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sched/uclamp: Make asym_fits_capacity() use util_fits_cpu()
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[ Upstream commit a2e7f03 ]

Use the new util_fits_cpu() to ensure migration margin and capacity
pressure are taken into account correctly when uclamp is being used
otherwise we will fail to consider CPUs as fitting in scenarios where
they should.

s/asym_fits_capacity/asym_fits_cpu/ to better reflect what it does now.

Fixes: b4c9c9f ("sched/fair: Prefer prev cpu in asymmetric wakeup path")
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220804143609.515789-6-qais.yousef@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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Qais Yousef authored and gregkh committed Dec 31, 2022
1 parent 3b9c155 commit 324ce6e
Showing 1 changed file with 13 additions and 8 deletions.
21 changes: 13 additions & 8 deletions kernel/sched/fair.c
Original file line number Diff line number Diff line change
Expand Up @@ -6807,10 +6807,13 @@ select_idle_capacity(struct task_struct *p, struct sched_domain *sd, int target)
return best_cpu;
}

static inline bool asym_fits_capacity(unsigned long task_util, int cpu)
static inline bool asym_fits_cpu(unsigned long util,
unsigned long util_min,
unsigned long util_max,
int cpu)
{
if (sched_asym_cpucap_active())
return fits_capacity(task_util, capacity_of(cpu));
return util_fits_cpu(util, util_min, util_max, cpu);

return true;
}
Expand All @@ -6822,7 +6825,7 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target)
{
bool has_idle_core = false;
struct sched_domain *sd;
unsigned long task_util;
unsigned long task_util, util_min, util_max;
int i, recent_used_cpu;

/*
Expand All @@ -6831,7 +6834,9 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target)
*/
if (sched_asym_cpucap_active()) {
sync_entity_load_avg(&p->se);
task_util = uclamp_task_util(p);
task_util = task_util_est(p);
util_min = uclamp_eff_value(p, UCLAMP_MIN);
util_max = uclamp_eff_value(p, UCLAMP_MAX);
}

/*
Expand All @@ -6840,15 +6845,15 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target)
lockdep_assert_irqs_disabled();

if ((available_idle_cpu(target) || sched_idle_cpu(target)) &&
asym_fits_capacity(task_util, target))
asym_fits_cpu(task_util, util_min, util_max, target))
return target;

/*
* If the previous CPU is cache affine and idle, don't be stupid:
*/
if (prev != target && cpus_share_cache(prev, target) &&
(available_idle_cpu(prev) || sched_idle_cpu(prev)) &&
asym_fits_capacity(task_util, prev))
asym_fits_cpu(task_util, util_min, util_max, prev))
return prev;

/*
Expand All @@ -6863,7 +6868,7 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target)
in_task() &&
prev == smp_processor_id() &&
this_rq()->nr_running <= 1 &&
asym_fits_capacity(task_util, prev)) {
asym_fits_cpu(task_util, util_min, util_max, prev)) {
return prev;
}

Expand All @@ -6875,7 +6880,7 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target)
cpus_share_cache(recent_used_cpu, target) &&
(available_idle_cpu(recent_used_cpu) || sched_idle_cpu(recent_used_cpu)) &&
cpumask_test_cpu(p->recent_used_cpu, p->cpus_ptr) &&
asym_fits_capacity(task_util, recent_used_cpu)) {
asym_fits_cpu(task_util, util_min, util_max, recent_used_cpu)) {
return recent_used_cpu;
}

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