wakelock查看

Android的wakelock分为两层

待机异常https://wenku.baidu.com/view/6b765c8802020740be1e9bd8.html

Linux层和应用层

1. 查看Linux的wakelock

   在adb shell中使用命令#cat /sys/power/wake_lock

   （1）内核没有加锁时，如下图显示

   

   （2）当内核有进程加锁时，例如我对屏幕进行解锁

   

2. 查看应用程序的wakelock，学习对dumpsys中各种log进行分析

   在adb shell中使用# dumpsys power命令

   1. 当没有应用程序打开时，如下显示
   2. 当有应用程序加锁时，如下显示

1. 对于内核状态的加锁情况，也可以使用cat /d/wakeup_sources命令查看，如下图

   

   其中各字段解析如下

count: wakelock被激活次数。如果该数值比较大，说明它处理了大量的事件，而该数值比较小则表示，花了很长的时间来处理这些事件，或wakelock没有正确释放。

expire_count：超时的wakelock的次数。

wake_count：

active_since：当前状态下，仍持有锁的wakelock，

total_time：wakelock 锁持有的总时间，该时间最重要。

sleep_time：wakelock 在系统休眠的时候锁持有的时间

max_time：wakelock单次花费最多的时间。

last_change:最后记录的时间。

原文

count, tells you how many times the wakelock was activated. If a

wakelock prevented suspend for a long time a large count tells you it

handled a lot of events while a small count tells you it took a long

time to process the events, or the wakelock was not released properly.

expire_count, tells you how many times the timeout expired. For the

input event wakelock in the android kernel (which has a timeout) an

expire count that matches the count tells you that someone opened an

input device but is not reading from it (this has happened several

times).

wake_count, tells you that this is the first wakelock that was

acquired in the resume path. This is currently less useful than I

would like on the Nexus One since it is usually "SMD_RPCCALL" which

does not tell me a lot.

active_since, tells you how long a a still active wakelock has been

active. If someone activated a wakelock and never released it, it will

be obvious here.

total_time, total time the wake lock has been active. This one should

be obvious.

sleep_time, total time the wake lock has been active when the screen was off.

max_time, longest time the wakelock was active uninterrupted. This

used less often, but the battery on a device was draining fast, but

the problem went away before looking at the stats this will show if a

wakelock was active for a long time.

查看串口log信息

echo 0x201 > /sys/module/lpm_levels/parameters/debug_mask

查看子系统是否进入待机

cat /d/rpm_stats

如果vdd min不为零则进入待机，如果vdd min为零则说明系统从未进入待机