[Patch v10 6/9] sched/fair: Enable periodic update of average thermal pressure

From: Thara Gopinath
Date: Fri Feb 21 2020 - 19:52:28 EST


Introduce support in scheduler periodic tick and other CFS bookkeeping
apis to trigger the process of computing average thermal pressure for a
cpu. Also consider avg_thermal.load_avg in others_have_blocked which
allows for decay of pelt signals.

Signed-off-by: Thara Gopinath <thara.gopinath@xxxxxxxxxx>
---
v8->v9:
- Moved periodic triggering of thermal pressure averaging from CFS
tick function to generic scheduler core tick function as per
Peter's review comments.

kernel/sched/core.c | 3 +++
kernel/sched/fair.c | 7 +++++++
2 files changed, 10 insertions(+)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index e94819d573be..160b5e9e8945 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3588,6 +3588,7 @@ void scheduler_tick(void)
struct rq *rq = cpu_rq(cpu);
struct task_struct *curr = rq->curr;
struct rq_flags rf;
+ unsigned long thermal_pressure;

arch_scale_freq_tick();
sched_clock_tick();
@@ -3595,6 +3596,8 @@ void scheduler_tick(void)
rq_lock(rq, &rf);

update_rq_clock(rq);
+ thermal_pressure = arch_scale_thermal_pressure(cpu_of(rq));
+ update_thermal_load_avg(rq_clock_task(rq), rq, thermal_pressure);
curr->sched_class->task_tick(rq, curr, 0);
calc_global_load_tick(rq);
psi_task_tick(rq);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index f38ff5a335d3..00b21a5b71f0 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7536,6 +7536,9 @@ static inline bool others_have_blocked(struct rq *rq)
if (READ_ONCE(rq->avg_dl.util_avg))
return true;

+ if (thermal_load_avg(rq))
+ return true;
+
#ifdef CONFIG_HAVE_SCHED_AVG_IRQ
if (READ_ONCE(rq->avg_irq.util_avg))
return true;
@@ -7561,6 +7564,7 @@ static bool __update_blocked_others(struct rq *rq, bool *done)
{
const struct sched_class *curr_class;
u64 now = rq_clock_pelt(rq);
+ unsigned long thermal_pressure;
bool decayed;

/*
@@ -7569,8 +7573,11 @@ static bool __update_blocked_others(struct rq *rq, bool *done)
*/
curr_class = rq->curr->sched_class;

+ thermal_pressure = arch_scale_thermal_pressure(cpu_of(rq));
+
decayed = update_rt_rq_load_avg(now, rq, curr_class == &rt_sched_class) |
update_dl_rq_load_avg(now, rq, curr_class == &dl_sched_class) |
+ update_thermal_load_avg(rq_clock_task(rq), rq, thermal_pressure) |
update_irq_load_avg(rq, 0);

if (others_have_blocked(rq))
--
2.20.1