blk-iocost: Add iocg idle state tracepoint

It will be helpful to trace the iocg's whole state, including active and
idle state. And we can easily expand the original iocost_iocg_activate
trace event to support a state trace class, including active and idle
state tracing.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-iocost.c

@@ -2185,6 +2185,9 @@ static int ioc_check_iocgs(struct ioc *ioc, struct ioc_now *now)
 							    WEIGHT_ONE);
 			}
 
+			TRACE_IOCG_PATH(iocg_idle, iocg, now,
+					atomic64_read(&iocg->active_period),
+					atomic64_read(&ioc->cur_period), vtime);
 			__propagate_weights(iocg, 0, 0, false, now);
 			list_del_init(&iocg->active_list);
 		}

include/trace/events/iocost.h

@@ -11,7 +11,7 @@ struct ioc_gq;
 
 #include <linux/tracepoint.h>
 
-TRACE_EVENT(iocost_iocg_activate,
+DECLARE_EVENT_CLASS(iocost_iocg_state,
 
 	TP_PROTO(struct ioc_gq *iocg, const char *path, struct ioc_now *now,
 		u64 last_period, u64 cur_period, u64 vtime),
@@ -59,6 +59,20 @@ TRACE_EVENT(iocost_iocg_activate,
 	)
 );
 
+DEFINE_EVENT(iocost_iocg_state, iocost_iocg_activate,
+	TP_PROTO(struct ioc_gq *iocg, const char *path, struct ioc_now *now,
+		 u64 last_period, u64 cur_period, u64 vtime),
+
+	TP_ARGS(iocg, path, now, last_period, cur_period, vtime)
+);
+
+DEFINE_EVENT(iocost_iocg_state, iocost_iocg_idle,
+	TP_PROTO(struct ioc_gq *iocg, const char *path, struct ioc_now *now,
+		 u64 last_period, u64 cur_period, u64 vtime),
+
+	TP_ARGS(iocg, path, now, last_period, cur_period, vtime)
+);
+
 DECLARE_EVENT_CLASS(iocg_inuse_update,
 
 	TP_PROTO(struct ioc_gq *iocg, const char *path, struct ioc_now *now,