| Kernel v2.6.25-rc7 /kernel/sched.c |
|---|
  2.6.25-rc7
kernel
 sched.c
diff --git a/kernel/sched.c b/kernel/sched.c
index e76b11c..28c73f0 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -22,6 +22,8 @@
* by Peter Williams
* 2007-05-06 Interactivity improvements to CFS by Mike Galbraith
* 2007-07-01 Group scheduling enhancements by Srivatsa Vaddagiri
+ * 2007-11-29 RT balancing improvements by Steven Rostedt, Gregory Haskins,
+ * Thomas Gleixner, Mike Kravetz
*/
#include <linux/mm.h>
@@ -63,6 +65,7 @@
#include <linux/reciprocal_div.h>
#include <linux/unistd.h>
#include <linux/pagemap.h>
+#include <linux/hrtimer.h>
#include <asm/tlb.h>
#include <asm/irq_regs.h>
@@ -96,10 +99,9 @@ unsigned long long __attribute__((weak)) sched_clock(void)
#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO))
/*
- * Some helpers for converting nanosecond timing to jiffy resolution
+ * Helpers for converting nanosecond timing to jiffy resolution
*/
#define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
-#define JIFFIES_TO_NS(TIME) ((TIME) * (NSEC_PER_SEC / HZ))
#define NICE_0_LOAD SCHED_LOAD_SCALE
#define NICE_0_SHIFT SCHED_LOAD_SHIFT
@@ -153,27 +155,40 @@ struct rt_prio_array {
struct list_head queue[MAX_RT_PRIO];
};
-#ifdef CONFIG_FAIR_GROUP_SCHED
+#ifdef CONFIG_GROUP_SCHED
#include <linux/cgroup.h>
struct cfs_rq;
+static LIST_HEAD(task_groups);
+
/* task group related information */
struct task_group {
-#ifdef CONFIG_FAIR_CGROUP_SCHED
+#ifdef CONFIG_CGROUP_SCHED
struct cgroup_subsys_state css;
#endif
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
/* schedulable entities of this group on each cpu */
struct sched_entity **se;
/* runqueue "owned" by this group on each cpu */
struct cfs_rq **cfs_rq;
unsigned long shares;
- /* spinlock to serialize modification to shares */
- spinlock_t lock;
+#endif
+
+#ifdef CONFIG_RT_GROUP_SCHED
+ struct sched_rt_entity **rt_se;
+ struct rt_rq **rt_rq;
+
+ u64 rt_runtime;
+#endif
+
struct rcu_head rcu;
+ struct list_head list;
};
+#ifdef CONFIG_FAIR_GROUP_SCHED
/* Default task group's sched entity on each cpu */
static DEFINE_PER_CPU(struct sched_entity, init_sched_entity);
/* Default task group's cfs_rq on each cpu */
@@ -181,31 +196,57 @@ static DEFINE_PER_CPU(struct cfs_rq, init_cfs_rq) ____cacheline_aligned_in_smp;
static struct sched_entity *init_sched_entity_p[NR_CPUS];
static struct cfs_rq *init_cfs_rq_p[NR_CPUS];
+#endif
+
+#ifdef CONFIG_RT_GROUP_SCHED
+static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity);
+static DEFINE_PER_CPU(struct rt_rq, init_rt_rq) ____cacheline_aligned_in_smp;
+
+static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS];
+static struct rt_rq *init_rt_rq_p[NR_CPUS];
+#endif
+
+/* task_group_lock serializes add/remove of task groups and also changes to
+ * a task group's cpu shares.
+ */
+static DEFINE_SPINLOCK(task_group_lock);
+
+/* doms_cur_mutex serializes access to doms_cur[] array */
+static DEFINE_MUTEX(doms_cur_mutex);
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+#ifdef CONFIG_USER_SCHED
+# define INIT_TASK_GROUP_LOAD (2*NICE_0_LOAD)
+#else
+# define INIT_TASK_GROUP_LOAD NICE_0_LOAD
+#endif
+
+static int init_task_group_load = INIT_TASK_GROUP_LOAD;
+#endif
/* Default task group.
* Every task in system belong to this group at bootup.
*/
struct task_group init_task_group = {
- .se = init_sched_entity_p,
+#ifdef CONFIG_FAIR_GROUP_SCHED
+ .se = init_sched_entity_p,
.cfs_rq = init_cfs_rq_p,
-};
-
-#ifdef CONFIG_FAIR_USER_SCHED
-# define INIT_TASK_GRP_LOAD 2*NICE_0_LOAD
-#else
-# define INIT_TASK_GRP_LOAD NICE_0_LOAD
#endif
-static int init_task_group_load = INIT_TASK_GRP_LOAD;
+#ifdef CONFIG_RT_GROUP_SCHED
+ .rt_se = init_sched_rt_entity_p,
+ .rt_rq = init_rt_rq_p,
+#endif
+};
/* return group to which a task belongs */
static inline struct task_group *task_group(struct task_struct *p)
{
struct task_group *tg;
-#ifdef CONFIG_FAIR_USER_SCHED
+#ifdef CONFIG_USER_SCHED
tg = p->user->tg;
-#elif defined(CONFIG_FAIR_CGROUP_SCHED)
+#elif defined(CONFIG_CGROUP_SCHED)
tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id),
struct task_group, css);
#else
@@ -215,17 +256,36 @@ static inline struct task_group *task_group(struct task_struct *p)
}
/* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
-static inline void set_task_cfs_rq(struct task_struct *p, unsigned int cpu)
+static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
{
+#ifdef CONFIG_FAIR_GROUP_SCHED
p->se.cfs_rq = task_group(p)->cfs_rq[cpu];
p->se.parent = task_group(p)->se[cpu];
+#endif
+
+#ifdef CONFIG_RT_GROUP_SCHED
+ p->rt.rt_rq = task_group(p)->rt_rq[cpu];
+ p->rt.parent = task_group(p)->rt_se[cpu];
+#endif
+}
+
+static inline void lock_doms_cur(void)
+{
+ mutex_lock(&doms_cur_mutex);
+}
+
+static inline void unlock_doms_cur(void)
+{
+ mutex_unlock(&doms_cur_mutex);
}
#else
-static inline void set_task_cfs_rq(struct task_struct *p, unsigned int cpu) { }
+static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
+static inline void lock_doms_cur(void) { }
+static inline void unlock_doms_cur(void) { }
-#endif /* CONFIG_FAIR_GROUP_SCHED */
+#endif /* CONFIG_GROUP_SCHED */
/* CFS-related fields in a runqueue */
struct cfs_rq {
@@ -241,7 +301,7 @@ struct cfs_rq {
/* 'curr' points to currently running entity on this cfs_rq.
* It is set to NULL otherwise (i.e when none are currently running).
*/
- struct sched_entity *curr;
+ struct sched_entity *curr, *next;
unsigned long nr_spread_over;
@@ -264,11 +324,59 @@ struct cfs_rq {
/* Real-Time classes' related field in a runqueue: */
struct rt_rq {
struct rt_prio_array active;
- int rt_load_balance_idx;
- struct list_head *rt_load_balance_head, *rt_load_balance_curr;
+ unsigned long rt_nr_running;
+#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
+ int highest_prio; /* highest queued rt task prio */
+#endif
+#ifdef CONFIG_SMP
+ unsigned long rt_nr_migratory;
+ int overloaded;
+#endif
+ int rt_throttled;
+ u64 rt_time;
+
+#ifdef CONFIG_RT_GROUP_SCHED
+ unsigned long rt_nr_boosted;
+
+ struct rq *rq;
+ struct list_head leaf_rt_rq_list;
+ struct task_group *tg;
+ struct sched_rt_entity *rt_se;
+#endif
+};
+
+#ifdef CONFIG_SMP
+
+/*
+ * We add the notion of a root-domain which will be used to define per-domain
+ * variables. Each exclusive cpuset essentially defines an island domain by
+ * fully partitioning the member cpus from any other cpuset. Whenever a new
+ * exclusive cpuset is created, we also create and attach a new root-domain
+ * object.
+ *
+ */
+struct root_domain {
+ atomic_t refcount;
+ cpumask_t span;
+ cpumask_t online;
+
+ /*
+ * The "RT overload" flag: it gets set if a CPU has more than
+ * one runnable RT task.
+ */
+ cpumask_t rto_mask;
+ atomic_t rto_count;
};
/*
+ * By default the system creates a single root-domain with all cpus as
+ * members (mimicking the global state we have today).
+ */
+static struct root_domain def_root_domain;
+
+#endif
+
+/*
* This is the main, per-CPU runqueue data structure.
