Messages in this thread Patch in this message | | | From | Lukasz Luba <> | Subject | [PATCH] arch_topology: Trace the update thermal pressure | Date | Tue, 19 Apr 2022 17:48:01 +0100 |
| |
Add trace event to capture the moment of the call for updating the thermal pressure value. It's helpful to investigate how often those events occurs in a system dealing with throttling. This trace event is needed since the old 'cdev_update' might not be used by some drivers. Also, the new trace event shows capacity value, not a cooling state.
We already have a trace point 'pelt_thermal_tp' which after a change to trace event can be paired with this new 'thermal_pressure_update' and derive more insight what is going on in the system under pressure (and why).
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> --- drivers/base/arch_topology.c | 4 ++++ include/trace/events/thermal.h | 19 +++++++++++++++++++ 2 files changed, 23 insertions(+)
diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index 1d6636ebaac5..4f0392de3081 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -19,6 +19,8 @@ #include <linux/rcupdate.h> #include <linux/sched.h> +#include <trace/events/thermal.h> + static DEFINE_PER_CPU(struct scale_freq_data __rcu *, sft_data); static struct cpumask scale_freq_counters_mask; static bool scale_freq_invariant; @@ -195,6 +197,8 @@ void topology_update_thermal_pressure(const struct cpumask *cpus, th_pressure = max_capacity - capacity; + trace_thermal_pressure_update(cpu, th_pressure); + for_each_cpu(cpu, cpus) WRITE_ONCE(per_cpu(thermal_pressure, cpu), th_pressure); } diff --git a/include/trace/events/thermal.h b/include/trace/events/thermal.h index 8a5f04888abd..1bf08ee1a25b 100644 --- a/include/trace/events/thermal.h +++ b/include/trace/events/thermal.h @@ -65,6 +65,25 @@ TRACE_EVENT(cdev_update, TP_printk("type=%s target=%lu", __get_str(type), __entry->target) ); +TRACE_EVENT(thermal_pressure_update, + + TP_PROTO(int cpu, unsigned long thermal_pressure), + + TP_ARGS(cpu, thermal_pressure), + + TP_STRUCT__entry( + __field(int, cpu) + __field(unsigned long, thermal_pressure) + ), + + TP_fast_assign( + __entry->cpu = cpu; + __entry->thermal_pressure = thermal_pressure; + ), + + TP_printk("cpu=%d thermal_pressure=%lu", __entry->cpu, __entry->thermal_pressure) +); + TRACE_EVENT(thermal_zone_trip, TP_PROTO(struct thermal_zone_device *tz, int trip, -- 2.17.1
| |