sched: revert revert of: fair-group: SMP-nice for group scheduling

Try again..

Initial commit: 18d95a2832
Revert: 6363ca57c7

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra 2008-06-27 13:41:14 +02:00 committed by Ingo Molnar
parent ced8aa16e1
commit c09595f63b
5 changed files with 490 additions and 76 deletions

View file

@ -765,6 +765,7 @@ struct sched_domain {
struct sched_domain *child; /* bottom domain must be null terminated */
struct sched_group *groups; /* the balancing groups of the domain */
cpumask_t span; /* span of all CPUs in this domain */
int first_cpu; /* cache of the first cpu in this domain */
unsigned long min_interval; /* Minimum balance interval ms */
unsigned long max_interval; /* Maximum balance interval ms */
unsigned int busy_factor; /* less balancing by factor if busy */

View file

@ -403,6 +403,43 @@ struct cfs_rq {
*/
struct list_head leaf_cfs_rq_list;
struct task_group *tg; /* group that "owns" this runqueue */
#ifdef CONFIG_SMP
unsigned long task_weight;
unsigned long shares;
/*
* We need space to build a sched_domain wide view of the full task
* group tree, in order to avoid depending on dynamic memory allocation
* during the load balancing we place this in the per cpu task group
* hierarchy. This limits the load balancing to one instance per cpu,
* but more should not be needed anyway.
*/
struct aggregate_struct {
/*
* load = weight(cpus) * f(tg)
*
* Where f(tg) is the recursive weight fraction assigned to
* this group.
*/
unsigned long load;
/*
* part of the group weight distributed to this span.
*/
unsigned long shares;
/*
* The sum of all runqueue weights within this span.
*/
unsigned long rq_weight;
/*
* Weight contributed by tasks; this is the part we can
* influence by moving tasks around.
*/
unsigned long task_weight;
} aggregate;
#endif
#endif
};
@ -1484,6 +1521,326 @@ static unsigned long source_load(int cpu, int type);
static unsigned long target_load(int cpu, int type);
static unsigned long cpu_avg_load_per_task(int cpu);
static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);
#ifdef CONFIG_FAIR_GROUP_SCHED
/*
* Group load balancing.
*
* We calculate a few balance domain wide aggregate numbers; load and weight.
* Given the pictures below, and assuming each item has equal weight:
*
* root 1 - thread
* / | \ A - group
* A 1 B
* /|\ / \
* C 2 D 3 4
* | |
* 5 6
*
* load:
* A and B get 1/3-rd of the total load. C and D get 1/3-rd of A's 1/3-rd,
* which equals 1/9-th of the total load.
*
* shares:
* The weight of this group on the selected cpus.
*
* rq_weight:
* Direct sum of all the cpu's their rq weight, e.g. A would get 3 while
* B would get 2.
*
* task_weight:
* Part of the rq_weight contributed by tasks; all groups except B would
* get 1, B gets 2.
*/
static inline struct aggregate_struct *
aggregate(struct task_group *tg, struct sched_domain *sd)
{
return &tg->cfs_rq[sd->first_cpu]->aggregate;
}
typedef void (*aggregate_func)(struct task_group *, 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 aggregate_walk_tree(aggregate_func down, aggregate_func up,
struct sched_domain *sd)
{
struct task_group *parent, *child;
rcu_read_lock();
parent = &root_task_group;
down:
(*down)(parent, sd);
list_for_each_entry_rcu(child, &parent->children, siblings) {
parent = child;
goto down;
up:
continue;
}
(*up)(parent, sd);
child = parent;
parent = parent->parent;
if (parent)
goto up;
rcu_read_unlock();
}
/*
* Calculate the aggregate runqueue weight.
*/
static
void aggregate_group_weight(struct task_group *tg, struct sched_domain *sd)