*
* Locking rule: those places that want to lock multiple runqueues
@@ -296,11 +404,17 @@ struct rq {
u64 nr_switches;
struct cfs_rq cfs;
+ struct rt_rq rt;
+ u64 rt_period_expire;
+ int rt_throttled;
+
#ifdef CONFIG_FAIR_GROUP_SCHED
/* list of leaf cfs_rq on this cpu: */
struct list_head leaf_cfs_rq_list;
#endif
- struct rt_rq rt;
+#ifdef CONFIG_RT_GROUP_SCHED
+ struct list_head leaf_rt_rq_list;
+#endif
/*
* This is part of a global counter where only the total sum
@@ -317,7 +431,7 @@ struct rq {
u64 clock, prev_clock_raw;
s64 clock_max_delta;
- unsigned int clock_warps, clock_overflows;
+ unsigned int clock_warps, clock_overflows, clock_underflows;
u64 idle_clock;
unsigned int clock_deep_idle_events;
u64 tick_timestamp;
@@ -325,6 +439,7 @@ struct rq {
atomic_t nr_iowait;
#ifdef CONFIG_SMP
+ struct root_domain *rd;
struct sched_domain *sd;
/* For active balancing */
@@ -337,6 +452,12 @@ struct rq {
struct list_head migration_queue;
#endif
+#ifdef CONFIG_SCHED_HRTICK
+ unsigned long hrtick_flags;
+ ktime_t hrtick_expire;
+ struct hrtimer hrtick_timer;
+#endif
+
#ifdef CONFIG_SCHEDSTATS
/* latency stats */
struct sched_info rq_sched_info;
@@ -363,7 +484,6 @@ struct rq {
};
static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
-static DEFINE_MUTEX(sched_hotcpu_mutex);
static inline void check_preempt_curr(struct rq *rq, struct task_struct *p)
{
@@ -441,6 +561,23 @@ static void update_rq_clock(struct rq *rq)
#define task_rq(p) cpu_rq(task_cpu(p))
#define cpu_curr(cpu) (cpu_rq(cpu)->curr)
+unsigned long rt_needs_cpu(int cpu)
+{
+ struct rq *rq = cpu_rq(cpu);
+ u64 delta;
+
+ if (!rq->rt_throttled)
+ return 0;
+
+ if (rq->clock > rq->rt_period_expire)
+ return 1;
+
+ delta = rq->rt_period_expire - rq->clock;
+ do_div(delta, NSEC_PER_SEC / HZ);
+
+ return (unsigned long)delta;
+}
+
/*
* Tunables that become constants when CONFIG_SCHED_DEBUG is off:
*/
@@ -457,16 +594,16 @@ enum {
SCHED_FEAT_NEW_FAIR_SLEEPERS = 1,
SCHED_FEAT_WAKEUP_PREEMPT = 2,
SCHED_FEAT_START_DEBIT = 4,
- SCHED_FEAT_TREE_AVG = 8,
- SCHED_FEAT_APPROX_AVG = 16,
+ SCHED_FEAT_HRTICK = 8,
+ SCHED_FEAT_DOUBLE_TICK = 16,
};
const_debug unsigned int sysctl_sched_features =
SCHED_FEAT_NEW_FAIR_SLEEPERS * 1 |
SCHED_FEAT_WAKEUP_PREEMPT * 1 |
SCHED_FEAT_START_DEBIT * 1 |
- SCHED_FEAT_TREE_AVG * 0 |
- SCHED_FEAT_APPROX_AVG * 0;
+ SCHED_FEAT_HRTICK * 1 |
+ SCHED_FEAT_DOUBLE_TICK * 0;
#define sched_feat(x) (sysctl_sched_features & SCHED_FEAT_##x)
@@ -477,6 +614,25 @@ const_debug unsigned int sysctl_sched_features =
const_debug unsigned int sysctl_sched_nr_migrate = 32;
/*
+ * period over which we measure -rt task cpu usage in us.
+ * default: 1s
+ */
+unsigned int sysctl_sched_rt_period = 1000000;
+
+static __read_mostly int scheduler_running;
+
+/*
+ * part of the period that we allow rt tasks to run in us.
+ * default: 0.95s
+ */
+int sysctl_sched_rt_runtime = 950000;
+
+/*
+ * single value that denotes runtime == period, ie unlimited time.
+ */
+#define RUNTIME_INF ((u64)~0ULL)
+
+/*
* For kernel-internal use: high-speed (but slightly incorrect) per-cpu
* clock constructed from sched_clock():
*/
@@ -486,14 +642,16 @@ unsigned long long cpu_clock(int cpu)
unsigned long flags;
struct rq *rq;
- local_irq_save(flags);
- rq = cpu_rq(cpu);
/*
* Only call sched_clock() if the scheduler has already been
* initialized (some code might call cpu_clock() very early):
*/
- if (rq->idle)
- update_rq_clock(rq);
+ if (unlikely(!scheduler_running))
+ return 0;
+
+ local_irq_save(flags);
+ rq = cpu_rq(cpu);
+ update_rq_clock(rq);
now = rq->clock;
local_irq_restore(flags);
@@ -668,7 +826,6 @@ void sched_clock_idle_wakeup_event(u64 delta_ns)
struct rq *rq = cpu_rq(smp_processor_id());
u64 now = sched_clock();
- touch_softlockup_watchdog();
rq->idle_clock += delta_ns;
/*
* Override the previous timestamp and ignore all
@@ -680,9 +837,177 @@ void sched_clock_idle_wakeup_event(u64 delta_ns)
rq->prev_clock_raw = now;
rq->clock += delta_ns;
spin_unlock(&rq->lock);
+ touch_softlockup_watchdog();
}
EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event);
+static void __resched_task(struct task_struct *p, int tif_bit);
+
+static inline void resched_task(struct task_struct *p)
+{
+ __resched_task(p, TIF_NEED_RESCHED);
+}
+
+#ifdef CONFIG_SCHED_HRTICK
+/*
+ * Use HR-timers to deliver accurate preemption points.
+ *
+ * Its all a bit involved since we cannot program an hrt while holding the
+ * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a
+ * reschedule event.
+ *
+ * When we get rescheduled we reprogram the hrtick_timer outside of the
+ * rq->lock.
+ */
+static inline void resched_hrt(struct task_struct *p)
+{
+ __resched_task(p, TIF_HRTICK_RESCHED);
+}
+
+static inline void resched_rq(struct rq *rq)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&rq->lock, flags);
+ resched_task(rq->curr);
+ spin_unlock_irqrestore(&rq->lock, flags);
+}
+
+enum {
+ HRTICK_SET, /* re-programm hrtick_timer */
+ HRTICK_RESET, /* not a new slice */
+};
+
+/*
+ * Use hrtick when:
+ * - enabled by features
+ * - hrtimer is actually high res
+ */
+static inline int hrtick_enabled(struct rq *rq)
+{
+ if (!sched_feat(HRTICK))
+ return 0;
+ return hrtimer_is_hres_active(&rq->hrtick_timer);
+}
+
+/*
+ * Called to set the hrtick timer state.
+ *
+ * called with rq->lock held and irqs disabled
+ */
+static void hrtick_start(struct rq *rq, u64 delay, int reset)
+{
+ assert_spin_locked(&rq->lock);
+
+ /*
+ * preempt at: now + delay
+ */
+ rq->hrtick_expire =
+ ktime_add_ns(rq->hrtick_timer.base->get_time(), delay);
+ /*
+ * indicate we need to program the timer
+ */
+ __set_bit(HRTICK_SET, &rq->hrtick_flags);
+ if (reset)
+ __set_bit(HRTICK_RESET, &rq->hrtick_flags);
+
+ /*
+ * New slices are called from the schedule path and don't need a
+ * forced reschedule.
+ */
+ if (reset)
+ resched_hrt(rq->curr);
+}
+
+static void hrtick_clear(struct rq *rq)
+{
+ if (hrtimer_active(&rq->hrtick_timer))
+ hrtimer_cancel(&rq->hrtick_timer);
+}
+
+/*
+ * Update the timer from the possible pending state.
+ */
+static void hrtick_set(struct rq *rq)
+{
+ ktime_t time;
+ int set, reset;
+ unsigned long flags;
+
+ WARN_ON_ONCE(cpu_of(rq) != smp_processor_id());
+
+ spin_lock_irqsave(&rq->lock, flags);
+ set = __test_and_clear_bit(HRTICK_SET, &rq->hrtick_flags);
+ reset = __test_and_clear_bit(HRTICK_RESET, &rq->hrtick_flags);
+ time = rq->hrtick_expire;
+ clear_thread_flag(TIF_HRTICK_RESCHED);
+ spin_unlock_irqrestore(&rq->lock, flags);
+
+ if (set) {
+ hrtimer_start(&rq->hrtick_timer, time, HRTIMER_MODE_ABS);
+ if (reset && !hrtimer_active(&rq->hrtick_timer))
+ resched_rq(rq);
+ } else
+ hrtick_clear(rq);
+}
+
+/*
+ * High-resolution timer tick.
+ * Runs from hardirq context with interrupts disabled.
+ */
+static enum hrtimer_restart hrtick(struct hrtimer *timer)
+{
+ struct rq *rq = container_of(timer, struct rq, hrtick_timer);
+
+ WARN_ON_ONCE(cpu_of(rq) != smp_processor_id());
+
+ spin_lock(&rq->lock);
+ __update_rq_clock(rq);
+ rq->curr->sched_class->task_tick(rq, rq->curr, 1);
+ spin_unlock(&rq->lock);
+
+ return HRTIMER_NORESTART;
+}
+
+static inline void init_rq_hrtick(struct rq *rq)
+{
+ rq->hrtick_flags = 0;
+ hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ rq->hrtick_timer.function = hrtick;
+ rq->hrtick_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;
+}
+
+void hrtick_resched(void)
+{
+ struct rq *rq;
+ unsigned long flags;
+
+ if (!test_thread_flag(TIF_HRTICK_RESCHED))
+ return;
+
+ local_irq_save(flags);
+ rq = cpu_rq(smp_processor_id());
+ hrtick_set(rq);
+ local_irq_restore(flags);
+}
+#else
+static inline void hrtick_clear(struct rq *rq)
+{
+}
+
+static inline void hrtick_set(struct rq *rq)
+{
+}
+
+static inline void init_rq_hrtick(struct rq *rq)
+{
+}
+
+void hrtick_resched(void)
+{
+}
+#endif
+
/*
* resched_task - mark a task 'to be rescheduled now'.
*
@@ -696,16 +1021,16 @@ EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event);
#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
#endif
-static void resched_task(struct task_struct *p)
+static void __resched_task(struct task_struct *p, int tif_bit)
{
int cpu;
assert_spin_locked(&task_rq(p)->lock);
- if (unlikely(test_tsk_thread_flag(p, TIF_NEED_RESCHED)))
+ if (unlikely(test_tsk_thread_flag(p, tif_bit)))
return;
- set_tsk_thread_flag(p, TIF_NEED_RESCHED);
+ set_tsk_thread_flag(p, tif_bit);
cpu = task_cpu(p);
if (cpu == smp_processor_id())
@@ -728,10 +1053,10 @@ static void resched_cpu(int cpu)
spin_unlock_irqrestore(&rq->lock, flags);
}
#else
-static inline void resched_task(struct task_struct *p)
+static void __resched_task(struct task_struct *p, int tif_bit)
{
assert_spin_locked(&task_rq(p)->lock);
- set_tsk_need_resched(p);
+ set_tsk_thread_flag(p, tif_bit);
}
#endif
@@ -755,7 +1080,7 @@ calc_delta_mine(unsigned long delta_exec, unsigned long weight,
u64 tmp;
if (unlikely(!lw->inv_weight))
- lw->inv_weight = (WMULT_CONST - lw->weight/2) / lw->weight + 1;
+ lw->inv_weight = (WMULT_CONST-lw->weight/2) / (lw->weight+1);
tmp = (u64)delta_exec * weight;
/*
@@ -779,11 +1104,13 @@ calc_delta_fair(unsigned long delta_exec, struct load_weight *lw)
static inline void update_load_add(struct load_weight *lw, unsigned long inc)
{
lw->weight += inc;
+ lw->inv_weight = 0;
}
static inline void update_load_sub(struct load_weight *lw, unsigned long dec)
{
lw->weight -= dec;
+ lw->inv_weight = 0;
}
/*
@@ -871,6 +1198,13 @@ static void cpuacct_charge(struct task_struct *tsk, u64 cputime);
static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}
#endif
+#ifdef CONFIG_SMP
+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);
+#endif /* CONFIG_SMP */
+
#include "sched_stats.h"
#include "sched_idletask.c"
#include "sched_fair.c"
@@ -881,21 +1215,6 @@ static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}
#define sched_class_highest (&rt_sched_class)
-/*
- * Update delta_exec, delta_fair fields for rq.
