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 de3fe4fe350ad576b873945c2a4a13b191fa0994..bf412961a9349a0d9c9f687c66c3984dac12b08f 100644 (file)
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -214,9 +214,6 @@ static void initcall_debug_report(struct device *dev, ktime_t calltime,
                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 @@ static int dpm_run_callback(pm_callback_t cb, struct device *dev,
        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 @@ static void device_complete(struct device *dev, pm_message_t state)
 
        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 @@ static int legacy_suspend(struct device *dev, pm_message_t state,
 
        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 @@ static int device_prepare(struct device *dev, pm_message_t state)
                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);
 

diff --git a/include/trace/events/power.h b/include/trace/events/power.h
index f88c8573e66c5e2281abb84213afb195e7ffd551..d19840b0cac844c8cd2fca6f4dac5d4bc62c75a3 100644 (file)
--- a/include/trace/events/power.h
+++ b/include/trace/events/power.h
@@ -93,6 +93,17 @@ TRACE_EVENT(pstate_sample,
 #define PWR_EVENT_EXIT -1
 #endif
 
+#define pm_verb_symbolic(event) \
+       __print_symbolic(event, \
+               { PM_EVENT_SUSPEND, "suspend" }, \
+               { PM_EVENT_RESUME, "resume" }, \
+               { PM_EVENT_FREEZE, "freeze" }, \
+               { PM_EVENT_QUIESCE, "quiesce" }, \
+               { PM_EVENT_HIBERNATE, "hibernate" }, \
+               { PM_EVENT_THAW, "thaw" }, \
+               { PM_EVENT_RESTORE, "restore" }, \
+               { PM_EVENT_RECOVER, "recover" })
+
 DEFINE_EVENT(cpu, cpu_frequency,
 
        TP_PROTO(unsigned int frequency, unsigned int cpu_id),
@@ -100,41 +111,54 @@ DEFINE_EVENT(cpu, cpu_frequency,
        TP_ARGS(frequency, cpu_id)
 );
 
-TRACE_EVENT(device_pm_report_time,
+TRACE_EVENT(device_pm_callback_start,
 
-       TP_PROTO(struct device *dev, const char *pm_ops, s64 ops_time,
-                char *pm_event_str, int error),
+       TP_PROTO(struct device *dev, const char *pm_ops, int event),
 
-       TP_ARGS(dev, pm_ops, ops_time, pm_event_str, error),
+       TP_ARGS(dev, pm_ops, event),
 
        TP_STRUCT__entry(
                __string(device, dev_name(dev))
                __string(driver, dev_driver_string(dev))
                __string(parent, dev->parent ? dev_name(dev->parent) : "none")
                __string(pm_ops, pm_ops ? pm_ops : "none ")
-               __string(pm_event_str, pm_event_str)
-               __field(s64, ops_time)
-               __field(int, error)
+               __field(int, event)
        ),
 
        TP_fast_assign(
-               const char *tmp = dev->parent ? dev_name(dev->parent) : "none";
-               const char *tmp_i = pm_ops ? pm_ops : "none ";
+               __assign_str(device, dev_name(dev));
+               __assign_str(driver, dev_driver_string(dev));
+               __assign_str(parent,
+                       dev->parent ? dev_name(dev->parent) : "none");
+               __assign_str(pm_ops, pm_ops ? pm_ops : "none ");
+               __entry->event = event;
+       ),
+
+       TP_printk("%s %s, parent: %s, %s[%s]", __get_str(driver),
+               __get_str(device), __get_str(parent), __get_str(pm_ops),
+               pm_verb_symbolic(__entry->event))
+);
+
+TRACE_EVENT(device_pm_callback_end,
+
+       TP_PROTO(struct device *dev, int error),
 
+       TP_ARGS(dev, error),
+
+       TP_STRUCT__entry(
+               __string(device, dev_name(dev))
+               __string(driver, dev_driver_string(dev))
+               __field(int, error)
+       ),
+
+       TP_fast_assign(
                __assign_str(device, dev_name(dev));
                __assign_str(driver, dev_driver_string(dev));
-               __assign_str(parent, tmp);
-               __assign_str(pm_ops, tmp_i);
-               __assign_str(pm_event_str, pm_event_str);
-               __entry->ops_time = ops_time;
                __entry->error = error;
        ),
 
-       /* ops_str has an extra space at the end */
-       TP_printk("%s %s parent=%s state=%s ops=%snsecs=%lld err=%d",
-               __get_str(driver), __get_str(device), __get_str(parent),
-               __get_str(pm_event_str), __get_str(pm_ops),
-               __entry->ops_time, __entry->error)
+       TP_printk("%s %s, err=%d",
+               __get_str(driver), __get_str(device), __entry->error)
 );
 
 TRACE_EVENT(suspend_resume,