sched: Create a helper function to calculate sched_group stats for fbg()
Impact: cleanup Create a helper function named update_sg_lb_stats() which can be invoked to calculate the individual group's statistics in find_busiest_group(). This reduces the lenght of find_busiest_group() considerably. Credit: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Aked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: "Balbir Singh" <balbir@in.ibm.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: "Dhaval Giani" <dhaval@linux.vnet.ibm.com> Cc: Bharata B Rao <bharata@linux.vnet.ibm.com> LKML-Reference: <20090325091351.13992.43461.stgit@sofia.in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
parent
381be78fdc
commit
1f8c553d0f
175
kernel/sched.c
175
kernel/sched.c
|
@ -3237,6 +3237,103 @@ static inline int get_sd_load_idx(struct sched_domain *sd,
|
|||
|
||||
return load_idx;
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* update_sg_lb_stats - Update sched_group's statistics for load balancing.
|
||||
* @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.
|
||||
* @sd_idle: Idle status of the sched_domain containing group.
|
||||
* @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_group *group, int this_cpu,
|
||||
enum cpu_idle_type idle, int load_idx, int *sd_idle,
|
||||
int local_group, const struct cpumask *cpus,
|
||||
int *balance, struct sg_lb_stats *sgs)
|
||||
{
|
||||
unsigned long load, max_cpu_load, min_cpu_load;
|
||||
int i;
|
||||
unsigned int balance_cpu = -1, first_idle_cpu = 0;
|
||||
unsigned long sum_avg_load_per_task;
|
||||
unsigned long avg_load_per_task;
|
||||
|
||||
if (local_group)
|
||||
balance_cpu = group_first_cpu(group);
|
||||
|
||||
/* Tally up the load of all CPUs in the group */
|
||||
sum_avg_load_per_task = avg_load_per_task = 0;
|
||||
max_cpu_load = 0;
|
||||
min_cpu_load = ~0UL;
|
||||
|
||||
for_each_cpu_and(i, sched_group_cpus(group), cpus) {
|
||||
struct rq *rq = cpu_rq(i);
|
||||
|
||||
if (*sd_idle && rq->nr_running)
|
||||
*sd_idle = 0;
|
||||
|
||||
/* Bias balancing toward cpus of our domain */
|
||||
if (local_group) {
|
||||
if (idle_cpu(i) && !first_idle_cpu) {
|
||||
first_idle_cpu = 1;
|
||||
balance_cpu = i;
|
||||
}
|
||||
|
||||
load = target_load(i, load_idx);
|
||||
} else {
|
||||
load = source_load(i, load_idx);
|
||||
if (load > max_cpu_load)
|
||||
max_cpu_load = load;
|
||||
if (min_cpu_load > load)
|
||||
min_cpu_load = load;
|
||||
}
|
||||
|
||||
sgs->group_load += load;
|
||||
sgs->sum_nr_running += rq->nr_running;
|
||||
sgs->sum_weighted_load += weighted_cpuload(i);
|
||||
|
||||
sum_avg_load_per_task += cpu_avg_load_per_task(i);
|
||||
}
|
||||
|
||||
/*
|
||||
* First idle cpu or the first cpu(busiest) in this sched group
|
||||
* is eligible for doing load balancing at this and above
|
||||
* domains. In the newly idle case, we will allow all the cpu's
|
||||
* to do the newly idle load balance.
|
||||
*/
|
||||
if (idle != CPU_NEWLY_IDLE && local_group &&
|
||||
balance_cpu != this_cpu && balance) {
|
||||
*balance = 0;
|
||||
return;
|
||||
}
|
||||
|
||||
/* Adjust by relative CPU power of the group */
|
||||
sgs->avg_load = sg_div_cpu_power(group,
|
||||
sgs->group_load * SCHED_LOAD_SCALE);
|
||||
|
||||
|
||||
/*
|
||||
* Consider the group unbalanced when the imbalance is larger
|
||||
* than the average weight of two tasks.
|
||||
*
|
||||
* APZ: with cgroup the avg task weight can vary wildly and
|
||||
* might not be a suitable number - should we keep a
|
||||
* normalized nr_running number somewhere that negates
|
||||
* the hierarchy?