- *
- * delta_fair clock advances at a rate inversely proportional to
- * total load (rq->load.weight) on the runqueue, while
- * delta_exec advances at the same rate as wall-clock (provided
- * cpu is not idle).
- *
- * delta_exec / delta_fair is a measure of the (smoothened) load on this
- * runqueue over any given interval. This (smoothened) load is used
- * during load balance.
- *
- * This function is called /before/ updating rq->load
- * and when switching tasks.
- */
static inline void inc_load(struct rq *rq, const struct task_struct *p)
{
update_load_add(&rq->load, p->se.load.weight);
@@ -1003,7 +1322,7 @@ static int effective_prio(struct task_struct *p)
*/
static void activate_task(struct rq *rq, struct task_struct *p, int wakeup)
{
- if (p->state == TASK_UNINTERRUPTIBLE)
+ if (task_contributes_to_load(p))
rq->nr_uninterruptible--;
enqueue_task(rq, p, wakeup);
@@ -1015,7 +1334,7 @@ static void activate_task(struct rq *rq, struct task_struct *p, int wakeup)
*/
static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep)
{
- if (p->state == TASK_UNINTERRUPTIBLE)
+ if (task_contributes_to_load(p))
rq->nr_uninterruptible++;
dequeue_task(rq, p, sleep);
@@ -1039,7 +1358,7 @@ unsigned long weighted_cpuload(const int cpu)
static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
{
- set_task_cfs_rq(p, cpu);
+ set_task_rq(p, cpu);
#ifdef CONFIG_SMP
/*
* After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
@@ -1051,16 +1370,34 @@ static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
#endif
}
+static inline void check_class_changed(struct rq *rq, struct task_struct *p,
+ const struct sched_class *prev_class,
+ int oldprio, int running)
+{
+ if (prev_class != p->sched_class) {
+ if (prev_class->switched_from)
+ prev_class->switched_from(rq, p, running);
+ p->sched_class->switched_to(rq, p, running);
+ } else
+ p->sched_class->prio_changed(rq, p, oldprio, running);
+}
+
#ifdef CONFIG_SMP
/*
* Is this task likely cache-hot:
*/
-static inline int
+static int
task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
{
s64 delta;
+ /*
+ * Buddy candidates are cache hot:
+ */
+ if (&p->se == cfs_rq_of(&p->se)->next)
+ return 1;
+
if (p->sched_class != &fair_sched_class)
return 0;
@@ -1281,7 +1618,7 @@ static unsigned long target_load(int cpu, int type)
/*
* Return the average load per task on the cpu's run queue
*/
-static inline unsigned long cpu_avg_load_per_task(int cpu)
+static unsigned long cpu_avg_load_per_task(int cpu)
{
struct rq *rq = cpu_rq(cpu);
unsigned long total = weighted_cpuload(cpu);
@@ -1438,58 +1775,6 @@ static int sched_balance_self(int cpu, int flag)
#endif /* CONFIG_SMP */
-/*
- * wake_idle() will wake a task on an idle cpu if task->cpu is
- * not idle and an idle cpu is available. The span of cpus to
- * search starts with cpus closest then further out as needed,
- * so we always favor a closer, idle cpu.
- *
- * Returns the CPU we should wake onto.
- */
-#if defined(ARCH_HAS_SCHED_WAKE_IDLE)
-static int wake_idle(int cpu, struct task_struct *p)
-{
- cpumask_t tmp;
- struct sched_domain *sd;
- int i;
-
- /*
- * If it is idle, then it is the best cpu to run this task.
- *
- * This cpu is also the best, if it has more than one task already.
- * Siblings must be also busy(in most cases) as they didn't already
- * pickup the extra load from this cpu and hence we need not check
- * sibling runqueue info. This will avoid the checks and cache miss
- * penalities associated with that.
- */
- if (idle_cpu(cpu) || cpu_rq(cpu)->nr_running > 1)
- return cpu;
-
- for_each_domain(cpu, sd) {
- if (sd->flags & SD_WAKE_IDLE) {
- cpus_and(tmp, sd->span, p->cpus_allowed);
- for_each_cpu_mask(i, tmp) {
- if (idle_cpu(i)) {
- if (i != task_cpu(p)) {
- schedstat_inc(p,
- se.nr_wakeups_idle);
- }
- return i;
- }
- }
- } else {
- break;
- }
- }
- return cpu;
-}
-#else
-static inline int wake_idle(int cpu, struct task_struct *p)
-{
- return cpu;
-}
-#endif
-
/***
* try_to_wake_up - wake up a thread
* @p: the to-be-woken-up thread
@@ -1510,12 +1795,8 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
unsigned long flags;
long old_state;
struct rq *rq;
-#ifdef CONFIG_SMP
- struct sched_domain *sd, *this_sd = NULL;
- unsigned long load, this_load;
- int new_cpu;
-#endif
+ smp_wmb();
rq = task_rq_lock(p, &flags);
old_state = p->state;
if (!(old_state & state))
@@ -1532,92 +1813,9 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
if (unlikely(task_running(rq, p)))
goto out_activate;
- new_cpu = cpu;
-
- schedstat_inc(rq, ttwu_count);
- if (cpu == this_cpu) {
- schedstat_inc(rq, ttwu_local);
- goto out_set_cpu;
- }
-
- for_each_domain(this_cpu, sd) {
- if (cpu_isset(cpu, sd->span)) {
- schedstat_inc(sd, ttwu_wake_remote);
- this_sd = sd;
- break;
- }
- }
-
- if (unlikely(!cpu_isset(this_cpu, p->cpus_allowed)))
- goto out_set_cpu;
-
- /*
- * Check for affine wakeup and passive balancing possibilities.
- */
- if (this_sd) {
- int idx = this_sd->wake_idx;
- unsigned int imbalance;
-
- imbalance = 100 + (this_sd->imbalance_pct - 100) / 2;
-
- load = source_load(cpu, idx);
- this_load = target_load(this_cpu, idx);
-
- new_cpu = this_cpu; /* Wake to this CPU if we can */
-
- if (this_sd->flags & SD_WAKE_AFFINE) {
- unsigned long tl = this_load;
- unsigned long tl_per_task;
-
- /*
- * Attract cache-cold tasks on sync wakeups:
- */
- if (sync && !task_hot(p, rq->clock, this_sd))
- goto out_set_cpu;
-
- 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(cpu, idx) <= tl_per_task) ||
- 100*(tl + p->se.load.weight) <= imbalance*load) {
- /*
- * This domain has SD_WAKE_AFFINE and
- * p is cache cold in this domain, and
- * there is no bad imbalance.
- */
- schedstat_inc(this_sd, ttwu_move_affine);
- schedstat_inc(p, se.nr_wakeups_affine);
- goto out_set_cpu;
- }
- }
-
- /*
- * Start passive balancing when half the imbalance_pct
- * limit is reached.
- */
- if (this_sd->flags & SD_WAKE_BALANCE) {
- if (imbalance*this_load <= 100*load) {
- schedstat_inc(this_sd, ttwu_move_balance);
- schedstat_inc(p, se.nr_wakeups_passive);
- goto out_set_cpu;
- }
- }
- }
-
- new_cpu = cpu; /* Could not wake to this_cpu. Wake to cpu instead */
-out_set_cpu:
- new_cpu = wake_idle(new_cpu, p);
- if (new_cpu != cpu) {
- set_task_cpu(p, new_cpu);
+ cpu = p->sched_class->select_task_rq(p, sync);
+ if (cpu != orig_cpu) {
+ set_task_cpu(p, cpu);
task_rq_unlock(rq, &flags);
/* might preempt at this point */
rq = task_rq_lock(p, &flags);
@@ -1631,6 +1829,21 @@ out_set_cpu:
cpu = task_cpu(p);
}
+#ifdef CONFIG_SCHEDSTATS
+ schedstat_inc(rq, ttwu_count);
+ if (cpu == this_cpu)
+ schedstat_inc(rq, ttwu_local);
+ else {
+ struct sched_domain *sd;
+ for_each_domain(this_cpu, sd) {
+ if (cpu_isset(cpu, sd->span)) {
+ schedstat_inc(sd, ttwu_wake_remote);
+ break;
+ }
+ }
+ }
+#endif
+
out_activate:
#endif /* CONFIG_SMP */
schedstat_inc(p, se.nr_wakeups);
@@ -1644,25 +1857,29 @@ out_activate:
schedstat_inc(p, se.nr_wakeups_remote);
update_rq_clock(rq);
activate_task(rq, p, 1);
- check_preempt_curr(rq, p);
success = 1;
out_running:
+ check_preempt_curr(rq, p);
+
p->state = TASK_RUNNING;
+#ifdef CONFIG_SMP
+ if (p->sched_class->task_wake_up)
+ p->sched_class->task_wake_up(rq, p);
+#endif
out:
task_rq_unlock(rq, &flags);
return success;
}
-int fastcall wake_up_process(struct task_struct *p)
+int wake_up_process(struct task_struct *p)
{
- return try_to_wake_up(p, TASK_STOPPED | TASK_TRACED |
- TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE, 0);
+ return try_to_wake_up(p, TASK_ALL, 0);
}
EXPORT_SYMBOL(wake_up_process);
-int fastcall wake_up_state(struct task_struct *p, unsigned int state)
+int wake_up_state(struct task_struct *p, unsigned int state)
{
return try_to_wake_up(p, state, 0);
}
@@ -1678,6 +1895,8 @@ static void __sched_fork(struct task_struct *p)
p->se.exec_start = 0;
p->se.sum_exec_runtime = 0;
p->se.prev_sum_exec_runtime = 0;
+ p->se.last_wakeup = 0;
+ p->se.avg_overlap = 0;
#ifdef CONFIG_SCHEDSTATS
p->se.wait_start = 0;
@@ -1691,7 +1910,7 @@ static void __sched_fork(struct task_struct *p)
p->se.wait_max = 0;
#endif
- INIT_LIST_HEAD(&p->run_list);
+ INIT_LIST_HEAD(&p->rt.run_list);
p->se.on_rq = 0;
#ifdef CONFIG_PREEMPT_NOTIFIERS
@@ -1749,7 +1968,7 @@ void sched_fork(struct task_struct *p, int clone_flags)
* that must be done for every newly created context, then puts the task
* on the runqueue and wakes it.
