Commit-ID: f9f240f96efc5bcec62379eac701523e11fbb45b Gitweb: https://git.kernel.org/tip/f9f240f96efc5bcec62379eac701523e11fbb45b Author: Qais Yousef <[email protected]> AuthorDate: Tue, 4 Jun 2019 12:14:58 +0100 Committer: Ingo Molnar <[email protected]> CommitDate: Mon, 24 Jun 2019 19:23:42 +0200
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]> --- include/trace/events/sched.h | 4 ++++ kernel/sched/fair.c | 10 ++++++++-- 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); } }
