#include <linux/vmalloc.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
+#include <linux/pid_namespace.h>
#include <linux/smp.h>
#include <linux/threads.h>
#include <linux/timer.h>
#include <linux/pagemap.h>
#include <asm/tlb.h>
+#include <asm/irq_regs.h>
/*
* Scheduler clock - returns current time in nanosec units.
*/
unsigned long long __attribute__((weak)) sched_clock(void)
{
- return (unsigned long long)jiffies * (1000000000 / HZ);
+ return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ);
}
/*
/*
* Some helpers for converting nanosecond timing to jiffy resolution
*/
-#define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (1000000000 / HZ))
-#define JIFFIES_TO_NS(TIME) ((TIME) * (1000000000 / HZ))
+#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
#ifdef CONFIG_FAIR_GROUP_SCHED
+#include <linux/cgroup.h>
+
struct cfs_rq;
/* task group related information */
-struct task_grp {
+struct task_group {
+#ifdef CONFIG_FAIR_CGROUP_SCHED
+ struct cgroup_subsys_state css;
+#endif
/* 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;
+
+ /*
+ * shares assigned to a task group governs how much of cpu bandwidth
+ * is allocated to the group. The more shares a group has, the more is
+ * the cpu bandwidth allocated to it.
+ *
+ * For ex, lets say that there are three task groups, A, B and C which
+ * have been assigned shares 1000, 2000 and 3000 respectively. Then,
+ * cpu bandwidth allocated by the scheduler to task groups A, B and C
+ * should be:
+ *
+ * Bw(A) = 1000/(1000+2000+3000) * 100 = 16.66%
+ * Bw(B) = 2000/(1000+2000+3000) * 100 = 33.33%
+ * Bw(C) = 3000/(1000+2000+3000) * 100 = 50%
+ *
+ * The weight assigned to a task group's schedulable entities on every
+ * cpu (task_group.se[a_cpu]->load.weight) is derived from the task
+ * group's shares. For ex: lets say that task group A has been
+ * assigned shares of 1000 and there are two CPUs in a system. Then,
+ *
+ * tg_A->se[0]->load.weight = tg_A->se[1]->load.weight = 1000;
+ *
+ * Note: It's not necessary that each of a task's group schedulable
+ * entity have the same weight on all CPUs. If the group
+ * has 2 of its tasks on CPU0 and 1 task on CPU1, then a
+ * better distribution of weight could be:
+ *
+ * tg_A->se[0]->load.weight = 2/3 * 2000 = 1333
+ * tg_A->se[1]->load.weight = 1/2 * 2000 = 667
+ *
+ * rebalance_shares() is responsible for distributing the shares of a
+ * task groups like this among the group's schedulable entities across
+ * cpus.
+ *
+ */
unsigned long shares;
+
+ struct rcu_head rcu;
};
/* Default task group's sched entity on each cpu */
static struct sched_entity *init_sched_entity_p[NR_CPUS];
static struct cfs_rq *init_cfs_rq_p[NR_CPUS];
+/* task_group_mutex serializes add/remove of task groups and also changes to
+ * a task group's cpu shares.
+ */
+static DEFINE_MUTEX(task_group_mutex);
+
+/* doms_cur_mutex serializes access to doms_cur[] array */
+static DEFINE_MUTEX(doms_cur_mutex);
+
+#ifdef CONFIG_SMP
+/* kernel thread that runs rebalance_shares() periodically */
+static struct task_struct *lb_monitor_task;
+static int load_balance_monitor(void *unused);
+#endif
+
+static void set_se_shares(struct sched_entity *se, unsigned long shares);
+
/* Default task group.
* Every task in system belong to this group at bootup.
*/
-struct task_grp init_task_grp = {
+struct task_group init_task_group = {
.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
+# define INIT_TASK_GROUP_LOAD 2*NICE_0_LOAD
#else
-# define INIT_TASK_GRP_LOAD NICE_0_LOAD
+# define INIT_TASK_GROUP_LOAD NICE_0_LOAD
#endif
-static int init_task_grp_load = INIT_TASK_GRP_LOAD;
+#define MIN_GROUP_SHARES 2
+
+static int init_task_group_load = INIT_TASK_GROUP_LOAD;
/* return group to which a task belongs */
-static inline struct task_grp *task_grp(struct task_struct *p)
+static inline struct task_group *task_group(struct task_struct *p)
{
- struct task_grp *tg;
+ struct task_group *tg;
#ifdef CONFIG_FAIR_USER_SCHED
tg = p->user->tg;
+#elif defined(CONFIG_FAIR_CGROUP_SCHED)
+ tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id),
+ struct task_group, css);
#else
- tg = &init_task_grp;
+ tg = &init_task_group;
#endif
-
return tg;
}
/* 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)
+static inline void set_task_cfs_rq(struct task_struct *p, unsigned int cpu)
+{
+ p->se.cfs_rq = task_group(p)->cfs_rq[cpu];
+ p->se.parent = task_group(p)->se[cpu];
+}
+
+static inline void lock_task_group_list(void)
+{
+ mutex_lock(&task_group_mutex);
+}
+
+static inline void unlock_task_group_list(void)
+{
+ mutex_unlock(&task_group_mutex);
+}
+
+static inline void lock_doms_cur(void)
+{
+ mutex_lock(&doms_cur_mutex);
+}
+
+static inline void unlock_doms_cur(void)
{
- p->se.cfs_rq = task_grp(p)->cfs_rq[task_cpu(p)];
- p->se.parent = task_grp(p)->se[task_cpu(p)];
+ mutex_unlock(&doms_cur_mutex);
}
#else
-static inline void set_task_cfs_rq(struct task_struct *p) { }
+static inline void set_task_cfs_rq(struct task_struct *p, unsigned int cpu) { }
+static inline void lock_task_group_list(void) { }
+static inline void unlock_task_group_list(void) { }
+static inline void lock_doms_cur(void) { }
+static inline void unlock_doms_cur(void) { }
#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_FAIR_GROUP_SCHED
struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */
- /* leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
+ /*
+ * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
* a hierarchy). Non-leaf lrqs hold other higher schedulable entities
* (like users, containers etc.)
*
* leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
* list is used during load balance.
*/
- struct list_head leaf_cfs_rq_list; /* Better name : task_cfs_rq_list? */
- struct task_grp *tg; /* group that "owns" this runqueue */
- struct rcu_head rcu;
+ struct list_head leaf_cfs_rq_list;
+ struct task_group *tg; /* group that "owns" this runqueue */
#endif
};
* acquire operations must be ordered by ascending &runqueue.
*/
struct rq {
- spinlock_t lock; /* runqueue lock */
+ /* runqueue lock: */
+ spinlock_t lock;
/*
* nr_running and cpu_load should be in the same cacheline because
#ifdef CONFIG_NO_HZ
unsigned char in_nohz_recently;
#endif
- struct load_weight load; /* capture load from *all* tasks on this cpu */
+ /* capture load from *all* tasks on this cpu: */
+ struct load_weight load;
unsigned long nr_load_updates;
u64 nr_switches;
struct cfs_rq cfs;
#ifdef CONFIG_FAIR_GROUP_SCHED
- struct list_head leaf_cfs_rq_list; /* list of leaf cfs_rq on this cpu */
+ /* list of leaf cfs_rq on this cpu: */
+ struct list_head leaf_cfs_rq_list;
#endif
- struct rt_rq rt;
+ struct rt_rq rt;
/*
* This is part of a global counter where only the total sum
/* For active balancing */
int active_balance;
int push_cpu;
- int cpu; /* cpu of this runqueue */
+ /* cpu of this runqueue: */
+ int cpu;
struct task_struct *migration_thread;
struct list_head migration_queue;
struct sched_info rq_sched_info;
/* sys_sched_yield() stats */
- unsigned long yld_exp_empty;
- unsigned long yld_act_empty;
- unsigned long yld_both_empty;
- unsigned long yld_count;
+ unsigned int yld_exp_empty;
+ unsigned int yld_act_empty;
+ unsigned int yld_both_empty;
+ unsigned int yld_count;
/* schedule() stats */
- unsigned long sched_switch;
- unsigned long sched_count;
- unsigned long sched_goidle;
+ unsigned int sched_switch;
+ unsigned int sched_count;
+ unsigned int sched_goidle;
/* try_to_wake_up() stats */
- unsigned long ttwu_count;
- unsigned long ttwu_local;
+ unsigned int ttwu_count;
+ unsigned int ttwu_local;
/* BKL stats */
- unsigned long bkl_count;
+ unsigned int bkl_count;
#endif
struct lock_class_key rq_lock_key;
};
*/
enum {
SCHED_FEAT_NEW_FAIR_SLEEPERS = 1,
- SCHED_FEAT_START_DEBIT = 2,
- SCHED_FEAT_USE_TREE_AVG = 4,
- SCHED_FEAT_APPROX_AVG = 8,
+ SCHED_FEAT_WAKEUP_PREEMPT = 2,
+ SCHED_FEAT_START_DEBIT = 4,
+ SCHED_FEAT_TREE_AVG = 8,
+ SCHED_FEAT_APPROX_AVG = 16,
};
const_debug unsigned int sysctl_sched_features =
- SCHED_FEAT_NEW_FAIR_SLEEPERS *1 |
- SCHED_FEAT_START_DEBIT *1 |
- SCHED_FEAT_USE_TREE_AVG *0 |
- SCHED_FEAT_APPROX_AVG *0;
+ 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;
#define sched_feat(x) (sysctl_sched_features & SCHED_FEAT_##x)
/*
+ * Number of tasks to iterate in a single balance run.
+ * Limited because this is done with IRQs disabled.
+ */
+const_debug unsigned int sysctl_sched_nr_migrate = 32;
+
+/*
* For kernel-internal use: high-speed (but slightly incorrect) per-cpu
* clock constructed from sched_clock():
*/
local_irq_save(flags);
rq = cpu_rq(cpu);
- update_rq_clock(rq);
+ /*
+ * 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);
now = rq->clock;
local_irq_restore(flags);
return now;
}
+EXPORT_SYMBOL_GPL(cpu_clock);
#ifndef prepare_arch_switch
# define prepare_arch_switch(next) do { } while (0)
# define finish_arch_switch(prev) do { } while (0)
#endif
+static inline int task_current(struct rq *rq, struct task_struct *p)
+{
+ return rq->curr == p;
+}
+
#ifndef __ARCH_WANT_UNLOCKED_CTXSW
static inline int task_running(struct rq *rq, struct task_struct *p)
{
- return rq->curr == p;
+ return task_current(rq, p);
}
static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
#ifdef CONFIG_SMP
return p->oncpu;
#else
- return rq->curr == p;
+ return task_current(rq, p);
#endif
}
static inline struct rq *__task_rq_lock(struct task_struct *p)
__acquires(rq->lock)
{
- struct rq *rq;
-
-repeat_lock_task:
- rq = task_rq(p);
- spin_lock(&rq->lock);
- if (unlikely(rq != task_rq(p))) {
+ for (;;) {
+ struct rq *rq = task_rq(p);
+ spin_lock(&rq->lock);
+ if (likely(rq == task_rq(p)))
+ return rq;
spin_unlock(&rq->lock);
- goto repeat_lock_task;
}
- return rq;
}
/*
* task_rq_lock - lock the runqueue a given task resides on and disable
- * interrupts. Note the ordering: we can safely lookup the task_rq without
+ * interrupts. Note the ordering: we can safely lookup the task_rq without
* explicitly disabling preemption.
*/
static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags)
{
struct rq *rq;
-repeat_lock_task:
- local_irq_save(*flags);
- rq = task_rq(p);
- spin_lock(&rq->lock);
- if (unlikely(rq != task_rq(p))) {
+ for (;;) {
+ local_irq_save(*flags);
+ rq = task_rq(p);
+ spin_lock(&rq->lock);
+ if (likely(rq == task_rq(p)))
+ return rq;
spin_unlock_irqrestore(&rq->lock, *flags);
- goto repeat_lock_task;
}
- return rq;
}
static void __task_rq_unlock(struct rq *rq)
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
* To aid in avoiding the subversion of "niceness" due to uneven distribution
* of tasks with abnormal "nice" values across CPUs the contribution that
* each task makes to its run queue's load is weighted according to its
- * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
+ * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
* scaled version of the new time slice allocation that they receive on time
* slice expiry etc.
