[git pull] scheduler fixes

Ingo Molnar
2008-05-29T15:46:24Z

Linus, please pull the latest sched-fixes git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git sched-fixes-for-linus

this fixes scheduler related sysbench (and other benchmarks)
performance regressions. The sysbench throughput results compared to
2.6.24-rc4 are:

[tx/sec, higher is better]

.26-rc4 .26-rc4+sched-fixes
-------------------------------------------------
1: 687 727 +5.43%
2: 1460 1480 +1.34%
4: 2911 3080 +5.49%
8: 5496 5932 +7.35%
16: 10049 10822 +7.14%
32: 7598 10082 +24.64%
64: 7958 9331 +14.71%
128: 8169 8574 +4.73%
256: 8398 8469 +0.84%
-------------------------------------------------
SUM: 52730 58501 +9.86%

with these fixes applied 2.6.26 is a net improvement over 2.6.25:

.25 .26-rc4+sched-fixes
-------------------------------------------------
1: 701 727 +3.47%
2: 1484 1480 -0.23%
4: 3050 3080 +0.96%
8: 5918 5932 +0.24%
16: 10794 10822 +0.26%
32: 10082 10082 -0.01%
64: 8894 9331 +4.68%
128: 7685 8574 +10.38%
256: 5258 8469 +37.92%
-------------------------------------------------
SUM: 53870 58501 +7.92%

the group balancing revert makes the linecount rather large, but
it was a relatively straightforward (albeit not automatic) revert.

it is a bit late because i was hoping for these patches from Peter
to work out:

http://programming.kicks-ass.net/kernel-patches/sched-smp-group-fixes/

but they ended up being more risky than the revert, so we'll go for the
revert for 2.6.26. Thanks to Peter and Mike for sorting out these issues.

Ingo

------------------>
Adrian Bunk (1):
show_schedstat(): fix memleak

Ingo Molnar (4):
revert ("sched: fair: weight calculations")
sched: cleanup
revert ("sched: fair-group: SMP-nice for group scheduling")
sched: re-tune NUMA topologies

Mike Galbraith (1):
sched: stop wake_affine from causing serious imbalance

Peter Zijlstra (1):
sched: fix sched_clock_cpu()

Roel Kluin (1):
sched: unite unlikely pairs in rt_policy() and schedule_debug()

include/linux/sched.h | 1 -
include/linux/topology.h | 4 +-
kernel/sched.c | 447 +++++-----------------------------------------
kernel/sched_clock.c | 18 ++-
kernel/sched_debug.c | 5 -
kernel/sched_fair.c | 254 ++++++++++-----------------
kernel/sched_rt.c | 4 -
kernel/sched_stats.h | 1 +
8 files changed, 150 insertions(+), 584 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 3e05e54..ae0be3c 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -766,7 +766,6 @@ 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 */
diff --git a/include/linux/topology.h b/include/linux/topology.h
index 4bb7074..24f3d22 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -166,7 +166,9 @@ void arch_update_cpu_topology(void);
.busy_idx = 3, \
.idle_idx = 3, \
.flags = SD_LOAD_BALANCE \
- | SD_SERIALIZE, \
+ | SD_BALANCE_NEWIDLE \
+ | SD_WAKE_AFFINE \
+ | SD_SERIALIZE, \
.last_balance = jiffies, \
.balance_interval = 64, \
}
diff --git a/kernel/sched.c b/kernel/sched.c
index cfa222a..bfb8ad8 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;
}
@@ -398,43 +398,6 @@ 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
};

@@ -1368,9 +1331,6 @@ 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)
@@ -1393,6 +1353,12 @@ 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 +1471,6 @@ 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 +1491,26 @@ 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 +1602,7 @@ 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 +1614,7 @@ 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 +2267,7 @@ 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 +3258,9 @@ 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 +3376,8 @@ 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 +3392,8 @@ 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 +4079,7 @@ 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));
@@ -4931,8 +4580,10 @@ 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 +4593,7 @@ 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 +6968,6 @@ 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 +6978,6 @@ 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 +6989,6 @@ 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 +7000,6 @@ 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 +7012,6 @@ 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 +7215,8 @@ 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 +7681,6 @@ void __init sched_init(void)
}

