sched/fair: Name utilization related data and functions consistently

Use the advent of the per-entity load tracking rewrite to streamline the
naming of utilization related data and functions by using
{prefix_}util{_suffix} consistently. Moreover call both signals
({se,cfs}.avg.util_avg) utilization.

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dietmar Eggemann <Dietmar.Eggemann@arm.com>
Cc: Juri Lelli <Juri.Lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: daniel.lezcano@linaro.org
Cc: mturquette@baylibre.com
Cc: pang.xunlei@zte.com.cn
Cc: rjw@rjwysocki.net
Cc: sgurrappadi@nvidia.com
Cc: vincent.guittot@linaro.org
Cc: yuyang.du@intel.com
Link: http://lkml.kernel.org/r/1439569394-11974-5-git-send-email-morten.rasmussen@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Dietmar Eggemann 2015-08-14 17:23:12 +01:00 committed by Ingo Molnar
parent e3279a2e6d
commit 9e91d61d9b
1 changed files with 19 additions and 18 deletions

View File

@ -4863,31 +4863,32 @@ static int select_idle_sibling(struct task_struct *p, int target)
return target;
}
/*
* get_cpu_usage returns the amount of capacity of a CPU that is used by CFS
* cpu_util returns the amount of capacity of a CPU that is used by CFS
* tasks. The unit of the return value must be the one of capacity so we can
* compare the usage with the capacity of the CPU that is available for CFS
* task (ie cpu_capacity).
* compare the utilization with the capacity of the CPU that is available for
* CFS task (ie cpu_capacity).
* cfs.avg.util_avg is the sum of running time of runnable tasks on a
* CPU. It represents the amount of utilization of a CPU in the range
* [0..SCHED_LOAD_SCALE]. The usage of a CPU can't be higher than the full
* capacity of the CPU because it's about the running time on this CPU.
* [0..SCHED_LOAD_SCALE]. The utilization of a CPU can't be higher than the
* full capacity of the CPU because it's about the running time on this CPU.
* Nevertheless, cfs.avg.util_avg can be higher than SCHED_LOAD_SCALE
* because of unfortunate rounding in util_avg or just
* after migrating tasks until the average stabilizes with the new running
* time. So we need to check that the usage stays into the range
* time. So we need to check that the utilization stays into the range
* [0..cpu_capacity_orig] and cap if necessary.
* Without capping the usage, a group could be seen as overloaded (CPU0 usage
* at 121% + CPU1 usage at 80%) whereas CPU1 has 20% of available capacity
* Without capping the utilization, a group could be seen as overloaded (CPU0
* utilization at 121% + CPU1 utilization at 80%) whereas CPU1 has 20% of
* available capacity.
*/
static int get_cpu_usage(int cpu)
static int cpu_util(int cpu)
{
unsigned long usage = cpu_rq(cpu)->cfs.avg.util_avg;
unsigned long util = cpu_rq(cpu)->cfs.avg.util_avg;
unsigned long capacity = capacity_orig_of(cpu);
if (usage >= SCHED_LOAD_SCALE)
if (util >= SCHED_LOAD_SCALE)
return capacity;
return (usage * capacity) >> SCHED_LOAD_SHIFT;
return (util * capacity) >> SCHED_LOAD_SHIFT;
}
/*
@ -5979,7 +5980,7 @@ struct sg_lb_stats {
unsigned long sum_weighted_load; /* Weighted load of group's tasks */
unsigned long load_per_task;
unsigned long group_capacity;
unsigned long group_usage; /* Total usage of the group */
unsigned long group_util; /* Total utilization of the group */
unsigned int sum_nr_running; /* Nr tasks running in the group */
unsigned int idle_cpus;
unsigned int group_weight;
@ -6212,8 +6213,8 @@ static inline int sg_imbalanced(struct sched_group *group)
* group_has_capacity returns true if the group has spare capacity that could
* be used by some tasks.
* We consider that a group has spare capacity if the * number of task is
* smaller than the number of CPUs or if the usage is lower than the available
* capacity for CFS tasks.
* smaller than the number of CPUs or if the utilization is lower than the
* available capacity for CFS tasks.
* For the latter, we use a threshold to stabilize the state, to take into
* account the variance of the tasks' load and to return true if the available
* capacity in meaningful for the load balancer.
@ -6227,7 +6228,7 @@ group_has_capacity(struct lb_env *env, struct sg_lb_stats *sgs)
return true;
if ((sgs->group_capacity * 100) >
(sgs->group_usage * env->sd->imbalance_pct))
(sgs->group_util * env->sd->imbalance_pct))
return true;
return false;
@ -6248,7 +6249,7 @@ group_is_overloaded(struct lb_env *env, struct sg_lb_stats *sgs)
return false;
if ((sgs->group_capacity * 100) <
(sgs->group_usage * env->sd->imbalance_pct))
(sgs->group_util * env->sd->imbalance_pct))
return true;
return false;
@ -6296,7 +6297,7 @@ static inline void update_sg_lb_stats(struct lb_env *env,
load = source_load(i, load_idx);
sgs->group_load += load;
sgs->group_usage += get_cpu_usage(i);
sgs->group_util += cpu_util(i);
sgs->sum_nr_running += rq->cfs.h_nr_running;
if (rq->nr_running > 1)