From: Morten Rasmussen <morten.rasmus...@arm.com>
Adds ftrace events for key variables related to the entity
load-tracking to help debugging scheduler behaviour. Allows tracing
of load contribution and runqueue residency ratio for both entities
and runqueues as well as entity CPU usage ratio.
Signed-off-by: Morten Rasmussen <morten.rasmus...@arm.com>
---
include/trace/events/sched.h | 125 ++++++++++++++++++++++++++++++++++++++++++
kernel/sched/fair.c | 7 +++
2 files changed, 132 insertions(+)
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index 5a8671e..847eb76 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -430,6 +430,131 @@ TRACE_EVENT(sched_pi_setprio,
__entry->oldprio, __entry->newprio)
);
+/*
+ * Tracepoint for showing tracked load contribution.
+ */
+TRACE_EVENT(sched_task_load_contrib,
+
+ TP_PROTO(struct task_struct *tsk, unsigned long load_contrib),
+
+ TP_ARGS(tsk, load_contrib),
+
+ TP_STRUCT__entry(
+ __array(char, comm, TASK_COMM_LEN)
+ __field(pid_t, pid)
+ __field(unsigned long, load_contrib)
+ ),
+
+ TP_fast_assign(
+ memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN);
+ __entry->pid = tsk->pid;
+ __entry->load_contrib = load_contrib;
+ ),
+
+ TP_printk("comm=%s pid=%d load_contrib=%lu",
+ __entry->comm, __entry->pid,
+ __entry->load_contrib)
+);
+
+/*
+ * Tracepoint for showing tracked task runnable ratio [0..1023].
+ */
+TRACE_EVENT(sched_task_runnable_ratio,
+
+ TP_PROTO(struct task_struct *tsk, unsigned long ratio),
+
+ TP_ARGS(tsk, ratio),
+
+ TP_STRUCT__entry(
+ __array(char, comm, TASK_COMM_LEN)
+ __field(pid_t, pid)
+ __field(unsigned long, ratio)
+ ),
+
+ TP_fast_assign(
+ memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN);
+ __entry->pid = tsk->pid;
+ __entry->ratio = ratio;
+ ),
+
+ TP_printk("comm=%s pid=%d ratio=%lu",
+ __entry->comm, __entry->pid,
+ __entry->ratio)
+);
+
+/*
+ * Tracepoint for showing tracked rq runnable ratio [0..1023].
+ */
+TRACE_EVENT(sched_rq_runnable_ratio,
+
+ TP_PROTO(int cpu, unsigned long ratio),
+
+ TP_ARGS(cpu, ratio),
+
+ TP_STRUCT__entry(
+ __field(int, cpu)
+ __field(unsigned long, ratio)
+ ),
+
+ TP_fast_assign(
+ __entry->cpu = cpu;
+ __entry->ratio = ratio;
+ ),
+
+ TP_printk("cpu=%d ratio=%lu",
+ __entry->cpu,
+ __entry->ratio)
+);
+
+/*
+ * Tracepoint for showing tracked rq runnable load.
+ */
+TRACE_EVENT(sched_rq_runnable_load,
+
+ TP_PROTO(int cpu, u64 load),
+
+ TP_ARGS(cpu, load),
+
+ TP_STRUCT__entry(
+ __field(int, cpu)
+ __field(u64, load)
+ ),
+
+ TP_fast_assign(
+ __entry->cpu = cpu;
+ __entry->load = load;
+ ),
+
+ TP_printk("cpu=%d load=%llu",
+ __entry->cpu,
+ __entry->load)
+);
+
+/*
+ * Tracepoint for showing tracked task cpu usage ratio [0..1023].
+ */
+TRACE_EVENT(sched_task_usage_ratio,
+
+ TP_PROTO(struct task_struct *tsk, unsigned long ratio),
+
+ TP_ARGS(tsk, ratio),
+
+ TP_STRUCT__entry(
+ __array(char, comm, TASK_COMM_LEN)
+ __field(pid_t, pid)
+ __field(unsigned long, ratio)
+ ),
+
+ TP_fast_assign(
+ memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN);
+ __entry->pid = tsk->pid;
+ __entry->ratio = ratio;
+ ),
+
+ TP_printk("comm=%s pid=%d ratio=%lu",
+ __entry->comm, __entry->pid,
+ __entry->ratio)
+);
#endif /* _TRACE_SCHED_H */
/* This part must be outside protection */
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 8f0f3b9..0be53be 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1192,9 +1192,11 @@ static inline void __update_task_entity_contrib(struct
sched_entity *se)
contrib = se->avg.runnable_avg_sum * scale_load_down(se->load.weight);
contrib /= (se->avg.runnable_avg_period + 1);
se->avg.load_avg_contrib = scale_load(contrib);
+ trace_sched_task_load_contrib(task_of(se), se->avg.load_avg_contrib);
contrib = se->avg.runnable_avg_sum * scale_load_down(NICE_0_LOAD);
contrib /= (se->avg.runnable_avg_period + 1);
se->avg.load_avg_ratio = scale_load(contrib);
+ trace_sched_task_runnable_ratio(task_of(se), se->avg.load_avg_ratio);
}
/* Compute the current contribution to load_avg by se, return any delta */
@@ -1286,9 +1288,14 @@ static void update_cfs_rq_blocked_load(struct cfs_rq
*cfs_rq, int force_update)
static inline void update_rq_runnable_avg(struct rq *rq, int runnable)
{
+ u32 contrib;
__update_entity_runnable_avg(rq->clock_task, &rq->avg, runnable,
runnable);
__update_tg_runnable_avg(&rq->avg, &rq->cfs);
+ contrib = rq->avg.runnable_avg_sum * scale_load_down(1024);
+ contrib /= (rq->avg.runnable_avg_period + 1);
+ trace_sched_rq_runnable_ratio(cpu_of(rq), scale_load(contrib));
+ trace_sched_rq_runnable_load(cpu_of(rq), rq->cfs.runnable_load_avg);
}
/* Add the load generated by se into cfs_rq's child load-average */
--
1.7.9.5
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