#ifdef CONFIG_SMP
- init_aggregate();
init_defrootdomain();
#endif

@@ -8599,11 +8245,14 @@ 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 +8262,8 @@ 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 +8302,8 @@ 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
diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c
index 9c597e3..ce05271 100644
--- a/kernel/sched_clock.c
+++ b/kernel/sched_clock.c
@@ -59,22 +59,26 @@ static inline struct sched_clock_data *cpu_sdc(int cpu)
return &per_cpu(sched_clock_data, cpu);
}

+static __read_mostly int sched_clock_running;
+
void sched_clock_init(void)
{
u64 ktime_now = ktime_to_ns(ktime_get());
- u64 now = 0;
+ unsigned long now_jiffies = jiffies;
int cpu;

for_each_possible_cpu(cpu) {
struct sched_clock_data *scd = cpu_sdc(cpu);

scd->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
- scd->prev_jiffies = jiffies;
- scd->prev_raw = now;
- scd->tick_raw = now;
+ scd->prev_jiffies = now_jiffies;
+ scd->prev_raw = 0;
+ scd->tick_raw = 0;
scd->tick_gtod = ktime_now;
scd->clock = ktime_now;
}
+
+ sched_clock_running = 1;
}

/*
@@ -136,6 +140,9 @@ u64 sched_clock_cpu(int cpu)
struct sched_clock_data *scd = cpu_sdc(cpu);
u64 now, clock;

+ if (unlikely(!sched_clock_running))
+ return 0ull;
+
WARN_ON_ONCE(!irqs_disabled());
now = sched_clock();

@@ -174,6 +181,9 @@ void sched_clock_tick(void)
struct sched_clock_data *scd = this_scd();
u64 now, now_gtod;

+ if (unlikely(!sched_clock_running))
+ return;
+
WARN_ON_ONCE(!irqs_disabled());

now = sched_clock();
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 5f06118..8bb7130 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -167,11 +167,6 @@ 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
}

static void print_cpu(struct seq_file *m, int cpu)
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index e24ecd3..08ae848 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -334,34 +334,6 @@ int sched_nr_latency_handler(struct ctl_table *table, int write,
#endif

/*
- * delta *= w / rw
- */
-static inline unsigned long
-calc_delta_weight(unsigned long delta, struct sched_entity *se)
-{
- for_each_sched_entity(se) {
- delta = calc_delta_mine(delta,
- se->load.weight, &cfs_rq_of(se)->load);
- }
-
- return delta;
-}
-
-/*
- * delta *= rw / w
- */
-static inline unsigned long
-calc_delta_fair(unsigned long delta, struct sched_entity *se)
-{
- for_each_sched_entity(se) {
- delta = calc_delta_mine(delta,
- cfs_rq_of(se)->load.weight, &se->load);
- }
-
- return delta;
-}
-
-/*
* The idea is to set a period in which each task runs once.
*
* When there are too many tasks (sysctl_sched_nr_latency) we have to stretch
@@ -390,54 +362,47 @@ static u64 __sched_period(unsigned long nr_running)
*/
static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- return calc_delta_weight(__sched_period(cfs_rq->nr_running), se);
+ u64 slice = __sched_period(cfs_rq->nr_running);
+
+ for_each_sched_entity(se) {
+ cfs_rq = cfs_rq_of(se);
+
+ slice *= se->load.weight;
+ do_div(slice, cfs_rq->load.weight);
+ }
+
+
+ return slice;
}

/*
* We calculate the vruntime slice of a to be inserted task
*
- * vs = s*rw/w = p
+ * vs = s/w = p/rw
*/
static u64 sched_vslice_add(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
unsigned long nr_running = cfs_rq->nr_running;
+ unsigned long weight;
+ u64 vslice;

if (!se->on_rq)
nr_running++;