*/
struct task_struct *(*next)(void *);
};
-static int balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_nr_move, unsigned long max_load_move,
- struct sched_domain *sd, enum cpu_idle_type idle,
- int *all_pinned, unsigned long *load_moved,
- int *this_best_prio, struct rq_iterator *iterator);
+#ifdef CONFIG_SMP
+static unsigned long
+balance_tasks(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 rq_iterator *iterator);
+
+static int
+iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
+ struct sched_domain *sd, enum cpu_idle_type idle,
+ struct rq_iterator *iterator);
+#endif
+
+#ifdef CONFIG_CGROUP_CPUACCT
+static void cpuacct_charge(struct task_struct *tsk, u64 cputime);
+#else
+static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}
+#endif
+
+static inline void inc_cpu_load(struct rq *rq, unsigned long load)
+{
+ update_load_add(&rq->load, load);
+}
+
+static inline void dec_cpu_load(struct rq *rq, unsigned long load)
+{
+ update_load_sub(&rq->load, load);
+}
#include "sched_stats.h"
#include "sched_idletask.c"
#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);
-}
-
-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 task_struct *p, struct rq *rq)
{
rq->nr_running--;
- dec_load(rq, p);
}
static void set_load_weight(struct task_struct *p)
static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
{
+ set_task_cfs_rq(p, cpu);
#ifdef CONFIG_SMP
+ /*
+ * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
+ * successfuly executed on another CPU. We must ensure that updates of
+ * per-task data have been completed by this moment.
+ */
+ smp_wmb();
task_thread_info(p)->cpu = cpu;
#endif
- set_task_cfs_rq(p);
}
#ifdef CONFIG_SMP
+/*
+ * Is this task likely cache-hot:
+ */
+static inline int
+task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
+{
+ s64 delta;
+
+ if (p->sched_class != &fair_sched_class)
+ return 0;
+
+ if (sysctl_sched_migration_cost == -1)
+ return 1;
+ if (sysctl_sched_migration_cost == 0)
+ return 0;
+
+ delta = now - p->se.exec_start;
+
+ return delta < (s64)sysctl_sched_migration_cost;
+}
+
+
void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
{
int old_cpu = task_cpu(p);
p->se.sleep_start -= clock_offset;
if (p->se.block_start)
p->se.block_start -= clock_offset;
+ if (old_cpu != new_cpu) {
+ schedstat_inc(p, se.nr_migrations);
+ if (task_hot(p, old_rq->clock, NULL))
+ schedstat_inc(p, se.nr_forced2_migrations);
+ }
#endif
p->se.vruntime -= old_cfsrq->min_vruntime -
new_cfsrq->min_vruntime;
int running, on_rq;
struct rq *rq;
-repeat:
- /*
- * We do the initial early heuristics without holding
- * any task-queue locks at all. We'll only try to get
- * the runqueue lock when things look like they will
- * work out!
- */
- rq = task_rq(p);
+ for (;;) {
+ /*
+ * We do the initial early heuristics without holding
+ * any task-queue locks at all. We'll only try to get
+ * the runqueue lock when things look like they will
+ * work out!
+ */
+ rq = task_rq(p);
- /*
- * If the task is actively running on another CPU
- * still, just relax and busy-wait without holding
- * any locks.
- *
- * NOTE! Since we don't hold any locks, it's not
- * even sure that "rq" stays as the right runqueue!
- * But we don't care, since "task_running()" will
- * return false if the runqueue has changed and p
- * is actually now running somewhere else!
- */
- while (task_running(rq, p))
- cpu_relax();
+ /*
+ * If the task is actively running on another CPU
+ * still, just relax and busy-wait without holding
+ * any locks.
+ *
+ * NOTE! Since we don't hold any locks, it's not
+ * even sure that "rq" stays as the right runqueue!
+ * But we don't care, since "task_running()" will
+ * return false if the runqueue has changed and p
+ * is actually now running somewhere else!
+ */
+ while (task_running(rq, p))
+ cpu_relax();
- /*
- * Ok, time to look more closely! We need the rq
- * lock now, to be *sure*. If we're wrong, we'll
- * just go back and repeat.
- */
- rq = task_rq_lock(p, &flags);
- running = task_running(rq, p);
- on_rq = p->se.on_rq;
- task_rq_unlock(rq, &flags);
+ /*
+ * Ok, time to look more closely! We need the rq
+ * lock now, to be *sure*. If we're wrong, we'll
+ * just go back and repeat.
+ */
+ rq = task_rq_lock(p, &flags);
+ running = task_running(rq, p);
+ on_rq = p->se.on_rq;
+ task_rq_unlock(rq, &flags);
- /*
- * Was it really running after all now that we
- * checked with the proper locks actually held?
- *
- * Oops. Go back and try again..
- */
- if (unlikely(running)) {
- cpu_relax();
- goto repeat;
- }
+ /*
+ * Was it really running after all now that we
+ * checked with the proper locks actually held?
+ *
+ * Oops. Go back and try again..
+ */
+ if (unlikely(running)) {
+ cpu_relax();
+ continue;
+ }
- /*
- * It's not enough that it's not actively running,
- * it must be off the runqueue _entirely_, and not
- * preempted!
- *
- * So if it wa still runnable (but just not actively
- * running right now), it's preempted, and we should
- * yield - it could be a while.
- */
- if (unlikely(on_rq)) {
- yield();
- goto repeat;
- }
+ /*
+ * It's not enough that it's not actively running,
+ * it must be off the runqueue _entirely_, and not
+ * preempted!
+ *
+ * So if it wa still runnable (but just not actively
+ * running right now), it's preempted, and we should
+ * yield - it could be a while.
+ */
+ if (unlikely(on_rq)) {
+ schedule_timeout_uninterruptible(1);
+ continue;
+ }
- /*
- * Ahh, all good. It wasn't running, and it wasn't
- * runnable, which means that it will never become
- * running in the future either. We're all done!
- */
+ /*
+ * Ahh, all good. It wasn't running, and it wasn't
+ * runnable, which means that it will never become
+ * running in the future either. We're all done!
+ */
+ break;
+ }
}
/***
/* Skip over this group if it has no CPUs allowed */
if (!cpus_intersects(group->cpumask, p->cpus_allowed))
- goto nextgroup;
+ continue;
local_group = cpu_isset(this_cpu, group->cpumask);
min_load = avg_load;
idlest = group;
}
-nextgroup:
- group = group->next;
- } while (group != sd->groups);
+ } while (group = group->next, group != sd->groups);
if (!idlest || 100*this_load < imbalance*min_load)
return NULL;
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 (idle_cpu(i)) {
+ if (i != task_cpu(p)) {
+ schedstat_inc(p,
+ se.nr_wakeups_idle);
+ }
return i;
+ }
}
} else {
break;
*/
static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
{
- int cpu, this_cpu, success = 0;
+ int cpu, orig_cpu, this_cpu, success = 0;
unsigned long flags;
long old_state;
struct rq *rq;
goto out_running;
cpu = task_cpu(p);
+ orig_cpu = cpu;
this_cpu = smp_processor_id();
#ifdef CONFIG_SMP
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);
/*
* there is no bad imbalance.
*/
schedstat_inc(this_sd, ttwu_move_affine);
+ schedstat_inc(p, se.nr_wakeups_affine);
goto out_set_cpu;
}
}
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;
}
}
out_activate:
#endif /* CONFIG_SMP */
+ schedstat_inc(p, se.nr_wakeups);
+ if (sync)
+ schedstat_inc(p, se.nr_wakeups_sync);
+ if (orig_cpu != cpu)
+ schedstat_inc(p, se.nr_wakeups_migrate);
+ if (cpu == this_cpu)
+ schedstat_inc(p, se.nr_wakeups_local);
+ else
+ schedstat_inc(p, se.nr_wakeups_remote);
update_rq_clock(rq);
activate_task(rq, p, 1);
- /*
- * Sync wakeups (i.e. those types of wakeups where the waker
- * has indicated that it will leave the CPU in short order)
- * don't trigger a preemption, if the woken up task will run on
- * this cpu. (in this case the 'I will reschedule' promise of
- * the waker guarantees that the freshly woken up task is going
- * to be considered on this CPU.)
- */
- if (!sync || cpu != this_cpu)
- check_preempt_curr(rq, p);
+ check_preempt_curr(rq, p);
success = 1;
out_running:
{
unsigned long flags;
struct rq *rq;
- int this_cpu;
rq = task_rq_lock(p, &flags);
BUG_ON(p->state != TASK_RUNNING);
- this_cpu = smp_processor_id(); /* parent's CPU */
update_rq_clock(rq);
p->prio = effective_prio(p);
- if (task_cpu(p) != this_cpu || !p->sched_class->task_new ||
- !current->se.on_rq) {
+ if (!p->sched_class->task_new || !current->se.on_rq) {
activate_task(rq, p, 0);
} else {
/*
* and do any other architecture-specific cleanup actions.
*
* Note that we may have delayed dropping an mm in context_switch(). If
- * so, we finish that here outside of the runqueue lock. (Doing it
+ * so, we finish that here outside of the runqueue lock. (Doing it
* with the lock held can cause deadlocks; see schedule() for
* details.)
*/
preempt_enable();
#endif
if (current->set_child_tid)
- put_user(current->pid, current->set_child_tid);
+ put_user(task_pid_vnr(current), current->set_child_tid);
}
/*
/*
* If dest_cpu is allowed for this process, migrate the task to it.
* This is accomplished by forcing the cpu_allowed mask to only
- * allow dest_cpu, which will force the cpu onto dest_cpu. Then
+ * allow dest_cpu, which will force the cpu onto dest_cpu. Then
* the cpu_allowed mask is restored.
*/
static void sched_migrate_task(struct task_struct *p, int dest_cpu)
* 2) cannot be migrated to this CPU due to cpus_allowed, or
* 3) are cache-hot on their current CPU.
*/
- if (!cpu_isset(this_cpu, p->cpus_allowed))
+ if (!cpu_isset(this_cpu, p->cpus_allowed)) {
+ schedstat_inc(p, se.nr_failed_migrations_affine);
return 0;
+ }
*all_pinned = 0;
- if (task_running(rq, p))
+ if (task_running(rq, p)) {
+ schedstat_inc(p, se.nr_failed_migrations_running);
return 0;
+ }
+
+ /*
+ * Aggressive migration if:
+ * 1) task is cache cold, or
+ * 2) too many balance attempts have failed.
+ */
+
+ if (!task_hot(p, rq->clock, sd) ||
+ sd->nr_balance_failed > sd->cache_nice_tries) {
+#ifdef CONFIG_SCHEDSTATS
+ if (task_hot(p, rq->clock, sd)) {
+ schedstat_inc(sd, lb_hot_gained[idle]);
+ schedstat_inc(p, se.nr_forced_migrations);
+ }
+#endif
+ return 1;
+ }
+ if (task_hot(p, rq->clock, sd)) {
+ schedstat_inc(p, se.nr_failed_migrations_hot);
+ return 0;
+ }
return 1;
}
-static int balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_nr_move, unsigned long max_load_move,
- struct sched_domain *sd, enum cpu_idle_type idle,
- int *all_pinned, unsigned long *load_moved,
- int *this_best_prio, struct rq_iterator *iterator)
+static unsigned long
+balance_tasks(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 rq_iterator *iterator)
{
- int pulled = 0, pinned = 0, skip_for_load;
+ int loops = 0, pulled = 0, pinned = 0, skip_for_load;
struct task_struct *p;
long rem_load_move = max_load_move;
- if (max_nr_move == 0 || max_load_move == 0)
+ if (max_load_move == 0)
goto out;
pinned = 1;
*/
p = iterator->start(iterator->arg);
next:
- if (!p)
+ if (!p || loops++ > sysctl_sched_nr_migrate)
goto out;
/*
- * To help distribute high priority tasks accross CPUs we don't
+ * To help distribute high priority tasks across CPUs we don't
* skip a task if it will be the highest priority task (i.e. smallest
* prio value) on its new queue regardless of its load weight
*/
rem_load_move -= p->se.load.weight;
/*
- * We only want to steal up to the prescribed number of tasks
- * and the prescribed amount of weighted load.
+ * We only want to steal up to the prescribed amount of weighted load.
*/
- if (pulled < max_nr_move && rem_load_move > 0) {
+ if (rem_load_move > 0) {
if (p->prio < *this_best_prio)
*this_best_prio = p->prio;
p = iterator->next(iterator->arg);
}
out:
/*
- * Right now, this is the only place pull_task() is called,
+ * Right now, this is one of only two places pull_task() is called,
* so we can safely collect pull_task() stats here rather than
* inside pull_task().
*/
if (all_pinned)
*all_pinned = pinned;
- *load_moved = max_load_move - rem_load_move;
- return pulled;
+
+ return max_load_move - rem_load_move;
}
/*
do {
total_load_moved +=
class->load_balance(this_rq, this_cpu, busiest,
- ULONG_MAX, max_load_move - total_load_moved,
+ max_load_move - total_load_moved,
sd, idle, all_pinned, &this_best_prio);
class = class->next;
} while (class && max_load_move > total_load_moved);
return total_load_moved > 0;
}
+static int
+iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
+ struct sched_domain *sd, enum cpu_idle_type idle,
+ struct rq_iterator *iterator)
+{
+ struct task_struct *p = iterator->start(iterator->arg);
+ int pinned = 0;
+
+ while (p) {
+ if (can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) {
+ pull_task(busiest, p, this_rq, this_cpu);
+ /*
+ * Right now, this is only the second place pull_task()
+ * is called, so we can safely collect pull_task()
+ * stats here rather than inside pull_task().
+ */
+ schedstat_inc(sd, lb_gained[idle]);
+
+ return 1;
+ }
+ p = iterator->next(iterator->arg);
+ }
+
+ return 0;
+}
+
/*
* move_one_task tries to move exactly one task from busiest to this_rq, as
* part of active balancing operations within "domain".
struct sched_domain *sd, enum cpu_idle_type idle)
{
const struct sched_class *class;
- int this_best_prio = MAX_PRIO;
for (class = sched_class_highest; class; class = class->next)
- if (class->load_balance(this_rq, this_cpu, busiest,
- 1, ULONG_MAX, sd, idle, NULL,
- &this_best_prio))
+ if (class->move_one_task(this_rq, this_cpu, busiest, sd, idle))
return 1;
return 0;
unsigned long max_pull;
unsigned long busiest_load_per_task, busiest_nr_running;
unsigned long this_load_per_task, this_nr_running;
- int load_idx;
+ int load_idx, group_imb = 0;
#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
int power_savings_balance = 1;
unsigned long leader_nr_running = 0, min_load_per_task = 0;
load_idx = sd->idle_idx;
do {
- unsigned long load, group_capacity;
+ unsigned long load, group_capacity, max_cpu_load, min_cpu_load;
int local_group;
int i;
+ int __group_imb = 0;
unsigned int balance_cpu = -1, first_idle_cpu = 0;
unsigned long sum_nr_running, sum_weighted_load;
/* Tally up the load of all CPUs in the group */
sum_weighted_load = sum_nr_running = avg_load = 0;
+ max_cpu_load = 0;
+ min_cpu_load = ~0UL;
for_each_cpu_mask(i, group->cpumask) {
struct rq *rq;
}
load = target_load(i, load_idx);
- } else
+ } else {
load = source_load(i, load_idx);
+ if (load > max_cpu_load)
+ max_cpu_load = load;
+ if (min_cpu_load > load)
+ min_cpu_load = load;
+ }
avg_load += load;
sum_nr_running += rq->nr_running;
avg_load = sg_div_cpu_power(group,
avg_load * SCHED_LOAD_SCALE);
+ if ((max_cpu_load - min_cpu_load) > SCHED_LOAD_SCALE)
+ __group_imb = 1;
+
group_capacity = group->__cpu_power / SCHED_LOAD_SCALE;
if (local_group) {
this_nr_running = sum_nr_running;
this_load_per_task = sum_weighted_load;
} else if (avg_load > max_load &&
- sum_nr_running > group_capacity) {
+ (sum_nr_running > group_capacity || __group_imb)) {
max_load = avg_load;
busiest = group;
busiest_nr_running = sum_nr_running;
busiest_load_per_task = sum_weighted_load;
+ group_imb = __group_imb;
}
#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
goto out_balanced;
busiest_load_per_task /= busiest_nr_running;
+ if (group_imb)
+ busiest_load_per_task = min(busiest_load_per_task, avg_load);
+
/*
* We're trying to get all the cpus to the average_load, so we don't
* want to push ourselves above the average load, nor do we wish to
* tasks around. Thus we look for the minimum possible imbalance.
* Negative imbalances (*we* are more loaded than anyone else) will
* be counted as no imbalance for these purposes -- we can't fix that
- * by pulling tasks to us. Be careful of negative numbers as they'll
+ * by pulling tasks to us. Be careful of negative numbers as they'll
* appear as very large values with unsigned longs.
*/
if (max_load <= busiest_load_per_task)
/*
* This condition is "impossible", if it occurs
- * we need to fix it. Originally reported by
+ * we need to fix it. Originally reported by
* Bjorn Helgaas on a 128-cpu setup.
*/
BUG_ON(busiest_rq == target_rq);
#ifdef CONFIG_NO_HZ
static struct {
atomic_t load_balancer;
- cpumask_t cpu_mask;
+ cpumask_t cpu_mask;
} nohz ____cacheline_aligned = {
.load_balancer = ATOMIC_INIT(-1),
.cpu_mask = CPU_MASK_NONE,
{
}
-/* Avoid "used but not defined" warning on UP */
-static int balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_nr_move, unsigned long max_load_move,
- struct sched_domain *sd, enum cpu_idle_type idle,
- int *all_pinned, unsigned long *load_moved,
- int *this_best_prio, struct rq_iterator *iterator)
-{
- *load_moved = 0;
-
- return 0;
-}
-
#endif
DEFINE_PER_CPU(struct kernel_stat, kstat);
rq = task_rq_lock(p, &flags);
ns = p->se.sum_exec_runtime;
- if (rq->curr == p) {
+ if (task_current(rq, p)) {
update_rq_clock(rq);
delta_exec = rq->clock - p->se.exec_start;
if ((s64)delta_exec > 0)
/*
* Account user cpu time to a process.
* @p: the process that the cpu time gets accounted to
- * @hardirq_offset: the offset to subtract from hardirq_count()
* @cputime: the cpu time spent in user space since the last update
*/
void account_user_time(struct task_struct *p, cputime_t cputime)
}
/*
+ * Account guest cpu time to a process.
+ * @p: the process that the cpu time gets accounted to
+ * @cputime: the cpu time spent in virtual machine since the last update
+ */
+static void account_guest_time(struct task_struct *p, cputime_t cputime)
+{
+ cputime64_t tmp;
+ struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+
+ tmp = cputime_to_cputime64(cputime);
+
+ p->utime = cputime_add(p->utime, cputime);
+ p->gtime = cputime_add(p->gtime, cputime);
+
+ cpustat->user = cputime64_add(cpustat->user, tmp);
+ cpustat->guest = cputime64_add(cpustat->guest, tmp);
+}
+
+/*
+ * Account scaled user cpu time to a process.
+ * @p: the process that the cpu time gets accounted to
+ * @cputime: the cpu time spent in user space since the last update
+ */
+void account_user_time_scaled(struct task_struct *p, cputime_t cputime)
+{
+ p->utimescaled = cputime_add(p->utimescaled, cputime);
+}
+
+/*
* Account system cpu time to a process.
* @p: the process that the cpu time gets accounted to
* @hardirq_offset: the offset to subtract from hardirq_count()
struct rq *rq = this_rq();
cputime64_t tmp;
+ if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0))
+ return account_guest_time(p, cputime);
+
p->stime = cputime_add(p->stime, cputime);
/* Add system time to cpustat. */
}
/*
+ * Account scaled system cpu time to a process.
+ * @p: the process that the cpu time gets accounted to
+ * @hardirq_offset: the offset to subtract from hardirq_count()
+ * @cputime: the cpu time spent in kernel space since the last update
+ */
+void account_system_time_scaled(struct task_struct *p, cputime_t cputime)
+{
+ p->stimescaled = cputime_add(p->stimescaled, cputime);
+}
+
+/*
* Account for involuntary wait time.
* @p: the process from which the cpu time has been stolen
* @steal: the cpu time spent in involuntary wait
*/
static noinline void __schedule_bug(struct task_struct *prev)
{
- printk(KERN_ERR "BUG: scheduling while atomic: %s/0x%08x/%d\n",
- prev->comm, preempt_count(), prev->pid);
+ struct pt_regs *regs = get_irq_regs();
+
+ printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n",
+ prev->comm, prev->pid, preempt_count());
+
debug_show_held_locks(prev);
if (irqs_disabled())
print_irqtrace_events(prev);
- dump_stack();
+
+ if (regs)
+ show_regs(regs);
+ else
+ dump_stack();
}
/*
static inline void schedule_debug(struct task_struct *prev)
{
/*
- * Test if we are atomic. Since do_exit() needs to call into
+ * Test if we are atomic. Since do_exit() needs to call into
* schedule() atomically, we ignore that path for now.
* Otherwise, whine if we are scheduling when we should not be.
*/
#ifdef CONFIG_PREEMPT
/*
* this is the entry point to schedule() from in-kernel preemption
- * off of preempt_enable. Kernel preemptions off return from interrupt
+ * off of preempt_enable. Kernel preemptions off return from interrupt
* occur there and call schedule directly.
*/
asmlinkage void __sched preempt_schedule(void)
#endif
/*
* If there is a non-zero preempt_count or interrupts are disabled,
- * we do not want to preempt the current task. Just return..
+ * we do not want to preempt the current task. Just return..
*/
if (likely(ti->preempt_count || irqs_disabled()))
return;
-need_resched:
- add_preempt_count(PREEMPT_ACTIVE);
- /*
- * We keep the big kernel semaphore locked, but we
- * clear ->lock_depth so that schedule() doesnt
- * auto-release the semaphore:
- */
+ do {
+ add_preempt_count(PREEMPT_ACTIVE);
+
+ /*
+ * We keep the big kernel semaphore locked, but we
+ * 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;
+ saved_lock_depth = task->lock_depth;
+ task->lock_depth = -1;
#endif
- schedule();
+ schedule();
#ifdef CONFIG_PREEMPT_BKL
- task->lock_depth = saved_lock_depth;
+ task->lock_depth = saved_lock_depth;
#endif
- sub_preempt_count(PREEMPT_ACTIVE);
+ sub_preempt_count(PREEMPT_ACTIVE);
- /* we could miss a preemption opportunity between schedule and now */
- barrier();
- if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
- goto need_resched;
+ /*
+ * Check again in case we missed a preemption opportunity
+ * between schedule and now.
+ */
+ barrier();
+ } while (unlikely(test_thread_flag(TIF_NEED_RESCHED)));
}
EXPORT_SYMBOL(preempt_schedule);
/* Catch callers which need to be fixed */
BUG_ON(ti->preempt_count || !irqs_disabled());
-need_resched:
- add_preempt_count(PREEMPT_ACTIVE);
- /*
- * We keep the big kernel semaphore locked, but we
- * clear ->lock_depth so that schedule() doesnt
- * auto-release the semaphore:
- */
+ do {
+ add_preempt_count(PREEMPT_ACTIVE);
+
+ /*
+ * We keep the big kernel semaphore locked, but we
+ * 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;
+ saved_lock_depth = task->lock_depth;
+ task->lock_depth = -1;
#endif
- local_irq_enable();
- schedule();
- local_irq_disable();
+ local_irq_enable();
+ schedule();
+ local_irq_disable();
#ifdef CONFIG_PREEMPT_BKL
- task->lock_depth = saved_lock_depth;
+ task->lock_depth = saved_lock_depth;
#endif
- sub_preempt_count(PREEMPT_ACTIVE);
+ sub_preempt_count(PREEMPT_ACTIVE);
- /* we could miss a preemption opportunity between schedule and now */
- barrier();
- if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
- goto need_resched;
+ /*
+ * Check again in case we missed a preemption opportunity
+ * between schedule and now.
+ */
+ barrier();
+ } while (unlikely(test_thread_flag(TIF_NEED_RESCHED)));
}
#endif /* CONFIG_PREEMPT */
EXPORT_SYMBOL(default_wake_function);
/*
- * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just
- * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve
+ * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just
+ * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve
* number) then we wake all the non-exclusive tasks and one exclusive task.
*
* There are circumstances in which we can try to wake a task which has already
- * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns
+ * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns
* zero in this (rare) case, and we handle it by continuing to scan the queue.