|
||||
*/
|
||||
avg_load_per_task = sg_div_cpu_power(group,
|
||||
sum_avg_load_per_task * SCHED_LOAD_SCALE);
|
||||
|
||||
if ((max_cpu_load - min_cpu_load) > 2*avg_load_per_task)
|
||||
sgs->group_imb = 1;
|
||||
|
||||
sgs->group_capacity = group->__cpu_power / SCHED_LOAD_SCALE;
|
||||
|
||||
}
|
||||
/******* find_busiest_group() helpers end here *********************/
|
||||
|
||||
/*
|
||||
|
@ -3270,92 +3367,20 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
|
|||
|
||||
do {
|
||||
struct sg_lb_stats sgs;
|
||||
unsigned long load, max_cpu_load, min_cpu_load;
|
||||
int local_group;
|
||||
int i;
|
||||
unsigned int balance_cpu = -1, first_idle_cpu = 0;
|
||||
unsigned long sum_avg_load_per_task;
|
||||
unsigned long avg_load_per_task;
|
||||
|
||||
local_group = cpumask_test_cpu(this_cpu,
|
||||
sched_group_cpus(group));
|
||||
memset(&sgs, 0, sizeof(sgs));
|
||||
update_sg_lb_stats(group, this_cpu, idle, load_idx, sd_idle,
|
||||
local_group, cpus, balance, &sgs);
|
||||
|
||||
if (local_group)
|
||||
balance_cpu = group_first_cpu(group);
|
||||
|
||||
/* Tally up the load of all CPUs in the group */
|
||||
sum_avg_load_per_task = avg_load_per_task = 0;
|
||||
|
||||
max_cpu_load = 0;
|
||||
min_cpu_load = ~0UL;
|
||||
|
||||
for_each_cpu_and(i, sched_group_cpus(group), cpus) {
|
||||
struct rq *rq = cpu_rq(i);
|
||||
|
||||
if (*sd_idle && rq->nr_running)
|
||||
*sd_idle = 0;
|
||||
|
||||
/* Bias balancing toward cpus of our domain */
|
||||
if (local_group) {
|
||||
if (idle_cpu(i) && !first_idle_cpu) {
|
||||
first_idle_cpu = 1;
|
||||
balance_cpu = i;
|
||||
}
|
||||
|
||||
load = target_load(i, load_idx);
|
||||
} else {
|
||||
load = source_load(i, load_idx);
|
||||
if (load > max_cpu_load)
|
||||
max_cpu_load = load;
|
||||
if (min_cpu_load > load)
|
||||
min_cpu_load = load;
|
||||
}
|
||||
|
||||
sgs.group_load += load;
|
||||
sgs.sum_nr_running += rq->nr_running;
|
||||
sgs.sum_weighted_load += weighted_cpuload(i);
|
||||
|
||||
sum_avg_load_per_task += cpu_avg_load_per_task(i);
|
||||
}
|
||||
|
||||
/*
|
||||
* First idle cpu or the first cpu(busiest) in this sched group
|
||||
* is eligible for doing load balancing at this and above
|
||||
* domains. In the newly idle case, we will allow all the cpu's
|
||||
* to do the newly idle load balance.
|
||||
*/
|
||||
if (idle != CPU_NEWLY_IDLE && local_group &&
|
||||
balance_cpu != this_cpu && balance) {
|
||||
*balance = 0;
|
||||
if (balance && !(*balance))
|
||||
goto ret;
|
||||
}
|
||||
|
||||
total_load += sgs.group_load;
|
||||
total_pwr += group->__cpu_power;
|
||||
|
||||
/* Adjust by relative CPU power of the group */
|
||||
sgs.avg_load = sg_div_cpu_power(group,
|
||||
sgs.group_load * SCHED_LOAD_SCALE);
|
||||
|
||||
|
||||
/*
|
||||
* Consider the group unbalanced when the imbalance is larger
|
||||
* than the average weight of two tasks.
|
||||
*
|
||||
* APZ: with cgroup the avg task weight can vary wildly and
|
||||
* might not be a suitable number - should we keep a
|
||||
* normalized nr_running number somewhere that negates
|
||||
* the hierarchy?
|
||||
*/
|
||||
avg_load_per_task = sg_div_cpu_power(group,
|
||||
sum_avg_load_per_task * SCHED_LOAD_SCALE);
|
||||
|
||||
if ((max_cpu_load - min_cpu_load) > 2*avg_load_per_task)
|
||||
sgs.group_imb = 1;
|
||||
|
||||
sgs.group_capacity = group->__cpu_power / SCHED_LOAD_SCALE;
|
||||
|
||||
if (local_group) {
|
||||
this_load = sgs.avg_load;
|
||||
this = group;
|
||||
|
|
Loading…
Reference in a new issue