- return __sched_period(nr_running);
-}
-
-/*
- * The goal of calc_delta_asym() is to be asymmetrically around NICE_0_LOAD, in
- * that it favours >=0 over <0.
- *
- * -20 |
- * |
- * 0 --------+-------
- * .'
- * 19 .'
- *
- */
-static unsigned long
-calc_delta_asym(unsigned long delta, struct sched_entity *se)
-{
- struct load_weight lw = {
- .weight = NICE_0_LOAD,
- .inv_weight = 1UL << (WMULT_SHIFT-NICE_0_SHIFT)
- };
+ vslice = __sched_period(nr_running);

for_each_sched_entity(se) {
- struct load_weight *se_lw = &se->load;
+ cfs_rq = cfs_rq_of(se);

- if (se->load.weight < NICE_0_LOAD)
- se_lw = &lw;
+ weight = cfs_rq->load.weight;
+ if (!se->on_rq)
+ weight += se->load.weight;

- delta = calc_delta_mine(delta,
- cfs_rq_of(se)->load.weight, se_lw);
+ vslice *= NICE_0_LOAD;
+ do_div(vslice, weight);
}

- return delta;
+ return vslice;
}

/*
@@ -454,7 +419,11 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,

curr->sum_exec_runtime += delta_exec;
schedstat_add(cfs_rq, exec_clock, delta_exec);
- delta_exec_weighted = calc_delta_fair(delta_exec, curr);
+ delta_exec_weighted = delta_exec;
+ if (unlikely(curr->load.weight != NICE_0_LOAD)) {
+ delta_exec_weighted = calc_delta_fair(delta_exec_weighted,
+ &curr->load);
+ }
curr->vruntime += delta_exec_weighted;
}

@@ -541,27 +510,10 @@ 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);
@@ -571,10 +523,6 @@ 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);
@@ -661,17 +609,8 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)

if (!initial) {
/* sleeps upto a single latency don't count. */
- if (sched_feat(NEW_FAIR_SLEEPERS)) {
- unsigned long thresh = sysctl_sched_latency;
-
- /*
- * convert the sleeper threshold into virtual time
- */
- if (sched_feat(NORMALIZED_SLEEPER))
- thresh = calc_delta_fair(thresh, se);
-
- vruntime -= thresh;
- }
+ if (sched_feat(NEW_FAIR_SLEEPERS))
+ vruntime -= sysctl_sched_latency;

/* ensure we never gain time by being placed backwards. */
vruntime = max_vruntime(se->vruntime, vruntime);
@@ -1057,16 +996,27 @@ wake_affine(struct rq *rq, struct sched_domain *this_sd, struct rq *this_rq,
struct task_struct *curr = this_rq->curr;
unsigned long tl = this_load;
unsigned long tl_per_task;
+ int balanced;

- if (!(this_sd->flags & SD_WAKE_AFFINE))
+ if (!(this_sd->flags & SD_WAKE_AFFINE) || !sched_feat(AFFINE_WAKEUPS))
return 0;

/*
+ * If sync wakeup then subtract the (maximum possible)
+ * effect of the currently running task from the load
+ * of the current CPU:
+ */
+ if (sync)
+ tl -= current->se.load.weight;
+
+ balanced = 100*(tl + p->se.load.weight) <= imbalance*load;
+
+ /*
* If the currently running task will sleep within
* a reasonable amount of time then attract this newly
* woken task:
*/
- if (sync && curr->sched_class == &fair_sched_class) {
+ if (sync && balanced && curr->sched_class == &fair_sched_class) {
if (curr->se.avg_overlap < sysctl_sched_migration_cost &&
p->se.avg_overlap < sysctl_sched_migration_cost)
return 1;
@@ -1075,16 +1025,8 @@ wake_affine(struct rq *rq, struct sched_domain *this_sd, struct rq *this_rq,
schedstat_inc(p, se.nr_wakeups_affine_attempts);
tl_per_task = cpu_avg_load_per_task(this_cpu);

- /*
- * If sync wakeup then subtract the (maximum possible)
- * effect of the currently running task from the load
- * of the current CPU:
- */
- if (sync)
- tl -= current->se.load.weight;
-
if ((tl <= load && tl + target_load(prev_cpu, idx) <= tl_per_task) ||
- 100*(tl + p->se.load.weight) <= imbalance*load) {
+ balanced) {
/*
* This domain has SD_WAKE_AFFINE and
* p is cache cold in this domain, and
@@ -1169,10 +1111,11 @@ static unsigned long wakeup_gran(struct sched_entity *se)
unsigned long gran = sysctl_sched_wakeup_granularity;

