sched: Add wait, sleep and iowait accounting tracepoints

Add 3 schedstat tracepoints to help account for wait-time,
sleep-time and iowait-time.

They can also be used as a perf-counter source to profile tasks
on these clocks.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
LKML-Reference: <new-submission>
[ build fix for the !CONFIG_SCHEDSTATS case ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 11 insertions, 1 deletions

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 471fa281f5e0..2ff850f90d1e 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -546,6 +546,13 @@ update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
         schedstat_set(se->wait_sum, se->wait_sum +
                         rq_of(cfs_rq)->clock - se->wait_start);
         schedstat_set(se->wait_start, 0);
+
+#ifdef CONFIG_SCHEDSTATS
+        if (entity_is_task(se)) {
+                trace_sched_stat_wait(task_of(se),
+                        rq_of(cfs_rq)->clock - se->wait_start);
+        }
+#endif
 }
 
 static inline void
@@ -636,8 +643,10 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
                 se->sleep_start = 0;
                 se->sum_sleep_runtime += delta;
 
-                if (tsk)
+                if (tsk) {
                         account_scheduler_latency(tsk, delta >> 10, 1);
+                        trace_sched_stat_sleep(tsk, delta);
+                }
         }
         if (se->block_start) {
                 u64 delta = rq_of(cfs_rq)->clock - se->block_start;
@@ -655,6 +664,7 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
                         if (tsk->in_iowait) {
                                 se->iowait_sum += delta;
                                 se->iowait_count++;
+                                trace_sched_stat_iowait(tsk, delta);
                         }
 
                         /*