*/
-void fastcall wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
+void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
{
unsigned long flags;
struct rq *rq;
@@ -1771,6 +1990,10 @@ void fastcall wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
inc_nr_running(p, rq);
}
check_preempt_curr(rq, p);
+#ifdef CONFIG_SMP
+ if (p->sched_class->task_wake_up)
+ p->sched_class->task_wake_up(rq, p);
+#endif
task_rq_unlock(rq, &flags);
}
@@ -1891,6 +2114,11 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
prev_state = prev->state;
finish_arch_switch(prev);
finish_lock_switch(rq, prev);
+#ifdef CONFIG_SMP
+ if (current->sched_class->post_schedule)
+ current->sched_class->post_schedule(rq);
+#endif
+
fire_sched_in_preempt_notifiers(current);
if (mm)
mmdrop(mm);
@@ -2124,11 +2352,13 @@ static void double_rq_unlock(struct rq *rq1, struct rq *rq2)
/*
* double_lock_balance - lock the busiest runqueue, this_rq is locked already.
*/
-static void double_lock_balance(struct rq *this_rq, struct rq *busiest)
+static int double_lock_balance(struct rq *this_rq, struct rq *busiest)
__releases(this_rq->lock)
__acquires(busiest->lock)
__acquires(this_rq->lock)
{
+ int ret = 0;
+
if (unlikely(!irqs_disabled())) {
/* printk() doesn't work good under rq->lock */
spin_unlock(&this_rq->lock);
@@ -2139,9 +2369,11 @@ static void double_lock_balance(struct rq *this_rq, struct rq *busiest)
spin_unlock(&this_rq->lock);
spin_lock(&busiest->lock);
spin_lock(&this_rq->lock);
+ ret = 1;
} else
spin_lock(&busiest->lock);
}
+ return ret;
}
/*
@@ -3485,12 +3717,14 @@ void scheduler_tick(void)
/*
* Let rq->clock advance by at least TICK_NSEC:
*/
- if (unlikely(rq->clock < next_tick))
+ if (unlikely(rq->clock < next_tick)) {
rq->clock = next_tick;
+ rq->clock_underflows++;
+ }
rq->tick_timestamp = rq->clock;
update_cpu_load(rq);
- if (curr != rq->idle) /* FIXME: needed? */
- curr->sched_class->task_tick(rq, curr);
+ curr->sched_class->task_tick(rq, curr, 0);
+ update_sched_rt_period(rq);
spin_unlock(&rq->lock);
#ifdef CONFIG_SMP
@@ -3501,7 +3735,7 @@ void scheduler_tick(void)
#if defined(CONFIG_PREEMPT) && defined(CONFIG_DEBUG_PREEMPT)
-void fastcall add_preempt_count(int val)
+void __kprobes add_preempt_count(int val)
{
/*
* Underflow?
@@ -3517,7 +3751,7 @@ void fastcall add_preempt_count(int val)
}
EXPORT_SYMBOL(add_preempt_count);
-void fastcall sub_preempt_count(int val)
+void __kprobes sub_preempt_count(int val)
{
/*
* Underflow?
@@ -3619,7 +3853,7 @@ pick_next_task(struct rq *rq, struct task_struct *prev)
asmlinkage void __sched schedule(void)
{
struct task_struct *prev, *next;
- long *switch_count;
+ unsigned long *switch_count;
struct rq *rq;
int cpu;
@@ -3636,6 +3870,8 @@ need_resched_nonpreemptible:
schedule_debug(prev);
+ hrtick_clear(rq);
+
/*
* Do the rq-clock update outside the rq lock:
*/
@@ -3646,7 +3882,7 @@ need_resched_nonpreemptible:
if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
if (unlikely((prev->state & TASK_INTERRUPTIBLE) &&
- unlikely(signal_pending(prev)))) {
+ signal_pending(prev))) {
prev->state = TASK_RUNNING;
} else {
deactivate_task(rq, prev, 1);
@@ -3654,6 +3890,11 @@ need_resched_nonpreemptible:
switch_count = &prev->nvcsw;
}
+#ifdef CONFIG_SMP
+ if (prev->sched_class->pre_schedule)
+ prev->sched_class->pre_schedule(rq, prev);
+#endif
+
if (unlikely(!rq->nr_running))
idle_balance(cpu, rq);
@@ -3668,14 +3909,20 @@ need_resched_nonpreemptible:
++*switch_count;
context_switch(rq, prev, next); /* unlocks the rq */
+ /*
+ * the context switch might have flipped the stack from under
+ * us, hence refresh the local variables.
+ */
+ cpu = smp_processor_id();
+ rq = cpu_rq(cpu);
} else
spin_unlock_irq(&rq->lock);
- if (unlikely(reacquire_kernel_lock(current) < 0)) {
- cpu = smp_processor_id();
- rq = cpu_rq(cpu);
+ hrtick_set(rq);
+
+ if (unlikely(reacquire_kernel_lock(current) < 0))
goto need_resched_nonpreemptible;
- }
+
preempt_enable_no_resched();
if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
goto need_resched;
@@ -3691,10 +3938,9 @@ EXPORT_SYMBOL(schedule);
asmlinkage void __sched preempt_schedule(void)
{
struct thread_info *ti = current_thread_info();
-#ifdef CONFIG_PREEMPT_BKL
struct task_struct *task = current;
int saved_lock_depth;
-#endif
+
/*
* If there is a non-zero preempt_count or interrupts are disabled,
* we do not want to preempt the current task. Just return..
@@ -3710,14 +3956,10 @@ asmlinkage void __sched preempt_schedule(void)
* clear ->lock_depth so that schedule() doesnt
* auto-release the semaphore:
*/
-#ifdef CONFIG_PREEMPT_BKL
saved_lock_depth = task->lock_depth;
task->lock_depth = -1;
-#endif
schedule();
-#ifdef CONFIG_PREEMPT_BKL
task->lock_depth = saved_lock_depth;
-#endif
sub_preempt_count(PREEMPT_ACTIVE);
/*
@@ -3738,10 +3980,9 @@ EXPORT_SYMBOL(preempt_schedule);
asmlinkage void __sched preempt_schedule_irq(void)
{
struct thread_info *ti = current_thread_info();
-#ifdef CONFIG_PREEMPT_BKL
struct task_struct *task = current;
int saved_lock_depth;
-#endif
+
/* Catch callers which need to be fixed */
BUG_ON(ti->preempt_count || !irqs_disabled());
@@ -3753,16 +3994,12 @@ asmlinkage void __sched preempt_schedule_irq(void)
* clear ->lock_depth so that schedule() doesnt
* auto-release the semaphore:
*/
-#ifdef CONFIG_PREEMPT_BKL
saved_lock_depth = task->lock_depth;
task->lock_depth = -1;
-#endif
local_irq_enable();
schedule();
local_irq_disable();
-#ifdef CONFIG_PREEMPT_BKL
task->lock_depth = saved_lock_depth;
-#endif
sub_preempt_count(PREEMPT_ACTIVE);
/*
@@ -3812,7 +4049,7 @@ static void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
* @nr_exclusive: how many wake-one or wake-many threads to wake up
* @key: is directly passed to the wakeup function
*/
-void fastcall __wake_up(wait_queue_head_t *q, unsigned int mode,
+void __wake_up(wait_queue_head_t *q, unsigned int mode,
int nr_exclusive, void *key)
{
unsigned long flags;
@@ -3826,7 +4063,7 @@ EXPORT_SYMBOL(__wake_up);
/*
* Same as __wake_up but called with the spinlock in wait_queue_head_t held.
*/
-void fastcall __wake_up_locked(wait_queue_head_t *q, unsigned int mode)
+void __wake_up_locked(wait_queue_head_t *q, unsigned int mode)
{
__wake_up_common(q, mode, 1, 0, NULL);
}
@@ -3844,7 +4081,7 @@ void fastcall __wake_up_locked(wait_queue_head_t *q, unsigned int mode)
*
* On UP it can prevent extra preemption.
*/
-void fastcall
+void
__wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
{
unsigned long flags;
@@ -3868,8 +4105,7 @@ void complete(struct completion *x)
spin_lock_irqsave(&x->wait.lock, flags);
x->done++;
- __wake_up_common(&x->wait, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
- 1, 0, NULL);
+ __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL);
spin_unlock_irqrestore(&x->wait.lock, flags);
}
EXPORT_SYMBOL(complete);
@@ -3880,8 +4116,7 @@ void complete_all(struct completion *x)
spin_lock_irqsave(&x->wait.lock, flags);
x->done += UINT_MAX/2;
- __wake_up_common(&x->wait, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
- 0, 0, NULL);
+ __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL);
spin_unlock_irqrestore(&x->wait.lock, flags);
}
EXPORT_SYMBOL(complete_all);
@@ -3895,8 +4130,10 @@ do_wait_for_common(struct completion *x, long timeout, int state)
wait.flags |= WQ_FLAG_EXCLUSIVE;
__add_wait_queue_tail(&x->wait, &wait);
do {
- if (state == TASK_INTERRUPTIBLE &&
- signal_pending(current)) {
+ if ((state == TASK_INTERRUPTIBLE &&
+ signal_pending(current)) ||
+ (state == TASK_KILLABLE &&
+ fatal_signal_pending(current))) {
__remove_wait_queue(&x->wait, &wait);
return -ERESTARTSYS;
}
@@ -3956,6 +4193,15 @@ wait_for_completion_interruptible_timeout(struct completion *x,
}
EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
+int __sched wait_for_completion_killable(struct completion *x)
+{
+ long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE);
+ if (t == -ERESTARTSYS)
+ return t;
+ return 0;
+}
+EXPORT_SYMBOL(wait_for_completion_killable);
+
static long __sched
sleep_on_common(wait_queue_head_t *q, int state, long timeout)
{
@@ -4019,6 +4265,7 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
unsigned long flags;
int oldprio, on_rq, running;
struct rq *rq;
+ const struct sched_class *prev_class = p->sched_class;
BUG_ON(prio < 0 || prio > MAX_PRIO);
@@ -4028,11 +4275,10 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
oldprio = p->prio;
on_rq = p->se.on_rq;
running = task_current(rq, p);
- if (on_rq) {
+ if (on_rq)
dequeue_task(rq, p, 0);
- if (running)
- p->sched_class->put_prev_task(rq, p);
- }
+ if (running)
+ p->sched_class->put_prev_task(rq, p);
if (rt_prio(prio))
p->sched_class = &rt_sched_class;
@@ -4041,21 +4287,12 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
p->prio = prio;
+ if (running)
+ p->sched_class->set_curr_task(rq);
if (on_rq) {
- if (running)
- p->sched_class->set_curr_task(rq);
enqueue_task(rq, p, 0);
- /*
- * Reschedule if we are currently running on this runqueue and
- * our priority decreased, or if we are not currently running on
- * this runqueue and our priority is higher than the current's
- */
- if (running) {
- if (p->prio > oldprio)
- resched_task(rq->curr);
- } else {
- check_preempt_curr(rq, p);
- }
+
+ check_class_changed(rq, p, prev_class, oldprio, running);
}
task_rq_unlock(rq, &flags);
}
@@ -4190,7 +4427,7 @@ int task_nice(const struct task_struct *p)
{
return TASK_NICE(p);
}
-EXPORT_SYMBOL_GPL(task_nice);
+EXPORT_SYMBOL(task_nice);
/**
* idle_cpu - is a given cpu idle currently?
