Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 91567930 authored by Dietmar Eggemann's avatar Dietmar Eggemann Committed by Quentin Perret
Browse files

ANDROID: sched/events: Introduce task_group load tracking trace event 



The trace event key load is mapped to:

 (1) load : cfs_rq->tg->load_avg

The cfs_rq owned by the task_group is used as the only parameter for the
trace event because it has a reference to the taskgroup and the cpu.
Using the taskgroup as a parameter instead would require the cpu as a
second parameter. A task_group is global and not per-cpu data. The cpu
key only tells on which cpu the value was gathered.

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

 (1) a task group:

     cpu=1 path=/tg1/tg11/tg111 load=517

 (2) an autogroup:

     cpu=1 path=/autogroup-10 load=1050

We don't maintain a load signal for a root task group.

The trace event is only defined if cfs group scheduling support
(CONFIG_FAIR_GROUP_SCHED) is enabled.

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>
Signed-off-by: default avatarDietmar Eggemann <dietmar.eggemann@arm.com>
Change-Id: I7de38e6b30a99d7c9887c94c707ded26b383b5f8
parent 42903694

include/trace/events/sched.h

+29 −0
Original line number Diff line number Diff line
@@ -686,6 +686,35 @@ TRACE_EVENT(sched_load_se, 
		  __entry->cpu, __get_str(path), __entry->comm, __entry->pid,

		  __entry->load, __entry->rbl_load, __entry->util)

);



/*

 * Tracepoint for task_group load tracking:

 */

#ifdef CONFIG_FAIR_GROUP_SCHED

TRACE_EVENT(sched_load_tg,



	TP_PROTO(struct cfs_rq *cfs_rq),



	TP_ARGS(cfs_rq),



	TP_STRUCT__entry(

		__field(	int,	cpu				)

		__dynamic_array(char,	path,

				__trace_sched_path(cfs_rq, NULL, 0)	)

		__field(	long,	load				)

	),



	TP_fast_assign(

		__entry->cpu	= cfs_rq->rq->cpu;

		__trace_sched_path(cfs_rq, __get_dynamic_array(path),

				   __get_dynamic_array_len(path));

		__entry->load	= atomic_long_read(&cfs_rq->tg->load_avg);

	),



	TP_printk("cpu=%d path=%s load=%ld", __entry->cpu, __get_str(path),

		  __entry->load)

);

#endif /* CONFIG_FAIR_GROUP_SCHED */

#endif /* CONFIG_SMP */

#endif /* _TRACE_SCHED_H */

kernel/sched/fair.c

+2 −0
Original line number Diff line number Diff line
@@ -3096,6 +3096,8 @@ static inline void update_tg_load_avg(struct cfs_rq *cfs_rq, int force) 
	if (force || abs(delta) > cfs_rq->tg_load_avg_contrib / 64) {

		atomic_long_add(delta, &cfs_rq->tg->load_avg);

		cfs_rq->tg_load_avg_contrib = cfs_rq->avg.load_avg;



		trace_sched_load_tg(cfs_rq);

	}

}