{
unsigned long rq_weight = 0;
unsigned long task_weight = 0;
int i;
for_each_cpu_mask(i, sd->span) {
rq_weight += tg->cfs_rq[i]->load.weight;
task_weight += tg->cfs_rq[i]->task_weight;
}
aggregate(tg, sd)->rq_weight = rq_weight;
aggregate(tg, sd)->task_weight = task_weight;
}
/*
* Compute the weight of this group on the given cpus.
*/
static
void aggregate_group_shares(struct task_group *tg, struct sched_domain *sd)
{
unsigned long shares = 0;
int i;
for_each_cpu_mask(i, sd->span)
shares += tg->cfs_rq[i]->shares;
if ((!shares && aggregate(tg, sd)->rq_weight) || shares > tg->shares)
shares = tg->shares;
aggregate(tg, sd)->shares = shares;
}
/*
* Compute the load fraction assigned to this group, relies on the aggregate
* weight and this group's parent's load, i.e. top-down.
*/
static
void aggregate_group_load(struct task_group *tg, struct sched_domain *sd)
{
unsigned long load;
if (!tg->parent) {
int i;
load = 0;
for_each_cpu_mask(i, sd->span)
load += cpu_rq(i)->load.weight;
} else {
load = aggregate(tg->parent, sd)->load;
/*
* shares is our weight in the parent's rq so
* shares/parent->rq_weight gives our fraction of the load
*/
load *= aggregate(tg, sd)->shares;
load /= aggregate(tg->parent, sd)->rq_weight + 1;
}
aggregate(tg, sd)->load = load;
}
static void __set_se_shares(struct sched_entity *se, unsigned long shares);
/*
* Calculate and set the cpu's group shares.
*/
static void
__update_group_shares_cpu(struct task_group *tg, struct sched_domain *sd,
int tcpu)
{
int boost = 0;
unsigned long shares;
unsigned long rq_weight;
if (!tg->se[tcpu])
return;
rq_weight = tg->cfs_rq[tcpu]->load.weight;
/*
* If there are currently no tasks on the cpu pretend there is one of
* average load so that when a new task gets to run here it will not
* get delayed by group starvation.
*/
if (!rq_weight) {
boost = 1;
rq_weight = NICE_0_LOAD;
}
/*
* \Sum shares * rq_weight
* shares = -----------------------
* \Sum rq_weight
*
*/
shares = aggregate(tg, sd)->shares * rq_weight;
shares /= aggregate(tg, sd)->rq_weight + 1;
/*
* record the actual number of shares, not the boosted amount.
*/
tg->cfs_rq[tcpu]->shares = boost ? 0 : shares;
if (shares < MIN_SHARES)
shares = MIN_SHARES;
else if (shares > MAX_SHARES)
shares = MAX_SHARES;
__set_se_shares(tg->se[tcpu], shares);
}
/*
* Re-adjust the weights on the cpu the task came from and on the cpu the
* task went to.
*/
static void
__move_group_shares(struct task_group *tg, struct sched_domain *sd,
int scpu, int dcpu)
{
unsigned long shares;
shares = tg->cfs_rq[scpu]->shares + tg->cfs_rq[dcpu]->shares;
__update_group_shares_cpu(tg, sd, scpu);
__update_group_shares_cpu(tg, sd, dcpu);
/*
* ensure we never loose shares due to rounding errors in the
* above redistribution.
*/
shares -= tg->cfs_rq[scpu]->shares + tg->cfs_rq[dcpu]->shares;
if (shares)
tg->cfs_rq[dcpu]->shares += shares;
}
/*
* Because changing a group's shares changes the weight of the super-group
* we need to walk up the tree and change all shares until we hit the root.
*/
static void
move_group_shares(struct task_group *tg, struct sched_domain *sd,
int scpu, int dcpu)
{
while (tg) {
__move_group_shares(tg, sd, scpu, dcpu);
tg = tg->parent;
}
}
static
void aggregate_group_set_shares(struct task_group *tg, struct sched_domain *sd)
{
unsigned long shares = aggregate(tg, sd)->shares;
int i;
for_each_cpu_mask(i, sd->span) {
struct rq *rq = cpu_rq(i);
unsigned long flags;
spin_lock_irqsave(&rq->lock, flags);