*/
static void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
}
EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */
-void fastcall complete(struct completion *x)
+void complete(struct completion *x)
{
unsigned long flags;
}
EXPORT_SYMBOL(complete);
-void fastcall complete_all(struct completion *x)
+void complete_all(struct completion *x)
{
unsigned long flags;
}
EXPORT_SYMBOL(complete_all);
-void fastcall __sched wait_for_completion(struct completion *x)
-{
- might_sleep();
-
- spin_lock_irq(&x->wait.lock);
- if (!x->done) {
- DECLARE_WAITQUEUE(wait, current);
-
- wait.flags |= WQ_FLAG_EXCLUSIVE;
- __add_wait_queue_tail(&x->wait, &wait);
- do {
- __set_current_state(TASK_UNINTERRUPTIBLE);
- spin_unlock_irq(&x->wait.lock);
- schedule();
- spin_lock_irq(&x->wait.lock);
- } while (!x->done);
- __remove_wait_queue(&x->wait, &wait);
- }
- x->done--;
- spin_unlock_irq(&x->wait.lock);
-}
-EXPORT_SYMBOL(wait_for_completion);
-
-unsigned long fastcall __sched
-wait_for_completion_timeout(struct completion *x, unsigned long timeout)
+static inline long __sched
+do_wait_for_common(struct completion *x, long timeout, int state)
{
- might_sleep();
-
- spin_lock_irq(&x->wait.lock);
if (!x->done) {
DECLARE_WAITQUEUE(wait, current);
wait.flags |= WQ_FLAG_EXCLUSIVE;
__add_wait_queue_tail(&x->wait, &wait);
do {
- __set_current_state(TASK_UNINTERRUPTIBLE);
+ if (state == TASK_INTERRUPTIBLE &&
+ signal_pending(current)) {
+ __remove_wait_queue(&x->wait, &wait);
+ return -ERESTARTSYS;
+ }
+ __set_current_state(state);
spin_unlock_irq(&x->wait.lock);
timeout = schedule_timeout(timeout);
spin_lock_irq(&x->wait.lock);
if (!timeout) {
__remove_wait_queue(&x->wait, &wait);
- goto out;
+ return timeout;
}
} while (!x->done);
__remove_wait_queue(&x->wait, &wait);
}
x->done--;
-out:
- spin_unlock_irq(&x->wait.lock);
return timeout;
}
-EXPORT_SYMBOL(wait_for_completion_timeout);
-int fastcall __sched wait_for_completion_interruptible(struct completion *x)
+static long __sched
+wait_for_common(struct completion *x, long timeout, int state)
{
- int ret = 0;
-
might_sleep();
spin_lock_irq(&x->wait.lock);
- if (!x->done) {
- DECLARE_WAITQUEUE(wait, current);
-
- wait.flags |= WQ_FLAG_EXCLUSIVE;
- __add_wait_queue_tail(&x->wait, &wait);
- do {
- if (signal_pending(current)) {
- ret = -ERESTARTSYS;
- __remove_wait_queue(&x->wait, &wait);
- goto out;
- }
- __set_current_state(TASK_INTERRUPTIBLE);
- spin_unlock_irq(&x->wait.lock);
- schedule();
- spin_lock_irq(&x->wait.lock);
- } while (!x->done);
- __remove_wait_queue(&x->wait, &wait);
- }
- x->done--;
-out:
+ timeout = do_wait_for_common(x, timeout, state);
spin_unlock_irq(&x->wait.lock);
-
- return ret;
+ return timeout;
}
-EXPORT_SYMBOL(wait_for_completion_interruptible);
-unsigned long fastcall __sched
-wait_for_completion_interruptible_timeout(struct completion *x,
- unsigned long timeout)
+void __sched wait_for_completion(struct completion *x)
{
- might_sleep();
-
- spin_lock_irq(&x->wait.lock);
- if (!x->done) {
- DECLARE_WAITQUEUE(wait, current);
+ wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL(wait_for_completion);
- wait.flags |= WQ_FLAG_EXCLUSIVE;
- __add_wait_queue_tail(&x->wait, &wait);
- do {
- if (signal_pending(current)) {
- timeout = -ERESTARTSYS;
- __remove_wait_queue(&x->wait, &wait);
- goto out;
- }
- __set_current_state(TASK_INTERRUPTIBLE);
- spin_unlock_irq(&x->wait.lock);
- timeout = schedule_timeout(timeout);
- spin_lock_irq(&x->wait.lock);
- if (!timeout) {
- __remove_wait_queue(&x->wait, &wait);
- goto out;
- }
- } while (!x->done);
- __remove_wait_queue(&x->wait, &wait);
- }
- x->done--;
-out:
- spin_unlock_irq(&x->wait.lock);
- return timeout;
+unsigned long __sched
+wait_for_completion_timeout(struct completion *x, unsigned long timeout)
+{
+ return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE);
}
-EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
+EXPORT_SYMBOL(wait_for_completion_timeout);
-static inline void
-sleep_on_head(wait_queue_head_t *q, wait_queue_t *wait, unsigned long *flags)
+int __sched wait_for_completion_interruptible(struct completion *x)
{
- spin_lock_irqsave(&q->lock, *flags);
- __add_wait_queue(q, wait);
- spin_unlock(&q->lock);
+ long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE);
+ if (t == -ERESTARTSYS)
+ return t;
+ return 0;
}
+EXPORT_SYMBOL(wait_for_completion_interruptible);
-static inline void
-sleep_on_tail(wait_queue_head_t *q, wait_queue_t *wait, unsigned long *flags)
+unsigned long __sched
+wait_for_completion_interruptible_timeout(struct completion *x,
+ unsigned long timeout)
{
- spin_lock_irq(&q->lock);
- __remove_wait_queue(q, wait);
- spin_unlock_irqrestore(&q->lock, *flags);
+ return wait_for_common(x, timeout, TASK_INTERRUPTIBLE);
}
+EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
-void __sched interruptible_sleep_on(wait_queue_head_t *q)
+static long __sched
+sleep_on_common(wait_queue_head_t *q, int state, long timeout)
{
unsigned long flags;
wait_queue_t wait;
init_waitqueue_entry(&wait, current);
- current->state = TASK_INTERRUPTIBLE;
+ __set_current_state(state);
- sleep_on_head(q, &wait, &flags);
- schedule();
- sleep_on_tail(q, &wait, &flags);
+ spin_lock_irqsave(&q->lock, flags);
+ __add_wait_queue(q, &wait);
+ spin_unlock(&q->lock);
+ timeout = schedule_timeout(timeout);
+ spin_lock_irq(&q->lock);
+ __remove_wait_queue(q, &wait);
+ spin_unlock_irqrestore(&q->lock, flags);
+
+ return timeout;
+}
+
+void __sched interruptible_sleep_on(wait_queue_head_t *q)
+{
+ sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
}
EXPORT_SYMBOL(interruptible_sleep_on);
long __sched
interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout)
{
- unsigned long flags;
- wait_queue_t wait;
-
- init_waitqueue_entry(&wait, current);
-
- current->state = TASK_INTERRUPTIBLE;
-
- sleep_on_head(q, &wait, &flags);
- timeout = schedule_timeout(timeout);
- sleep_on_tail(q, &wait, &flags);
-
- return timeout;
+ return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout);
}
EXPORT_SYMBOL(interruptible_sleep_on_timeout);
void __sched sleep_on(wait_queue_head_t *q)
{
- unsigned long flags;
- wait_queue_t wait;
-
- init_waitqueue_entry(&wait, current);
-
- current->state = TASK_UNINTERRUPTIBLE;
-
- sleep_on_head(q, &wait, &flags);
- schedule();
- sleep_on_tail(q, &wait, &flags);
+ sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
}
EXPORT_SYMBOL(sleep_on);
long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout)
{
- unsigned long flags;
- wait_queue_t wait;
-
- init_waitqueue_entry(&wait, current);
-
- current->state = TASK_UNINTERRUPTIBLE;
-
- sleep_on_head(q, &wait, &flags);
- timeout = schedule_timeout(timeout);
- sleep_on_tail(q, &wait, &flags);
-
- return timeout;
+ return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout);
}
EXPORT_SYMBOL(sleep_on_timeout);
oldprio = p->prio;
on_rq = p->se.on_rq;
- running = task_running(rq, p);
+ running = task_current(rq, p);
if (on_rq) {
dequeue_task(rq, p, 0);
if (running)
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);
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:
*/
static struct task_struct *find_process_by_pid(pid_t pid)
{
- return pid ? find_task_by_pid(pid) : current;
+ return pid ? find_task_by_vpid(pid) : current;
}
/* Actually do priority change: must hold rq lock. */
}
update_rq_clock(rq);
on_rq = p->se.on_rq;
- running = task_running(rq, p);
+ running = task_current(rq, p);
if (on_rq) {
deactivate_task(rq, p, 0);
if (running)
* @policy: new policy.
* @param: structure containing the new RT priority.
*/
-asmlinkage long sys_sched_setscheduler(pid_t pid, int policy,
- struct sched_param __user *param)
+asmlinkage long
+sys_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param)
{
/* negative values for policy are not valid */
if (policy < 0)
asmlinkage long sys_sched_getscheduler(pid_t pid)
{
struct task_struct *p;
- int retval = -EINVAL;
+ int retval;
if (pid < 0)
- goto out_nounlock;
+ return -EINVAL;
retval = -ESRCH;
read_lock(&tasklist_lock);
retval = p->policy;
}
read_unlock(&tasklist_lock);
-
-out_nounlock:
return retval;
}
{
struct sched_param lp;
struct task_struct *p;
- int retval = -EINVAL;
+ int retval;
if (!param || pid < 0)
- goto out_nounlock;
+ return -EINVAL;
read_lock(&tasklist_lock);
p = find_process_by_pid(pid);
*/
retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0;
-out_nounlock:
return retval;
out_unlock:
/*
* It is not safe to call set_cpus_allowed with the
- * tasklist_lock held. We will bump the task_struct's
+ * tasklist_lock held. We will bump the task_struct's
* usage count and then drop tasklist_lock.
*/
get_task_struct(p);
cpus_allowed = cpuset_cpus_allowed(p);
cpus_and(new_mask, new_mask, cpus_allowed);
+ again:
retval = set_cpus_allowed(p, new_mask);
+ if (!retval) {
+ cpus_allowed = cpuset_cpus_allowed(p);
+ if (!cpus_subset(new_mask, cpus_allowed)) {
+ /*
+ * We must have raced with a concurrent cpuset
+ * update. Just reset the cpus_allowed to the
+ * cpuset's cpus_allowed
+ */
+ new_mask = cpus_allowed;
+ goto again;
+ }
+ }
out_unlock:
put_task_struct(p);
mutex_unlock(&sched_hotcpu_mutex);
* cond_resched_lock() - if a reschedule is pending, drop the given lock,
* call schedule, and on return reacquire the lock.
*
- * This works OK both with and without CONFIG_PREEMPT. We do strange low-level
+ * This works OK both with and without CONFIG_PREEMPT. We do strange low-level
* operations here to prevent schedule() from being called twice (once via
* spin_unlock(), once by hand).
*/
EXPORT_SYMBOL(yield);
/*
- * This task is about to go to sleep on IO. Increment rq->nr_iowait so
+ * This task is about to go to sleep on IO. Increment rq->nr_iowait so
* that process accounting knows that this is a task in IO wait state.
*
* But don't do that if it is a deliberate, throttling IO wait (this task
{
struct task_struct *p;
unsigned int time_slice;
- int retval = -EINVAL;
+ int retval;
struct timespec t;
if (pid < 0)
- goto out_nounlock;
+ return -EINVAL;
retval = -ESRCH;
read_lock(&tasklist_lock);
if (retval)
goto out_unlock;
- if (p->policy == SCHED_FIFO)
- time_slice = 0;
- else if (p->policy == SCHED_RR)
+ /*
+ * Time slice is 0 for SCHED_FIFO tasks and for SCHED_OTHER
+ * tasks that are on an otherwise idle runqueue:
+ */
+ time_slice = 0;
+ if (p->policy == SCHED_RR) {
time_slice = DEF_TIMESLICE;
- else {
+ } else {
struct sched_entity *se = &p->se;
unsigned long flags;
struct rq *rq;
rq = task_rq_lock(p, &flags);
- time_slice = NS_TO_JIFFIES(sched_slice(cfs_rq_of(se), se));
+ if (rq->cfs.load.weight)
+ time_slice = NS_TO_JIFFIES(sched_slice(&rq->cfs, se));
task_rq_unlock(rq, &flags);
}
read_unlock(&tasklist_lock);
jiffies_to_timespec(time_slice, &t);
retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
-out_nounlock:
return retval;
+
out_unlock:
read_unlock(&tasklist_lock);
return retval;
unsigned state;
state = p->state ? __ffs(p->state) + 1 : 0;
- printk("%-13.13s %c", p->comm,
+ printk(KERN_INFO "%-13.13s %c", p->comm,
state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
#if BITS_PER_LONG == 32
if (state == TASK_RUNNING)
- printk(" running ");
+ printk(KERN_CONT " running ");
else
- printk(" %08lx ", thread_saved_pc(p));
+ printk(KERN_CONT " %08lx ", thread_saved_pc(p));
#else
if (state == TASK_RUNNING)
- printk(" running task ");
+ printk(KERN_CONT " running task ");
else
- printk(" %016lx ", thread_saved_pc(p));
+ printk(KERN_CONT " %016lx ", thread_saved_pc(p));
#endif
#ifdef CONFIG_DEBUG_STACK_USAGE
{
free = (unsigned long)n - (unsigned long)end_of_stack(p);
}
#endif
- printk("%5lu %5d %6d\n", free, p->pid, p->parent->pid);
+ 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);
*/
cpumask_t nohz_cpu_mask = CPU_MASK_NONE;
+/*
+ * Increase the granularity value when there are more CPUs,
+ * because with more CPUs the 'effective latency' as visible
+ * to users decreases. But the relationship is not linear,
+ * so pick a second-best guess by going with the log2 of the
+ * number of CPUs.
