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Commit 768d0c27 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

sched: Add wait, sleep and iowait accounting tracepoints 



Add 3 schedstat tracepoints to help account for wait-time,
sleep-time and iowait-time.

They can also be used as a perf-counter source to profile tasks
on these clocks.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
LKML-Reference: <new-submission>
[ build fix for the !CONFIG_SCHEDSTATS case ]
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 8f0dfc34

include/trace/events/sched.h

+95 −0
Original line number Diff line number Diff line
@@ -340,6 +340,101 @@ TRACE_EVENT(sched_signal_send, 
		  __entry->sig, __entry->comm, __entry->pid)

);



/*

 * XXX the below sched_stat tracepoints only apply to SCHED_OTHER/BATCH/IDLE

 *     adding sched_stat support to SCHED_FIFO/RR would be welcome.

 */



/*

 * Tracepoint for accounting wait time (time the task is runnable

 * but not actually running due to scheduler contention).

 */

TRACE_EVENT(sched_stat_wait,



	TP_PROTO(struct task_struct *tsk, u64 delay),



	TP_ARGS(tsk, delay),



	TP_STRUCT__entry(

		__array( char,	comm,	TASK_COMM_LEN	)

		__field( pid_t,	pid			)

		__field( u64,	delay			)

	),



	TP_fast_assign(

		memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN);

		__entry->pid	= tsk->pid;

		__entry->delay	= delay;

	)

	TP_perf_assign(

		__perf_count(delay);

	),



	TP_printk("task: %s:%d wait: %Lu [ns]",

			__entry->comm, __entry->pid,

			(unsigned long long)__entry->delay)

);



/*

 * Tracepoint for accounting sleep time (time the task is not runnable,

 * including iowait, see below).

 */

TRACE_EVENT(sched_stat_sleep,



	TP_PROTO(struct task_struct *tsk, u64 delay),



	TP_ARGS(tsk, delay),



	TP_STRUCT__entry(

		__array( char,	comm,	TASK_COMM_LEN	)

		__field( pid_t,	pid			)

		__field( u64,	delay			)

	),



	TP_fast_assign(

		memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN);

		__entry->pid	= tsk->pid;

		__entry->delay	= delay;

	)

	TP_perf_assign(

		__perf_count(delay);

	),



	TP_printk("task: %s:%d sleep: %Lu [ns]",

			__entry->comm, __entry->pid,

			(unsigned long long)__entry->delay)

);



/*

 * Tracepoint for accounting iowait time (time the task is not runnable

 * due to waiting on IO to complete).

 */

TRACE_EVENT(sched_stat_iowait,



	TP_PROTO(struct task_struct *tsk, u64 delay),



	TP_ARGS(tsk, delay),



	TP_STRUCT__entry(

		__array( char,	comm,	TASK_COMM_LEN	)

		__field( pid_t,	pid			)

		__field( u64,	delay			)

	),



	TP_fast_assign(

		memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN);

		__entry->pid	= tsk->pid;

		__entry->delay	= delay;

	)

	TP_perf_assign(

		__perf_count(delay);

	),



	TP_printk("task: %s:%d iowait: %Lu [ns]",

			__entry->comm, __entry->pid,

			(unsigned long long)__entry->delay)

);



#endif /* _TRACE_SCHED_H */



/* This part must be outside protection */

kernel/sched_fair.c

+11 −1
Original line number Diff line number Diff line
@@ -546,6 +546,13 @@ update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se) 
	schedstat_set(se->wait_sum, se->wait_sum +

			rq_of(cfs_rq)->clock - se->wait_start);

	schedstat_set(se->wait_start, 0);



#ifdef CONFIG_SCHEDSTATS

	if (entity_is_task(se)) {

		trace_sched_stat_wait(task_of(se),

			rq_of(cfs_rq)->clock - se->wait_start);

	}

#endif

}



static inline void
@@ -636,8 +643,10 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) 
		se->sleep_start = 0;

		se->sum_sleep_runtime += delta;



		if (tsk)

		if (tsk) {

			account_scheduler_latency(tsk, delta >> 10, 1);

			trace_sched_stat_sleep(tsk, delta);

		}

	}

	if (se->block_start) {

		u64 delta = rq_of(cfs_rq)->clock - se->block_start;
@@ -655,6 +664,7 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) 
			if (tsk->in_iowait) {

				se->iowait_sum += delta;

				se->iowait_count++;

				trace_sched_stat_iowait(tsk, delta);

			}



			/*