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sched: Implement dynamic cpu_power 

Recompute the cpu_power for each cpu during load-balance.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Acked-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Acked-by: Gautham R Shenoy <ego@in.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
LKML-Reference: <20090901083826.162033479@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra 2009-09-01 10:34:36 +02:00 committed by Ingo Molnar
parent a52bfd7358
commit ab29230e67
1 changed files with 35 additions and 3 deletions
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38
kernel/sched.c
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@ -3699,14 +3699,46 @@ static inline int check_power_save_busiest_group(struct sd_lb_stats *sds,
}
#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
static void update_sched_power(struct sched_domain *sd)
unsigned long __weak arch_smt_gain(struct sched_domain *sd, int cpu)
{
unsigned long weight = cpumask_weight(sched_domain_span(sd));
unsigned long smt_gain = sd->smt_gain;
smt_gain /= weight;
return smt_gain;
}
static void update_cpu_power(struct sched_domain *sd, int cpu)
{
unsigned long weight = cpumask_weight(sched_domain_span(sd));
unsigned long power = SCHED_LOAD_SCALE;
struct sched_group *sdg = sd->groups;
unsigned long old = sdg->__cpu_power;
/* here we could scale based on cpufreq */
if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) {
power *= arch_smt_gain(sd, cpu);
power >>= SCHED_LOAD_SHIFT;
}
/* here we could scale based on RT time */
if (power != old) {
sdg->__cpu_power = power;
sdg->reciprocal_cpu_power = reciprocal_value(power);
}
}
static 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 = sdg->__cpu_power;
if (!child) {
/* compute cpu power for this cpu */
update_cpu_power(sd, cpu);
return;
}
@ -3749,7 +3781,7 @@ static inline void update_sg_lb_stats(struct sched_domain *sd,
if (local_group) {
balance_cpu = group_first_cpu(group);
if (balance_cpu == this_cpu)
update_sched_power(sd);
update_group_power(sd, this_cpu);
}
/* Tally up the load of all CPUs in the group */