+ *
+ * This idea comes from the SD scheduler of Con Kolivas:
+ */
+static inline void sched_init_granularity(void)
+{
+ unsigned int factor = 1 + ilog2(num_online_cpus());
+ const unsigned long limit = 200000000;
+
+ sysctl_sched_min_granularity *= factor;
+ if (sysctl_sched_min_granularity > limit)
+ sysctl_sched_min_granularity = limit;
+
+ sysctl_sched_latency *= factor;
+ if (sysctl_sched_latency > limit)
+ sysctl_sched_latency = limit;
+
+ sysctl_sched_wakeup_granularity *= factor;
+ sysctl_sched_batch_wakeup_granularity *= factor;
+}
+
#ifdef CONFIG_SMP
/*
* This is how migration works:
* is removed from the allowed bitmask.
*
* NOTE: the caller must have a valid reference to the task, the
- * task must not exit() & deallocate itself prematurely. The
+ * task must not exit() & deallocate itself prematurely. The
* call is not atomic; no spinlocks may be held.
*/
int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
EXPORT_SYMBOL_GPL(set_cpus_allowed);
/*
- * Move (not current) task off this cpu, onto dest cpu. We're doing
+ * Move (not current) task off this cpu, onto dest cpu. We're doing
* this because either it can't run here any more (set_cpus_allowed()
* away from this CPU, or CPU going down), or because we're
* attempting to rebalance this task on exec (sched_exec).
}
#ifdef CONFIG_HOTPLUG_CPU
+
+static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu)
+{
+ int ret;
+
+ local_irq_disable();
+ ret = __migrate_task(p, src_cpu, dest_cpu);
+ local_irq_enable();
+ return ret;
+}
+
/*
- * Figure out where task on dead CPU should go, use force if neccessary.
+ * Figure out where task on dead CPU should go, use force if necessary.
* NOTE: interrupts should be disabled by the caller
*/
static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
struct rq *rq;
int dest_cpu;
-restart:
- /* On same node? */
- mask = node_to_cpumask(cpu_to_node(dead_cpu));
- cpus_and(mask, mask, p->cpus_allowed);
- dest_cpu = any_online_cpu(mask);
-
- /* On any allowed CPU? */
- if (dest_cpu == NR_CPUS)
- dest_cpu = any_online_cpu(p->cpus_allowed);
-
- /* No more Mr. Nice Guy. */
- if (dest_cpu == NR_CPUS) {
- rq = task_rq_lock(p, &flags);
- cpus_setall(p->cpus_allowed);
- dest_cpu = any_online_cpu(p->cpus_allowed);
- task_rq_unlock(rq, &flags);
+ do {
+ /* On same node? */
+ mask = node_to_cpumask(cpu_to_node(dead_cpu));
+ cpus_and(mask, mask, p->cpus_allowed);
+ dest_cpu = any_online_cpu(mask);
+
+ /* On any allowed CPU? */
+ if (dest_cpu == NR_CPUS)
+ dest_cpu = any_online_cpu(p->cpus_allowed);
+
+ /* No more Mr. Nice Guy. */
+ if (dest_cpu == NR_CPUS) {
+ cpumask_t cpus_allowed = cpuset_cpus_allowed_locked(p);
+ /*
+ * Try to stay on the same cpuset, where the
+ * current cpuset may be a subset of all cpus.
+ * The cpuset_cpus_allowed_locked() variant of
+ * cpuset_cpus_allowed() will not block. It must be
+ * called within calls to cpuset_lock/cpuset_unlock.
+ */
+ rq = task_rq_lock(p, &flags);
+ p->cpus_allowed = cpus_allowed;
+ dest_cpu = any_online_cpu(p->cpus_allowed);
+ task_rq_unlock(rq, &flags);
- /*
- * Don't tell them about moving exiting tasks or
- * kernel threads (both mm NULL), since they never
- * leave kernel.
- */
- if (p->mm && printk_ratelimit())
- printk(KERN_INFO "process %d (%s) no "
- "longer affine to cpu%d\n",
- p->pid, p->comm, dead_cpu);
- }
- if (!__migrate_task(p, dead_cpu, dest_cpu))
- goto restart;
+ /*
+ * Don't tell them about moving exiting tasks or
+ * kernel threads (both mm NULL), since they never
+ * leave kernel.
+ */
+ if (p->mm && printk_ratelimit()) {
+ printk(KERN_INFO "process %d (%s) no "
+ "longer affine to cpu%d\n",
+ task_pid_nr(p), p->comm, dead_cpu);
+ }
+ }
+ } while (!__migrate_task_irq(p, dead_cpu, dest_cpu));
}
/*
{
struct task_struct *p, *t;
- write_lock_irq(&tasklist_lock);
+ read_lock(&tasklist_lock);
do_each_thread(t, p) {
if (p == current)
move_task_off_dead_cpu(src_cpu, p);
} while_each_thread(t, p);
- write_unlock_irq(&tasklist_lock);
-}
-
-/*
- * activate_idle_task - move idle task to the _front_ of runqueue.
- */
-static void activate_idle_task(struct task_struct *p, struct rq *rq)
-{
- update_rq_clock(rq);
-
- if (p->state == TASK_UNINTERRUPTIBLE)
- rq->nr_uninterruptible--;
-
- enqueue_task(rq, p, 0);
- inc_nr_running(p, rq);
+ read_unlock(&tasklist_lock);
}
/*
* Schedules idle task to be the next runnable task on current CPU.
- * It does so by boosting its priority to highest possible and adding it to
- * the _front_ of the runqueue. Used by CPU offline code.
+ * It does so by boosting its priority to highest possible.
+ * Used by CPU offline code.
*/
void sched_idle_next(void)
{
__setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1);
- /* Add idle task to the _front_ of its priority queue: */
- activate_idle_task(p, rq);
+ update_rq_clock(rq);
+ activate_task(rq, p, 0);
spin_unlock_irqrestore(&rq->lock, flags);
}
struct rq *rq = cpu_rq(dead_cpu);
/* Must be exiting, otherwise would be on tasklist. */
- BUG_ON(p->exit_state != EXIT_ZOMBIE && p->exit_state != EXIT_DEAD);
+ BUG_ON(!p->exit_state);
/* Cannot have done final schedule yet: would have vanished. */
BUG_ON(p->state == TASK_DEAD);
/*
* Drop lock around migration; if someone else moves it,
- * that's OK. No task can be added to this CPU, so iteration is
+ * that's OK. No task can be added to this CPU, so iteration is
* fine.
- * NOTE: interrupts should be left disabled --dev@
*/
- spin_unlock(&rq->lock);
+ spin_unlock_irq(&rq->lock);
move_task_off_dead_cpu(dead_cpu, p);
- spin_lock(&rq->lock);
+ spin_lock_irq(&rq->lock);
put_task_struct(p);
}
.procname = "sched_domain",
.mode = 0555,
},
- {0,},
+ {0, },
};
static struct ctl_table sd_ctl_root[] = {
.mode = 0555,
.child = sd_ctl_dir,
},
- {0,},
+ {0, },
};
static struct ctl_table *sd_alloc_ctl_entry(int n)
{
struct ctl_table *entry =
- kmalloc(n * sizeof(struct ctl_table), GFP_KERNEL);
-
- BUG_ON(!entry);
- memset(entry, 0, n * sizeof(struct ctl_table));
+ kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL);
return entry;
}
+static void sd_free_ctl_entry(struct ctl_table **tablep)
+{
+ struct ctl_table *entry;
+
+ /*
+ * In the intermediate directories, both the child directory and
+ * procname are dynamically allocated and could fail but the mode
+ * will always be set. In the lowest directory the names are
+ * static strings and all have proc handlers.
+ */
+ for (entry = *tablep; entry->mode; entry++) {
+ if (entry->child)
+ sd_free_ctl_entry(&entry->child);
+ if (entry->proc_handler == NULL)
+ kfree(entry->procname);
+ }
+
+ kfree(*tablep);
+ *tablep = NULL;
+}
+
static void
set_table_entry(struct ctl_table *entry,
const char *procname, void *data, int maxlen,
static struct ctl_table *
sd_alloc_ctl_domain_table(struct sched_domain *sd)
{
- struct ctl_table *table = sd_alloc_ctl_entry(14);
+ struct ctl_table *table = sd_alloc_ctl_entry(12);
+
+ if (table == NULL)
+ return NULL;
set_table_entry(&table[0], "min_interval", &sd->min_interval,
sizeof(long), 0644, proc_doulongvec_minmax);
sizeof(int), 0644, proc_dointvec_minmax);
set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct,
sizeof(int), 0644, proc_dointvec_minmax);
- set_table_entry(&table[10], "cache_nice_tries",
+ set_table_entry(&table[9], "cache_nice_tries",
&sd->cache_nice_tries,
sizeof(int), 0644, proc_dointvec_minmax);
- set_table_entry(&table[12], "flags", &sd->flags,
+ set_table_entry(&table[10], "flags", &sd->flags,
sizeof(int), 0644, proc_dointvec_minmax);
+ /* &table[11] is terminator */
return table;
}
for_each_domain(cpu, sd)
domain_num++;
entry = table = sd_alloc_ctl_entry(domain_num + 1);
+ if (table == NULL)
+ return NULL;
i = 0;
for_each_domain(cpu, sd) {
}
static struct ctl_table_header *sd_sysctl_header;
-static void init_sched_domain_sysctl(void)
+static void register_sched_domain_sysctl(void)
{
int i, cpu_num = num_online_cpus();
struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
char buf[32];
+ WARN_ON(sd_ctl_dir[0].child);
sd_ctl_dir[0].child = entry;
- for (i = 0; i < cpu_num; i++, entry++) {
+ if (entry == NULL)
+ return;
+
+ for_each_online_cpu(i) {
snprintf(buf, 32, "cpu%d", i);
entry->procname = kstrdup(buf, GFP_KERNEL);
entry->mode = 0555;
entry->child = sd_alloc_ctl_cpu_table(i);
+ entry++;
}
+
+ WARN_ON(sd_sysctl_header);
sd_sysctl_header = register_sysctl_table(sd_ctl_root);
}
+
+/* may be called multiple times per register */
+static void unregister_sched_domain_sysctl(void)
+{
+ if (sd_sysctl_header)
+ unregister_sysctl_table(sd_sysctl_header);
+ sd_sysctl_header = NULL;
+ if (sd_ctl_dir[0].child)
+ sd_free_ctl_entry(&sd_ctl_dir[0].child);
+}
#else
-static void init_sched_domain_sysctl(void)
+static void register_sched_domain_sysctl(void)
+{
+}
+static void unregister_sched_domain_sysctl(void)
{
}
#endif
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
- /* Strictly unneccessary, as first user will wake it. */
+ /* Strictly unnecessary, as first user will wake it. */
wake_up_process(cpu_rq(cpu)->migration_thread);
break;
case CPU_UP_CANCELED_FROZEN:
if (!cpu_rq(cpu)->migration_thread)
break;
- /* Unbind it from offline cpu so it can run. Fall thru. */
+ /* Unbind it from offline cpu so it can run. Fall thru. */
kthread_bind(cpu_rq(cpu)->migration_thread,
any_online_cpu(cpu_online_map));
kthread_stop(cpu_rq(cpu)->migration_thread);
case CPU_DEAD:
case CPU_DEAD_FROZEN:
+ cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */
migrate_live_tasks(cpu);
rq = cpu_rq(cpu);
kthread_stop(rq->migration_thread);
rq->migration_thread = NULL;
/* Idle task back to normal (off runqueue, low prio) */
- rq = task_rq_lock(rq->idle, &flags);
+ spin_lock_irq(&rq->lock);
update_rq_clock(rq);
deactivate_task(rq, rq->idle, 0);
rq->idle->static_prio = MAX_PRIO;
__setscheduler(rq, rq->idle, SCHED_NORMAL, 0);
rq->idle->sched_class = &idle_sched_class;
migrate_dead_tasks(cpu);
- task_rq_unlock(rq, &flags);
+ spin_unlock_irq(&rq->lock);
+ cpuset_unlock();
migrate_nr_uninterruptible(rq);
BUG_ON(rq->nr_running != 0);
- /* No need to migrate the tasks: it was best-effort if
- * they didn't take sched_hotcpu_mutex. Just wake up
- * the requestors. */
+ /*
+ * No need to migrate the tasks: it was best-effort if
+ * they didn't take sched_hotcpu_mutex. Just wake up
+ * the requestors.
