aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorQais Yousef <[email protected]>2019-06-04 12:14:58 +0100
committerIngo Molnar <[email protected]>2019-06-24 19:23:42 +0200
commitf9f240f96efc5bcec62379eac701523e11fbb45b (patch)
tree14db974778a89448c842dd5c05946a78fafd560d
parent8de6242cca17d9299e654e29c966d8612d397272 (diff)
sched/debug: Add sched_overutilized tracepoint
The new tracepoint allows us to track the changes in overutilized status. Overutilized status is associated with EAS. It indicates that the system is in high performance state. EAS is disabled when the system is in this state since there's not much energy savings while high performance tasks are pushing the system to the limit and it's better to default to the spreading behavior of the scheduler. This tracepoint helps understanding and debugging the conditions under which this happens. Signed-off-by: Qais Yousef <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Dietmar Eggemann <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Pavankumar Kondeti <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Quentin Perret <[email protected]> Cc: Sebastian Andrzej Siewior <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Uwe Kleine-Konig <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
-rw-r--r--include/trace/events/sched.h4
-rw-r--r--kernel/sched/fair.c10
2 files changed, 12 insertions, 2 deletions
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index c7dd9bc7f001..420e80e56e55 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -621,6 +621,10 @@ DECLARE_TRACE(pelt_se_tp,
TP_PROTO(struct sched_entity *se),
TP_ARGS(se));
+DECLARE_TRACE(sched_overutilized_tp,
+ TP_PROTO(struct root_domain *rd, bool overutilized),
+ TP_ARGS(rd, overutilized));
+
#endif /* _TRACE_SCHED_H */
/* This part must be outside protection */
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 75218ab1fa07..11ec52709323 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5181,8 +5181,10 @@ static inline bool cpu_overutilized(int cpu)
static inline void update_overutilized_status(struct rq *rq)
{
- if (!READ_ONCE(rq->rd->overutilized) && cpu_overutilized(rq->cpu))
+ if (!READ_ONCE(rq->rd->overutilized) && cpu_overutilized(rq->cpu)) {
WRITE_ONCE(rq->rd->overutilized, SG_OVERUTILIZED);
+ trace_sched_overutilized_tp(rq->rd, SG_OVERUTILIZED);
+ }
}
#else
static inline void update_overutilized_status(struct rq *rq) { }
@@ -8214,8 +8216,12 @@ next_group:
/* Update over-utilization (tipping point, U >= 0) indicator */
WRITE_ONCE(rd->overutilized, sg_status & SG_OVERUTILIZED);
+ trace_sched_overutilized_tp(rd, sg_status & SG_OVERUTILIZED);
} else if (sg_status & SG_OVERUTILIZED) {
- WRITE_ONCE(env->dst_rq->rd->overutilized, SG_OVERUTILIZED);
+ struct root_domain *rd = env->dst_rq->rd;
+
+ WRITE_ONCE(rd->overutilized, SG_OVERUTILIZED);
+ trace_sched_overutilized_tp(rd, SG_OVERUTILIZED);
}
}