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Commit acfe25da authored by Dietmar Eggemann's avatar Dietmar Eggemann Committed by Chris Redpath
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ANDROID: sched/events: Introduce sched_entity load tracking trace event 



The trace event keys load and util (utilization) are mapped to:

 (1) load : se->avg.load_avg

 (2) util : se->avg.util_avg

To let this trace event work for configurations w/ and w/o group
scheduling support for cfs (CONFIG_FAIR_GROUP_SCHED) the following
special handling is necessary for non-existent key=value pairs:

 path = "(null)" : In case of !CONFIG_FAIR_GROUP_SCHED or the
                   sched_entity represents a task.

 comm = "(null)" : In case sched_entity represents a task_group.

 pid = -1        : In case sched_entity represents a task_group.

The following list shows examples of the key=value pairs in different
configurations for:

 (1) a task:

     cpu=0 path=(null) comm=sshd pid=2206 load=102 util=102

 (2) a taskgroup:

     cpu=1 path=/tg1/tg11/tg111 comm=(null) pid=-1 load=882 util=510

 (3) an autogroup:

     cpu=0 path=/autogroup-13 comm=(null) pid=-1 load=49 util=48

 (4) w/o CONFIG_FAIR_GROUP_SCHED:

     cpu=0 path=(null) comm=sshd pid=2211 load=301 util=265

The trace event is only defined for CONFIG_SMP.

The helper functions __trace_sched_cpu(), __trace_sched_path() and
__trace_sched_id() are extended to deal with sched_entities as well.

Signed-off-by: default avatarDietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Change-Id: Ia628795d7f0fd54e22a1daeb6e3d37b30ab85583
Signed-off-by: default avatarChris Redpath <chris.redpath@arm.com>
parent 15f5eaa7

include/trace/events/sched.h

+56 −9
Original line number Diff line number Diff line
@@ -574,14 +574,15 @@ TRACE_EVENT(sched_wake_idle_without_ipi, 
#ifdef CONFIG_SMP

#ifdef CREATE_TRACE_POINTS

static inline

int __trace_sched_cpu(struct cfs_rq *cfs_rq)

int __trace_sched_cpu(struct cfs_rq *cfs_rq, struct sched_entity *se)

{

#ifdef CONFIG_FAIR_GROUP_SCHED

	struct rq *rq = cfs_rq->rq;

	struct rq *rq = cfs_rq ? cfs_rq->rq : NULL;

#else

	struct rq *rq = container_of(cfs_rq, struct rq, cfs);

	struct rq *rq = cfs_rq ? container_of(cfs_rq, struct rq, cfs) : NULL;

#endif

	return cpu_of(rq);

	return rq ? cpu_of(rq)

		  : task_cpu((container_of(se, struct task_struct, se)));

}



static inline
@@ -590,18 +591,26 @@ int __trace_sched_path(struct cfs_rq *cfs_rq, char *path, int len) 
#ifdef CONFIG_FAIR_GROUP_SCHED

	int l = path ? len : 0;



	if (task_group_is_autogroup(cfs_rq->tg))

	if (cfs_rq && task_group_is_autogroup(cfs_rq->tg))

		return autogroup_path(cfs_rq->tg, path, l) + 1;

	else

	else if (cfs_rq && cfs_rq->tg->css.cgroup)

		return cgroup_path(cfs_rq->tg->css.cgroup, path, l) + 1;

#else

#endif

	if (path)

		strcpy(path, "(null)");



	return strlen("(null)");

#endif

}



static inline

struct cfs_rq *__trace_sched_group_cfs_rq(struct sched_entity *se)

{

#ifdef CONFIG_FAIR_GROUP_SCHED

	return se->my_q;

#else

	return NULL;

#endif

}

#endif /* CREATE_TRACE_POINTS */



/*
@@ -622,7 +631,7 @@ TRACE_EVENT(sched_load_cfs_rq, 
	),



	TP_fast_assign(

		__entry->cpu	= __trace_sched_cpu(cfs_rq);

		__entry->cpu	= __trace_sched_cpu(cfs_rq, NULL);

		__trace_sched_path(cfs_rq, __get_dynamic_array(path),

				   __get_dynamic_array_len(path));

		__entry->load	= cfs_rq->runnable_load_avg;
@@ -632,6 +641,44 @@ TRACE_EVENT(sched_load_cfs_rq, 
	TP_printk("cpu=%d path=%s load=%lu util=%lu", __entry->cpu,

		  __get_str(path), __entry->load, __entry->util)

);



/*

 * Tracepoint for sched_entity load tracking:

 */

TRACE_EVENT(sched_load_se,



	TP_PROTO(struct sched_entity *se),



	TP_ARGS(se),



	TP_STRUCT__entry(

		__field(	int,		cpu			      )

		__dynamic_array(char,		path,

		  __trace_sched_path(__trace_sched_group_cfs_rq(se), NULL, 0) )

		__array(	char,		comm,	TASK_COMM_LEN	      )

		__field(	pid_t,		pid			      )

		__field(	unsigned long,	load			      )

		__field(	unsigned long,	util			      )

	),



	TP_fast_assign(

		struct cfs_rq *gcfs_rq = __trace_sched_group_cfs_rq(se);

		struct task_struct *p = gcfs_rq ? NULL

				    : container_of(se, struct task_struct, se);



		__entry->cpu = __trace_sched_cpu(gcfs_rq, se);

		__trace_sched_path(gcfs_rq, __get_dynamic_array(path),

				   __get_dynamic_array_len(path));

		memcpy(__entry->comm, p ? p->comm : "(null)", TASK_COMM_LEN);

		__entry->pid = p ? p->pid : -1;

		__entry->load = se->avg.load_avg;

		__entry->util = se->avg.util_avg;

	),



	TP_printk("cpu=%d path=%s comm=%s pid=%d load=%lu util=%lu",

		  __entry->cpu, __get_str(path), __entry->comm,

		  __entry->pid, __entry->load, __entry->util)

);

#endif /* CONFIG_SMP */

#endif /* _TRACE_SCHED_H */

kernel/sched/fair.c

+3 −0
Original line number Diff line number Diff line
@@ -3025,6 +3025,8 @@ ___update_load_avg(u64 now, int cpu, struct sched_avg *sa, 


	if (cfs_rq)

		trace_sched_load_cfs_rq(cfs_rq);

	else

		trace_sched_load_se(container_of(sa, struct sched_entity, avg));



	return 1;

}
@@ -3270,6 +3272,7 @@ static inline int propagate_entity_load_avg(struct sched_entity *se) 
	update_tg_cfs_load(cfs_rq, se);



	trace_sched_load_cfs_rq(cfs_rq);

	trace_sched_load_se(se);



	return 1;

}