From bd939f45da24e25e08a8f5c993c50b1afada0fef Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 2 May 2012 14:20:37 +0200 Subject: [PATCH] sched/fair: Propagate 'struct lb_env' usage into find_busiest_group More function argument passing reduction. Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-v66ivjfqdiqdso01lqgqx6qf@git.kernel.org Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 175 +++++++++++++++++++++----------------------- 1 file changed, 82 insertions(+), 93 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index cf86f74bcac2..9bd3366dbb1c 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3082,7 +3082,7 @@ struct lb_env { struct rq *dst_rq; enum cpu_idle_type idle; - long load_move; + long imbalance; unsigned int flags; unsigned int loop; @@ -3218,7 +3218,7 @@ static unsigned long task_h_load(struct task_struct *p); static const unsigned int sched_nr_migrate_break = 32; /* - * move_tasks tries to move up to load_move weighted load from busiest to + * move_tasks tries to move up to imbalance weighted load from busiest to * this_rq, as part of a balancing operation within domain "sd". * Returns 1 if successful and 0 otherwise. * @@ -3231,7 +3231,7 @@ static int move_tasks(struct lb_env *env) unsigned long load; int pulled = 0; - if (env->load_move <= 0) + if (env->imbalance <= 0) return 0; while (!list_empty(tasks)) { @@ -3257,7 +3257,7 @@ static int move_tasks(struct lb_env *env) if (sched_feat(LB_MIN) && load < 16 && !env->sd->nr_balance_failed) goto next; - if ((load / 2) > env->load_move) + if ((load / 2) > env->imbalance) goto next; if (!can_migrate_task(p, env)) @@ -3265,7 +3265,7 @@ static int move_tasks(struct lb_env *env) move_task(p, env); pulled++; - env->load_move -= load; + env->imbalance -= load; #ifdef CONFIG_PREEMPT /* @@ -3281,7 +3281,7 @@ static int move_tasks(struct lb_env *env) * We only want to steal up to the prescribed amount of * weighted load. */ - if (env->load_move <= 0) + if (env->imbalance <= 0) break; continue; @@ -3578,10 +3578,9 @@ static inline void update_sd_power_savings_stats(struct sched_group *group, /** * check_power_save_busiest_group - see if there is potential for some power-savings balance + * @env: load balance environment * @sds: Variable containing the statistics of the sched_domain * under consideration. - * @this_cpu: Cpu at which we're currently performing load-balancing. - * @imbalance: Variable to store the imbalance. * * Description: * Check if we have potential to perform some power-savings balance. @@ -3591,8 +3590,8 @@ static inline void update_sd_power_savings_stats(struct sched_group *group, * Returns 1 if there is potential to perform power-savings balance. * Else returns 0. */ -static inline int check_power_save_busiest_group(struct sd_lb_stats *sds, - int this_cpu, unsigned long *imbalance) +static inline +int check_power_save_busiest_group(struct lb_env *env, struct sd_lb_stats *sds) { if (!sds->power_savings_balance) return 0; @@ -3601,7 +3600,7 @@ static inline int check_power_save_busiest_group(struct sd_lb_stats *sds, sds->group_leader == sds->group_min) return 0; - *imbalance = sds->min_load_per_task; + env->imbalance = sds->min_load_per_task; sds->busiest = sds->group_min; return 1; @@ -3620,8 +3619,8 @@ static inline void update_sd_power_savings_stats(struct sched_group *group, return; } -static inline int check_power_save_busiest_group(struct sd_lb_stats *sds, - int this_cpu, unsigned long *imbalance) +static inline +int check_power_save_busiest_group(struct lb_env *env, struct sd_lb_stats *sds) { return 0; } @@ -3765,25 +3764,22 @@ fix_small_capacity(struct sched_domain *sd, struct sched_group *group) * update_sg_lb_stats - Update sched_group's statistics for load balancing. * @sd: The sched_domain whose