@@ -4258,6 +4495,7 @@ int sched_setscheduler(struct task_struct *p, int policy,
{
int retval, oldprio, oldpolicy = -1, on_rq, running;
unsigned long flags;
+ const struct sched_class *prev_class = p->sched_class;
struct rq *rq;
/* may grab non-irq protected spin_locks */
@@ -4316,6 +4554,15 @@ recheck:
return -EPERM;
}
+#ifdef CONFIG_RT_GROUP_SCHED
+ /*
+ * Do not allow realtime tasks into groups that have no runtime
+ * assigned.
+ */
+ if (rt_policy(policy) && task_group(p)->rt_runtime == 0)
+ return -EPERM;
+#endif
+
retval = security_task_setscheduler(p, policy, param);
if (retval)
return retval;
@@ -4339,30 +4586,20 @@ recheck:
update_rq_clock(rq);
on_rq = p->se.on_rq;
running = task_current(rq, p);
- if (on_rq) {
+ if (on_rq)
deactivate_task(rq, p, 0);
- if (running)
- p->sched_class->put_prev_task(rq, p);
- }
+ if (running)
+ p->sched_class->put_prev_task(rq, p);
oldprio = p->prio;
__setscheduler(rq, p, policy, param->sched_priority);
+ if (running)
+ p->sched_class->set_curr_task(rq);
if (on_rq) {
- if (running)
- p->sched_class->set_curr_task(rq);
activate_task(rq, p, 0);
- /*
- * Reschedule if we are currently running on this runqueue and
- * our priority decreased, or if we are not currently running on
- * this runqueue and our priority is higher than the current's
- */
- if (running) {
- if (p->prio > oldprio)
- resched_task(rq->curr);
- } else {
- check_preempt_curr(rq, p);
- }
+
+ check_class_changed(rq, p, prev_class, oldprio, running);
}
__task_rq_unlock(rq);
spin_unlock_irqrestore(&p->pi_lock, flags);
@@ -4490,13 +4727,13 @@ long sched_setaffinity(pid_t pid, cpumask_t new_mask)
struct task_struct *p;
int retval;
- mutex_lock(&sched_hotcpu_mutex);
+ get_online_cpus();
read_lock(&tasklist_lock);
p = find_process_by_pid(pid);
if (!p) {
read_unlock(&tasklist_lock);
- mutex_unlock(&sched_hotcpu_mutex);
+ put_online_cpus();
return -ESRCH;
}
@@ -4536,7 +4773,7 @@ long sched_setaffinity(pid_t pid, cpumask_t new_mask)
}
out_unlock:
put_task_struct(p);
- mutex_unlock(&sched_hotcpu_mutex);
+ put_online_cpus();
return retval;
}
@@ -4593,7 +4830,7 @@ long sched_getaffinity(pid_t pid, cpumask_t *mask)
struct task_struct *p;
int retval;
- mutex_lock(&sched_hotcpu_mutex);
+ get_online_cpus();
read_lock(&tasklist_lock);
retval = -ESRCH;
@@ -4609,7 +4846,7 @@ long sched_getaffinity(pid_t pid, cpumask_t *mask)
out_unlock:
read_unlock(&tasklist_lock);
- mutex_unlock(&sched_hotcpu_mutex);
+ put_online_cpus();
return retval;
}
@@ -4683,7 +4920,8 @@ static void __cond_resched(void)
} while (need_resched());
}
-int __sched cond_resched(void)
+#if !defined(CONFIG_PREEMPT) || defined(CONFIG_PREEMPT_VOLUNTARY)
+int __sched _cond_resched(void)
{
if (need_resched() && !(preempt_count() & PREEMPT_ACTIVE) &&
system_state == SYSTEM_RUNNING) {
@@ -4692,7 +4930,8 @@ int __sched cond_resched(void)
}
return 0;
}
-EXPORT_SYMBOL(cond_resched);
+EXPORT_SYMBOL(_cond_resched);
+#endif
/*
* cond_resched_lock() - if a reschedule is pending, drop the given lock,
@@ -4704,19 +4943,15 @@ EXPORT_SYMBOL(cond_resched);
*/
int cond_resched_lock(spinlock_t *lock)
{
+ int resched = need_resched() && system_state == SYSTEM_RUNNING;
int ret = 0;
- if (need_lockbreak(lock)) {
+ if (spin_needbreak(lock) || resched) {
spin_unlock(lock);
- cpu_relax();
- ret = 1;
- spin_lock(lock);
- }
- if (need_resched() && system_state == SYSTEM_RUNNING) {
- spin_release(&lock->dep_map, 1, _THIS_IP_);
- _raw_spin_unlock(lock);
- preempt_enable_no_resched();
- __cond_resched();
+ if (resched && need_resched())
+ __cond_resched();
+ else
+ cpu_relax();
ret = 1;
spin_lock(lock);
}
@@ -4868,7 +5103,7 @@ long sys_sched_rr_get_interval(pid_t pid, struct timespec __user *interval)
time_slice = 0;
if (p->policy == SCHED_RR) {
time_slice = DEF_TIMESLICE;
- } else {
+ } else if (p->policy != SCHED_FIFO) {
struct sched_entity *se = &p->se;
unsigned long flags;
struct rq *rq;
@@ -4890,7 +5125,7 @@ out_unlock:
static const char stat_nam[] = "RSDTtZX";
-static void show_task(struct task_struct *p)
+void sched_show_task(struct task_struct *p)
{
unsigned long free = 0;
unsigned state;
@@ -4920,8 +5155,7 @@ static void show_task(struct task_struct *p)
printk(KERN_CONT "%5lu %5d %6d\n", free,
task_pid_nr(p), task_pid_nr(p->real_parent));
- if (state != TASK_RUNNING)
- show_stack(p, NULL);
+ show_stack(p, NULL);
}
void show_state_filter(unsigned long state_filter)
@@ -4943,7 +5177,7 @@ void show_state_filter(unsigned long state_filter)
*/
touch_nmi_watchdog();
if (!state_filter || (p->state & state_filter))
- show_task(p);
+ sched_show_task(p);
} while_each_thread(g, p);
touch_all_softlockup_watchdogs();
@@ -4992,11 +5226,8 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
spin_unlock_irqrestore(&rq->lock, flags);
/* Set the preempt count _outside_ the spinlocks! */
-#if defined(CONFIG_PREEMPT) && !defined(CONFIG_PREEMPT_BKL)
- task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0);
-#else
task_thread_info(idle)->preempt_count = 0;
-#endif
+
/*
* The idle tasks have their own, simple scheduling class:
*/
@@ -5077,7 +5308,13 @@ int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
goto out;
}
- p->cpus_allowed = new_mask;
+ if (p->sched_class->set_cpus_allowed)
+ p->sched_class->set_cpus_allowed(p, &new_mask);
+ else {
+ p->cpus_allowed = new_mask;
+ p->rt.nr_cpus_allowed = cpus_weight(new_mask);
+ }
+
/* Can the task run on the task's current CPU? If so, we're done */
if (cpu_isset(task_cpu(p), new_mask))
goto out;
@@ -5569,9 +5806,6 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
struct rq *rq;
switch (action) {
- case CPU_LOCK_ACQUIRE:
- mutex_lock(&sched_hotcpu_mutex);
- break;
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
@@ -5590,6 +5824,15 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
case CPU_ONLINE_FROZEN:
/* Strictly unnecessary, as first user will wake it. */
wake_up_process(cpu_rq(cpu)->migration_thread);
+
+ /* Update our root-domain */
+ rq = cpu_rq(cpu);
+ spin_lock_irqsave(&rq->lock, flags);
+ if (rq->rd) {
+ BUG_ON(!cpu_isset(cpu, rq->rd->span));
+ cpu_set(cpu, rq->rd->online);
+ }
+ spin_unlock_irqrestore(&rq->lock, flags);
break;
#ifdef CONFIG_HOTPLUG_CPU
@@ -5640,10 +5883,19 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
}
spin_unlock_irq(&rq->lock);
break;
-#endif
- case CPU_LOCK_RELEASE:
- mutex_unlock(&sched_hotcpu_mutex);
+
+ case CPU_DYING:
+ case CPU_DYING_FROZEN:
+ /* Update our root-domain */
+ rq = cpu_rq(cpu);
+ spin_lock_irqsave(&rq->lock, flags);
+ if (rq->rd) {
+ BUG_ON(!cpu_isset(cpu, rq->rd->span));
+ cpu_clear(cpu, rq->rd->online);
+ }
+ spin_unlock_irqrestore(&rq->lock, flags);
break;
+#endif
}
return NOTIFY_OK;
}
@@ -5831,11 +6083,76 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
return 1;
}
+static void rq_attach_root(struct rq *rq, struct root_domain *rd)
+{
+ unsigned long flags;
+ const struct sched_class *class;
+
+ spin_lock_irqsave(&rq->lock, flags);
+
+ if (rq->rd) {
+ struct root_domain *old_rd = rq->rd;
+
+ for (class = sched_class_highest; class; class = class->next) {
+ if (class->leave_domain)
+ class->leave_domain(rq);
+ }
+
+ cpu_clear(rq->cpu, old_rd->span);
+ cpu_clear(rq->cpu, old_rd->online);
+
+ if (atomic_dec_and_test(&old_rd->refcount))
+ kfree(old_rd);
+ }
+
+ atomic_inc(&rd->refcount);
+ rq->rd = rd;
+
+ cpu_set(rq->cpu, rd->span);
+ if (cpu_isset(rq->cpu, cpu_online_map))
+ cpu_set(rq->cpu, rd->online);
+
+ for (class = sched_class_highest; class; class = class->next) {
+ if (class->join_domain)
+ class->join_domain(rq);
+ }
+
+ spin_unlock_irqrestore(&rq->lock, flags);
+}
+
+static void init_rootdomain(struct root_domain *rd)
+{
+ memset(rd, 0, sizeof(*rd));
+
+ cpus_clear(rd->span);
+ cpus_clear(rd->online);
+}
+
+static void init_defrootdomain(void)
+{
+ init_rootdomain(&def_root_domain);
+ atomic_set(&def_root_domain.refcount, 1);
+}
+
+static struct root_domain *alloc_rootdomain(void)
+{
+ struct root_domain *rd;
+
+ rd = kmalloc(sizeof(*rd), GFP_KERNEL);
+ if (!rd)
+ return NULL;
+
+ init_rootdomain(rd);
+
+ return rd;
+}
+
/*
- * Attach the domain 'sd' to 'cpu' as its base domain. Callers must
+ * Attach the domain 'sd' to 'cpu' as its base domain. Callers must
* hold the hotplug lock.