+ */
spin_lock_irq(&rq->lock);
while (!list_empty(&rq->migration_queue)) {
struct migration_req *req;
.priority = 10
};
-int __init migration_init(void)
+void __init migration_init(void)
{
void *cpu = (void *)(long)smp_processor_id();
int err;
BUG_ON(err == NOTIFY_BAD);
migration_call(&migration_notifier, CPU_ONLINE, cpu);
register_cpu_notifier(&migration_notifier);
-
- return 0;
}
#endif
EXPORT_SYMBOL(nr_cpu_ids);
#ifdef CONFIG_SCHED_DEBUG
-static void sched_domain_debug(struct sched_domain *sd, int cpu)
+
+static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level)
{
- int level = 0;
+ struct sched_group *group = sd->groups;
+ cpumask_t groupmask;
+ char str[NR_CPUS];
- if (!sd) {
- printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu);
- return;
- }
+ cpumask_scnprintf(str, NR_CPUS, sd->span);
+ cpus_clear(groupmask);
- printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu);
+ printk(KERN_DEBUG "%*s domain %d: ", level, "", level);
- do {
- int i;
- char str[NR_CPUS];
- struct sched_group *group = sd->groups;
- cpumask_t groupmask;
-
- cpumask_scnprintf(str, NR_CPUS, sd->span);
- cpus_clear(groupmask);
-
- printk(KERN_DEBUG);
- for (i = 0; i < level + 1; i++)
- printk(" ");
- printk("domain %d: ", level);
-
- if (!(sd->flags & SD_LOAD_BALANCE)) {
- printk("does not load-balance\n");
- if (sd->parent)
- printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain"
- " has parent");
- break;
- }
+ if (!(sd->flags & SD_LOAD_BALANCE)) {
+ printk("does not load-balance\n");
+ if (sd->parent)
+ printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain"
+ " has parent");
+ return -1;
+ }
- printk("span %s\n", str);
+ printk(KERN_CONT "span %s\n", str);
- if (!cpu_isset(cpu, sd->span))
- printk(KERN_ERR "ERROR: domain->span does not contain "
- "CPU%d\n", cpu);
- if (!cpu_isset(cpu, group->cpumask))
- printk(KERN_ERR "ERROR: domain->groups does not contain"
- " CPU%d\n", cpu);
+ if (!cpu_isset(cpu, sd->span)) {
+ printk(KERN_ERR "ERROR: domain->span does not contain "
+ "CPU%d\n", cpu);
+ }
+ if (!cpu_isset(cpu, group->cpumask)) {
+ printk(KERN_ERR "ERROR: domain->groups does not contain"
+ " CPU%d\n", cpu);
+ }
- printk(KERN_DEBUG);
- for (i = 0; i < level + 2; i++)
- printk(" ");
- printk("groups:");
- do {
- if (!group) {
- printk("\n");
- printk(KERN_ERR "ERROR: group is NULL\n");
- break;
- }
+ printk(KERN_DEBUG "%*s groups:", level + 1, "");
+ do {
+ if (!group) {
+ printk("\n");
+ printk(KERN_ERR "ERROR: group is NULL\n");
+ break;
+ }
- if (!group->__cpu_power) {
- printk("\n");
- printk(KERN_ERR "ERROR: domain->cpu_power not "
- "set\n");
- break;
- }
+ if (!group->__cpu_power) {
+ printk(KERN_CONT "\n");
+ printk(KERN_ERR "ERROR: domain->cpu_power not "
+ "set\n");
+ break;
+ }
- if (!cpus_weight(group->cpumask)) {
- printk("\n");
- printk(KERN_ERR "ERROR: empty group\n");
- break;
- }
+ if (!cpus_weight(group->cpumask)) {
+ printk(KERN_CONT "\n");
+ printk(KERN_ERR "ERROR: empty group\n");
+ break;
+ }
- if (cpus_intersects(groupmask, group->cpumask)) {
- printk("\n");
- printk(KERN_ERR "ERROR: repeated CPUs\n");
- break;
- }
+ if (cpus_intersects(groupmask, group->cpumask)) {
+ printk(KERN_CONT "\n");
+ printk(KERN_ERR "ERROR: repeated CPUs\n");
+ break;
+ }
- cpus_or(groupmask, groupmask, group->cpumask);
+ cpus_or(groupmask, groupmask, group->cpumask);
- cpumask_scnprintf(str, NR_CPUS, group->cpumask);
- printk(" %s", str);
+ cpumask_scnprintf(str, NR_CPUS, group->cpumask);
+ printk(KERN_CONT " %s", str);
- group = group->next;
- } while (group != sd->groups);
- printk("\n");
+ group = group->next;
+ } while (group != sd->groups);
+ printk(KERN_CONT "\n");
+
+ if (!cpus_equal(sd->span, groupmask))
+ printk(KERN_ERR "ERROR: groups don't span domain->span\n");
- if (!cpus_equal(sd->span, groupmask))
- printk(KERN_ERR "ERROR: groups don't span "
- "domain->span\n");
+ if (sd->parent && !cpus_subset(groupmask, sd->parent->span))
+ printk(KERN_ERR "ERROR: parent span is not a superset "
+ "of domain->span\n");
+ return 0;
+}
+static void sched_domain_debug(struct sched_domain *sd, int cpu)
+{
+ int level = 0;
+
+ if (!sd) {
+ printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu);
+ return;
+ }
+
+ printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu);
+
+ for (;;) {
+ if (sched_domain_debug_one(sd, cpu, level))
+ break;
level++;
sd = sd->parent;
if (!sd)
- continue;
-
- if (!cpus_subset(groupmask, sd->span))
- printk(KERN_ERR "ERROR: parent span is not a superset "
- "of domain->span\n");
-
- } while (sd);
+ break;
+ }
}
#else
# define sched_domain_debug(sd, cpu) do { } while (0)
* @node: node whose sched_domain we're building
* @used_nodes: nodes already in the sched_domain
*
- * Find the next node to include in a given scheduling domain. Simply
+ * Find the next node to include in a given scheduling domain. Simply
* finds the closest node not already in the @used_nodes map.
*
* Should use nodemask_t.
* @node: node whose cpumask we're constructing
* @size: number of nodes to include in this span
*
- * Given a node, construct a good cpumask for its sched_domain to span. It
+ * Given a node, construct a good cpumask for its sched_domain to span. It
* should be one that prevents unnecessary balancing, but also spreads tasks
* out optimally.
*/
static DEFINE_PER_CPU(struct sched_domain, cpu_domains);
static DEFINE_PER_CPU(struct sched_group, sched_group_cpus);
-static int cpu_to_cpu_group(int cpu, const cpumask_t *cpu_map,
- struct sched_group **sg)
+static int
+cpu_to_cpu_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg)
{
if (sg)
*sg = &per_cpu(sched_group_cpus, cpu);
#endif
#if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT)
-static int cpu_to_core_group(int cpu, const cpumask_t *cpu_map,
- struct sched_group **sg)
+static int
+cpu_to_core_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg)
{
int group;
- cpumask_t mask = cpu_sibling_map[cpu];
+ cpumask_t mask = per_cpu(cpu_sibling_map, cpu);
cpus_and(mask, mask, *cpu_map);
group = first_cpu(mask);
if (sg)
return group;
}
#elif defined(CONFIG_SCHED_MC)
-static int cpu_to_core_group(int cpu, const cpumask_t *cpu_map,
- struct sched_group **sg)
+static int
+cpu_to_core_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg)
{
if (sg)
*sg = &per_cpu(sched_group_core, cpu);
static DEFINE_PER_CPU(struct sched_domain, phys_domains);
static DEFINE_PER_CPU(struct sched_group, sched_group_phys);
-static int cpu_to_phys_group(int cpu, const cpumask_t *cpu_map,
- struct sched_group **sg)
+static int
+cpu_to_phys_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg)
{
int group;
#ifdef CONFIG_SCHED_MC
cpus_and(mask, mask, *cpu_map);
group = first_cpu(mask);
#elif defined(CONFIG_SCHED_SMT)
- cpumask_t mask = cpu_sibling_map[cpu];
+ cpumask_t mask = per_cpu(cpu_sibling_map, cpu);
cpus_and(mask, mask, *cpu_map);
group = first_cpu(mask);
#else
if (!sg)
return;
-next_sg:
- for_each_cpu_mask(j, sg->cpumask) {
- struct sched_domain *sd;
+ do {
+ for_each_cpu_mask(j, sg->cpumask) {
+ struct sched_domain *sd;
- sd = &per_cpu(phys_domains, j);
- if (j != first_cpu(sd->groups->cpumask)) {
- /*
- * Only add "power" once for each
- * physical package.
- */
- continue;
- }
+ sd = &per_cpu(phys_domains, j);
+ if (j != first_cpu(sd->groups->cpumask)) {
+ /*
+ * Only add "power" once for each
+ * physical package.
+ */
+ continue;
+ }
- sg_inc_cpu_power(sg, sd->groups->__cpu_power);
- }
- sg = sg->next;
- if (sg != group_head)
- goto next_sg;
+ sg_inc_cpu_power(sg, sd->groups->__cpu_power);
+ }
+ sg = sg->next;
+ } while (sg != group_head);
}
#endif
/*
* Allocate the per-node list of sched groups
*/
- sched_group_nodes = kzalloc(sizeof(struct sched_group *)*MAX_NUMNODES,
- GFP_KERNEL);
+ sched_group_nodes = kcalloc(MAX_NUMNODES, sizeof(struct sched_group *),
+ GFP_KERNEL);
if (!sched_group_nodes) {
printk(KERN_WARNING "Can not alloc sched group node list\n");
return -ENOMEM;
p = sd;
sd = &per_cpu(cpu_domains, i);
*sd = SD_SIBLING_INIT;
- sd->span = cpu_sibling_map[i];
+ sd->span = per_cpu(cpu_sibling_map, i);
cpus_and(sd->span, sd->span, *cpu_map);
sd->parent = p;
p->child = sd;
#ifdef CONFIG_SCHED_SMT
/* Set up CPU (sibling) groups */
for_each_cpu_mask(i, *cpu_map) {
- cpumask_t this_sibling_map = cpu_sibling_map[i];
+ cpumask_t this_sibling_map = per_cpu(cpu_sibling_map, i);
cpus_and(this_sibling_map, this_sibling_map, *cpu_map);
if (i != first_cpu(this_sibling_map))
continue;
return -ENOMEM;
#endif
}
+
+static cpumask_t *doms_cur; /* current sched domains */
+static int ndoms_cur; /* number of sched domains in 'doms_cur' */
+
+/*
+ * Special case: If a kmalloc of a doms_cur partition (array of
+ * cpumask_t) fails, then fallback to a single sched domain,
+ * as determined by the single cpumask_t fallback_doms.
+ */
+static cpumask_t fallback_doms;
+
/*
- * Set up scheduler domains and groups. Callers must hold the hotplug lock.
+ * Set up scheduler domains and groups. Callers must hold the hotplug lock.
+ * For now this just excludes isolated cpus, but could be used to
+ * exclude other special cases in the future.
*/
static int arch_init_sched_domains(const cpumask_t *cpu_map)
{
- cpumask_t cpu_default_map;
int err;
- /*
- * Setup mask for cpus without special case scheduling requirements.
- * For now this just excludes isolated cpus, but could be used to
- * exclude other special cases in the future.
