. */ sd->nr_balance_failed = 0; } else { @@ -8488,12 +9509,13 @@ static inline bool nohz_kick_needed(struct rq *rq) if (time_before(now, nohz.next_balance)) return false; - if (rq->nr_running >= 2) + if (rq->nr_running >= 2 && + (!energy_aware() || cpu_overutilized(cpu))) return true; rcu_read_lock(); sds = rcu_dereference(per_cpu(sd_llc_shared, cpu)); - if (sds) { + if (sds && !energy_aware()) { /* * XXX: write a coherent comment on why we do this. * See also: http://lkml.kernel.org/r/20111202010832.602203411@sbsiddha-desk.sc.intel.com @@ -8601,6 +9623,16 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued) if (static_branch_unlikely(&sched_numa_balancing)) task_tick_numa(rq, curr); + +#ifdef CONFIG_SMP + if (!rq->rd->overutilized && cpu_overutilized(task_cpu(curr))) { + rq->rd->overutilized = true; + trace_sched_overutilized(true); + } + + rq->misfit_task = !task_fits_max(curr, rq->cpu); +#endif + } /* |