*/
-static void cpu_attach_domain(struct sched_domain *sd, int cpu)
+static void
+cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
{
struct rq *rq = cpu_rq(cpu);
struct sched_domain *tmp;
@@ -5860,6 +6177,7 @@ static void cpu_attach_domain(struct sched_domain *sd, int cpu)
sched_domain_debug(sd, cpu);
+ rq_attach_root(rq, rd);
rcu_assign_pointer(rq->sd, sd);
}
@@ -6228,6 +6546,7 @@ static void init_sched_groups_power(int cpu, struct sched_domain *sd)
static int build_sched_domains(const cpumask_t *cpu_map)
{
int i;
+ struct root_domain *rd;
#ifdef CONFIG_NUMA
struct sched_group **sched_group_nodes = NULL;
int sd_allnodes = 0;
@@ -6244,6 +6563,12 @@ static int build_sched_domains(const cpumask_t *cpu_map)
sched_group_nodes_bycpu[first_cpu(*cpu_map)] = sched_group_nodes;
#endif
+ rd = alloc_rootdomain();
+ if (!rd) {
+ printk(KERN_WARNING "Cannot alloc root domain\n");
+ return -ENOMEM;
+ }
+
/*
* Set up domains for cpus specified by the cpu_map.
*/
@@ -6460,7 +6785,7 @@ static int build_sched_domains(const cpumask_t *cpu_map)
#else
sd = &per_cpu(phys_domains, i);
#endif
- cpu_attach_domain(sd, i);
+ cpu_attach_domain(sd, rd, i);
}
return 0;
@@ -6482,6 +6807,10 @@ static int ndoms_cur; /* number of sched domains in 'doms_cur' */
*/
static cpumask_t fallback_doms;
+void __attribute__((weak)) arch_update_cpu_topology(void)
+{
+}
+
/*
* Set up scheduler domains and groups. Callers must hold the hotplug lock.
* For now this just excludes isolated cpus, but could be used to
@@ -6491,6 +6820,7 @@ static int arch_init_sched_domains(const cpumask_t *cpu_map)
{
int err;
+ arch_update_cpu_topology();
ndoms_cur = 1;
doms_cur = kmalloc(sizeof(cpumask_t), GFP_KERNEL);
if (!doms_cur)
@@ -6518,7 +6848,7 @@ static void detach_destroy_domains(const cpumask_t *cpu_map)
unregister_sched_domain_sysctl();
for_each_cpu_mask(i, *cpu_map)
- cpu_attach_domain(NULL, i);
+ cpu_attach_domain(NULL, &def_root_domain, i);
synchronize_sched();
arch_destroy_sched_domains(cpu_map);
}
@@ -6548,6 +6878,8 @@ void partition_sched_domains(int ndoms_new, cpumask_t *doms_new)
{
int i, j;
+ lock_doms_cur();
+
/* always unregister in case we don't destroy any domains */
unregister_sched_domain_sysctl();
@@ -6588,17 +6920,19 @@ match2:
ndoms_cur = ndoms_new;
register_sched_domain_sysctl();
+
+ unlock_doms_cur();
}
#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
-static int arch_reinit_sched_domains(void)
+int arch_reinit_sched_domains(void)
{
int err;
- mutex_lock(&sched_hotcpu_mutex);
+ get_online_cpus();
detach_destroy_domains(&cpu_online_map);
err = arch_init_sched_domains(&cpu_online_map);
- mutex_unlock(&sched_hotcpu_mutex);
+ put_online_cpus();
return err;
}
@@ -6709,12 +7043,12 @@ void __init sched_init_smp(void)
{
cpumask_t non_isolated_cpus;
- mutex_lock(&sched_hotcpu_mutex);
+ get_online_cpus();
arch_init_sched_domains(&cpu_online_map);
cpus_andnot(non_isolated_cpus, cpu_possible_map, cpu_isolated_map);
if (cpus_empty(non_isolated_cpus))
cpu_set(smp_processor_id(), non_isolated_cpus);
- mutex_unlock(&sched_hotcpu_mutex);
+ put_online_cpus();
/* XXX: Theoretical race here - CPU may be hotplugged now */
hotcpu_notifier(update_sched_domains, 0);
@@ -6746,13 +7080,90 @@ static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq)
cfs_rq->min_vruntime = (u64)(-(1LL << 20));
}
+static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq)
+{
+ struct rt_prio_array *array;
+ int i;
+
+ array = &rt_rq->active;
+ for (i = 0; i < MAX_RT_PRIO; i++) {
+ INIT_LIST_HEAD(array->queue + i);
+ __clear_bit(i, array->bitmap);
+ }
+ /* delimiter for bitsearch: */
+ __set_bit(MAX_RT_PRIO, array->bitmap);
+
+#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
+ rt_rq->highest_prio = MAX_RT_PRIO;
+#endif
+#ifdef CONFIG_SMP
+ rt_rq->rt_nr_migratory = 0;
+ rt_rq->overloaded = 0;
+#endif
+
+ rt_rq->rt_time = 0;
+ rt_rq->rt_throttled = 0;
+
+#ifdef CONFIG_RT_GROUP_SCHED
+ rt_rq->rt_nr_boosted = 0;
+ rt_rq->rq = rq;
+#endif
+}
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+static void init_tg_cfs_entry(struct rq *rq, struct task_group *tg,
+ struct cfs_rq *cfs_rq, struct sched_entity *se,
+ int cpu, int add)
+{
+ tg->cfs_rq[cpu] = cfs_rq;
+ init_cfs_rq(cfs_rq, rq);
+ cfs_rq->tg = tg;
+ if (add)
+ list_add(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list);
+
+ tg->se[cpu] = se;
+ se->cfs_rq = &rq->cfs;
+ se->my_q = cfs_rq;
+ se->load.weight = tg->shares;
+ se->load.inv_weight = div64_64(1ULL<<32, se->load.weight);
+ se->parent = NULL;
+}
+#endif
+
+#ifdef CONFIG_RT_GROUP_SCHED
+static void init_tg_rt_entry(struct rq *rq, struct task_group *tg,
+ struct rt_rq *rt_rq, struct sched_rt_entity *rt_se,
+ int cpu, int add)
+{
+ tg->rt_rq[cpu] = rt_rq;
+ init_rt_rq(rt_rq, rq);
+ rt_rq->tg = tg;
+ rt_rq->rt_se = rt_se;
+ if (add)
+ list_add(&rt_rq->leaf_rt_rq_list, &rq->leaf_rt_rq_list);
+
+ tg->rt_se[cpu] = rt_se;
+ rt_se->rt_rq = &rq->rt;
+ rt_se->my_q = rt_rq;
+ rt_se->parent = NULL;
+ INIT_LIST_HEAD(&rt_se->run_list);
+}
+#endif
+
void __init sched_init(void)
{
int highest_cpu = 0;
int i, j;
+#ifdef CONFIG_SMP
+ init_defrootdomain();
+#endif
+
+#ifdef CONFIG_GROUP_SCHED
+ list_add(&init_task_group.list, &task_groups);
+#endif
+
for_each_possible_cpu(i) {
- struct rt_prio_array *array;
struct rq *rq;
rq = cpu_rq(i);
@@ -6761,52 +7172,42 @@ void __init sched_init(void)
rq->nr_running = 0;
rq->clock = 1;
init_cfs_rq(&rq->cfs, rq);
+ init_rt_rq(&rq->rt, rq);
#ifdef CONFIG_FAIR_GROUP_SCHED
- INIT_LIST_HEAD(&rq->leaf_cfs_rq_list);
- {
- struct cfs_rq *cfs_rq = &per_cpu(init_cfs_rq, i);
- struct sched_entity *se =
- &per_cpu(init_sched_entity, i);
-
- init_cfs_rq_p[i] = cfs_rq;
- init_cfs_rq(cfs_rq, rq);
- cfs_rq->tg = &init_task_group;
- list_add(&cfs_rq->leaf_cfs_rq_list,
- &rq->leaf_cfs_rq_list);
-
- init_sched_entity_p[i] = se;
- se->cfs_rq = &rq->cfs;
- se->my_q = cfs_rq;
- se->load.weight = init_task_group_load;
- se->load.inv_weight =
- div64_64(1ULL<<32, init_task_group_load);
- se->parent = NULL;
- }
init_task_group.shares = init_task_group_load;
- spin_lock_init(&init_task_group.lock);
+ INIT_LIST_HEAD(&rq->leaf_cfs_rq_list);
+ init_tg_cfs_entry(rq, &init_task_group,
+ &per_cpu(init_cfs_rq, i),
+ &per_cpu(init_sched_entity, i), i, 1);
+
+#endif
+#ifdef CONFIG_RT_GROUP_SCHED
+ init_task_group.rt_runtime =
+ sysctl_sched_rt_runtime * NSEC_PER_USEC;
+ INIT_LIST_HEAD(&rq->leaf_rt_rq_list);
+ init_tg_rt_entry(rq, &init_task_group,
+ &per_cpu(init_rt_rq, i),
+ &per_cpu(init_sched_rt_entity, i), i, 1);
#endif
+ rq->rt_period_expire = 0;
+ rq->rt_throttled = 0;
for (j = 0; j < CPU_LOAD_IDX_MAX; j++)
rq->cpu_load[j] = 0;
#ifdef CONFIG_SMP
rq->sd = NULL;
+ rq->rd = NULL;
rq->active_balance = 0;
rq->next_balance = jiffies;
rq->push_cpu = 0;
rq->cpu = i;
rq->migration_thread = NULL;
INIT_LIST_HEAD(&rq->migration_queue);
+ rq_attach_root(rq, &def_root_domain);
#endif
+ init_rq_hrtick(rq);
atomic_set(&rq->nr_iowait, 0);
-
- array = &rq->rt.active;
- for (j = 0; j < MAX_RT_PRIO; j++) {
- INIT_LIST_HEAD(array->queue + j);
- __clear_bit(j, array->bitmap);
- }
highest_cpu = i;
- /* delimiter for bitsearch: */
- __set_bit(MAX_RT_PRIO, array->bitmap);
}
set_load_weight(&init_task);
@@ -6841,6 +7242,8 @@ void __init sched_init(void)
* During early bootup we pretend to be a normal task:
*/
current->sched_class = &fair_sched_class;
+
