mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-16 08:44:21 +08:00
43720bd601
The text in Documentation said it would be removed in 2.6.41; the text in the Kconfig said removal in the 3.1 release. Either way you look at it, we are well past both, so push it off a cliff. Note that the POWER_CSTATE and the POWER_PSTATE are part of the legacy tracing API. Remove all tracepoints which use these flags. As can be seen from context, most already have a trace entry via trace_cpu_idle anyways. Also, the cpufreq/cpufreq.c PSTATE one is actually unpaired, as compared to the CSTATE ones which all have a clear start/stop. As part of this, the trace_power_frequency also becomes orphaned, so it too is deleted. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
66 lines
2.0 KiB
Plaintext
66 lines
2.0 KiB
Plaintext
|
|
Subsystem Trace Points: power
|
|
|
|
The power tracing system captures events related to power transitions
|
|
within the kernel. Broadly speaking there are three major subheadings:
|
|
|
|
o Power state switch which reports events related to suspend (S-states),
|
|
cpuidle (C-states) and cpufreq (P-states)
|
|
o System clock related changes
|
|
o Power domains related changes and transitions
|
|
|
|
This document describes what each of the tracepoints is and why they
|
|
might be useful.
|
|
|
|
Cf. include/trace/events/power.h for the events definitions.
|
|
|
|
1. Power state switch events
|
|
============================
|
|
|
|
1.1 Trace API
|
|
-----------------
|
|
|
|
A 'cpu' event class gathers the CPU-related events: cpuidle and
|
|
cpufreq.
|
|
|
|
cpu_idle "state=%lu cpu_id=%lu"
|
|
cpu_frequency "state=%lu cpu_id=%lu"
|
|
|
|
A suspend event is used to indicate the system going in and out of the
|
|
suspend mode:
|
|
|
|
machine_suspend "state=%lu"
|
|
|
|
|
|
Note: the value of '-1' or '4294967295' for state means an exit from the current state,
|
|
i.e. trace_cpu_idle(4, smp_processor_id()) means that the system
|
|
enters the idle state 4, while trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id())
|
|
means that the system exits the previous idle state.
|
|
|
|
The event which has 'state=4294967295' in the trace is very important to the user
|
|
space tools which are using it to detect the end of the current state, and so to
|
|
correctly draw the states diagrams and to calculate accurate statistics etc.
|
|
|
|
2. Clocks events
|
|
================
|
|
The clock events are used for clock enable/disable and for
|
|
clock rate change.
|
|
|
|
clock_enable "%s state=%lu cpu_id=%lu"
|
|
clock_disable "%s state=%lu cpu_id=%lu"
|
|
clock_set_rate "%s state=%lu cpu_id=%lu"
|
|
|
|
The first parameter gives the clock name (e.g. "gpio1_iclk").
|
|
The second parameter is '1' for enable, '0' for disable, the target
|
|
clock rate for set_rate.
|
|
|
|
3. Power domains events
|
|
=======================
|
|
The power domain events are used for power domains transitions
|
|
|
|
power_domain_target "%s state=%lu cpu_id=%lu"
|
|
|
|
The first parameter gives the power domain name (e.g. "mpu_pwrdm").
|
|
The second parameter is the power domain target state.
|
|
|