statistics are to be updated. * @group: sched_group whose statistics are to be updated. - * @this_cpu: Cpu for which load balance is currently performed. - * @idle: Idle status of this_cpu * @load_idx: Load index of sched_domain of this_cpu for load calc. * @local_group: Does group contain this_cpu. * @cpus: Set of cpus considered for load balancing. * @balance: Should we balance. * @sgs: variable to hold the statistics for this group. */ -static inline void update_sg_lb_stats(struct sched_domain *sd, - struct sched_group *group, int this_cpu, - enum cpu_idle_type idle, int load_idx, +static inline void update_sg_lb_stats(struct lb_env *env, + struct sched_group *group, int load_idx, int local_group, const struct cpumask *cpus, int *balance, struct sg_lb_stats *sgs) { unsigned long load, max_cpu_load, min_cpu_load, max_nr_running; - int i; unsigned int balance_cpu = -1; unsigned long balance_load = ~0UL; unsigned long avg_load_per_task = 0; + int i; if (local_group) balance_cpu = group_first_cpu(group); @@ -3827,15 +3823,15 @@ static inline void update_sg_lb_stats(struct sched_domain *sd, * to do the newly idle load balance. */ if (local_group) { - if (idle != CPU_NEWLY_IDLE) { - if (balance_cpu != this_cpu || + if (env->idle != CPU_NEWLY_IDLE) { + if (balance_cpu != env->dst_cpu || cmpxchg(&group->balance_cpu, -1, balance_cpu) != -1) { *balance = 0; return; } - update_group_power(sd, this_cpu); + update_group_power(env->sd, env->dst_cpu); } else if (time_after_eq(jiffies, group->sgp->next_update)) - update_group_power(sd, this_cpu); + update_group_power(env->sd, env->dst_cpu); } /* Adjust by relative CPU power of the group */ @@ -3859,7 +3855,7 @@ static inline void update_sg_lb_stats(struct sched_domain *sd, sgs->group_capacity = DIV_ROUND_CLOSEST(group->sgp->power, SCHED_POWER_SCALE); if (!sgs->group_capacity) - sgs->group_capacity = fix_small_capacity(sd, group); + sgs->group_capacity = fix_small_capacity(env->sd, group); sgs->group_weight = group->group_weight; if (sgs->group_capacity > sgs->sum_nr_running) @@ -3877,11 +3873,10 @@ static inline void update_sg_lb_stats(struct sched_domain *sd, * Determine if @sg is a busier group than the previously selected * busiest group. */ -static bool update_sd_pick_busiest(struct sched_domain *sd, +static bool update_sd_pick_busiest(struct lb_env *env, struct sd_lb_stats *sds, struct sched_group *sg, - struct sg_lb_stats *sgs, - int this_cpu) + struct sg_lb_stats *sgs) { if (sgs->avg_load <= sds->max_load) return false; @@ -3897,8 +3892,8 @@ static bool update_sd_pick_busiest(struct sched_domain *sd, * numbered CPUs in the group, therefore mark all groups * higher than ourself as busy. */ - if ((sd->flags & SD_ASYM_PACKING) && sgs->sum_nr_running && - this_cpu < group_first_cpu(sg)) { + if ((env->sd->flags & SD_ASYM_PACKING) && sgs->sum_nr_running && + env->dst_cpu < group_first_cpu(sg)) { if (!sds->busiest) return true; @@ -3918,28 +3913,28 @@ static bool update_sd_pick_busiest(struct sched_domain *sd, * @balance: Should we balance. * @sds: variable to hold the statistics for this sched_domain. */ -static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu, - enum cpu_idle_type idle, const struct cpumask *cpus, - int *balance, struct sd_lb_stats *sds) +static inline void update_sd_lb_stats(struct lb_env *env, + const struct cpumask *cpus, + int *balance, struct sd_lb_stats *sds) { - struct sched_domain *child = sd->child; - struct sched_group *sg = sd->groups; + struct sched_domain *child = env->sd->child; + struct sched_group *sg = env->sd->groups; struct sg_lb_stats sgs; int load_idx, prefer_sibling = 0; if (child && child->flags & SD_PREFER_SIBLING) prefer_sibling = 1; - init_sd_power_savings_stats(sd, sds, idle); - load_idx = get_sd_load_idx(sd, idle); + init_sd_power_savings_stats(env->sd, sds, env->idle); + load_idx = get_sd_load_idx(env->sd, env->idle); do { int local_group; - local_group = cpumask_test_cpu(this_cpu, sched_group_cpus(sg)); + local_group = cpumask_test_cpu(env->dst_cpu, sched_group_cpus(sg)); memset(&sgs, 0, sizeof(sgs)); - update_sg_lb_stats(sd, sg, this_cpu, idle, load_idx, - local_group, cpus, balance, &sgs); + update_sg_lb_stats(env, sg, load_idx, local_group, + cpus, balance, &sgs); if (local_group && !