PM / sleep: trace events for device PM callbacks
Adds two trace events which supply the same info that initcall_debug
provides, but via ftrace instead of dmesg. The existing initcall_debug
calls require the pm_print_times_enabled var to be set (either via
sysfs or via the kernel cmd line). The new trace events provide all the
same info as the initcall_debug prints but with less overhead, and also
with coverage of device prepare and complete device callbacks.
These events replace the device_pm_report_time event (which has been
removed). device_pm_callback_start is called first and provides the device
and callback info. device_pm_callback_end is called after with the
device name and error info. The time and pid are gathered from the trace
data headers.
Signed-off-by: Todd Brandt <todd.e.brandt@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index de3fe4fe..bf41296 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -214,9 +214,6 @@
pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
error, (unsigned long long)nsecs >> 10);
}
-
- trace_device_pm_report_time(dev, info, nsecs, pm_verb(state.event),
- error);
}
/**
@@ -387,7 +384,9 @@
calltime = initcall_debug_start(dev);
pm_dev_dbg(dev, state, info);
+ trace_device_pm_callback_start(dev, info, state.event);
error = cb(dev);
+ trace_device_pm_callback_end(dev, error);
suspend_report_result(cb, error);
initcall_debug_report(dev, calltime, error, state, info);
@@ -919,7 +918,9 @@
if (callback) {
pm_dev_dbg(dev, state, info);
+ trace_device_pm_callback_start(dev, info, state.event);
callback(dev);
+ trace_device_pm_callback_end(dev, 0);
}
device_unlock(dev);
@@ -1307,7 +1308,9 @@
calltime = initcall_debug_start(dev);
+ trace_device_pm_callback_start(dev, info, state.event);
error = cb(dev, state);
+ trace_device_pm_callback_end(dev, error);
suspend_report_result(cb, error);
initcall_debug_report(dev, calltime, error, state, info);
@@ -1563,8 +1566,11 @@
callback = dev->driver->pm->prepare;
}
- if (callback)
+ if (callback) {
+ trace_device_pm_callback_start(dev, info, state.event);
ret = callback(dev);
+ trace_device_pm_callback_end(dev, ret);
+ }
device_unlock(dev);