- */
- cpus_andnot(cpu_default_map, *cpu_map, cpu_isolated_map);
-
- err = build_sched_domains(&cpu_default_map);
+ ndoms_cur = 1;
+ doms_cur = kmalloc(sizeof(cpumask_t), GFP_KERNEL);
+ if (!doms_cur)
+ doms_cur = &fallback_doms;
+ cpus_andnot(*doms_cur, *cpu_map, cpu_isolated_map);
+ err = build_sched_domains(doms_cur);
+ register_sched_domain_sysctl();
return err;
}
{
int i;
+ unregister_sched_domain_sysctl();
+
for_each_cpu_mask(i, *cpu_map)
cpu_attach_domain(NULL, i);
synchronize_sched();
}
/*
- * Partition sched domains as specified by the cpumasks below.
- * This attaches all cpus from the cpumasks to the NULL domain,
- * waits for a RCU quiescent period, recalculates sched
- * domain information and then attaches them back to the
- * correct sched domains
+ * Partition sched domains as specified by the 'ndoms_new'
+ * cpumasks in the array doms_new[] of cpumasks. This compares
+ * doms_new[] to the current sched domain partitioning, doms_cur[].
+ * It destroys each deleted domain and builds each new domain.
+ *
+ * 'doms_new' is an array of cpumask_t's of length 'ndoms_new'.
+ * The masks don't intersect (don't overlap.) We should setup one
+ * sched domain for each mask. CPUs not in any of the cpumasks will
+ * not be load balanced. If the same cpumask appears both in the
+ * current 'doms_cur' domains and in the new 'doms_new', we can leave
+ * it as it is.
+ *
+ * The passed in 'doms_new' should be kmalloc'd. This routine takes
+ * ownership of it and will kfree it when done with it. If the caller
+ * failed the kmalloc call, then it can pass in doms_new == NULL,
+ * and partition_sched_domains() will fallback to the single partition
+ * 'fallback_doms'.
+ *
* Call with hotplug lock held
*/
-int partition_sched_domains(cpumask_t *partition1, cpumask_t *partition2)
+void partition_sched_domains(int ndoms_new, cpumask_t *doms_new)
{
- cpumask_t change_map;
- int err = 0;
+ int i, j;
- cpus_and(*partition1, *partition1, cpu_online_map);
- cpus_and(*partition2, *partition2, cpu_online_map);
- cpus_or(change_map, *partition1, *partition2);
+ lock_doms_cur();
- /* Detach sched domains from all of the affected cpus */
- detach_destroy_domains(&change_map);
- if (!cpus_empty(*partition1))
- err = build_sched_domains(partition1);
- if (!err && !cpus_empty(*partition2))
- err = build_sched_domains(partition2);
+ /* always unregister in case we don't destroy any domains */
+ unregister_sched_domain_sysctl();
- return err;
+ if (doms_new == NULL) {
+ ndoms_new = 1;
+ doms_new = &fallback_doms;
+ cpus_andnot(doms_new[0], cpu_online_map, cpu_isolated_map);
+ }
+
+ /* Destroy deleted domains */
+ for (i = 0; i < ndoms_cur; i++) {
+ for (j = 0; j < ndoms_new; j++) {
+ if (cpus_equal(doms_cur[i], doms_new[j]))
+ goto match1;
+ }
+ /* no match - a current sched domain not in new doms_new[] */
+ detach_destroy_domains(doms_cur + i);
+match1:
+ ;
+ }
+
+ /* Build new domains */
+ for (i = 0; i < ndoms_new; i++) {
+ for (j = 0; j < ndoms_cur; j++) {
+ if (cpus_equal(doms_new[i], doms_cur[j]))
+ goto match2;
+ }
+ /* no match - add a new doms_new */
+ build_sched_domains(doms_new + i);
+match2:
+ ;
+ }
+
+ /* Remember the new sched domains */
+ if (doms_cur != &fallback_doms)
+ kfree(doms_cur);
+ doms_cur = doms_new;
+ ndoms_cur = ndoms_new;
+
+ register_sched_domain_sysctl();
+
+ unlock_doms_cur();
}
#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
#endif
/*
- * Force a reinitialization of the sched domains hierarchy. The domains
+ * Force a reinitialization of the sched domains hierarchy. The domains
* and groups cannot be updated in place without racing with the balancing
* code, so we temporarily attach all running cpus to the NULL domain
* which will prevent rebalancing while the sched domains are recalculated.
/* XXX: Theoretical race here - CPU may be hotplugged now */
hotcpu_notifier(update_sched_domains, 0);
- init_sched_domain_sysctl();
-
/* Move init over to a non-isolated CPU */
if (set_cpus_allowed(current, non_isolated_cpus) < 0)
BUG();
+ sched_init_granularity();
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+ if (nr_cpu_ids == 1)
+ return;
+
+ lb_monitor_task = kthread_create(load_balance_monitor, NULL,
+ "group_balance");
+ if (!IS_ERR(lb_monitor_task)) {
+ lb_monitor_task->flags |= PF_NOFREEZE;
+ wake_up_process(lb_monitor_task);
+ } else {
+ printk(KERN_ERR "Could not create load balance monitor thread"
+ "(error = %ld) \n", PTR_ERR(lb_monitor_task));
+ }
+#endif
}
#else
void __init sched_init_smp(void)
{
+ sched_init_granularity();
}
#endif /* CONFIG_SMP */
int in_sched_functions(unsigned long addr)
{
- /* Linker adds these: start and end of __sched functions */
- extern char __sched_text_start[], __sched_text_end[];
-
return in_lock_functions(addr) ||
(addr >= (unsigned long)__sched_text_start
&& addr < (unsigned long)__sched_text_end);
init_cfs_rq_p[i] = cfs_rq;
init_cfs_rq(cfs_rq, rq);
- cfs_rq->tg = &init_task_grp;
+ 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_grp_load;
+ se->load.weight = init_task_group_load;
se->load.inv_weight =
- div64_64(1ULL<<32, init_task_grp_load);
+ div64_64(1ULL<<32, init_task_group_load);
se->parent = NULL;
}
- init_task_grp.shares = init_task_grp_load;
+ init_task_group.shares = init_task_group_load;
#endif
for (j = 0; j < CPU_LOAD_IDX_MAX; j++)
#endif
#ifdef CONFIG_MAGIC_SYSRQ
+static void normalize_task(struct rq *rq, struct task_struct *p)
+{
+ int on_rq;
+ update_rq_clock(rq);
+ on_rq = p->se.on_rq;
+ if (on_rq)
+ deactivate_task(rq, p, 0);
+ __setscheduler(rq, p, SCHED_NORMAL, 0);
+ if (on_rq) {
+ activate_task(rq, p, 0);
+ resched_task(rq->curr);
+ }
+}
+
void normalize_rt_tasks(void)
{
struct task_struct *g, *p;
unsigned long flags;
struct rq *rq;
- int on_rq;
read_lock_irq(&tasklist_lock);
do_each_thread(g, p) {
+ /*
+ * Only normalize user tasks:
+ */
+ if (!p->mm)
+ continue;
+
p->se.exec_start = 0;
#ifdef CONFIG_SCHEDSTATS
p->se.wait_start = 0;
spin_lock_irqsave(&p->pi_lock, flags);
rq = __task_rq_lock(p);
-#ifdef CONFIG_SMP
- /*
- * Do not touch the migration thread:
- */
- if (p == rq->migration_thread)
- goto out_unlock;
-#endif
- update_rq_clock(rq);
- on_rq = p->se.on_rq;
- if (on_rq)
- deactivate_task(rq, p, 0);
- __setscheduler(rq, p, SCHED_NORMAL, 0);
- if (on_rq) {
- activate_task(rq, p, 0);
- resched_task(rq->curr);
- }
-#ifdef CONFIG_SMP
- out_unlock:
-#endif
+ normalize_task(rq, p);
+
__task_rq_unlock(rq);
spin_unlock_irqrestore(&p->pi_lock, flags);
} while_each_thread(g, p);
* @p: the task pointer to set.
*
* Description: This function must only be used when non-maskable interrupts
- * are serviced on a separate stack. It allows the architecture to switch the
- * notion of the current task on a cpu in a non-blocking manner. This function
+ * are serviced on a separate stack. It allows the architecture to switch the
+ * notion of the current task on a cpu in a non-blocking manner. This function
* must be called with all CPU's synchronized, and interrupts disabled, the
* and caller must save the original value of the current task (see
* curr_task() above) and restore that value before reenabling interrupts and
#ifdef CONFIG_FAIR_GROUP_SCHED
+#ifdef CONFIG_SMP
+/*
+ * distribute shares of all task groups among their schedulable entities,
+ * to reflect load distrbution across cpus.
+ */
+static int rebalance_shares(struct sched_domain *sd, int this_cpu)
+{
+ struct cfs_rq *cfs_rq;
+ struct rq *rq = cpu_rq(this_cpu);
+ cpumask_t sdspan = sd->span;
+ int balanced = 1;
+
+ /* Walk thr' all the task groups that we have */
+ for_each_leaf_cfs_rq(rq, cfs_rq) {
+ int i;
+ unsigned long total_load = 0, total_shares;
+ struct task_group *tg = cfs_rq->tg;
+
+ /* Gather total task load of this group across cpus */
+ for_each_cpu_mask(i, sdspan)
+ total_load += tg->cfs_rq[i]->load.weight;
+
+ /* Nothing to do if this group has no load */
+ if (!total_load)
+ continue;
+
+ /*
+ * tg->shares represents the number of cpu shares the task group
+ * is eligible to hold on a single cpu. On N cpus, it is
+ * eligible to hold (N * tg->shares) number of cpu shares.
+ */
+ total_shares = tg->shares * cpus_weight(sdspan);
+
+ /*
+ * redistribute total_shares across cpus as per the task load
+ * distribution.
+ */
+ for_each_cpu_mask(i, sdspan) {
+ unsigned long local_load, local_shares;
+
+ local_load = tg->cfs_rq[i]->load.weight;
+ local_shares = (local_load * total_shares) / total_load;
+ if (!local_shares)
+ local_shares = MIN_GROUP_SHARES;
+ if (local_shares == tg->se[i]->load.weight)
+ continue;
+
+ spin_lock_irq(&cpu_rq(i)->lock);
+ set_se_shares(tg->se[i], local_shares);
+ spin_unlock_irq(&cpu_rq(i)->lock);
+ balanced = 0;
+ }
+ }
+
+ return balanced;
+}
+
+/*
+ * How frequently should we rebalance_shares() across cpus?
+ *
+ * The more frequently we rebalance shares, the more accurate is the fairness
+ * of cpu bandwidth distribution between task groups. However higher frequency
+ * also implies increased scheduling overhead.
+ *
+ * sysctl_sched_min_bal_int_shares represents the minimum interval between
+ * consecutive calls to rebalance_shares() in the same sched domain.
+ *
+ * sysctl_sched_max_bal_int_shares represents the maximum interval between
+ * consecutive calls to rebalance_shares() in the same sched domain.
+ *
+ * These settings allows for the appropriate tradeoff between accuracy of
+ * fairness and the associated overhead.
+ *
+ */
+
+/* default: 8ms, units: milliseconds */
+const_debug unsigned int sysctl_sched_min_bal_int_shares = 8;
+
+/* default: 128ms, units: milliseconds */
+const_debug unsigned int sysctl_sched_max_bal_int_shares = 128;
+
+/* kernel thread that runs rebalance_shares() periodically */
+static int load_balance_monitor(void *unused)
+{
+ unsigned int timeout = sysctl_sched_min_bal_int_shares;
+ struct sched_param schedparm;
+ int ret;
+
+ /*
+ * We don't want this thread's execution to be limited by the shares
+ * assigned to default group (init_task_group). Hence make it run
+ * as a SCHED_RR RT task at the lowest priority.
+ */
+ schedparm.sched_priority = 1;
+ ret = sched_setscheduler(current, SCHED_RR, &schedparm);
+ if (ret)
+ printk(KERN_ERR "Couldn't set SCHED_RR policy for load balance"
+ " monitor thread (error = %d) \n", ret);
+
+ while (!kthread_should_stop()) {
+ int i, cpu, balanced = 1;
+
+ /* Prevent cpus going down or coming up */
+ lock_cpu_hotplug();
+ /* lockout changes to doms_cur[] array */
+ lock_doms_cur();
+ /*
+ * Enter a rcu read-side critical section to safely walk rq->sd
+ * chain on various cpus and to walk task group list
+ * (rq->leaf_cfs_rq_list) in rebalance_shares().
