PM / QoS: Add pm_qos_request tracepoints

Adds tracepoints to pm_qos_add_request, pm_qos_update_request,
pm_qos_remove_request, and pm_qos_update_request_timeout.
It's useful for checking pm_qos_class, value, and timeout_us.

Signed-off-by: Sahara <[e-mail]>
Signed-off-by: Rafael J. Wysocki <[e-mail]>

include/trace/events/power.h

···
 /*
  * The pm qos events are used for pm qos update
  */
+DECLARE_EVENT_CLASS(pm_qos_request,
+
+	TP_PROTO(int pm_qos_class, s32 value),
+
+	TP_ARGS(pm_qos_class, value),
+
+	TP_STRUCT__entry(
+		__field( int,                    pm_qos_class   )
+		__field( s32,                    value          )
+	),
+
+	TP_fast_assign(
+		__entry->pm_qos_class = pm_qos_class;
+		__entry->value = value;
+	),
+
+	TP_printk("pm_qos_class=%s value=%d",
+		  __print_symbolic(__entry->pm_qos_class,
+			{ PM_QOS_CPU_DMA_LATENCY,	"CPU_DMA_LATENCY" },
+			{ PM_QOS_NETWORK_LATENCY,	"NETWORK_LATENCY" },
+			{ PM_QOS_NETWORK_THROUGHPUT,	"NETWORK_THROUGHPUT" }),
+		  __entry->value)
+);
+
+DEFINE_EVENT(pm_qos_request, pm_qos_add_request,
+
+	TP_PROTO(int pm_qos_class, s32 value),
+
+	TP_ARGS(pm_qos_class, value)
+);
+
+DEFINE_EVENT(pm_qos_request, pm_qos_update_request,
+
+	TP_PROTO(int pm_qos_class, s32 value),
+
+	TP_ARGS(pm_qos_class, value)
+);
+
+DEFINE_EVENT(pm_qos_request, pm_qos_remove_request,
+
+	TP_PROTO(int pm_qos_class, s32 value),
+
+	TP_ARGS(pm_qos_class, value)
+);
+
+TRACE_EVENT(pm_qos_update_request_timeout,
+
+	TP_PROTO(int pm_qos_class, s32 value, unsigned long timeout_us),
+
+	TP_ARGS(pm_qos_class, value, timeout_us),
+
+	TP_STRUCT__entry(
+		__field( int,                    pm_qos_class   )
+		__field( s32,                    value          )
+		__field( unsigned long,          timeout_us     )
+	),
+
+	TP_fast_assign(
+		__entry->pm_qos_class = pm_qos_class;
+		__entry->value = value;
+		__entry->timeout_us = timeout_us;
+	),
+
+	TP_printk("pm_qos_class=%s value=%d, timeout_us=%ld",
+		  __print_symbolic(__entry->pm_qos_class,
+			{ PM_QOS_CPU_DMA_LATENCY,	"CPU_DMA_LATENCY" },
+			{ PM_QOS_NETWORK_LATENCY,	"NETWORK_LATENCY" },
+			{ PM_QOS_NETWORK_THROUGHPUT,	"NETWORK_THROUGHPUT" }),
+		  __entry->value, __entry->timeout_us)
+);
+
 DECLARE_EVENT_CLASS(pm_qos_update,
 
 	TP_PROTO(enum pm_qos_req_action action, int prev_value, int curr_value),

kernel/power/qos.c

···
 	}
 	req->pm_qos_class = pm_qos_class;
 	INIT_DELAYED_WORK(&req->work, pm_qos_work_fn);
+	trace_pm_qos_add_request(pm_qos_class, value);
 	pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints,
 			     &req->node, PM_QOS_ADD_REQ, value);
 }
···
 
 	cancel_delayed_work_sync(&req->work);
 
+	trace_pm_qos_update_request(req->pm_qos_class, new_value);
 	if (new_value != req->node.prio)
 		pm_qos_update_target(
 			pm_qos_array[req->pm_qos_class]->constraints,
···
 
 	cancel_delayed_work_sync(&req->work);
 
+	trace_pm_qos_update_request_timeout(req->pm_qos_class,
+					    new_value, timeout_us);
 	if (new_value != req->node.prio)
 		pm_qos_update_target(
 			pm_qos_array[req->pm_qos_class]->constraints,
···
 
 	cancel_delayed_work_sync(&req->work);
 
+	trace_pm_qos_remove_request(req->pm_qos_class, PM_QOS_DEFAULT_VALUE);
 	pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints,
 			     &req->node, PM_QOS_REMOVE_REQ,
 			     PM_QOS_DEFAULT_VALUE);