[PATCH 07/14] sched: add schedstats for -deadline tasks.

From: Juri Lelli
Date: Mon Feb 11 2013 - 13:52:03 EST


From: Dario Faggioli <raistlin@xxxxxxxx>

Add some typical sched-debug output to dl_rq(s) and some
schedstats to -deadline tasks.

Signed-off-by: Dario Faggioli <raistlin@xxxxxxxx>
Signed-off-by: Juri Lelli <juri.lelli@xxxxxxxxx>
---
include/linux/sched.h | 13 +++++++++++++
kernel/sched/deadline.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
kernel/sched/debug.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
kernel/sched/sched.h | 9 ++++++++-
4 files changed, 112 insertions(+), 1 deletion(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 4bfda68..d4f8f9e 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1274,6 +1274,15 @@ struct sched_rt_entity {
#endif
};

+#ifdef CONFIG_SCHEDSTATS
+struct sched_stats_dl {
+ u64 last_dmiss;
+ u64 last_rorun;
+ u64 dmiss_max;
+ u64 rorun_max;
+};
+#endif
+
struct sched_dl_entity {
struct rb_node rb_node;

@@ -1313,6 +1322,10 @@ struct sched_dl_entity {
* own bandwidth to be enforced, thus we need one timer per task.
*/
struct hrtimer dl_timer;
+
+#ifdef CONFIG_SCHEDSTATS
+ struct sched_stats_dl stats;
+#endif
};

/*
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 92546f3..c2381f3 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -517,6 +517,25 @@ int dl_runtime_exceeded(struct rq *rq, struct sched_dl_entity *dl_se)
return 0;

/*
+ * Record statistics about last and maximum deadline
+ * misses and runtime overruns.
+ */
+ if (dmiss) {
+ u64 damount = rq->clock - dl_se->deadline;
+
+ schedstat_set(dl_se->stats.last_dmiss, damount);
+ schedstat_set(dl_se->stats.dmiss_max,
+ max(dl_se->stats.dmiss_max, damount));
+ }
+ if (rorun) {
+ u64 ramount = -dl_se->runtime;
+
+ schedstat_set(dl_se->stats.last_rorun, ramount);
+ schedstat_set(dl_se->stats.rorun_max,
+ max(dl_se->stats.rorun_max, ramount));
+ }
+
+ /*
* If we are beyond our current deadline and we are still
* executing, then we have already used some of the runtime of
* the next instance. Thus, if we do not account that, we are
@@ -556,6 +575,7 @@ static void update_curr_dl(struct rq *rq)
max(curr->se.statistics.exec_max, delta_exec));

curr->se.sum_exec_runtime += delta_exec;
+ schedstat_add(&rq->dl, exec_clock, delta_exec);
account_group_exec_runtime(curr, delta_exec);

curr->se.exec_start = rq->clock_task;
@@ -907,6 +927,18 @@ static void start_hrtick_dl(struct rq *rq, struct task_struct *p)
}
#endif

+#ifdef CONFIG_SCHED_DEBUG
+struct sched_dl_entity *__pick_dl_last_entity(struct dl_rq *dl_rq)
+{
+ struct rb_node *last = rb_last(&dl_rq->rb_root);
+
+ if (!last)
+ return NULL;
+
+ return rb_entry(last, struct sched_dl_entity, rb_node);
+}
+#endif /* CONFIG_SCHED_DEBUG */
+
static struct sched_dl_entity *pick_next_dl_entity(struct rq *rq,
struct dl_rq *dl_rq)
{
@@ -1583,3 +1615,16 @@ const struct sched_class dl_sched_class = {
.switched_from = switched_from_dl,
.switched_to = switched_to_dl,
};
+
+#ifdef CONFIG_SCHED_DEBUG
+extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq);
+
+void print_dl_stats(struct seq_file *m, int cpu)
+{
+ struct dl_rq *dl_rq = &cpu_rq(cpu)->dl;
+
+ rcu_read_lock();
+ print_dl_rq(m, cpu, dl_rq);
+ rcu_read_unlock();
+}
+#endif /* CONFIG_SCHED_DEBUG */
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 7ae4c4c..487d8df 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -258,6 +258,45 @@ void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
#undef P
}

+extern struct sched_dl_entity *__pick_dl_last_entity(struct dl_rq *dl_rq);
+extern void print_dl_stats(struct seq_file *m, int cpu);
+
+void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq)
+{
+ s64 min_deadline = -1, max_deadline = -1;
+ struct rq *rq = cpu_rq(cpu);
+ struct sched_dl_entity *last;
+ unsigned long flags;
+
+ SEQ_printf(m, "\ndl_rq[%d]:\n", cpu);
+
+ raw_spin_lock_irqsave(&rq->lock, flags);
+ if (dl_rq->rb_leftmost)
+ min_deadline = (rb_entry(dl_rq->rb_leftmost,
+ struct sched_dl_entity,
+ rb_node))->deadline;
+ last = __pick_dl_last_entity(dl_rq);
+ if (last)
+ max_deadline = last->deadline;
+ raw_spin_unlock_irqrestore(&rq->lock, flags);
+
+#define P(x) \
+ SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(dl_rq->x))
+#define __PN(x) \
+ SEQ_printf(m, " .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(x))
+#define PN(x) \
+ SEQ_printf(m, " .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(dl_rq->x))
+
+ P(dl_nr_running);
+ PN(exec_clock);
+ __PN(min_deadline);
+ __PN(max_deadline);
+
+#undef PN
+#undef __PN
+#undef P
+}
+
extern __read_mostly int sched_clock_running;

static void print_cpu(struct seq_file *m, int cpu)
@@ -325,6 +364,7 @@ do { \
spin_lock_irqsave(&sched_debug_lock, flags);
print_cfs_stats(m, cpu);
print_rt_stats(m, cpu);
+ print_dl_stats(m, cpu);

rcu_read_lock();
print_rq(m, rq, cpu);
@@ -476,6 +516,12 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
P(se.statistics.nr_wakeups_affine_attempts);
P(se.statistics.nr_wakeups_passive);
P(se.statistics.nr_wakeups_idle);
+ if (dl_task(p)) {
+ PN(dl.stats.last_dmiss);
+ PN(dl.stats.dmiss_max);
+ PN(dl.stats.last_rorun);
+ PN(dl.stats.rorun_max);
+ }

{
u64 avg_atom, avg_per_cpu;
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 95ded83..5364c3e 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -342,6 +342,8 @@ struct dl_rq {

unsigned long dl_nr_running;

+ u64 exec_clock;
+
#ifdef CONFIG_SMP
/*
* Deadline values of the currently executing and the
@@ -368,6 +370,11 @@ struct dl_rq {
#endif
};

+#ifdef CONFIG_SCHED_DEBUG
+struct sched_dl_entity *__pick_dl_last_entity(struct dl_rq *dl_rq);
+void print_dl_stats(struct seq_file *m, int cpu);
+#endif
+
#ifdef CONFIG_SMP

/*
@@ -1236,7 +1243,7 @@ extern void print_rt_stats(struct seq_file *m, int cpu);

extern void init_cfs_rq(struct cfs_rq *cfs_rq);
extern void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq);
-extern void init_dl_rq(struct dl_rq *rt_rq, struct rq *rq);
+extern void init_dl_rq(struct dl_rq *dl_rq, struct rq *rq);

extern void account_cfs_bandwidth_used(int enabled, int was_enabled);

--
1.7.9.5

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