[RFC][PATCH v5 06/14] sched: create a new field with available capacity

From: Vincent Guittot
Date: Fri Oct 18 2013 - 07:56:29 EST


This new field power_available reflects the available capacity of a CPU
unlike the cpu_power which reflects the current capacity.

Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
---
kernel/sched/fair.c | 14 +++++++++++---
kernel/sched/sched.h | 3 ++-
2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 5568980..db9b871 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4584,15 +4584,19 @@ static void update_cpu_power(struct sched_domain *sd, int cpu)
if (!power)
power = 1;

+ cpu_rq(cpu)->cpu_available = power;
+ sdg->sgp->power_available = power;
+
cpu_rq(cpu)->cpu_power = power;
sdg->sgp->power = power;
+
}

void update_group_power(struct sched_domain *sd, int cpu)
{
struct sched_domain *child = sd->child;
struct sched_group *group, *sdg = sd->groups;
- unsigned long power;
+ unsigned long power, available;
unsigned long interval;

interval = msecs_to_jiffies(sd->balance_interval);
@@ -4604,7 +4608,7 @@ void update_group_power(struct sched_domain *sd, int cpu)
return;
}

- power = 0;
+ power = available = 0;

if (child->flags & SD_OVERLAP) {
/*
@@ -4614,6 +4618,8 @@ void update_group_power(struct sched_domain *sd, int cpu)

for_each_cpu(cpu, sched_group_cpus(sdg))
power += power_of(cpu);
+ available += available_of(cpu);
+
} else {
/*
* !SD_OVERLAP domains can assume that child groups
@@ -4623,11 +4629,13 @@ void update_group_power(struct sched_domain *sd, int cpu)
group = child->groups;
do {
power += group->sgp->power;
+ available += group->sgp->power_available;
group = group->next;
} while (group != child->groups);
}

- sdg->sgp->power_orig = sdg->sgp->power = power;
+ sdg->sgp->power_orig = sdg->sgp->power_available = available;
+ sdg->sgp->power = power;
}

/*
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 22e3f1d..d5a4ec0 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -459,6 +459,7 @@ struct rq {
struct sched_domain *sd;

unsigned long cpu_power;
+ unsigned long cpu_available;

unsigned char idle_balance;
/* For active balancing */
@@ -603,7 +604,7 @@ struct sched_group_power {
* CPU power of this group, SCHED_LOAD_SCALE being max power for a
* single CPU.
*/
- unsigned int power, power_orig;
+ unsigned int power, power_orig, power_available;
unsigned long next_update;
/*
* Number of busy cpus in this group.
--
1.7.9.5

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