+ scheduler_running = 1;
}
#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
@@ -6889,7 +7292,7 @@ void normalize_rt_tasks(void)
unsigned long flags;
struct rq *rq;
- read_lock_irq(&tasklist_lock);
+ read_lock_irqsave(&tasklist_lock, flags);
do_each_thread(g, p) {
/*
* Only normalize user tasks:
@@ -6915,16 +7318,16 @@ void normalize_rt_tasks(void)
continue;
}
- spin_lock_irqsave(&p->pi_lock, flags);
+ spin_lock(&p->pi_lock);
rq = __task_rq_lock(p);
normalize_task(rq, p);
__task_rq_unlock(rq);
- spin_unlock_irqrestore(&p->pi_lock, flags);
+ spin_unlock(&p->pi_lock);
} while_each_thread(g, p);
- read_unlock_irq(&tasklist_lock);
+ read_unlock_irqrestore(&tasklist_lock, flags);
}
#endif /* CONFIG_MAGIC_SYSRQ */
@@ -6973,21 +7376,31 @@ void set_curr_task(int cpu, struct task_struct *p)
#endif
+#ifdef CONFIG_GROUP_SCHED
+
#ifdef CONFIG_FAIR_GROUP_SCHED
+static void free_fair_sched_group(struct task_group *tg)
+{
+ int i;
-/* allocate runqueue etc for a new task group */
-struct task_group *sched_create_group(void)
+ for_each_possible_cpu(i) {
+ if (tg->cfs_rq)
+ kfree(tg->cfs_rq[i]);
+ if (tg->se)
+ kfree(tg->se[i]);
+ }
+
+ kfree(tg->cfs_rq);
+ kfree(tg->se);
+}
+
+static int alloc_fair_sched_group(struct task_group *tg)
{
- struct task_group *tg;
struct cfs_rq *cfs_rq;
struct sched_entity *se;
struct rq *rq;
int i;
- tg = kzalloc(sizeof(*tg), GFP_KERNEL);
- if (!tg)
- return ERR_PTR(-ENOMEM);
-
tg->cfs_rq = kzalloc(sizeof(cfs_rq) * NR_CPUS, GFP_KERNEL);
if (!tg->cfs_rq)
goto err;
@@ -6995,96 +7408,204 @@ struct task_group *sched_create_group(void)
if (!tg->se)
goto err;
+ tg->shares = NICE_0_LOAD;
+
for_each_possible_cpu(i) {
rq = cpu_rq(i);
- cfs_rq = kmalloc_node(sizeof(struct cfs_rq), GFP_KERNEL,
- cpu_to_node(i));
+ cfs_rq = kmalloc_node(sizeof(struct cfs_rq),
+ GFP_KERNEL|__GFP_ZERO, cpu_to_node(i));
if (!cfs_rq)
goto err;
- se = kmalloc_node(sizeof(struct sched_entity), GFP_KERNEL,
- cpu_to_node(i));
+ se = kmalloc_node(sizeof(struct sched_entity),
+ GFP_KERNEL|__GFP_ZERO, cpu_to_node(i));
if (!se)
goto err;
- memset(cfs_rq, 0, sizeof(struct cfs_rq));
- memset(se, 0, sizeof(struct sched_entity));
+ init_tg_cfs_entry(rq, tg, cfs_rq, se, i, 0);
+ }
- tg->cfs_rq[i] = cfs_rq;
- init_cfs_rq(cfs_rq, rq);
- cfs_rq->tg = tg;
+ return 1;
- tg->se[i] = se;
- se->cfs_rq = &rq->cfs;
- se->my_q = cfs_rq;
- se->load.weight = NICE_0_LOAD;
- se->load.inv_weight = div64_64(1ULL<<32, NICE_0_LOAD);
- se->parent = NULL;
- }
+ err:
+ return 0;
+}
- for_each_possible_cpu(i) {
- rq = cpu_rq(i);
- cfs_rq = tg->cfs_rq[i];
- list_add_rcu(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list);
- }
+static inline void register_fair_sched_group(struct task_group *tg, int cpu)
+{
+ list_add_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list,
+ &cpu_rq(cpu)->leaf_cfs_rq_list);
+}
- tg->shares = NICE_0_LOAD;
- spin_lock_init(&tg->lock);
+static inline void unregister_fair_sched_group(struct task_group *tg, int cpu)
+{
+ list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list);
+}
+#else
+static inline void free_fair_sched_group(struct task_group *tg)
+{
+}
- return tg;
+static inline int alloc_fair_sched_group(struct task_group *tg)
+{
+ return 1;
+}
+
+static inline void register_fair_sched_group(struct task_group *tg, int cpu)
+{
+}
+
+static inline void unregister_fair_sched_group(struct task_group *tg, int cpu)
+{
+}
+#endif
+
+#ifdef CONFIG_RT_GROUP_SCHED
+static void free_rt_sched_group(struct task_group *tg)
+{
+ int i;
-err:
for_each_possible_cpu(i) {
- if (tg->cfs_rq)
- kfree(tg->cfs_rq[i]);
- if (tg->se)
- kfree(tg->se[i]);
+ if (tg->rt_rq)
+ kfree(tg->rt_rq[i]);
+ if (tg->rt_se)
+ kfree(tg->rt_se[i]);
}
- kfree(tg->cfs_rq);
- kfree(tg->se);
- kfree(tg);
- return ERR_PTR(-ENOMEM);
+ kfree(tg->rt_rq);
+ kfree(tg->rt_se);
}
-/* rcu callback to free various structures associated with a task group */
-static void free_sched_group(struct rcu_head *rhp)
+static int alloc_rt_sched_group(struct task_group *tg)
{
- struct task_group *tg = container_of(rhp, struct task_group, rcu);
- struct cfs_rq *cfs_rq;
- struct sched_entity *se;
+ struct rt_rq *rt_rq;
+ struct sched_rt_entity *rt_se;
+ struct rq *rq;
int i;
- /* now it should be safe to free those cfs_rqs */
+ tg->rt_rq = kzalloc(sizeof(rt_rq) * NR_CPUS, GFP_KERNEL);
+ if (!tg->rt_rq)
+ goto err;
+ tg->rt_se = kzalloc(sizeof(rt_se) * NR_CPUS, GFP_KERNEL);
+ if (!tg->rt_se)
+ goto err;
+
+ tg->rt_runtime = 0;
+
for_each_possible_cpu(i) {
- cfs_rq = tg->cfs_rq[i];
- kfree(cfs_rq);
+ rq = cpu_rq(i);
+
+ rt_rq = kmalloc_node(sizeof(struct rt_rq),
+ GFP_KERNEL|__GFP_ZERO, cpu_to_node(i));
+ if (!rt_rq)
+ goto err;
+
+ rt_se = kmalloc_node(sizeof(struct sched_rt_entity),
+ GFP_KERNEL|__GFP_ZERO, cpu_to_node(i));
+ if (!rt_se)
+ goto err;
- se = tg->se[i];
- kfree(se);
+ init_tg_rt_entry(rq, tg, rt_rq, rt_se, i, 0);
}
- kfree(tg->cfs_rq);
- kfree(tg->se);
+ return 1;
+
+ err:
+ return 0;
+}
+
+static inline void register_rt_sched_group(struct task_group *tg, int cpu)
+{
+ list_add_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list,
+ &cpu_rq(cpu)->leaf_rt_rq_list);
+}
+
+static inline void unregister_rt_sched_group(struct task_group *tg, int cpu)
+{
+ list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list);
+}
+#else
+static inline void free_rt_sched_group(struct task_group *tg)
+{
+}
+
+static inline int alloc_rt_sched_group(struct task_group *tg)
+{
+ return 1;
+}
+
+static inline void register_rt_sched_group(struct task_group *tg, int cpu)
+{
+}
+
+static inline void unregister_rt_sched_group(struct task_group *tg, int cpu)
+{
+}
+#endif
+
+static void free_sched_group(struct task_group *tg)
+{
+ free_fair_sched_group(tg);
+ free_rt_sched_group(tg);
kfree(tg);
}
+/* allocate runqueue etc for a new task group */
+struct task_group *sched_create_group(void)
+{
+ struct task_group *tg;
+ unsigned long flags;
+ int i;
+
+ tg = kzalloc(sizeof(*tg), GFP_KERNEL);
+ if (!tg)
+ return ERR_PTR(-ENOMEM);
+
+ if (!alloc_fair_sched_group(tg))
+ goto err;
+
+ if (!alloc_rt_sched_group(tg))
+ goto err;
+
+ spin_lock_irqsave(&task_group_lock, flags);
+ for_each_possible_cpu(i) {
+ register_fair_sched_group(tg, i);
+ register_rt_sched_group(tg, i);
+ }
+ list_add_rcu(&tg->list, &task_groups);
+ spin_unlock_irqrestore(&task_group_lock, flags);
+
+ return tg;
+
+err:
+ free_sched_group(tg);
+ return ERR_PTR(-ENOMEM);
+}
+
+/* rcu callback to free various structures associated with a task group */
+static void free_sched_group_rcu(struct rcu_head *rhp)
+{
+ /* now it should be safe to free those cfs_rqs */
+ free_sched_group(container_of(rhp, struct task_group, rcu));
+}
+
/* Destroy runqueue etc associated with a task group */
void sched_destroy_group(struct task_group *tg)
{
- struct cfs_rq *cfs_rq = NULL;
+ unsigned long flags;
int i;
+ spin_lock_irqsave(&task_group_lock, flags);
for_each_possible_cpu(i) {
- cfs_rq = tg->cfs_rq[i];
- list_del_rcu(&cfs_rq->leaf_cfs_rq_list);
+ unregister_fair_sched_group(tg, i);
+ unregister_rt_sched_group(tg, i);
}
-
- BUG_ON(!cfs_rq);
+ list_del_rcu(&tg->list);
+ spin_unlock_irqrestore(&task_group_lock, flags);
/* wait for possible concurrent references to cfs_rqs complete */
- call_rcu(&tg->rcu, free_sched_group);
+ call_rcu(&tg->rcu, free_sched_group_rcu);
}
/* change task's runqueue when it moves between groups.