/*
- * More easily preempt - nice tasks, while not making it harder for
- * + nice tasks.
+ * More easily preempt - nice tasks, while not making
+ * it harder for + nice tasks.
*/
- gran = calc_delta_asym(sysctl_sched_wakeup_granularity, se);
+ if (unlikely(se->load.weight > NICE_0_LOAD))
+ gran = calc_delta_fair(gran, &se->load);

return gran;
}
@@ -1366,90 +1309,75 @@ static struct task_struct *load_balance_next_fair(void *arg)
return __load_balance_iterator(cfs_rq, cfs_rq->balance_iterator);
}

-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)
+#ifdef CONFIG_FAIR_GROUP_SCHED
+static int cfs_rq_best_prio(struct cfs_rq *cfs_rq)
{
- struct rq_iterator cfs_rq_iterator;
+ struct sched_entity *curr;
+ struct task_struct *p;

- cfs_rq_iterator.start = load_balance_start_fair;
- cfs_rq_iterator.next = load_balance_next_fair;
- cfs_rq_iterator.arg = cfs_rq;
+ if (!cfs_rq->nr_running || !first_fair(cfs_rq))
+ return MAX_PRIO;
+
+ curr = cfs_rq->curr;
+ if (!curr)
+ curr = __pick_next_entity(cfs_rq);
+
+ p = task_of(curr);

- return balance_tasks(this_rq, this_cpu, busiest,
- max_load_move, sd, idle, all_pinned,
- this_best_prio, &cfs_rq_iterator);
+ return p->prio;
}
+#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;
- int busiest_cpu = cpu_of(busiest);
- struct task_group *tg;
-
- rcu_read_lock();
- list_for_each_entry(tg, &task_groups, list) {
- long imbalance;
- unsigned long this_weight, busiest_weight;
- long rem_load, max_load, moved_load;
-
- /*
- * empty group
- */
- if (!aggregate(tg, sd)->task_weight)
- continue;
-
- rem_load = rem_load_move * aggregate(tg, sd)->rq_weight;
- rem_load /= aggregate(tg, sd)->load + 1;
-
- this_weight = tg->cfs_rq[this_cpu]->task_weight;
- busiest_weight = tg->cfs_rq[busiest_cpu]->task_weight;
+ struct rq_iterator cfs_rq_iterator;

- imbalance = (busiest_weight - this_weight) / 2;
+ cfs_rq_iterator.start = load_balance_start_fair;
+ cfs_rq_iterator.next = load_balance_next_fair;

- if (imbalance < 0)
- imbalance = busiest_weight;
+ for_each_leaf_cfs_rq(busiest, busy_cfs_rq) {
+#ifdef CONFIG_FAIR_GROUP_SCHED
+ struct cfs_rq *this_cfs_rq;
+ long imbalance;
+ unsigned long maxload;

- 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]);
+ this_cfs_rq = cpu_cfs_rq(busy_cfs_rq, this_cpu);

- if (!moved_load)
+ 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)
continue;

- move_group_shares(tg, sd, busiest_cpu, this_cpu);
+ /* Don't pull more than imbalance/2 */
+ imbalance /= 2;
+ maxload = min(rem_load_move, imbalance);

- moved_load *= aggregate(tg, sd)->load;
- moved_load /= aggregate(tg, sd)->rq_weight + 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);

- rem_load_move -= moved_load;
- if (rem_load_move < 0)
+ 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,
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 060e87b..3432d57 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -513,8 +513,6 @@ static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup)
*/
for_each_sched_rt_entity(rt_se)
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)
@@ -534,8 +532,6 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep)
if (rt_rq && rt_rq->rt_nr_running)
enqueue_rt_entity(rt_se);
}
-
- dec_cpu_load(rq, p->se.load.weight);
}

/*
diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h
index 5bae2e0..a38878e 100644
--- a/kernel/sched_stats.h
+++ b/kernel/sched_stats.h
@@ -67,6 +67,7 @@ static int show_schedstat(struct seq_file *seq, void *v)
preempt_enable();
#endif
}
+ kfree(mask_str);
return 0;
}