tracing/sched: Track per-cpu rt and non-rt cpu_load.

Add a new tracepoint trace_sched_enq_deq_task to track
per-cpu rt and non-rt cpu_load during task enqueue
and dequeue.

This is useful to visualize and compare the load on
different cpus and also to understand how balanced
the load is at any point of time.

Note: We only print cpu_load[0] because we only care about
the most recent load history for tracking load balancer
effectiveness.

Change-Id: I46f0bb84e81652099ed5edf8c2686c70c8b8330c
Signed-off-by: Arun Bharadwaj <abharadw@codeaurora.org>
This commit is contained in:
Arun Bharadwaj 2013-06-19 16:55:29 -07:00 committed by Stephen Boyd
parent 5128a0e3a2
commit 241bfbb3ba
2 changed files with 40 additions and 0 deletions

View file

@ -50,6 +50,44 @@ TRACE_EVENT(sched_kthread_stop_ret,
TP_printk("ret=%d", __entry->ret)
);
/*
* Tracepoint for task enqueue/dequeue:
*/
TRACE_EVENT(sched_enq_deq_task,
TP_PROTO(struct task_struct *p, int enqueue),
TP_ARGS(p, enqueue),
TP_STRUCT__entry(
__array( char, comm, TASK_COMM_LEN )
__field( pid_t, pid )
__field( int, prio )
__field( int, cpu )
__field( int, enqueue )
__field(unsigned int, nr_running )
__field(unsigned long, cpu_load )
__field(unsigned int, rt_nr_running )
),
TP_fast_assign(
memcpy(__entry->comm, p->comm, TASK_COMM_LEN);
__entry->pid = p->pid;
__entry->prio = p->prio;
__entry->cpu = task_cpu(p);
__entry->enqueue = enqueue;
__entry->nr_running = task_rq(p)->nr_running;
__entry->cpu_load = task_rq(p)->cpu_load[0];
__entry->rt_nr_running = task_rq(p)->rt.rt_nr_running;
),
TP_printk("cpu=%d %s comm=%s pid=%d prio=%d nr_running=%u cpu_load=%lu rt_nr_running=%u",
__entry->cpu, __entry->enqueue ? "enqueue" : "dequeue",
__entry->comm, __entry->pid,
__entry->prio, __entry->nr_running,
__entry->cpu_load, __entry->rt_nr_running)
);
/*
* Tracepoint for waking up a task:
*/

View file

@ -777,6 +777,7 @@ static void enqueue_task(struct rq *rq, struct task_struct *p, int flags)
update_rq_clock(rq);
sched_info_queued(p);
p->sched_class->enqueue_task(rq, p, flags);
trace_sched_enq_deq_task(p, 1);
}
static void dequeue_task(struct rq *rq, struct task_struct *p, int flags)
@ -784,6 +785,7 @@ static void dequeue_task(struct rq *rq, struct task_struct *p, int flags)
update_rq_clock(rq);
sched_info_dequeued(p);
p->sched_class->dequeue_task(rq, p, flags);
trace_sched_enq_deq_task(p, 0);
}
void activate_task(struct rq *rq, struct task_struct *p, int flags)