Merge branch 'linus' into x86/xentip-x86-xen-2008-06-16_09.21_Mon

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