Commit eb755805 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

sched: extract walk_tg_tree() 



Extract walk_tg_tree() and make it a little more generic so we can use it
in the schedulablity test.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 0b148fa0

kernel/sched.c

+46 −33
Original line number Diff line number Diff line
@@ -1387,38 +1387,24 @@ static inline void dec_cpu_load(struct rq *rq, unsigned long load) 
	update_load_sub(&rq->load, load);

}



#ifdef CONFIG_SMP

static unsigned long source_load(int cpu, int type);

static unsigned long target_load(int cpu, int type);

static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);



static unsigned long cpu_avg_load_per_task(int cpu)

{

	struct rq *rq = cpu_rq(cpu);



	if (rq->nr_running)

		rq->avg_load_per_task = rq->load.weight / rq->nr_running;



	return rq->avg_load_per_task;

}



#ifdef CONFIG_FAIR_GROUP_SCHED



typedef void (*tg_visitor)(struct task_group *, int, struct sched_domain *);

#if (defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED))

typedef int (*tg_visitor)(struct task_group *, void *);



/*

 * Iterate the full tree, calling @down when first entering a node and @up when

 * leaving it for the final time.

 */

static void

walk_tg_tree(tg_visitor down, tg_visitor up, int cpu, struct sched_domain *sd)

static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)

{

	struct task_group *parent, *child;

	int ret;



	rcu_read_lock();

	parent = &root_task_group;

down:

	(*down)(parent, cpu, sd);

	ret = (*down)(parent, data);

	if (ret)

		goto out_unlock;

	list_for_each_entry_rcu(child, &parent->children, siblings) {

		parent = child;

		goto down;
@@ -1426,14 +1412,42 @@ down: 
up:

		continue;

	}

	(*up)(parent, cpu, sd);

	ret = (*up)(parent, data);

	if (ret)

		goto out_unlock;



	child = parent;

	parent = parent->parent;

	if (parent)

		goto up;

out_unlock:

	rcu_read_unlock();



	return ret;

}



static int tg_nop(struct task_group *tg, void *data)

{

	return 0;

}

#endif



#ifdef CONFIG_SMP

static unsigned long source_load(int cpu, int type);

static unsigned long target_load(int cpu, int type);

static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);



static unsigned long cpu_avg_load_per_task(int cpu)

{

	struct rq *rq = cpu_rq(cpu);



	if (rq->nr_running)

		rq->avg_load_per_task = rq->load.weight / rq->nr_running;



	return rq->avg_load_per_task;

}



#ifdef CONFIG_FAIR_GROUP_SCHED



static void __set_se_shares(struct sched_entity *se, unsigned long shares);
@@ -1493,11 +1507,11 @@ __update_group_shares_cpu(struct task_group *tg, int cpu, 
 * This needs to be done in a bottom-up fashion because the rq weight of a

 * parent group depends on the shares of its child groups.

 */

static void

tg_shares_up(struct task_group *tg, int cpu, struct sched_domain *sd)

static int tg_shares_up(struct task_group *tg, void *data)

{

	unsigned long rq_weight = 0;

	unsigned long shares = 0;

	struct sched_domain *sd = data;

	int i;



	for_each_cpu_mask(i, sd->span) {
@@ -1522,6 +1536,8 @@ tg_shares_up(struct task_group *tg, int cpu, struct sched_domain *sd) 
		__update_group_shares_cpu(tg, i, shares, rq_weight);

		spin_unlock_irqrestore(&rq->lock, flags);

	}



	return 0;

}



/*
@@ -1529,10 +1545,10 @@ tg_shares_up(struct task_group *tg, int cpu, struct sched_domain *sd) 
 * This needs to be done in a top-down fashion because the load of a child

 * group is a fraction of its parents load.

 */

static void

tg_load_down(struct task_group *tg, int cpu, struct sched_domain *sd)

static int tg_load_down(struct task_group *tg, void *data)

{

	unsigned long load;

	long cpu = (long)data;



	if (!tg->parent) {

		load = cpu_rq(cpu)->load.weight;
@@ -1543,11 +1559,8 @@ tg_load_down(struct task_group *tg, int cpu, struct sched_domain *sd) 
	}



	tg->cfs_rq[cpu]->h_load = load;

}



static void

tg_nop(struct task_group *tg, int cpu, struct sched_domain *sd)

{

	return 0;

}



static void update_shares(struct sched_domain *sd)
@@ -1557,7 +1570,7 @@ static void update_shares(struct sched_domain *sd) 


	if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) {

		sd->last_update = now;

		walk_tg_tree(tg_nop, tg_shares_up, 0, sd);

		walk_tg_tree(tg_nop, tg_shares_up, sd);

	}

}
@@ -1568,9 +1581,9 @@ static void update_shares_locked(struct rq *rq, struct sched_domain *sd) 
	spin_lock(&rq->lock);

}



static void update_h_load(int cpu)

static void update_h_load(long cpu)

{

	walk_tg_tree(tg_load_down, tg_nop, cpu, NULL);

	walk_tg_tree(tg_load_down, tg_nop, (void *)cpu);

}



#else