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sched: Simple helper functions for find_busiest_group()

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Impact: cleanup

Currently the load idx calculation code is in find_busiest_group().
Move that to a static inline helper function.

Similary, to find the first cpu of a sched_group we use
cpumask_first(sched_group_cpus(group))

Use a helper to that. It improves readability in some cases.

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Acked-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>
Cc: "Vaidyanathan Srinivasan" <svaidy@linux.vnet.ibm.com>
LKML-Reference: <20090325091335.13992.55424.stgit@sofia.in.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Gautham R Shenoy 2009-03-25 14:43:35 +05:30 committed by Ingo Molnar
parent b6d9842258
commit 67bb6c036d
1 changed files with 43 additions and 12 deletions
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55
kernel/sched.c
View file

@ -3189,6 +3189,43 @@ static int move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
return 0;
}
/********** Helpers for find_busiest_group ************************/
/**
* group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
* @group: The group whose first cpu is to be returned.
*/
static inline unsigned int group_first_cpu(struct sched_group *group)
{
return cpumask_first(sched_group_cpus(group));
}
/**
* get_sd_load_idx - Obtain the load index for a given sched domain.
* @sd: The sched_domain whose load_idx is to be obtained.
* @idle: The Idle status of the CPU for whose sd load_icx is obtained.
*/
static inline int get_sd_load_idx(struct sched_domain *sd,
enum cpu_idle_type idle)
{
int load_idx;
switch (idle) {
case CPU_NOT_IDLE:
load_idx = sd->busy_idx;
break;
case CPU_NEWLY_IDLE:
load_idx = sd->newidle_idx;
break;
default:
load_idx = sd->idle_idx;
break;
}
return load_idx;
}
/******* find_busiest_group() helpers end here *********************/
/*
* find_busiest_group finds and returns the busiest CPU group within the
@ -3217,12 +3254,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
busiest_load_per_task = busiest_nr_running = 0;
this_load_per_task = this_nr_running = 0;
if (idle == CPU_NOT_IDLE)
load_idx = sd->busy_idx;
else if (idle == CPU_NEWLY_IDLE)
load_idx = sd->newidle_idx;
else
load_idx = sd->idle_idx;
load_idx = get_sd_load_idx(sd, idle);
do {
unsigned long load, group_capacity, max_cpu_load, min_cpu_load;
@ -3238,7 +3270,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
sched_group_cpus(group));
if (local_group)
balance_cpu = cpumask_first(sched_group_cpus(group));
balance_cpu = group_first_cpu(group);
/* Tally up the load of all CPUs in the group */
sum_weighted_load = sum_nr_running = avg_load = 0;
@ -3359,8 +3391,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
*/
if ((sum_nr_running < min_nr_running) ||
(sum_nr_running == min_nr_running &&
cpumask_first(sched_group_cpus(group)) >
cpumask_first(sched_group_cpus(group_min)))) {
group_first_cpu(group) > group_first_cpu(group_min))) {
group_min = group;
min_nr_running = sum_nr_running;
min_load_per_task = sum_weighted_load /
@ -3375,8 +3406,8 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
if (sum_nr_running <= group_capacity - 1) {
if (sum_nr_running > leader_nr_running ||
(sum_nr_running == leader_nr_running &&
cpumask_first(sched_group_cpus(group)) <
cpumask_first(sched_group_cpus(group_leader)))) {
group_first_cpu(group) <
group_first_cpu(group_leader))) {
group_leader = group;
leader_nr_running = sum_nr_running;
}
@ -3504,7 +3535,7 @@ out_balanced:
*imbalance = min_load_per_task;
if (sched_mc_power_savings >= POWERSAVINGS_BALANCE_WAKEUP) {
cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu =
cpumask_first(sched_group_cpus(group_leader));
group_first_cpu(group_leader);
}
return group_min;
}