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sched/fair: Use load instead of runnable load in wakeup path

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Runnable load was originally introduced to take into account the case where
blocked load biases the wake up path which may end to select an overloaded
CPU with a large number of runnable tasks instead of an underutilized
CPU with a huge blocked load.

Tha wake up path now starts looking for idle CPUs before comparing
runnable load and it's worth aligning the wake up path with the
load_balance() logic.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Morten.Rasmussen@arm.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: hdanton@sina.com
Cc: parth@linux.ibm.com
Cc: pauld@redhat.com
Cc: quentin.perret@arm.com
Cc: riel@surriel.com
Cc: srikar@linux.vnet.ibm.com
Cc: valentin.schneider@arm.com
Link: https://lkml.kernel.org/r/1571405198-27570-10-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Vincent Guittot 2019-10-18 15:26:36 +02:00 committed by Ingo Molnar
parent c63be7be59
commit 11f10e5420
1 changed files with 10 additions and 10 deletions
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20
kernel/sched/fair.c
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@ -1474,7 +1474,12 @@ bool should_numa_migrate_memory(struct task_struct *p, struct page * page,
group_faults_cpu(ng, src_nid) * group_faults(p, dst_nid) * 4;
}
static unsigned long cpu_runnable_load(struct rq *rq);
static inline unsigned long cfs_rq_runnable_load_avg(struct cfs_rq *cfs_rq);
static unsigned long cpu_runnable_load(struct rq *rq)
{
return cfs_rq_runnable_load_avg(&rq->cfs);
}
/* Cached statistics for all CPUs within a node */
struct numa_stats {
@ -5370,11 +5375,6 @@ static int sched_idle_cpu(int cpu)
rq->nr_running);
}
static unsigned long cpu_runnable_load(struct rq *rq)
{
return cfs_rq_runnable_load_avg(&rq->cfs);
}
static unsigned long cpu_load(struct rq *rq)
{
return cfs_rq_load_avg(&rq->cfs);
@ -5475,7 +5475,7 @@ wake_affine_weight(struct sched_domain *sd, struct task_struct *p,
s64 this_eff_load, prev_eff_load;
unsigned long task_load;
this_eff_load = cpu_runnable_load(cpu_rq(this_cpu));
this_eff_load = cpu_load(cpu_rq(this_cpu));
if (sync) {
unsigned long current_load = task_h_load(current);
@ -5493,7 +5493,7 @@ wake_affine_weight(struct sched_domain *sd, struct task_struct *p,
this_eff_load *= 100;
this_eff_load *= capacity_of(prev_cpu);
prev_eff_load = cpu_runnable_load(cpu_rq(prev_cpu));
prev_eff_load = cpu_load(cpu_rq(prev_cpu));
prev_eff_load -= task_load;
if (sched_feat(WA_BIAS))
prev_eff_load *= 100 + (sd->imbalance_pct - 100) / 2;
@ -5581,7 +5581,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p,
max_spare_cap = 0;
for_each_cpu(i, sched_group_span(group)) {
load = cpu_runnable_load(cpu_rq(i));
load = cpu_load(cpu_rq(i));
runnable_load += load;
avg_load += cfs_rq_load_avg(&cpu_rq(i)->cfs);
@ -5722,7 +5722,7 @@ find_idlest_group_cpu(struct sched_group *group, struct task_struct *p, int this
continue;
}
load = cpu_runnable_load(cpu_rq(i));
load = cpu_load(cpu_rq(i));
if (load < min_load) {
min_load = load;
least_loaded_cpu = i;