For easier access, less dereferences and more consisent value, store
the group power in update_sg_lb_stats() and use it thereafter. The
actual value in sched_group::sched_group_power::power can change
throughout the load-balance pass if we're unlucky.
Signed-off-by: Peter Zijlstra <pet...@infradead.org>
---
kernel/sched/fair.c | 41 ++++++++++++++++++++++-------------------
1 file changed, 22 insertions(+), 19 deletions(-)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4288,6 +4288,7 @@ struct sg_lb_stats {
unsigned long group_capacity;
unsigned long idle_cpus;
unsigned long group_weight;
+ unsigned long group_power;
int group_imb; /* Is there an imbalance in the group ? */
int group_has_capacity; /* Is there extra capacity in the group? */
};
@@ -4546,7 +4547,8 @@ static inline void update_sg_lb_stats(st
update_group_power(env->sd, env->dst_cpu);
/* Adjust by relative CPU power of the group */
- sgs->avg_load = (sgs->group_load*SCHED_POWER_SCALE) / group->sgp->power;
+ sgs->group_power = group->sgp->power;
+ sgs->avg_load = (sgs->group_load*SCHED_POWER_SCALE) / sgs->group_power;
/*
* Consider the group unbalanced when the imbalance is larger
@@ -4565,7 +4567,7 @@ static inline void update_sg_lb_stats(st
sgs->group_imb = 1;
sgs->group_capacity =
- DIV_ROUND_CLOSEST(group->sgp->power, SCHED_POWER_SCALE);
+ DIV_ROUND_CLOSEST(sgs->group_power, SCHED_POWER_SCALE);
if (!sgs->group_capacity)
sgs->group_capacity = fix_small_capacity(env->sd, group);
@@ -4668,7 +4670,7 @@ static inline void update_sd_lb_stats(st
/* Now, start updating sd_lb_stats */
sds->total_load += sgs->group_load;
- sds->total_pwr += sg->sgp->power;
+ sds->total_pwr += sgs->group_power;
if (!local_group && update_sd_pick_busiest(env, sds, sg, sgs)) {
sds->busiest = sg;
@@ -4716,8 +4718,9 @@ static int check_asym_packing(struct lb_
if (env->dst_cpu > busiest_cpu)
return 0;
- env->imbalance = DIV_ROUND_CLOSEST(sds->busiest_stat.avg_load *
- sds->busiest->sgp->power, SCHED_POWER_SCALE);
+ env->imbalance = DIV_ROUND_CLOSEST(
+ sds->busiest_stat.avg_load * sds->busiest_stat.group_power,
+ SCHED_POWER_SCALE);
return 1;
}
@@ -4747,7 +4750,7 @@ void fix_small_imbalance(struct lb_env *
scaled_busy_load_per_task =
(busiest->load_per_task * SCHED_POWER_SCALE) /
- sds->busiest->sgp->power;
+ busiest->group_power;
if (busiest->avg_load - this->avg_load + scaled_busy_load_per_task >=
(scaled_busy_load_per_task * imbn)) {
@@ -4761,32 +4764,32 @@ void fix_small_imbalance(struct lb_env *
* moving them.
*/
- pwr_now += sds->busiest->sgp->power *
+ pwr_now += busiest->group_power *
min(busiest->load_per_task, busiest->avg_load);
- pwr_now += sds->this->sgp->power *
+ pwr_now += this->group_power *
min(this->load_per_task, this->avg_load);
pwr_now /= SCHED_POWER_SCALE;
/* Amount of load we'd subtract */
tmp = (busiest->load_per_task * SCHED_POWER_SCALE) /
- sds->busiest->sgp->power;
+ busiest->group_power;
if (busiest->avg_load > tmp) {
- pwr_move += sds->busiest->sgp->power *
+ pwr_move += busiest->group_power *
min(busiest->load_per_task,
busiest->avg_load - tmp);
}
/* Amount of load we'd add */
- if (busiest->avg_load * sds->busiest->sgp->power <
+ if (busiest->avg_load * busiest->group_power <
busiest->load_per_task * SCHED_POWER_SCALE) {
- tmp = (busiest->avg_load * sds->busiest->sgp->power) /
- sds->this->sgp->power;
+ tmp = (busiest->avg_load * busiest->group_power) /
+ this->group_power;
} else {
tmp = (busiest->load_per_task * SCHED_POWER_SCALE) /
- sds->this->sgp->power;
+ this->group_power;
}
- pwr_move += sds->this->sgp->power *
- min(this->load_per_task, this->avg_load + tmp);
+ pwr_move += this->group_power *
+ min(this->load_per_task, this->avg_load + tmp);
pwr_move /= SCHED_POWER_SCALE;
/* Move if we gain throughput */
@@ -4831,7 +4834,7 @@ static inline void calculate_imbalance(s
(busiest->sum_nr_running - busiest->group_capacity);
load_above_capacity *= (SCHED_LOAD_SCALE * SCHED_POWER_SCALE);
- load_above_capacity /= sds->busiest->sgp->power;
+ load_above_capacity /= busiest->group_power;
}
/*
@@ -4849,8 +4852,8 @@ static inline void calculate_imbalance(s
/* How much load to actually move to equalise the imbalance */
env->imbalance = min(
- max_pull * sds->busiest->sgp->power,
- (sds->avg_load - this->avg_load) * sds->this->sgp->power
+ max_pull * busiest->group_power,
+ (sds->avg_load - this->avg_load) * this->group_power
) / SCHED_POWER_SCALE;
/*
--
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