sched/cpufreq: Rename arch_update_thermal_pressure() => arch_update_hw_pressure()

2024-04-24T10:08:01Z

Now that cpufreq provides a pressure value to the scheduler, rename arch_update_thermal_pressure into HW pressure to reflect that it returns a pressure applied by HW (i.e. with a high frequency change) and not always related to thermal mitigation but also generated by max current limitation as an example. Such high frequency signal needs filtering to be smoothed and provide an value that reflects the average available capacity into the scheduler time scale. Signed-off-by: Vincent Guittot Signed-off-by: Ingo Molnar Tested-by: Lukasz Luba Reviewed-by: Qais Yousef Reviewed-by: Lukasz Luba Link: https://lore.kernel.org/r/20240326091616.3696851-5-vincent.guittot@linaro.org

arch_topology: Trace the update thermal pressure

2022-05-06T07:57:38Z

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 occur in a system dealing with throttling. This trace event is needed since the old 'cdev_update' might not be used by some drivers. The old 'cdev_update' trace event only provides a cooling state value: [0, n]. That state value then needs additional tools to translate it: state -> freq -> capacity -> thermal pressure. This new trace event just stores proper thermal pressure value in the trace buffer, no need for additional logic. This is helpful for cooperation when someone can simply sends to the list the trace buffer output from the platform (no need from additional information from other subsystems). There are also platforms which due to some design reasons don't use cooling devices and thus don't trigger old 'cdev_update' trace event. They are also important and measuring latency for the thermal signal raising/decaying characteristics is in scope. This new trace event would cover them as well. 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 thermal pressure (and why). Signed-off-by: Lukasz Luba Acked-by: Sudeep Holla Link: https://lore.kernel.org/r/20220427080806.1906-1-lukasz.luba@arm.com Signed-off-by: Greg Kroah-Hartman

pm24.git/include/trace/events/thermal_pressure.h, branch master

sched/cpufreq: Rename arch_update_thermal_pressure() => arch_update_hw_pressure()

arch_topology: Trace the update thermal pressure