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: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra 2008-08-19 12:33:05 +02:00 committed by Ingo Molnar
parent 0b148fa048
commit eb755805f2

View file

@ -1387,6 +1387,51 @@ static inline void dec_cpu_load(struct rq *rq, unsigned long load)
update_load_sub(&rq->load, load);
}
#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 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:
ret = (*down)(parent, data);
if (ret)
goto out_unlock;
list_for_each_entry_rcu(child, &parent->children, siblings) {
parent = child;
goto down;
up:
continue;
}
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);
@ -1404,37 +1449,6 @@ static unsigned long cpu_avg_load_per_task(int cpu)
#ifdef CONFIG_FAIR_GROUP_SCHED
typedef void (*tg_visitor)(struct task_group *, int, struct sched_domain *);
/*
* 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)
{
struct task_group *parent, *child;
rcu_read_lock();
parent = &root_task_group;
down:
(*down)(parent, cpu, sd);
list_for_each_entry_rcu(child, &parent->children, siblings) {
parent = child;
goto down;
up:
continue;
}
(*up)(parent, cpu, sd);
child = parent;
parent = parent->parent;
if (parent)
goto up;
rcu_read_unlock();
}
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