(*balance)) return; @@ -3967,7 +3962,7 @@ static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu, sds->this_load_per_task = sgs.sum_weighted_load; sds->this_has_capacity = sgs.group_has_capacity; sds->this_idle_cpus = sgs.idle_cpus; - } else if (update_sd_pick_busiest(sd, sds, sg, &sgs, this_cpu)) { + } else if (update_sd_pick_busiest(env, sds, sg, &sgs)) { sds->max_load = sgs.avg_load; sds->busiest = sg; sds->busiest_nr_running = sgs.sum_nr_running; @@ -3981,7 +3976,7 @@ static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu, update_sd_power_savings_stats(sg, sds, local_group, &sgs); sg = sg->next; - } while (sg != sd->groups); + } while (sg != env->sd->groups); } /** @@ -4009,24 +4004,23 @@ static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu, * @this_cpu: The cpu at whose sched_domain we're performing load-balance. * @imbalance: returns amount of imbalanced due to packing. */ -static int check_asym_packing(struct sched_domain *sd, - struct sd_lb_stats *sds, - int this_cpu, unsigned long *imbalance) +static int check_asym_packing(struct lb_env *env, struct sd_lb_stats *sds) { int busiest_cpu; - if (!(sd->flags & SD_ASYM_PACKING)) + if (!(env->sd->flags & SD_ASYM_PACKING)) return 0; if (!sds->busiest) return 0; busiest_cpu = group_first_cpu(sds->busiest); - if (this_cpu > busiest_cpu) + if (env->dst_cpu > busiest_cpu) return 0; - *imbalance = DIV_ROUND_CLOSEST(sds->max_load * sds->busiest->sgp->power, - SCHED_POWER_SCALE); + env->imbalance = DIV_ROUND_CLOSEST( + sds->max_load * sds->busiest->sgp->power, SCHED_POWER_SCALE); + return 1; } @@ -4038,8 +4032,8 @@ static int check_asym_packing(struct sched_domain *sd, * @this_cpu: The cpu at whose sched_domain we're performing load-balance. * @imbalance: Variable to store the imbalance. */ -static inline void fix_small_imbalance(struct sd_lb_stats *sds, - int this_cpu, unsigned long *imbalance) +static inline +void fix_small_imbalance(struct lb_env *env, struct sd_lb_stats *sds) { unsigned long tmp, pwr_now = 0, pwr_move = 0; unsigned int imbn = 2; @@ -4050,9 +4044,10 @@ static inline void fix_small_imbalance(struct sd_lb_stats *sds, if (sds->busiest_load_per_task > sds->this_load_per_task) imbn = 1; - } else + } else { sds->this_load_per_task = - cpu_avg_load_per_task(this_cpu); + cpu_avg_load_per_task(env->dst_cpu); + } scaled_busy_load_per_task = sds->busiest_load_per_task * SCHED_POWER_SCALE; @@ -4060,7 +4055,7 @@ static inline void fix_small_imbalance(struct sd_lb_stats *sds, if (sds->max_load - sds->this_load + scaled_busy_load_per_task >= (scaled_busy_load_per_task * imbn)) { - *imbalance = sds->busiest_load_per_task; + env->imbalance = sds->busiest_load_per_task; return; } @@ -4097,18 +4092,16 @@ static inline void fix_small_imbalance(struct sd_lb_stats *sds, /* Move if we gain throughput */ if (pwr_move > pwr_now) - *imbalance = sds->busiest_load_per_task; + env->imbalance = sds->busiest_load_per_task; } /** * calculate_imbalance - Calculate the amount of imbalance present within the * groups of a given sched_domain during load balance. + * @env: load balance environment * @sds: statistics of the sched_domain whose imbalance is to be calculated. - * @this_cpu: Cpu for which currently load balance is being performed. - * @imbalance: The variable to store the