[Patch v6 4/7] sched/fair: Enable periodic update of average thermal pressure

From: Thara Gopinath
Date: Wed Dec 11 2019 - 23:12:01 EST


Introduce support in CFS periodic tick and other 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>
---
kernel/sched/fair.c | 8 ++++++++
1 file changed, 8 insertions(+)

v4->v5:
- Updated both versions of update_blocked_averages to trigger the
process of computing average thermal pressure.
- Updated others_have_blocked to considerd avg_thermal.load_avg.

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 08a233e..e12a375 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7462,6 +7462,9 @@ static inline bool others_have_blocked(struct rq *rq)
if (READ_ONCE(rq->avg_dl.util_avg))
return true;

+ if (READ_ONCE(rq->avg_thermal.load_avg))
+ return true;
+
#ifdef CONFIG_HAVE_SCHED_AVG_IRQ
if (READ_ONCE(rq->avg_irq.util_avg))
return true;
@@ -7487,6 +7490,7 @@ 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 = arch_scale_thermal_capacity(cpu_of(rq));
bool decayed;

/*
@@ -7497,6 +7501,8 @@ static bool __update_blocked_others(struct rq *rq, bool *done)

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))
@@ -10263,6 +10269,7 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)
{
struct cfs_rq *cfs_rq;
struct sched_entity *se = &curr->se;
+ unsigned long thermal_pressure = arch_scale_thermal_capacity(cpu_of(rq));

for_each_sched_entity(se) {
cfs_rq = cfs_rq_of(se);
@@ -10274,6 +10281,7 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)

update_misfit_status(curr, rq);
update_overutilized_status(task_rq(curr));
+ update_thermal_load_avg(rq_clock_task(rq), rq, thermal_pressure);
}

/*
--
2.1.4