@@ -7100,34 +7621,32 @@ void sched_move_task(struct task_struct *tsk)
rq = task_rq_lock(tsk, &flags);
- if (tsk->sched_class != &fair_sched_class) {
- set_task_cfs_rq(tsk, task_cpu(tsk));
- goto done;
- }
-
update_rq_clock(rq);
running = task_current(rq, tsk);
on_rq = tsk->se.on_rq;
- if (on_rq) {
+ if (on_rq)
dequeue_task(rq, tsk, 0);
- if (unlikely(running))
- tsk->sched_class->put_prev_task(rq, tsk);
- }
+ if (unlikely(running))
+ tsk->sched_class->put_prev_task(rq, tsk);
- set_task_cfs_rq(tsk, task_cpu(tsk));
+ set_task_rq(tsk, task_cpu(tsk));
- if (on_rq) {
- if (unlikely(running))
- tsk->sched_class->set_curr_task(rq);
+#ifdef CONFIG_FAIR_GROUP_SCHED
+ if (tsk->sched_class->moved_group)
+ tsk->sched_class->moved_group(tsk);
+#endif
+
+ if (unlikely(running))
+ tsk->sched_class->set_curr_task(rq);
+ if (on_rq)
enqueue_task(rq, tsk, 0);
- }
-done:
task_rq_unlock(rq, &flags);
}
+#ifdef CONFIG_FAIR_GROUP_SCHED
static void set_se_shares(struct sched_entity *se, unsigned long shares)
{
struct cfs_rq *cfs_rq = se->cfs_rq;
@@ -7149,9 +7668,12 @@ static void set_se_shares(struct sched_entity *se, unsigned long shares)
spin_unlock_irq(&rq->lock);
}
+static DEFINE_MUTEX(shares_mutex);
+
int sched_group_set_shares(struct task_group *tg, unsigned long shares)
{
int i;
+ unsigned long flags;
/*
* A weight of 0 or 1 can cause arithmetics problems.
@@ -7161,16 +7683,36 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares)
if (shares < 2)
shares = 2;
- spin_lock(&tg->lock);
+ mutex_lock(&shares_mutex);
if (tg->shares == shares)
goto done;
+ spin_lock_irqsave(&task_group_lock, flags);
+ for_each_possible_cpu(i)
+ unregister_fair_sched_group(tg, i);
+ spin_unlock_irqrestore(&task_group_lock, flags);
+
+ /* wait for any ongoing reference to this group to finish */
+ synchronize_sched();
+
+ /*
+ * Now we are free to modify the group's share on each cpu
+ * w/o tripping rebalance_share or load_balance_fair.
+ */
tg->shares = shares;
for_each_possible_cpu(i)
set_se_shares(tg->se[i], shares);
+ /*
+ * Enable load balance activity on this group, by inserting it back on
+ * each cpu's rq->leaf_cfs_rq_list.
+ */
+ spin_lock_irqsave(&task_group_lock, flags);
+ for_each_possible_cpu(i)
+ register_fair_sched_group(tg, i);
+ spin_unlock_irqrestore(&task_group_lock, flags);
done:
- spin_unlock(&tg->lock);
+ mutex_unlock(&shares_mutex);
return 0;
}
@@ -7178,10 +7720,97 @@ unsigned long sched_group_shares(struct task_group *tg)
{
return tg->shares;
}
+#endif
-#endif /* CONFIG_FAIR_GROUP_SCHED */
+#ifdef CONFIG_RT_GROUP_SCHED
+/*
+ * Ensure that the real time constraints are schedulable.
+ */
+static DEFINE_MUTEX(rt_constraints_mutex);
+
+static unsigned long to_ratio(u64 period, u64 runtime)
+{
+ if (runtime == RUNTIME_INF)
+ return 1ULL << 16;
+
+ return div64_64(runtime << 16, period);
+}
+
+static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
+{
+ struct task_group *tgi;
+ unsigned long total = 0;
+ unsigned long global_ratio =
+ to_ratio(sysctl_sched_rt_period,
+ sysctl_sched_rt_runtime < 0 ?
+ RUNTIME_INF : sysctl_sched_rt_runtime);
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(tgi, &task_groups, list) {
+ if (tgi == tg)
+ continue;
+
+ total += to_ratio(period, tgi->rt_runtime);
+ }
+ rcu_read_unlock();
+
+ return total + to_ratio(period, runtime) < global_ratio;
+}
+
+/* Must be called with tasklist_lock held */
+static inline int tg_has_rt_tasks(struct task_group *tg)
+{
+ struct task_struct *g, *p;
+ do_each_thread(g, p) {
+ if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg)
+ return 1;
+ } while_each_thread(g, p);
+ return 0;
+}
+
+int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us)
+{
+ u64 rt_runtime, rt_period;
+ int err = 0;
-#ifdef CONFIG_FAIR_CGROUP_SCHED
+ rt_period = (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
+ rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC;
+ if (rt_runtime_us == -1)
+ rt_runtime = RUNTIME_INF;
+
+ mutex_lock(&rt_constraints_mutex);
+ read_lock(&tasklist_lock);
+ if (rt_runtime_us == 0 && tg_has_rt_tasks(tg)) {
+ err = -EBUSY;
+ goto unlock;
+ }
+ if (!__rt_schedulable(tg, rt_period, rt_runtime)) {
+ err = -EINVAL;
+ goto unlock;
+ }
+ tg->rt_runtime = rt_runtime;
+ unlock:
+ read_unlock(&tasklist_lock);
+ mutex_unlock(&rt_constraints_mutex);
+
+ return err;
+}
+
+long sched_group_rt_runtime(struct task_group *tg)
+{
+ u64 rt_runtime_us;
+
+ if (tg->rt_runtime == RUNTIME_INF)
+ return -1;
+
+ rt_runtime_us = tg->rt_runtime;
+ do_div(rt_runtime_us, NSEC_PER_USEC);
+ return rt_runtime_us;
+}
+#endif
+#endif /* CONFIG_GROUP_SCHED */
+
+#ifdef CONFIG_CGROUP_SCHED
/* return corresponding task_group object of a cgroup */
static inline struct task_group *cgroup_tg(struct cgroup *cgrp)
@@ -7227,9 +7856,15 @@ static int
cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
struct task_struct *tsk)
{
+#ifdef CONFIG_RT_GROUP_SCHED
+ /* Don't accept realtime tasks when there is no way for them to run */
+ if (rt_task(tsk) && cgroup_tg(cgrp)->rt_runtime == 0)
+ return -EINVAL;
+#else
/* We don't support RT-tasks being in separate groups */
if (tsk->sched_class != &fair_sched_class)
return -EINVAL;
+#endif
return 0;
}
@@ -7241,6 +7876,7 @@ cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
sched_move_task(tsk);
}
+#ifdef CONFIG_FAIR_GROUP_SCHED
static int cpu_shares_write_uint(struct cgroup *cgrp, struct cftype *cftype,
u64 shareval)
{
@@ -7253,13 +7889,70 @@ static u64 cpu_shares_read_uint(struct cgroup *cgrp, struct cftype *cft)
return (u64) tg->shares;
}
+#endif
+
+#ifdef CONFIG_RT_GROUP_SCHED
+static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft,
+ struct file *file,
+ const char __user *userbuf,
+ size_t nbytes, loff_t *unused_ppos)
+{
+ char buffer[64];
+ int retval = 0;
+ s64 val;
+ char *end;
+
+ if (!nbytes)
+ return -EINVAL;
+ if (nbytes >= sizeof(buffer))
+ return -E2BIG;
+ if (copy_from_user(buffer, userbuf, nbytes))
+ return -EFAULT;
+
+ buffer[nbytes] = 0; /* nul-terminate */
+
+ /* strip newline if necessary */
+ if (nbytes && (buffer[nbytes-1] == '\n'))
+ buffer[nbytes-1] = 0;
+ val = simple_strtoll(buffer, &end, 0);
+ if (*end)
+ return -EINVAL;
+
+ /* Pass to subsystem */
+ retval = sched_group_set_rt_runtime(cgroup_tg(cgrp), val);
+ if (!retval)
+ retval = nbytes;
+ return retval;
+}
+
+static ssize_t cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft,
+ struct file *file,
+ char __user *buf, size_t nbytes,
+ loff_t *ppos)
+{
+ char tmp[64];
+ long val = sched_group_rt_runtime(cgroup_tg(cgrp));
+ int len = sprintf(tmp, "%ld\n", val);
+
+ return simple_read_from_buffer(buf, nbytes, ppos, tmp, len);
+}
+#endif
static struct cftype cpu_files[] = {
+#ifdef CONFIG_FAIR_GROUP_SCHED
{
.name = "shares",
.read_uint = cpu_shares_read_uint,
.write_uint = cpu_shares_write_uint,
},
+#endif
+#ifdef CONFIG_RT_GROUP_SCHED
+ {
+ .name = "rt_runtime_us",
+ .read = cpu_rt_runtime_read,
+ .write = cpu_rt_runtime_write,
+ },
+#endif
};
static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont)
@@ -7278,7 +7971,7 @@ struct cgroup_subsys cpu_cgroup_subsys = {
.early_init = 1,
};
-#endif /* CONFIG_FAIR_CGROUP_SCHED */
+#endif /* CONFIG_CGROUP_SCHED */
#ifdef CONFIG_CGROUP_CPUACCT
|
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