diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/trace/events-power.txt | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/Documentation/trace/events-power.txt')
-rw-r--r-- | kernel/Documentation/trace/events-power.txt | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/kernel/Documentation/trace/events-power.txt b/kernel/Documentation/trace/events-power.txt new file mode 100644 index 000000000..21d514ced --- /dev/null +++ b/kernel/Documentation/trace/events-power.txt @@ -0,0 +1,96 @@ + + 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. + +4. PM QoS events +================ +The PM QoS events are used for QoS add/update/remove request and for +target/flags update. + +pm_qos_add_request "pm_qos_class=%s value=%d" +pm_qos_update_request "pm_qos_class=%s value=%d" +pm_qos_remove_request "pm_qos_class=%s value=%d" +pm_qos_update_request_timeout "pm_qos_class=%s value=%d, timeout_us=%ld" + +The first parameter gives the QoS class name (e.g. "CPU_DMA_LATENCY"). +The second parameter is value to be added/updated/removed. +The third parameter is timeout value in usec. + +pm_qos_update_target "action=%s prev_value=%d curr_value=%d" +pm_qos_update_flags "action=%s prev_value=0x%x curr_value=0x%x" + +The first parameter gives the QoS action name (e.g. "ADD_REQ"). +The second parameter is the previous QoS value. +The third parameter is the current QoS value to update. + +And, there are also events used for device PM QoS add/update/remove request. + +dev_pm_qos_add_request "device=%s type=%s new_value=%d" +dev_pm_qos_update_request "device=%s type=%s new_value=%d" +dev_pm_qos_remove_request "device=%s type=%s new_value=%d" + +The first parameter gives the device name which tries to add/update/remove +QoS requests. +The second parameter gives the request type (e.g. "DEV_PM_QOS_RESUME_LATENCY"). +The third parameter is value to be added/updated/removed. |