[PATCH] sched: Take thermal pressure into account when determine rt fits capacity

From: Xuewen Yan
Date: Thu Apr 07 2022 - 01:50:57 EST


There are cases when the cpu max capacity might be reduced due to thermal.
Take into the thermal pressure into account when judge whether the rt task
fits the cpu. And when schedutil govnor get cpu util, the thermal pressure
also should be considered.

Signed-off-by: Xuewen Yan <xuewen.yan@xxxxxxxxxx>
---
kernel/sched/cpufreq_schedutil.c | 1 +
kernel/sched/rt.c | 1 +
2 files changed, 2 insertions(+)

diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 3dbf351d12d5..285ad51caf0f 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -159,6 +159,7 @@ static void sugov_get_util(struct sugov_cpu *sg_cpu)
struct rq *rq = cpu_rq(sg_cpu->cpu);
unsigned long max = arch_scale_cpu_capacity(sg_cpu->cpu);

+ max -= arch_scale_thermal_pressure(sg_cpu->cpu);
sg_cpu->max = max;
sg_cpu->bw_dl = cpu_bw_dl(rq);
sg_cpu->util = effective_cpu_util(sg_cpu->cpu, cpu_util_cfs(sg_cpu->cpu), max,
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index a32c46889af8..d9982ebd4821 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -466,6 +466,7 @@ static inline bool rt_task_fits_capacity(struct task_struct *p, int cpu)
max_cap = uclamp_eff_value(p, UCLAMP_MAX);

cpu_cap = capacity_orig_of(cpu);
+ cpu_cap -= arch_scale_thermal_pressure(cpu);

return cpu_cap >= min(min_cap, max_cap);
}
--
2.25.1