[PATCH 6.0 0095/1073] sched/uclamp: Make task_fits_capacity() use util_fits_cpu()

Greg Kroah-Hartman
2022-12-28T15:05:31Z

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

[ Upstream commit b48e16a69792b5dc4a09d6807369d11b2970cc36 ]

So that the new uclamp rules in regard to migration margin and capacity
pressure are taken into account correctly.

Fixes: a7008c07a568 ("sched/fair: Make task_fits_capacity() consider uclamp restrictions")
Co-developed-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220804143609.515789-3-qais.yousef@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/sched/fair.c | 26 ++++++++++++++++----------
kernel/sched/sched.h | 9 +++++++++
2 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 4ccd21e9a29f..fd0eb93e1bbb 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4377,10 +4377,12 @@ static inline int util_fits_cpu(unsigned long util,
return fits;
}

-static inline int task_fits_capacity(struct task_struct *p,
- unsigned long capacity)
+static inline int task_fits_cpu(struct task_struct *p, int cpu)
{
- return fits_capacity(uclamp_task_util(p), capacity);
+ unsigned long uclamp_min = uclamp_eff_value(p, UCLAMP_MIN);
+ unsigned long uclamp_max = uclamp_eff_value(p, UCLAMP_MAX);
+ unsigned long util = task_util_est(p);
+ return util_fits_cpu(util, uclamp_min, uclamp_max, cpu);
}

static inline void update_misfit_status(struct task_struct *p, struct rq *rq)
@@ -4393,7 +4395,7 @@ static inline void update_misfit_status(struct task_struct *p, struct rq *rq)
return;
}

- if (task_fits_capacity(p, capacity_of(cpu_of(rq)))) {
+ if (task_fits_cpu(p, cpu_of(rq))) {
rq->misfit_task_load = 0;
return;
}
@@ -8231,7 +8233,7 @@ static int detach_tasks(struct lb_env *env)

case migrate_misfit:
/* This is not a misfit task */
- if (task_fits_capacity(p, capacity_of(env->src_cpu)))
+ if (task_fits_cpu(p, env->src_cpu))
goto next;

env->imbalance = 0;
@@ -9236,6 +9238,10 @@ static inline void update_sg_wakeup_stats(struct sched_domain *sd,

memset(sgs, 0, sizeof(*sgs));

+ /* Assume that task can't fit any CPU of the group */
+ if (sd->flags & SD_ASYM_CPUCAPACITY)
+ sgs->group_misfit_task_load = 1;
+
for_each_cpu(i, sched_group_span(group)) {
struct rq *rq = cpu_rq(i);
unsigned int local;
@@ -9255,12 +9261,12 @@ static inline void update_sg_wakeup_stats(struct sched_domain *sd,
if (!nr_running && idle_cpu_without(i, p))
sgs->idle_cpus++;

- }
+ /* Check if task fits in the CPU */
+ if (sd->flags & SD_ASYM_CPUCAPACITY &&
+ sgs->group_misfit_task_load &&
+ task_fits_cpu(p, i))
+ sgs->group_misfit_task_load = 0;

- /* Check if task fits in the group */
- if (sd->flags & SD_ASYM_CPUCAPACITY &&
- !task_fits_capacity(p, group->sgc->max_capacity)) {
- sgs->group_misfit_task_load = 1;
}

sgs->group_capacity = group->sgc->capacity;
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index f34b489636ff..1b8a5d791907 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -3044,6 +3044,15 @@ static inline bool uclamp_is_used(void)
return static_branch_likely(&sched_uclamp_used);
}
#else /* CONFIG_UCLAMP_TASK */
+static inline unsigned long uclamp_eff_value(struct task_struct *p,
+ enum uclamp_id clamp_id)
+{
+ if (clamp_id == UCLAMP_MIN)
+ return 0;
+
+ return SCHED_CAPACITY_SCALE;
+}
+
static inline
unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util,
struct task_struct *p)
--
2.35.1