imbalance. */ -static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu, - unsigned long *imbalance) +static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *sds) { unsigned long max_pull, load_above_capacity = ~0UL; @@ -4124,8 +4117,8 @@ static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu, * its cpu_power, while calculating max_load..) */ if (sds->max_load < sds->avg_load) { - *imbalance = 0; - return fix_small_imbalance(sds, this_cpu, imbalance); + env->imbalance = 0; + return fix_small_imbalance(env, sds); } if (!sds->group_imb) { @@ -4153,7 +4146,7 @@ static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu, max_pull = min(sds->max_load - sds->avg_load, load_above_capacity); /* How much load to actually move to equalise the imbalance */ - *imbalance = min(max_pull * sds->busiest->sgp->power, + env->imbalance = min(max_pull * sds->busiest->sgp->power, (sds->avg_load - sds->this_load) * sds->this->sgp->power) / SCHED_POWER_SCALE; @@ -4163,8 +4156,8 @@ static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu, * a think about bumping its value to force at least one task to be * moved */ - if (*imbalance < sds->busiest_load_per_task) - return fix_small_imbalance(sds, this_cpu, imbalance); + if (env->imbalance < sds->busiest_load_per_task) + return fix_small_imbalance(env, sds); } @@ -4195,9 +4188,7 @@ static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu, * put to idle by rebalancing its tasks onto our group. */ static struct sched_group * -find_busiest_group(struct sched_domain *sd, int this_cpu, - unsigned long *imbalance, enum cpu_idle_type idle, - const struct cpumask *cpus, int *balance) +find_busiest_group(struct lb_env *env, const struct cpumask *cpus, int *balance) { struct sd_lb_stats sds; @@ -4207,7 +4198,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, * Compute the various statistics relavent for load balancing at * this level. */ - update_sd_lb_stats(sd, this_cpu, idle, cpus, balance, &sds); + update_sd_lb_stats(env, cpus, balance, &sds); /* * this_cpu is not the appropriate cpu to perform load balancing at @@ -4216,8 +4207,8 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, if (!(*balance)) goto ret; - if ((idle == CPU_IDLE || idle == CPU_NEWLY_IDLE) && - check_asym_packing(sd, &sds, this_cpu, imbalance)) + if ((env->idle == CPU_IDLE || env->idle == CPU_NEWLY_IDLE) && + check_asym_packing(env, &sds)) return sds.busiest; /* There is no busy sibling group to pull tasks from */ @@ -4235,7 +4226,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, goto force_balance; /* SD_BALANCE_NEWIDLE trumps SMP nice when underutilized */ - if (idle == CPU_NEWLY_IDLE && sds.this_has_capacity && + if (env->idle == CPU_NEWLY_IDLE && sds.this_has_capacity && !sds.busiest_has_capacity) goto force_balance; @@ -4253,7 +4244,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, if (sds.this_load >= sds.avg_load) goto out_balanced; - if (idle == CPU_IDLE) { + if (env->idle == CPU_IDLE) { /* * This cpu is idle. If the busiest group load doesn't * have more tasks than the number of available cpu's and @@ -4268,13 +4259,13 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, * In the CPU_NEWLY_IDLE, CPU_NOT_IDLE cases, use * imbalance_pct to be conservative. */ - if (100 * sds.max_load <= sd->imbalance_pct * sds.this_load) + if (100 * sds.max_load <= env->sd->imbalance_pct * sds.this_load) goto out_balanced; } force_balance: /* Looks like there is an imbalance. Compute it */ - calculate_imbalance(&sds, this_cpu, imbalance); + calculate_imbalance(env, &sds); return sds.busiest; out_balanced: @@ -4282,20 +4273,19 @@ out_balanced: * There is no obvious imbalance. But check if we can do some balancing * to save power. */ - if (check_power_save_busiest_group(&sds, this_cpu, imbalance)) + if (check_power_save_busiest_group(env, &sds)) return sds.busiest; ret: - *imbalance = 0; + env->imbalance = 0; return NULL; } /* * find_busiest_queue - find the busiest runqueue among the cpus in group. */ -static struct rq * -find_busiest_queue(struct sched_domain *sd, struct sched_group *group, - enum cpu_idle_type idle, unsigned long imbalance, - const struct cpumask *cpus) +static struct rq *find_busiest_queue(struct lb_env *env, + struct sched_group *group, + const struct cpumask *cpus) { struct rq *busiest = NULL, *rq; unsigned long max_load = 0; @@ -4308,7 +4298,7 @@ find_busiest_queue(struct sched_domain *sd, struct sched_group *group, unsigned long wl; if (!capacity) - capacity = fix_small_capacity(sd, group); + capacity = fix_small_capacity(env->sd, group); if (!cpumask_test_cpu(i, cpus)) continue; @@ -4320,7 +4310,7 @@ find_busiest_queue(struct sched_domain *sd, struct sched_group *group, * When comparing with imbalance, use weighted_cpuload() * which is not scaled with the cpu power. */ - if (capacity && rq->nr_running == 1 && wl > imbalance) + if (capacity && rq->nr_running == 1 && wl > env->imbalance) continue; /* @@ -4349,17 +4339,18 @@ find_busiest_queue(struct sched_domain *sd, struct sched_group *group, /* Working cpumask for load_balance and load_balance_newidle. */ DEFINE_PER_CPU(cpumask_var_t, load_balance_tmpmask); -static int need_active_balance(struct sched_domain *sd, int idle, - int busiest_cpu, int this_cpu) +static int need_active_balance(struct lb_env *env) { - if (idle == CPU_NEWLY_IDLE) { + struct sched_domain *sd = env->sd; + + if (env->idle == CPU_NEWLY_IDLE) { /* * ASYM_PACKING needs to force migrate tasks from busy but * higher numbered CPUs in order to pack all tasks in the * lowest numbered CPUs. */ - if ((sd->flags & SD_ASYM_PACKING) && busiest_cpu > this_cpu) + if ((sd->flags & SD_ASYM_PACKING) && env->src_cpu > env->dst_cpu) return 1; /* @@ -4400,7 +4391,6 @@ static int load_balance(int this_cpu, struct rq *this_rq, { int ld_moved, active_balance = 0; struct sched_group *group; - unsigned long imbalance; struct rq *busiest; unsigned long flags; struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask); @@ -4418,8 +4408,7 @@ static int load_balance(int this_cpu, struct rq *this_rq, schedstat_inc(sd, lb_count[idle]); redo: - group = find_busiest_group(sd, this_cpu, &imbalance, idle, - cpus, balance); + group = find_busiest_group(&env, cpus, balance); if (*balance == 0) goto out_balanced; @@ -4429,7 +4418,7 @@ redo: goto out_balanced; } - busiest = find_busiest_queue(sd, group, idle, imbalance, cpus); + busiest = find_busiest_queue(&env, group, cpus); if (!busiest) { schedstat_inc(sd, lb_nobusyq[idle]); goto out_balanced; @@ -4437,7 +4426,7 @@ redo: BUG_ON(busiest == this_rq); - schedstat_add(sd, lb_imbalance[idle], imbalance); + schedstat_add(sd, lb_imbalance[idle], env.imbalance); ld_moved = 0; if (busiest->nr_running > 1) { @@ -4448,7 +4437,6 @@ redo: * correctly treated as an imbalance. */ env.flags |= LBF_ALL_PINNED; - env.load_move = imbalance; env.src_cpu = busiest->cpu; env.src_rq = busiest; env.loop_max = min(sysctl_sched_nr_migrate, busiest->nr_running); @@ -4493,7 +4481,7 @@ more_balance: if (idle != CPU_NEWLY_IDLE) sd->nr_balance_failed++; - if (need_active_balance(sd, idle, cpu_of(busiest), this_cpu)) { + if (need_active_balance(&env)) { raw_spin_lock_irqsave(&busiest->lock, flags); /* don't kick the active_load_balance_cpu_stop, @@ -4520,10 +4508,11 @@ more_balance: } raw_spin_unlock_irqrestore(&busiest->lock, flags); - if (active_balance) + if (active_balance) { stop_one_cpu_nowait(cpu_of(busiest), active_load_balance_cpu_stop, busiest, &busiest->active_balance_work); + } /* * We've kicked active balancing, reset the failure -- 2.20.1