sched/fair: Propagate 'struct lb_env' usage into find_busiest_group
More function argument passing reduction.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-v66ivjfqdiqdso01lqgqx6qf@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index cf86f74..9bd3366 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3082,7 +3082,7 @@
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 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 @@
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 @@
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 @@
move_task(p, env);
pulled++;
- env->load_move -= load;
+ env->imbalance -= load;
#ifdef CONFIG_PREEMPT
/*
@@ -3281,7 +3281,7 @@
* 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 @@
/**
* 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 @@
* 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 @@
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 @@
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 @@
* 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 @@
* 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 @@
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 @@
* 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 @@
* 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 @@
* @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 @@
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 @@
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 @@
* @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 @@
* @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 @@
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 @@
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 @@
/* 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 @@
* 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 @@
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 @@
* 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 @@
* 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 @@
* 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 @@
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 @@
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 @@
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 @@
* 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 @@
* 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 @@
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 @@
* 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 @@
/* 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 @@
{
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 @@
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 @@
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 @@
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 @@
* 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 @@
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 @@
}
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
