[PATCH 4/8] sched: set initial runnable avg for new task

[Alex Shi]

---
 kernel/sched/core.c  |  2 ++
 kernel/sched/fair.c  | 15 +++++++++++++++
 kernel/sched/sched.h |  2 ++
 3 files changed, 19 insertions(+)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index ecec7f1..c17925b 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1716,6 +1716,8 @@ void wake_up_new_task(struct task_struct *p)
 	set_task_cpu(p, select_task_rq(p, SD_BALANCE_FORK, 0));
 #endif
 
+	/* Give new task a start runnable time */
+	set_task_runnable_avg(p);
 	rq = __task_rq_lock(p);
 	activate_task(rq, p, 0);
 	p->on_rq = 1;
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 2881d42..4ec5f29 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -661,6 +661,21 @@ static u64 sched_vslice(struct cfs_rq *cfs_rq, struct sched_entity *se)
 	return calc_delta_fair(sched_slice(cfs_rq, se), se);
 }
 
+#ifdef CONFIG_SMP
+void set_task_runnable_avg(struct task_struct *p)
+{
+	u64 slice;
+
+	slice = sched_slice(task_cfs_rq(p), &p->se);
+	p->se.avg.runnable_avg_sum = slice;
+	p->se.avg.runnable_avg_period = slice;
+}
+#else
+void set_task_runnable_avg(struct task_struct *p)
+{
+}
+#endif
+
 /*
  * Update the current task's runtime statistics. Skip current tasks that
  * are not in our scheduling class.
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index c6634f1..518f3d8a 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -900,6 +900,8 @@ extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime
 
 extern void update_idle_cpu_load(struct rq *this_rq);
 
+extern void set_task_runnable_avg(struct task_struct *p);
+
 #ifdef CONFIG_CGROUP_CPUACCT
 #include <linux/cgroup.h>
 /* track cpu usage of a group of tasks and its child groups */
-- 
1.7.12

-- 
Thanks
    Alex
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