Monitor the activity level of each group of each sched_domain level. The
activity is the amount of cpu_power that is currently used on a CPU. We use
the runnable_avg_sum and _period to evaluate this activity level. In the
special use case where the CPU is fully loaded by more than 1 task, the
activity level is set above the cpu_power in order to reflect the overload of
The cpu
Signed-off-by: Vincent Guittot <vincent.guit...@linaro.org>
---
kernel/sched/fair.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index db9b871..7e26f65 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -179,6 +179,11 @@ void sched_init_granularity(void)
}
#ifdef CONFIG_SMP
+static unsigned long available_of(int cpu)
+{
+ return cpu_rq(cpu)->cpu_available;
+}
+
#ifdef CONFIG_SCHED_PACKING_TASKS
/*
* Save the id of the optimal CPU that should be used to pack small tasks
@@ -3549,6 +3554,22 @@ done:
return target;
}
+static int get_cpu_activity(int cpu)
+{
+ struct rq *rq = cpu_rq(cpu);
+ u32 sum = rq->avg.runnable_avg_sum;
+ u32 period = rq->avg.runnable_avg_period;
+
+ sum = min(sum, period);
+
+ if (sum == period) {
+ u32 overload = rq->nr_running > 1 ? 1 : 0;
+ return available_of(cpu) + overload;
+ }
+
+ return (sum * available_of(cpu)) / period;
+}
+
/*
* sched_balance_self: balance the current task (running on cpu) in domains
* that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and
@@ -4430,6 +4451,7 @@ struct sg_lb_stats {
unsigned long sum_weighted_load; /* Weighted load of group's tasks */
unsigned long load_per_task;
unsigned long group_power;
+ unsigned long group_activity; /* Total activity of the group */
unsigned int sum_nr_running; /* Nr tasks running in the group */
unsigned int group_capacity;
unsigned int idle_cpus;
@@ -4446,6 +4468,7 @@ struct sd_lb_stats {
struct sched_group *busiest; /* Busiest group in this sd */
struct sched_group *local; /* Local group in this sd */
unsigned long total_load; /* Total load of all groups in sd */
+ unsigned long total_activity; /* Total activity of all groups in sd */
unsigned long total_pwr; /* Total power of all groups in sd */
unsigned long avg_load; /* Average load across all groups in sd */
@@ -4465,6 +4488,7 @@ static inline void init_sd_lb_stats(struct sd_lb_stats
*sds)
.busiest = NULL,
.local = NULL,
.total_load = 0UL,
+ .total_activity = 0UL,
.total_pwr = 0UL,
.busiest_stat = {
.avg_load = 0UL,
@@ -4771,6 +4795,7 @@ static inline void update_sg_lb_stats(struct lb_env *env,
}
sgs->group_load += load;
+ sgs->group_activity += get_cpu_activity(i);
sgs->sum_nr_running += nr_running;
sgs->sum_weighted_load += weighted_cpuload(i);
if (idle_cpu(i))
@@ -4894,6 +4919,7 @@ static inline void update_sd_lb_stats(struct lb_env *env,
/* Now, start updating sd_lb_stats */
sds->total_load += sgs->group_load;
+ sds->total_activity += sgs->group_activity;
sds->total_pwr += sgs->group_power;
if (!local_group && update_sd_pick_busiest(env, sds, sg, sgs)) {
--
1.7.9.5
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