__update_group_shares_cpu(tg, sd, i);
spin_unlock_irqrestore(&rq->lock, flags);
}
aggregate_group_shares(tg, sd);
/*
* ensure we never loose shares due to rounding errors in the
* above redistribution.
*/
shares -= aggregate(tg, sd)->shares;
if (shares) {
tg->cfs_rq[sd->first_cpu]->shares += shares;
aggregate(tg, sd)->shares += shares;
}
}
/*
* Calculate the accumulative weight and recursive load of each task group
* while walking down the tree.
*/
static
void aggregate_get_down(struct task_group *tg, struct sched_domain *sd)
{
aggregate_group_weight(tg, sd);
aggregate_group_shares(tg, sd);
aggregate_group_load(tg, sd);
}
/*
* Rebalance the cpu shares while walking back up the tree.
*/
static
void aggregate_get_up(struct task_group *tg, struct sched_domain *sd)
{
aggregate_group_set_shares(tg, sd);
}
static DEFINE_PER_CPU(spinlock_t, aggregate_lock);
static void __init init_aggregate(void)
{
int i;
for_each_possible_cpu(i)
spin_lock_init(&per_cpu(aggregate_lock, i));
}
static int get_aggregate(struct sched_domain *sd)
{
if (!spin_trylock(&per_cpu(aggregate_lock, sd->first_cpu)))
return 0;
aggregate_walk_tree(aggregate_get_down, aggregate_get_up, sd);
return 1;
}
static void put_aggregate(struct sched_domain *sd)
{
spin_unlock(&per_cpu(aggregate_lock, sd->first_cpu));
}
static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares)
{
cfs_rq->shares = shares;
}
#else
static inline void init_aggregate(void)
{
}
static inline int get_aggregate(struct sched_domain *sd)
{
return 0;
}
static inline void put_aggregate(struct sched_domain *sd)
{
}
#endif
#endif
#include "sched_stats.h"
@ -1498,26 +1855,14 @@ static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);
#define for_each_class(class) \
for (class = sched_class_highest; class; class = class->next)
static inline void inc_load(struct rq *rq, const struct task_struct *p)
{
update_load_add(&rq->load, p->se.load.weight);
}
static inline void dec_load(struct rq *rq, const struct task_struct *p)
{
update_load_sub(&rq->load, p->se.load.weight);
}
static void inc_nr_running(struct task_struct *p, struct rq *rq)
static void inc_nr_running(struct rq *rq)
{
rq->nr_running++;
inc_load(rq, p);
}
static void dec_nr_running(struct task_struct *p, struct rq *rq)
static void dec_nr_running(struct rq *rq)
{
rq->nr_running--;
dec_load(rq, p);
}
static void set_load_weight(struct task_struct *p)
@ -1609,7 +1954,7 @@ static void activate_task(struct rq *rq, struct task_struct *p, int wakeup)
rq->nr_uninterruptible--;
enqueue_task(rq, p, wakeup);
inc_nr_running(p, rq);
inc_nr_running(rq);
}
/*
@ -1621,7 +1966,7 @@ static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep)
rq->nr_uninterruptible++;
dequeue_task(rq, p, sleep);
dec_nr_running(p, rq);
dec_nr_running(rq);
}
/**
@ -2274,7 +2619,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
* management (if any):
*/
p->sched_class->task_new(rq, p);
inc_nr_running(p, rq);
inc_nr_running(rq);
}
check_preempt_curr(rq, p);
#ifdef CONFIG_SMP
@ -3265,9 +3610,12 @@ static int load_balance(int this_cpu, struct rq *this_rq,
unsigned long imbalance;
struct rq *busiest;
unsigned long flags;
int unlock_aggregate;
cpus_setall(*cpus);
unlock_aggregate = get_aggregate(sd);
/*
* When power savings policy is enabled for the parent domain, idle
* sibling can pick up load irrespective of busy siblings. In this case,
@ -3383,8 +3731,9 @@ redo:
if (!ld_moved && !sd_idle && sd->flags & SD_SHARE_CPUPOWER &&
!test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
return -1;
return ld_moved;
ld_moved = -1;
