Query the current frequency of the core during the scheduler tick.
The scheduler subsystem maintains its own copies of the aperf/mperf
structure because it will query the frequency more frequently than what
the cpufreq subsystem does. This can lead to inaccurate measurements,
but it is not problematic here.
Co-developed-by: Damien Carver <carverdamien@xxxxxxxxx>
Signed-off-by: Damien Carver <carverdamien@xxxxxxxxx>
Signed-off-by: Redha Gouicem <redha.gouicem@xxxxxxxxx>
---
kernel/sched/core.c | 11 +++++++++++
kernel/sched/sched.h | 4 ++++
2 files changed, 15 insertions(+)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index c36dc1ae58be..d6d27a6fc23c 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3976,6 +3976,15 @@ unsigned long long task_sched_runtime(struct task_struct *p)
return ns;
}
+struct freq_sample {
+ unsigned int khz;
+ ktime_t time;
+ u64 aperf;
+ u64 mperf;
+};
+
+DEFINE_PER_CPU(struct freq_sample, freq_sample);
+
/*
* This function gets called by the timer code, with HZ frequency.
* We call it with interrupts disabled.
@@ -3996,6 +4005,8 @@ void scheduler_tick(void)
update_rq_clock(rq);
thermal_pressure = arch_scale_thermal_pressure(cpu_of(rq));
update_thermal_load_avg(rq_clock_thermal(rq), rq, thermal_pressure);
+ rq->freq = arch_freq_get_on_cpu_from_sample(cpu,
+ this_cpu_ptr(&freq_sample));
curr->sched_class->task_tick(rq, curr, 0);
calc_global_load_tick(rq);
psi_task_tick(rq);
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 28709f6b0975..7d794ab756d2 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1048,6 +1048,10 @@ struct rq {
/* Must be inspected within a rcu lock section */
struct cpuidle_state *idle_state;
#endif
+
+ /* Frequency measured at the last tick */
+ unsigned int freq;
+
};
#ifdef CONFIG_FAIR_GROUP_SCHED
--
2.28.0
