Research on power consumption test development under Linux

1. Preface

Linux embedded devices are developed for high power consumption requirements. In the case of problems, the positioning means are limited.

About power consumption is a static power consumption, refers to a certain state of the power consumption situation, in this state to minimize the power dissipation, such as Cpuidle, suspend, Cpuhotplug, etc.

The other is the dynamic power consumption, refers to the various states of the switch, such as Susped-resume, Cpuidle different state switches, interrupts, wakelock and so on.

The static power of the debugging, can be measured in a specific state of power consumption, gradually optimized; however, in the dynamic power consumption, that is, when the system is running, the factors that affect power consumption vary widely, and need to grasp the system running trajectory when measuring power consumption.

2. What anchor points need to be grasped?

To measure power consumption, understand what those kernel behaviors are causing power consumption to increase or decrease? What tracks do you need to capture, such as:

1. suspend-Resume (when to enter suspend, duration, when to exit suspend, who wakes up the system): Machine_suspend2. Cpuidle ( Switching point, Duration, status): Cpuidle3. Cpufreq (when to switch, switch to what frequency, how long): Cpu_frequency4. Interrupt (which interrupt, when to trigger , interrupt function processing time): Irq_handler_entry, Irq_handler_exit5. Wakeup Source (): Wakeup_source_activate, Wakeup_ Source_deactivate6. Power domain (which power domain, set State): Power_domain_target7. Clock (which clock, when to open, when to close, frequency changes): Clock_enable, Clock_disable, clock_set_rate

Other tracks:

8. Timers (timer creation, start, timeout, cancellation, including low-precision timers and high-precision timers): Low-precision timers (Timer_init, Timer_start, Timer_cancel, Timer_expire_entry, Timer_ Expire_exit), high-precision timers (Hrtimer_init, Hrtimer_start, Hrtimer_expire_entry, Hrtimer_expire_exit, Hrtimer_cancel)

9 .....

These individual traceevents can be viewed as power information anchor points, each of which is analyzed below.

2.1 Trace_machine_suspend

2.2 trace_cpu_idle_rcuidle/

2.3 trace_cpu_frequency

2.4 Trace_irq_handler_entry/trace_irq_handler_exit

2.5 trace_wakeup_source_activate/trace_wakeup_source_deactivate

2.6

2.7

2.8 Trace_timer_start/trace_timer_cancel/trace_timer_expire_entry/trace_timer_expire_exit

Research on power consumption test development under Linux