goto out;
out_balanced:
schedstat_inc(sd, lb_balanced[idle]);
@ -3399,8 +3748,13 @@ out_one_pinned:
if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER &&
!test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
return -1;
return 0;
ld_moved = -1;
else
ld_moved = 0;
out:
if (unlock_aggregate)
put_aggregate(sd);
return ld_moved;
}
/*
@ -4588,10 +4942,8 @@ void set_user_nice(struct task_struct *p, long nice)
goto out_unlock;
}
on_rq = p->se.on_rq;
if (on_rq) {
if (on_rq)
dequeue_task(rq, p, 0);
dec_load(rq, p);
}
p->static_prio = NICE_TO_PRIO(nice);
set_load_weight(p);
@ -4601,7 +4953,6 @@ void set_user_nice(struct task_struct *p, long nice)
if (on_rq) {
enqueue_task(rq, p, 0);
inc_load(rq, p);
/*
* If the task increased its priority or is running and
* lowered its priority, then reschedule its CPU:
@ -7016,6 +7367,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map,
SD_INIT(sd, ALLNODES);
set_domain_attribute(sd, attr);
sd->span = *cpu_map;
sd->first_cpu = first_cpu(sd->span);
cpu_to_allnodes_group(i, cpu_map, &sd->groups, tmpmask);
p = sd;
sd_allnodes = 1;
@ -7026,6 +7378,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map,
SD_INIT(sd, NODE);
set_domain_attribute(sd, attr);
sched_domain_node_span(cpu_to_node(i), &sd->span);
sd->first_cpu = first_cpu(sd->span);
sd->parent = p;
if (p)
p->child = sd;
@ -7037,6 +7390,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map,
SD_INIT(sd, CPU);
set_domain_attribute(sd, attr);
sd->span = *nodemask;
sd->first_cpu = first_cpu(sd->span);
sd->parent = p;
if (p)
p->child = sd;
@ -7048,6 +7402,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map,
SD_INIT(sd, MC);
set_domain_attribute(sd, attr);
sd->span = cpu_coregroup_map(i);
sd->first_cpu = first_cpu(sd->span);
cpus_and(sd->span, sd->span, *cpu_map);
sd->parent = p;
p->child = sd;
@ -7060,6 +7415,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map,
SD_INIT(sd, SIBLING);
set_domain_attribute(sd, attr);
sd->span = per_cpu(cpu_sibling_map, i);
sd->first_cpu = first_cpu(sd->span);
cpus_and(sd->span, sd->span, *cpu_map);
sd->parent = p;
p->child = sd;
@ -7757,6 +8113,7 @@ void __init sched_init(void)
}
#ifdef CONFIG_SMP
init_aggregate();
init_defrootdomain();
#endif
@ -8322,14 +8679,11 @@ void sched_move_task(struct task_struct *tsk)
#endif /* CONFIG_GROUP_SCHED */
#ifdef CONFIG_FAIR_GROUP_SCHED
static void set_se_shares(struct sched_entity *se, unsigned long shares)
static void __set_se_shares(struct sched_entity *se, unsigned long shares)
{
struct cfs_rq *cfs_rq = se->cfs_rq;
struct rq *rq = cfs_rq->rq;
int on_rq;
spin_lock_irq(&rq->lock);
on_rq = se->on_rq;
if (on_rq)
dequeue_entity(cfs_rq, se, 0);
@ -8339,8 +8693,17 @@ static void set_se_shares(struct sched_entity *se, unsigned long shares)
if (on_rq)
enqueue_entity(cfs_rq, se, 0);
}
spin_unlock_irq(&rq->lock);
static void set_se_shares(struct sched_entity *se, unsigned long shares)
{
struct cfs_rq *cfs_rq = se->cfs_rq;
struct rq *rq = cfs_rq->rq;
unsigned long flags;
spin_lock_irqsave(&rq->lock, flags);
__set_se_shares(se, shares);
spin_unlock_irqrestore(&rq->lock, flags);
}
static DEFINE_MUTEX(shares_mutex);
@ -8379,8 +8742,13 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares)
* w/o tripping rebalance_share or load_balance_fair.
*/
tg->shares = shares;
for_each_possible_cpu(i)
for_each_possible_cpu(i) {
/*
* force a rebalance
*/
cfs_rq_set_shares(tg->cfs_rq[i], 0);
set_se_shares(tg->se[i], shares);
}
/*
* Enable load balance activity on this group, by inserting it back on

View file

@ -167,6 +167,11 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
#endif
SEQ_printf(m, " .%-30s: %ld\n", "nr_spread_over",
cfs_rq->nr_spread_over);
#ifdef CONFIG_FAIR_GROUP_SCHED
#ifdef CONFIG_SMP
SEQ_printf(m, " .%-30s: %lu\n", "shares", cfs_rq->shares);
#endif
#endif
}
void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)

View file

@ -567,10 +567,27 @@ update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
* Scheduling class queueing methods:
*/
#if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED
static void
add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight)
{
cfs_rq->task_weight += weight;
}
#else
static inline void
add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight)
{
}
#endif
static void
account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
update_load_add(&cfs_rq->load, se->load.weight);
if (!parent_entity(se))
inc_cpu_load(rq_of(cfs_rq), se->load.weight);
if (entity_is_task(se))
add_cfs_task_weight(cfs_rq, se->load.weight);
cfs_rq->nr_running++;
se->on_rq = 1;
list_add(&se->group_node, &cfs_rq->tasks);
@ -580,6 +597,10 @@ static void
account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
update_load_sub(&cfs_rq->load, se->load.weight);
if (!parent_entity(se))
dec_cpu_load(rq_of(cfs_rq), se->load.weight);
if (entity_is_task(se))
add_cfs_task_weight(cfs_rq, -se->load.weight);
cfs_rq->nr_running--;
se->on_rq = 0;
list_del_init(&se->group_node);
@ -1372,75 +1393,90 @@ static struct task_struct *load_balance_next_fair(void *arg)
return __load_balance_iterator(cfs_rq, cfs_rq->balance_iterator);
}
#ifdef CONFIG_FAIR_GROUP_SCHED
static int cfs_rq_best_prio(struct cfs_rq *cfs_rq)
static unsigned long
__load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
unsigned long max_load_move, struct sched_domain *sd,
enum cpu_idle_type idle, int *all_pinned, int *this_best_prio,
struct cfs_rq *cfs_rq)
{
struct sched_entity *curr;
struct task_struct *p;
struct rq_iterator cfs_rq_iterator;
if (!cfs_rq->nr_running || !first_fair(cfs_rq))
return MAX_PRIO;
cfs_rq_iterator.start = load_balance_start_fair;
cfs_rq_iterator.next = load_balance_next_fair;
cfs_rq_iterator.arg = cfs_rq;
curr = cfs_rq->curr;
if (!curr)
curr = __pick_next_entity(cfs_rq);
p = task_of(curr);
return p->prio;
return balance_tasks(this_rq, this_cpu, busiest,
max_load_move, sd, idle, all_pinned,
this_best_prio, &cfs_rq_iterator);
}
#endif
#ifdef CONFIG_FAIR_GROUP_SCHED
static unsigned long
load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
unsigned long max_load_move,
struct sched_domain *sd, enum cpu_idle_type idle,
int *all_pinned, int *this_best_prio)
{
struct cfs_rq *busy_cfs_rq;
long rem_load_move = max_load_move;
struct rq_iterator cfs_rq_iterator;
int busiest_cpu = cpu_of(busiest);
struct task_group *tg;
cfs_rq_iterator.start = load_balance_start_fair;
cfs_rq_iterator.next = load_balance_next_fair;
for_each_leaf_cfs_rq(busiest, busy_cfs_rq) {
#ifdef CONFIG_FAIR_GROUP_SCHED
struct cfs_rq *this_cfs_rq;
rcu_read_lock();
list_for_each_entry(tg, &task_groups, list) {
long imbalance;
unsigned long maxload;
unsigned long this_weight, busiest_weight;
long rem_load, max_load, moved_load;
this_cfs_rq = cpu_cfs_rq(busy_cfs_rq, this_cpu);
imbalance = busy_cfs_rq->load.weight - this_cfs_rq->load.weight;
/* Don't pull if this_cfs_rq has more load than busy_cfs_rq */
if (imbalance <= 0)
/*
* empty group
*/
if (!aggregate(tg, sd)->task_weight)
continue;
/* Don't pull more than imbalance/2 */
imbalance /= 2;
maxload = min(rem_load_move, imbalance);
rem_load = rem_load_move * aggregate(tg, sd)->rq_weight;
rem_load /= aggregate(tg, sd)->load + 1;
*this_best_prio = cfs_rq_best_prio(this_cfs_rq);
#else
# define maxload rem_load_move
#endif
/*
* pass busy_cfs_rq argument into
* load_balance_[start|next]_fair iterators
*/
cfs_rq_iterator.arg = busy_cfs_rq;
rem_load_move -= balance_tasks(this_rq, this_cpu, busiest,
maxload, sd, idle, all_pinned,
this_best_prio,
&cfs_rq_iterator);
this_weight = tg->cfs_rq[this_cpu]->task_weight;
busiest_weight = tg->cfs_rq[busiest_cpu]->task_weight;
if (rem_load_move <= 0)
imbalance = (busiest_weight - this_weight) / 2;
if (imbalance < 0)
imbalance = busiest_weight;
max_load = max(rem_load, imbalance);
moved_load = __load_balance_fair(this_rq, this_cpu, busiest,
max_load, sd, idle, all_pinned, this_best_prio,
tg->cfs_rq[busiest_cpu]);
if (!moved_load)
continue;
move_group_shares(tg, sd, busiest_cpu, this_cpu);
moved_load *= aggregate(tg, sd)->load;
moved_load /= aggregate(tg, sd)->rq_weight + 1;
rem_load_move -= moved_load;
if (rem_load_move < 0)
break;
}
rcu_read_unlock();
return max_load_move - rem_load_move;
}
#else
static unsigned long
load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
unsigned long max_load_move,
struct sched_domain *sd, enum cpu_idle_type idle,
int *all_pinned, int *this_best_prio)
{
return __load_balance_fair(this_rq, this_cpu, busiest,
max_load_move, sd, idle, all_pinned,
this_best_prio, &busiest->cfs);
}
#endif
static int
move_one_task_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,

View file

@ -670,6 +670,8 @@ static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup)
rt_se->timeout = 0;
enqueue_rt_entity(rt_se);
inc_cpu_load(rq, p->se.load.weight);
}
static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep)
@ -678,6 +680,8 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep)
update_curr_rt(rq);
dequeue_rt_entity(rt_se);
dec_cpu_load(rq, p->se.load.weight);
}
/*