[PATCH 6.0 0099/1073] sched/uclamp: Make asym_fits_capacity() use util_fits_cpu()

Greg Kroah-Hartman
2022-12-28T15:11:09Z

From: Qais Yousef <qais.yousef@arm.com>

[ Upstream commit a2e7f03ed28fce26c78b985f87913b6ce3accf9d ]

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: b4c9c9f15649 ("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>
---
kernel/sched/fair.c | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 1fe3f3b96251..cb4d47441a41 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6631,10 +6631,13 @@ 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;
}
@@ -6646,7 +6649,7 @@ 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;

/*
@@ -6655,7 +6658,9 @@ 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);
}

/*
@@ -6664,7 +6669,7 @@ 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;

/*
@@ -6672,7 +6677,7 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target)
*/
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;

/*
@@ -6687,7 +6692,7 @@ 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;
}

@@ -6699,7 +6704,7 @@ 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;
}

--
2.35.1