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-rw-r--r--kernel/sched_stats.h42
1 files changed, 33 insertions, 9 deletions
diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h
index 80179ef..8385d43 100644
--- a/kernel/sched_stats.h
+++ b/kernel/sched_stats.h
@@ -118,6 +118,13 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta)
if (rq)
rq->rq_sched_info.cpu_time += delta;
}
+
+static inline void
+rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
+{
+ if (rq)
+ rq->rq_sched_info.run_delay += delta;
+}
# define schedstat_inc(rq, field) do { (rq)->field++; } while (0)
# define schedstat_add(rq, field, amt) do { (rq)->field += (amt); } while (0)
# define schedstat_set(var, val) do { var = (val); } while (0)
@@ -126,6 +133,9 @@ static inline void
rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
{}
static inline void
+rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
+{}
+static inline void
rq_sched_info_depart(struct rq *rq, unsigned long long delta)
{}
# define schedstat_inc(rq, field) do { } while (0)
@@ -134,6 +144,11 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta)
#endif
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
+static inline void sched_info_reset_dequeued(struct task_struct *t)
+{
+ t->sched_info.last_queued = 0;
+}
+
/*
* Called when a process is dequeued from the active array and given
* the cpu. We should note that with the exception of interactive
@@ -143,15 +158,22 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta)
* active queue, thus delaying tasks in the expired queue from running;
* see scheduler_tick()).
*
- * This function is only called from sched_info_arrive(), rather than
- * dequeue_task(). Even though a task may be queued and dequeued multiple
- * times as it is shuffled about, we're really interested in knowing how
- * long it was from the *first* time it was queued to the time that it
- * finally hit a cpu.
+ * Though we are interested in knowing how long it was from the *first* time a
+ * task was queued to the time that it finally hit a cpu, we call this routine
+ * from dequeue_task() to account for possible rq->clock skew across cpus. The
+ * delta taken on each cpu would annul the skew.
*/
static inline void sched_info_dequeued(struct task_struct *t)
{
- t->sched_info.last_queued = 0;
+ unsigned long long now = task_rq(t)->clock, delta = 0;
+
+ if (unlikely(sched_info_on()))
+ if (t->sched_info.last_queued)
+ delta = now - t->sched_info.last_queued;
+ sched_info_reset_dequeued(t);
+ t->sched_info.run_delay += delta;
+
+ rq_sched_info_dequeued(task_rq(t), delta);
}
/*
@@ -165,7 +187,7 @@ static void sched_info_arrive(struct task_struct *t)
if (t->sched_info.last_queued)
delta = now - t->sched_info.last_queued;
- sched_info_dequeued(t);
+ sched_info_reset_dequeued(t);
t->sched_info.run_delay += delta;
t->sched_info.last_arrival = now;
t->sched_info.pcount++;
@@ -242,7 +264,9 @@ sched_info_switch(struct task_struct *prev, struct task_struct *next)
__sched_info_switch(prev, next);
}
#else
-#define sched_info_queued(t) do { } while (0)
-#define sched_info_switch(t, next) do { } while (0)
+#define sched_info_queued(t) do { } while (0)
+#define sched_info_reset_dequeued(t) do { } while (0)
+#define sched_info_dequeued(t) do { } while (0)
+#define sched_info_switch(t, next) do { } while (0)
#endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */