summaryrefslogtreecommitdiff
path: root/kernel/sched.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c469
1 files changed, 55 insertions, 414 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index cfa222a91539..eaf6751e7612 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -136,7 +136,7 @@ static inline void sg_inc_cpu_power(struct sched_group *sg, u32 val)
static inline int rt_policy(int policy)
{
- if (unlikely(policy == SCHED_FIFO) || unlikely(policy == SCHED_RR))
+ if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR))
return 1;
return 0;
}
@@ -312,12 +312,15 @@ static DEFINE_SPINLOCK(task_group_lock);
#endif
/*
- * A weight of 0, 1 or ULONG_MAX can cause arithmetics problems.
+ * A weight of 0 or 1 can cause arithmetics problems.
+ * A weight of a cfs_rq is the sum of weights of which entities
+ * are queued on this cfs_rq, so a weight of a entity should not be
+ * too large, so as the shares value of a task group.
* (The default weight is 1024 - so there's no practical
* limitation from this.)
*/
#define MIN_SHARES 2
-#define MAX_SHARES (ULONG_MAX - 1)
+#define MAX_SHARES (1UL << 18)
static int init_task_group_load = INIT_TASK_GROUP_LOAD;
#endif
@@ -398,43 +401,6 @@ 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
};
@@ -1368,17 +1334,19 @@ static void __resched_task(struct task_struct *p, int tif_bit)
*/
#define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y))
-/*
- * delta *= weight / lw
- */
static unsigned long
calc_delta_mine(unsigned long delta_exec, unsigned long weight,
struct load_weight *lw)
{
u64 tmp;
- if (!lw->inv_weight)
- lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2)/(lw->weight+1);
+ if (!lw->inv_weight) {
+ if (BITS_PER_LONG > 32 && unlikely(lw->weight >= WMULT_CONST))
+ lw->inv_weight = 1;
+ else
+ lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2)
+ / (lw->weight+1);
+ }
tmp = (u64)delta_exec * weight;
/*
@@ -1393,6 +1361,12 @@ calc_delta_mine(unsigned long delta_exec, unsigned long weight,
return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX);
}
+static inline unsigned long
+calc_delta_fair(unsigned long delta_exec, struct load_weight *lw)
+{
+ return calc_delta_mine(delta_exec, NICE_0_LOAD, lw);
+}
+
static inline void update_load_add(struct load_weight *lw, unsigned long inc)
{
lw->weight += inc;
@@ -1505,326 +1479,6 @@ 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
-
#else /* CONFIG_SMP */
#ifdef CONFIG_FAIR_GROUP_SCHED
@@ -1845,14 +1499,26 @@ static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares)
#define sched_class_highest (&rt_sched_class)
-static void inc_nr_running(struct rq *rq)
+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)
{
rq->nr_running++;
+ inc_load(rq, p);
}
-static void dec_nr_running(struct rq *rq)
+static void dec_nr_running(struct task_struct *p, struct rq *rq)
{
rq->nr_running--;
+ dec_load(rq, p);
}
static void set_load_weight(struct task_struct *p)
@@ -1944,7 +1610,7 @@ static void activate_task(struct rq *rq, struct task_struct *p, int wakeup)
rq->nr_uninterruptible--;
enqueue_task(rq, p, wakeup);
- inc_nr_running(rq);
+ inc_nr_running(p, rq);
}
/*
@@ -1956,7 +1622,7 @@ static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep)
rq->nr_uninterruptible++;
dequeue_task(rq, p, sleep);
- dec_nr_running(rq);
+ dec_nr_running(p, rq);
}
/**
@@ -2609,7 +2275,7 @@ 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(rq);
+ inc_nr_running(p, rq);
}
check_preempt_curr(rq, p);
#ifdef CONFIG_SMP
@@ -3600,12 +3266,9 @@ 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,
@@ -3721,9 +3384,8 @@ redo:
if (!ld_moved && !sd_idle && sd->flags & SD_SHARE_CPUPOWER &&
!test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
- ld_moved = -1;
-
- goto out;
+ return -1;
+ return ld_moved;
out_balanced:
schedstat_inc(sd, lb_balanced[idle]);
@@ -3738,13 +3400,8 @@ out_one_pinned:
if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER &&
!test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
- ld_moved = -1;
- else
- ld_moved = 0;
-out:
- if (unlock_aggregate)
- put_aggregate(sd);
- return ld_moved;
+ return -1;
+ return 0;
}
/*
@@ -4430,7 +4087,7 @@ static inline void schedule_debug(struct task_struct *prev)
* schedule() atomically, we ignore that path for now.
* Otherwise, whine if we are scheduling when we should not be.
*/
- if (unlikely(in_atomic_preempt_off()) && unlikely(!prev->exit_state))
+ if (unlikely(in_atomic_preempt_off() && !prev->exit_state))
__schedule_bug(prev);
profile_hit(SCHED_PROFILING, __builtin_return_address(0));
@@ -4510,12 +4167,10 @@ need_resched_nonpreemptible:
clear_tsk_need_resched(prev);
if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
- if (unlikely((prev->state & TASK_INTERRUPTIBLE) &&
- signal_pending(prev))) {
+ if (unlikely(signal_pending_state(prev->state, prev)))
prev->state = TASK_RUNNING;
- } else {
+ else
deactivate_task(rq, prev, 1);
- }
switch_count = &prev->nvcsw;
}
@@ -4931,8 +4586,10 @@ 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);
@@ -4942,6 +4599,7 @@ 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:
@@ -7316,7 +6974,6 @@ 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;
@@ -7327,7 +6984,6 @@ 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;
@@ -7339,7 +6995,6 @@ 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;
@@ -7351,7 +7006,6 @@ 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;
@@ -7364,7 +7018,6 @@ 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;
@@ -7568,8 +7221,8 @@ static int build_sched_domains(const cpumask_t *cpu_map)
static cpumask_t *doms_cur; /* current sched domains */
static int ndoms_cur; /* number of sched domains in 'doms_cur' */
-static struct sched_domain_attr *dattr_cur; /* attribues of custom domains
- in 'doms_cur' */
+static struct sched_domain_attr *dattr_cur;
+ /* attribues of custom domains in 'doms_cur' */
/*
* Special case: If a kmalloc of a doms_cur partition (array of
@@ -8034,7 +7687,6 @@ void __init sched_init(void)
}
#ifdef CONFIG_SMP
- init_aggregate();
init_defrootdomain();
#endif
@@ -8599,11 +8251,14 @@ void sched_move_task(struct task_struct *tsk)
#endif
#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);
@@ -8613,17 +8268,8 @@ static void __set_se_shares(struct sched_entity *se, unsigned long shares)
if (on_rq)
enqueue_entity(cfs_rq, se, 0);
-}
-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);
+ spin_unlock_irq(&rq->lock);
}
static DEFINE_MUTEX(shares_mutex);
@@ -8662,13 +8308,8 @@ 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) {
- /*
- * force a rebalance
- */
- cfs_rq_set_shares(tg->cfs_rq[i], 0);
+ for_each_possible_cpu(i)
set_se_shares(tg->se[i], shares);
- }
/*
* Enable load balance activity on this group, by inserting it back on
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-01 02:32:34 +0000