+ */
+ rcu_read_lock();
+
+ for (i = 0; i < ndoms_cur; i++) {
+ cpumask_t cpumap = doms_cur[i];
+ struct sched_domain *sd = NULL, *sd_prev = NULL;
+
+ cpu = first_cpu(cpumap);
+
+ /* Find the highest domain at which to balance shares */
+ for_each_domain(cpu, sd) {
+ if (!(sd->flags & SD_LOAD_BALANCE))
+ continue;
+ sd_prev = sd;
+ }
+
+ sd = sd_prev;
+ /* sd == NULL? No load balance reqd in this domain */
+ if (!sd)
+ continue;
+
+ balanced &= rebalance_shares(sd, cpu);
+ }
+
+ rcu_read_unlock();
+
+ unlock_doms_cur();
+ unlock_cpu_hotplug();
+
+ if (!balanced)
+ timeout = sysctl_sched_min_bal_int_shares;
+ else if (timeout < sysctl_sched_max_bal_int_shares)
+ timeout *= 2;
+
+ msleep_interruptible(timeout);
+ }
+
+ return 0;
+}
+#endif /* CONFIG_SMP */
+
/* allocate runqueue etc for a new task group */
-struct task_grp *sched_create_group(void)
+struct task_group *sched_create_group(void)
{
- struct task_grp *tg;
+ struct task_group *tg;
struct cfs_rq *cfs_rq;
struct sched_entity *se;
struct rq *rq;
se->parent = NULL;
}
+ tg->shares = NICE_0_LOAD;
+
+ lock_task_group_list();
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);
}
-
- tg->shares = NICE_0_LOAD;
+ unlock_task_group_list();
return tg;
err:
for_each_possible_cpu(i) {
- if (tg->cfs_rq && tg->cfs_rq[i])
+ if (tg->cfs_rq)
kfree(tg->cfs_rq[i]);
- if (tg->se && tg->se[i])
+ if (tg->se)
kfree(tg->se[i]);
}
- if (tg->cfs_rq)
- kfree(tg->cfs_rq);
- if (tg->se)
- kfree(tg->se);
- if (tg)
- kfree(tg);
+ kfree(tg->cfs_rq);
+ kfree(tg->se);
+ kfree(tg);
return ERR_PTR(-ENOMEM);
}
/* rcu callback to free various structures associated with a task group */
static void free_sched_group(struct rcu_head *rhp)
{
- struct cfs_rq *cfs_rq = container_of(rhp, struct cfs_rq, rcu);
- struct task_grp *tg = cfs_rq->tg;
+ struct task_group *tg = container_of(rhp, struct task_group, rcu);
+ struct cfs_rq *cfs_rq;
struct sched_entity *se;
int i;
}
/* Destroy runqueue etc associated with a task group */
-void sched_destroy_group(struct task_grp *tg)
+void sched_destroy_group(struct task_group *tg)
{
- struct cfs_rq *cfs_rq;
+ struct cfs_rq *cfs_rq = NULL;
int i;
+ lock_task_group_list();
for_each_possible_cpu(i) {
cfs_rq = tg->cfs_rq[i];
list_del_rcu(&cfs_rq->leaf_cfs_rq_list);
}
+ unlock_task_group_list();
- cfs_rq = tg->cfs_rq[0];
+ BUG_ON(!cfs_rq);
/* wait for possible concurrent references to cfs_rqs complete */
- call_rcu(&cfs_rq->rcu, free_sched_group);
+ call_rcu(&tg->rcu, free_sched_group);
}
/* change task's runqueue when it moves between groups.
rq = task_rq_lock(tsk, &flags);
- if (tsk->sched_class != &fair_sched_class)
+ if (tsk->sched_class != &fair_sched_class) {
+ set_task_cfs_rq(tsk, task_cpu(tsk));
goto done;
+ }
update_rq_clock(rq);
- running = task_running(rq, tsk);
+ running = task_current(rq, tsk);
on_rq = tsk->se.on_rq;
if (on_rq) {
tsk->sched_class->put_prev_task(rq, tsk);
}
- set_task_cfs_rq(tsk);
+ set_task_cfs_rq(tsk, task_cpu(tsk));
if (on_rq) {
if (unlikely(running))
task_rq_unlock(rq, &flags);
}
+/* rq->lock to be locked by caller */
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);
+ if (!shares)
+ shares = MIN_GROUP_SHARES;
on_rq = se->on_rq;
- if (on_rq)
+ if (on_rq) {
dequeue_entity(cfs_rq, se, 0);
+ dec_cpu_load(rq, se->load.weight);
+ }
se->load.weight = shares;
se->load.inv_weight = div64_64((1ULL<<32), shares);
- if (on_rq)
+ if (on_rq) {
enqueue_entity(cfs_rq, se, 0);
-
- spin_unlock_irq(&rq->lock);
+ inc_cpu_load(rq, se->load.weight);
+ }
}
-int sched_group_set_shares(struct task_grp *tg, unsigned long shares)
+int sched_group_set_shares(struct task_group *tg, unsigned long shares)
{
int i;
+ struct cfs_rq *cfs_rq;
+ struct rq *rq;
+ lock_task_group_list();
if (tg->shares == shares)
- return 0;
+ goto done;
- /* return -EINVAL if the new value is not sane */
+ if (shares < MIN_GROUP_SHARES)
+ shares = MIN_GROUP_SHARES;
+ /*
+ * Prevent any load balance activity (rebalance_shares,
+ * load_balance_fair) from referring to this group first,
+ * by taking it off the rq->leaf_cfs_rq_list on each cpu.
+ */
+ for_each_possible_cpu(i) {
+ cfs_rq = tg->cfs_rq[i];
+ list_del_rcu(&cfs_rq->leaf_cfs_rq_list);
+ }
+
+ /* 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)
+ for_each_possible_cpu(i) {
+ spin_lock_irq(&cpu_rq(i)->lock);
set_se_shares(tg->se[i], shares);
+ spin_unlock_irq(&cpu_rq(i)->lock);
+ }
+ /*
+ * Enable load balance activity on this group, by inserting it back on
+ * each cpu's rq->leaf_cfs_rq_list.
+ */
+ 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);
+ }
+done:
+ unlock_task_group_list();
return 0;
}
+unsigned long sched_group_shares(struct task_group *tg)
+{
+ return tg->shares;
+}
+
#endif /* CONFIG_FAIR_GROUP_SCHED */
+
+#ifdef CONFIG_FAIR_CGROUP_SCHED
+
+/* return corresponding task_group object of a cgroup */
+static inline struct task_group *cgroup_tg(struct cgroup *cgrp)
+{
+ return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id),
+ struct task_group, css);
+}
+
+static struct cgroup_subsys_state *
+cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp)
+{
+ struct task_group *tg;
+
+ if (!cgrp->parent) {
+ /* This is early initialization for the top cgroup */
+ init_task_group.css.cgroup = cgrp;
+ return &init_task_group.css;
+ }
+
+ /* we support only 1-level deep hierarchical scheduler atm */
+ if (cgrp->parent->parent)
+ return ERR_PTR(-EINVAL);
+
+ tg = sched_create_group();
+ if (IS_ERR(tg))
+ return ERR_PTR(-ENOMEM);
+
+ /* Bind the cgroup to task_group object we just created */
+ tg->css.cgroup = cgrp;
+
+ return &tg->css;
+}
+
+static void
+cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
+{
+ struct task_group *tg = cgroup_tg(cgrp);
+
+ sched_destroy_group(tg);
+}
+
+static int
+cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
+ struct task_struct *tsk)
+{
+ /* We don't support RT-tasks being in separate groups */
+ if (tsk->sched_class != &fair_sched_class)
+ return -EINVAL;
+
+ return 0;
+}
+
+static void
+cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
+ struct cgroup *old_cont, struct task_struct *tsk)
+{
+ sched_move_task(tsk);
+}
+
+static int cpu_shares_write_uint(struct cgroup *cgrp, struct cftype *cftype,
+ u64 shareval)
+{
+ return sched_group_set_shares(cgroup_tg(cgrp), shareval);
+}
+
+static u64 cpu_shares_read_uint(struct cgroup *cgrp, struct cftype *cft)
+{
+ struct task_group *tg = cgroup_tg(cgrp);
+
+ return (u64) tg->shares;
+}
+
+static struct cftype cpu_files[] = {
+ {
+ .name = "shares",
+ .read_uint = cpu_shares_read_uint,
+ .write_uint = cpu_shares_write_uint,
+ },
+};
+
+static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont)
+{
+ return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files));
+}
+
+struct cgroup_subsys cpu_cgroup_subsys = {
+ .name = "cpu",
+ .create = cpu_cgroup_create,
+ .destroy = cpu_cgroup_destroy,
+ .can_attach = cpu_cgroup_can_attach,
+ .attach = cpu_cgroup_attach,
+ .populate = cpu_cgroup_populate,
+ .subsys_id = cpu_cgroup_subsys_id,
+ .early_init = 1,
+};
+
+#endif /* CONFIG_FAIR_CGROUP_SCHED */
+
+#ifdef CONFIG_CGROUP_CPUACCT
+
+/*
+ * CPU accounting code for task groups.
+ *
+ * Based on the work by Paul Menage (menage@google.com) and Balbir Singh
+ * (balbir@in.ibm.com).
+ */
+
+/* track cpu usage of a group of tasks */
+struct cpuacct {
+ struct cgroup_subsys_state css;
+ /* cpuusage holds pointer to a u64-type object on every cpu */
+ u64 *cpuusage;
+};
+
+struct cgroup_subsys cpuacct_subsys;
+
+/* return cpu accounting group corresponding to this container */
+static inline struct cpuacct *cgroup_ca(struct cgroup *cont)
+{
+ return container_of(cgroup_subsys_state(cont, cpuacct_subsys_id),
+ struct cpuacct, css);
+}
+
+/* return cpu accounting group to which this task belongs */
+static inline struct cpuacct *task_ca(struct task_struct *tsk)
+{
+ return container_of(task_subsys_state(tsk, cpuacct_subsys_id),
+ struct cpuacct, css);
+}
+
+/* create a new cpu accounting group */
+static struct cgroup_subsys_state *cpuacct_create(
+ struct cgroup_subsys *ss, struct cgroup *cont)
+{
+ struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL);
+
+ if (!ca)
+ return ERR_PTR(-ENOMEM);
+
+ ca->cpuusage = alloc_percpu(u64);
+ if (!ca->cpuusage) {
+ kfree(ca);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ return &ca->css;
+}
+
+/* destroy an existing cpu accounting group */
+static void
+cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cont)
+{
+ struct cpuacct *ca = cgroup_ca(cont);
+
+ free_percpu(ca->cpuusage);
+ kfree(ca);
+}
+
+/* return total cpu usage (in nanoseconds) of a group */
+static u64 cpuusage_read(struct cgroup *cont, struct cftype *cft)
+{
+ struct cpuacct *ca = cgroup_ca(cont);
+ u64 totalcpuusage = 0;
+ int i;
+
+ for_each_possible_cpu(i) {
+ u64 *cpuusage = percpu_ptr(ca->cpuusage, i);
+
+ /*
+ * Take rq->lock to make 64-bit addition safe on 32-bit
+ * platforms.
+ */
+ spin_lock_irq(&cpu_rq(i)->lock);
+ totalcpuusage += *cpuusage;
+ spin_unlock_irq(&cpu_rq(i)->lock);
+ }
+
+ return totalcpuusage;
+}
+
+static struct cftype files[] = {
+ {
+ .name = "usage",
+ .read_uint = cpuusage_read,
+ },
+};
+
+static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cont)
+{
+ return cgroup_add_files(cont, ss, files, ARRAY_SIZE(files));
+}
+
+/*
+ * charge this task's execution time to its accounting group.
+ *
+ * called with rq->lock held.
+ */
+static void cpuacct_charge(struct task_struct *tsk, u64 cputime)
+{
+ struct cpuacct *ca;
+
+ if (!cpuacct_subsys.active)
+ return;
+
+ ca = task_ca(tsk);
+ if (ca) {
+ u64 *cpuusage = percpu_ptr(ca->cpuusage, task_cpu(tsk));
+
+ *cpuusage += cputime;
+ }
+}
+
+struct cgroup_subsys cpuacct_subsys = {
+ .name = "cpuacct",
+ .create = cpuacct_create,
+ .destroy = cpuacct_destroy,
+ .populate = cpuacct_populate,
+ .subsys_id = cpuacct_subsys_id,
+};
+#endif /* CONFIG_CGROUP_CPUACCT */
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff