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Commit dd41f596 authored by Ingo Molnar's avatar Ingo Molnar
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sched: cfs core code 

apply the CFS core code.

this change switches over the scheduler core to CFS's modular
design and makes use of kernel/sched_fair/rt/idletask.c to implement
Linux's scheduling policies.

thanks to Andrew Morton and Thomas Gleixner for lots of detailed review
feedback and for fixlets.
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarMike Galbraith <efault@gmx.de>
Signed-off-by: default avatarDmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: default avatarSrivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
parent f3479f10
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Showing with 758 additions and 774 deletions
kernel/sched.c
View file @ dd41f596
......@@ -391,6 +391,11 @@ struct rq {
static DEFINE_PER_CPU(struct rq, runqueues) ____cacheline_aligned_in_smp;
static DEFINE_MUTEX(sched_hotcpu_mutex);
static inline void check_preempt_curr(struct rq *rq, struct task_struct *p)
{
rq->curr->sched_class->check_preempt_curr(rq, p);
}
static inline int cpu_of(struct rq *rq)
{
#ifdef CONFIG_SMP
......@@ -669,8 +674,6 @@ static inline void resched_task(struct task_struct *p)
}
#endif
#include "sched_stats.h"
static u64 div64_likely32(u64 divident, unsigned long divisor)
{
#if BITS_PER_LONG == 32
......@@ -788,120 +791,146 @@ static void update_curr_load(struct rq *rq, u64 now)
* this code will need modification
*/
#define TIME_SLICE_NICE_ZERO DEF_TIMESLICE
#define LOAD_WEIGHT(lp) \
#define load_weight(lp) \
(((lp) * SCHED_LOAD_SCALE) / TIME_SLICE_NICE_ZERO)
#define PRIO_TO_LOAD_WEIGHT(prio) \
LOAD_WEIGHT(static_prio_timeslice(prio))
load_weight(static_prio_timeslice(prio))
#define RTPRIO_TO_LOAD_WEIGHT(rp) \
(PRIO_TO_LOAD_WEIGHT(MAX_RT_PRIO) + LOAD_WEIGHT(rp))
(PRIO_TO_LOAD_WEIGHT(MAX_RT_PRIO) + load_weight(rp))
#define WEIGHT_IDLEPRIO 2
#define WMULT_IDLEPRIO (1 << 31)
/*
* Nice levels are multiplicative, with a gentle 10% change for every
* nice level changed. I.e. when a CPU-bound task goes from nice 0 to
* nice 1, it will get ~10% less CPU time than another CPU-bound task
* that remained on nice 0.
*
* The "10% effect" is relative and cumulative: from _any_ nice level,
* if you go up 1 level, it's -10% CPU usage, if you go down 1 level
* it's +10% CPU usage.
*/
static const int prio_to_weight[40] = {
/* -20 */ 88818, 71054, 56843, 45475, 36380, 29104, 23283, 18626, 14901, 11921,
/* -10 */ 9537, 7629, 6103, 4883, 3906, 3125, 2500, 2000, 1600, 1280,
/* 0 */ NICE_0_LOAD /* 1024 */,
/* 1 */ 819, 655, 524, 419, 336, 268, 215, 172, 137,
/* 10 */ 110, 87, 70, 56, 45, 36, 29, 23, 18, 15,
};
static const u32 prio_to_wmult[40] = {
48356, 60446, 75558, 94446, 118058, 147573,
184467, 230589, 288233, 360285, 450347,
562979, 703746, 879575, 1099582, 1374389,
717986, 2147483, 2684354, 3355443, 4194304,
244160, 6557201, 8196502, 10250518, 12782640,
16025997, 19976592, 24970740, 31350126, 39045157,
49367440, 61356675, 76695844, 95443717, 119304647,
148102320, 186737708, 238609294, 286331153,
};
static inline void
inc_raw_weighted_load(struct rq *rq, const struct task_struct *p)
inc_load(struct rq *rq, const struct task_struct *p, u64 now)
{
rq->raw_weighted_load += p->load_weight;
update_curr_load(rq, now);
update_load_add(&rq->ls.load, p->se.load.weight);
}
static inline void
dec_raw_weighted_load(struct rq *rq, const struct task_struct *p)
dec_load(struct rq *rq, const struct task_struct *p, u64 now)
{
rq->raw_weighted_load -= p->load_weight;
update_curr_load(rq, now);
update_load_sub(&rq->ls.load, p->se.load.weight);
}
static inline void inc_nr_running(struct task_struct *p, struct rq *rq)
static inline void inc_nr_running(struct task_struct *p, struct rq *rq, u64 now)
{
rq->nr_running++;
inc_raw_weighted_load(rq, p);
inc_load(rq, p, now);
}
static inline void dec_nr_running(struct task_struct *p, struct rq *rq)
static inline void dec_nr_running(struct task_struct *p, struct rq *rq, u64 now)
{
rq->nr_running--;
dec_raw_weighted_load(rq, p);
dec_load(rq, p, now);
}
static void activate_task(struct rq *rq, struct task_struct *p, int wakeup);
/*
* runqueue iterator, to support SMP load-balancing between different
* scheduling classes, without having to expose their internal data
* structures to the load-balancing proper:
*/
struct rq_iterator {
void *arg;
struct task_struct *(*start)(void *);
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, int best_prio, int best_prio_seen,
struct rq_iterator *iterator);
#include "sched_stats.h"
#include "sched_rt.c"
#include "sched_fair.c"
#include "sched_idletask.c"
#ifdef CONFIG_SCHED_DEBUG
# include "sched_debug.c"
#endif
#define sched_class_highest (&rt_sched_class)
static void set_load_weight(struct task_struct *p)
{
task_rq(p)->cfs.wait_runtime -= p->se.wait_runtime;
p->se.wait_runtime = 0;
if (task_has_rt_policy(p)) {
#ifdef CONFIG_SMP
if (p == task_rq(p)->migration_thread)
/*
* The migration thread does the actual balancing.
* Giving its load any weight will skew balancing
* adversely.
*/
p->load_weight = 0;
else
#endif
p->load_weight = RTPRIO_TO_LOAD_WEIGHT(p->rt_priority);
} else
p->load_weight = PRIO_TO_LOAD_WEIGHT(p->static_prio);
}
p->se.load.weight = prio_to_weight[0] * 2;
p->se.load.inv_weight = prio_to_wmult[0] >> 1;
return;
}
/*
* Adding/removing a task to/from a priority array:
*/
static void dequeue_task(struct task_struct *p, struct prio_array *array)
{
array->nr_active--;
list_del(&p->run_list);
if (list_empty(array->queue + p->prio))
__clear_bit(p->prio, array->bitmap);
}
/*
* SCHED_IDLE tasks get minimal weight:
*/
if (p->policy == SCHED_IDLE) {
p->se.load.weight = WEIGHT_IDLEPRIO;
p->se.load.inv_weight = WMULT_IDLEPRIO;
return;
}
static void enqueue_task(struct task_struct *p, struct prio_array *array)
{
sched_info_queued(p);
list_add_tail(&p->run_list, array->queue + p->prio);
__set_bit(p->prio, array->bitmap);
array->nr_active++;
p->array = array;
p->se.load.weight = prio_to_weight[p->static_prio - MAX_RT_PRIO];
p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO];
}
/*
* Put task to the end of the run list without the overhead of dequeue
* followed by enqueue.
*/
static void requeue_task(struct task_struct *p, struct prio_array *array)
static void
enqueue_task(struct rq *rq, struct task_struct *p, int wakeup, u64 now)
{
list_move_tail(&p->run_list, array->queue + p->prio);
sched_info_queued(p);
p->sched_class->enqueue_task(rq, p, wakeup, now);
p->se.on_rq = 1;
}
static inline void
enqueue_task_head(struct task_struct *p, struct prio_array *array)
static void
dequeue_task(struct rq *rq, struct task_struct *p, int sleep, u64 now)
{
list_add(&p->run_list, array->queue + p->prio);
__set_bit(p->prio, array->bitmap);
array->nr_active++;
p->array = array;
p->sched_class->dequeue_task(rq, p, sleep, now);
p->se.on_rq = 0;
}
/*
* __normal_prio - return the priority that is based on the static
* priority but is modified by bonuses/penalties.
*
* We scale the actual sleep average [0 .... MAX_SLEEP_AVG]
* into the -5 ... 0 ... +5 bonus/penalty range.
*
* We use 25% of the full 0...39 priority range so that:
*
* 1) nice +19 interactive tasks do not preempt nice 0 CPU hogs.
* 2) nice -20 CPU hogs do not get preempted by nice 0 tasks.
*
* Both properties are important to certain workloads.
* __normal_prio - return the priority that is based on the static prio
*/
static inline int __normal_prio(struct task_struct *p)
{
int bonus, prio;
bonus = 0;
prio = p->static_prio - bonus;
if (prio < MAX_RT_PRIO)
prio = MAX_RT_PRIO;
if (prio > MAX_PRIO-1)
prio = MAX_PRIO-1;
return prio;
return p->static_prio;
}
/*
......@@ -943,84 +972,45 @@ static int effective_prio(struct task_struct *p)
}
/*
* __activate_task - move a task to the runqueue.
* activate_task - move a task to the runqueue.
*/
static void __activate_task(struct task_struct *p, struct rq *rq)
static void activate_task(struct rq *rq, struct task_struct *p, int wakeup)
{
struct prio_array *target = rq->active;
u64 now = rq_clock(rq);
if (batch_task(p))
target = rq->expired;
enqueue_task(p, target);
inc_nr_running(p, rq);
}
/*
* __activate_idle_task - move idle task to the _front_ of runqueue.
*/
static inline void __activate_idle_task(struct task_struct *p, struct rq *rq)
{
enqueue_task_head(p, rq->active);
inc_nr_running(p, rq);
}
if (p->state == TASK_UNINTERRUPTIBLE)
rq->nr_uninterruptible--;
/*
* Recalculate p->normal_prio and p->prio after having slept,
* updating the sleep-average too:
*/
static int recalc_task_prio(struct task_struct *p, unsigned long long now)
{
return effective_prio(p);
enqueue_task(rq, p, wakeup, now);
inc_nr_running(p, rq, now);
}
/*
* activate_task - move a task to the runqueue and do priority recalculation
*
* Update all the scheduling statistics stuff. (sleep average
* calculation, priority modifiers, etc.)
* activate_idle_task - move idle task to the _front_ of runqueue.
*/
static void activate_task(struct task_struct *p, struct rq *rq, int local)
static inline void activate_idle_task(struct task_struct *p, struct rq *rq)
{
unsigned long long now;
if (rt_task(p))
goto out;
now = sched_clock();
#ifdef CONFIG_SMP
if (!local) {
/* Compensate for drifting sched_clock */
struct rq *this_rq = this_rq();
now = (now - this_rq->most_recent_timestamp)
+ rq->most_recent_timestamp;
}
#endif
u64 now = rq_clock(rq);
/*
* Sleep time is in units of nanosecs, so shift by 20 to get a
* milliseconds-range estimation of the amount of time that the task
* spent sleeping:
*/
if (unlikely(prof_on == SLEEP_PROFILING)) {
if (p->state == TASK_UNINTERRUPTIBLE)
profile_hits(SLEEP_PROFILING, (void *)get_wchan(p),
(now - p->timestamp) >> 20);
}
if (p->state == TASK_UNINTERRUPTIBLE)
rq->nr_uninterruptible--;
p->prio = recalc_task_prio(p, now);
p->timestamp = now;
out:
__activate_task(p, rq);
enqueue_task(rq, p, 0, now);
inc_nr_running(p, rq, now);
}
/*
* deactivate_task - remove a task from the runqueue.
*/
static void deactivate_task(struct task_struct *p, struct rq *rq)
static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep)
{
dec_nr_running(p, rq);
dequeue_task(p, p->array);
p->array = NULL;
u64 now = rq_clock(rq);
if (p->state == TASK_UNINTERRUPTIBLE)
rq->nr_uninterruptible++;
dequeue_task(rq, p, sleep, now);
dec_nr_running(p, rq, now);
}
/**
......@@ -1035,14 +1025,40 @@ inline int task_curr(const struct task_struct *p)
/* Used instead of source_load when we know the type == 0 */
unsigned long weighted_cpuload(const int cpu)
{
return cpu_rq(cpu)->raw_weighted_load;
return cpu_rq(cpu)->ls.load.weight;
}
static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
{
#ifdef CONFIG_SMP
task_thread_info(p)->cpu = cpu;
set_task_cfs_rq(p);
#endif
}
#ifdef CONFIG_SMP
void set_task_cpu(struct task_struct *p, unsigned int cpu)
void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
{
task_thread_info(p)->cpu = cpu;
int old_cpu = task_cpu(p);
struct rq *old_rq = cpu_rq(old_cpu), *new_rq = cpu_rq(new_cpu);
u64 clock_offset, fair_clock_offset;
clock_offset = old_rq->clock - new_rq->clock;
fair_clock_offset = old_rq->cfs.fair_clock -
new_rq->cfs.fair_clock;
if (p->se.wait_start)
p->se.wait_start -= clock_offset;
if (p->se.wait_start_fair)
p->se.wait_start_fair -= fair_clock_offset;
if (p->se.sleep_start)
p->se.sleep_start -= clock_offset;
if (p->se.block_start)
p->se.block_start -= clock_offset;
if (p->se.sleep_start_fair)
p->se.sleep_start_fair -= fair_clock_offset;
__set_task_cpu(p, new_cpu);
}
struct migration_req {
......@@ -1067,7 +1083,7 @@ migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req)
* If the task is not on a runqueue (and not running), then
* it is sufficient to simply update the task's cpu field.
*/
if (!p->array && !task_running(rq, p)) {
if (!p->se.on_rq && !task_running(rq, p)) {
set_task_cpu(p, dest_cpu);
return 0;
}
......@@ -1092,9 +1108,8 @@ migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req)
void wait_task_inactive(struct task_struct *p)
{
unsigned long flags;
int running, on_rq;
struct rq *rq;
struct prio_array *array;
int running;
repeat:
/*
......@@ -1126,7 +1141,7 @@ void wait_task_inactive(struct task_struct *p)
*/
rq = task_rq_lock(p, &flags);
running = task_running(rq, p);
array = p->array;
on_rq = p->se.on_rq;
task_rq_unlock(rq, &flags);
/*
......@@ -1149,7 +1164,7 @@ void wait_task_inactive(struct task_struct *p)
* running right now), it's preempted, and we should
* yield - it could be a while.
*/
if (unlikely(array)) {
if (unlikely(on_rq)) {
yield();
goto repeat;
}
......@@ -1195,11 +1210,12 @@ void kick_process(struct task_struct *p)
static inline unsigned long source_load(int cpu, int type)
{
struct rq *rq = cpu_rq(cpu);
unsigned long total = weighted_cpuload(cpu);
if (type == 0)
return rq->raw_weighted_load;
return total;
return min(rq->cpu_load[type-1], rq->raw_weighted_load);
return min(rq->cpu_load[type-1], total);
}
/*
......@@ -1209,11 +1225,12 @@ static inline unsigned long source_load(int cpu, int type)
static inline unsigned long target_load(int cpu, int type)
{
struct rq *rq = cpu_rq(cpu);
unsigned long total = weighted_cpuload(cpu);
if (type == 0)
return rq->raw_weighted_load;
return total;
return max(rq->cpu_load[type-1], rq->raw_weighted_load);
return max(rq->cpu_load[type-1], total);
}
/*
......@@ -1222,9 +1239,10 @@ static inline unsigned long target_load(int cpu, int type)
static inline unsigned long cpu_avg_load_per_task(int cpu)
{
struct rq *rq = cpu_rq(cpu);
unsigned long total = weighted_cpuload(cpu);
unsigned long n = rq->nr_running;
return n ? rq->raw_weighted_load / n : SCHED_LOAD_SCALE;
return n ? total / n : SCHED_LOAD_SCALE;
}
/*
......@@ -1455,7 +1473,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
if (!(old_state & state))
goto out;
if (p->array)
if (p->se.on_rq)
goto out_running;
cpu = task_cpu(p);
......@@ -1510,11 +1528,11 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
* of the current CPU:
*/
if (sync)
tl -= current->load_weight;
tl -= current->se.load.weight;
if ((tl <= load &&
tl + target_load(cpu, idx) <= tl_per_task) ||
100*(tl + p->load_weight) <= imbalance*load) {
100*(tl + p->se.load.weight) <= imbalance*load) {
/*
* This domain has SD_WAKE_AFFINE and
* p is cache cold in this domain, and
......@@ -1548,7 +1566,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
old_state = p->state;
if (!(old_state & state))
goto out;
if (p->array)
if (p->se.on_rq)
goto out_running;
this_cpu = smp_processor_id();
......@@ -1557,10 +1575,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
out_activate:
#endif /* CONFIG_SMP */
if (old_state == TASK_UNINTERRUPTIBLE)
rq->nr_uninterruptible--;
activate_task(p, rq, cpu == this_cpu);
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)
......@@ -1569,10 +1584,8 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
* the waker guarantees that the freshly woken up task is going
* to be considered on this CPU.)
*/
if (!sync || cpu != this_cpu) {
if (TASK_PREEMPTS_CURR(p, rq))
resched_task(rq->curr);
}
if (!sync || cpu != this_cpu)
check_preempt_curr(rq, p);
success = 1;
out_running:
......@@ -1595,19 +1608,36 @@ int fastcall wake_up_state(struct task_struct *p, unsigned int state)
return try_to_wake_up(p, state, 0);
}
static void task_running_tick(struct rq *rq, struct task_struct *p);
/*
* Perform scheduler related setup for a newly forked process p.
* p is forked by current.
*/
void fastcall sched_fork(struct task_struct *p, int clone_flags)
{
int cpu = get_cpu();
*
* __sched_fork() is basic setup used by init_idle() too:
*/
static void __sched_fork(struct task_struct *p)
{
p->se.wait_start_fair = 0;
p->se.wait_start = 0;
p->se.exec_start = 0;
p->se.sum_exec_runtime = 0;
p->se.delta_exec = 0;
p->se.delta_fair_run = 0;
p->se.delta_fair_sleep = 0;
p->se.wait_runtime = 0;
p->se.sum_wait_runtime = 0;
p->se.sum_sleep_runtime = 0;
p->se.sleep_start = 0;
p->se.sleep_start_fair = 0;
p->se.block_start = 0;
p->se.sleep_max = 0;
p->se.block_max = 0;
p->se.exec_max = 0;
p->se.wait_max = 0;
p->se.wait_runtime_overruns = 0;
p->se.wait_runtime_underruns = 0;
#ifdef CONFIG_SMP
cpu = sched_balance_self(cpu, SD_BALANCE_FORK);
#endif
set_task_cpu(p, cpu);
INIT_LIST_HEAD(&p->run_list);
p->se.on_rq = 0;
/*
* We mark the process as running here, but have not actually
......@@ -1616,16 +1646,29 @@ void fastcall sched_fork(struct task_struct *p, int clone_flags)
* event cannot wake it up and insert it on the runqueue either.
*/
p->state = TASK_RUNNING;
}
/*
* fork()/clone()-time setup:
*/
void sched_fork(struct task_struct *p, int clone_flags)
{
int cpu = get_cpu();
__sched_fork(p);
#ifdef CONFIG_SMP
cpu = sched_balance_self(cpu, SD_BALANCE_FORK);
#endif
__set_task_cpu(p, cpu);
/*
* Make sure we do not leak PI boosting priority to the child:
*/
p->prio = current->normal_prio;
INIT_LIST_HEAD(&p->run_list);
p->array = NULL;
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
if (unlikely(sched_info_on()))
if (likely(sched_info_on()))
memset(&p->sched_info, 0, sizeof(p->sched_info));
#endif
#if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW)
......@@ -1635,33 +1678,15 @@ void fastcall sched_fork(struct task_struct *p, int clone_flags)
/* Want to start with kernel preemption disabled. */
task_thread_info(p)->preempt_count = 1;
#endif
/*
* Share the timeslice between parent and child, thus the
* total amount of pending timeslices in the system doesn't change,
* resulting in more scheduling fairness.
*/
local_irq_disable();
p->time_slice = (current->time_slice + 1) >> 1;
/*
* The remainder of the first timeslice might be recovered by
* the parent if the child exits early enough.
*/
p->first_time_slice = 1;
current->time_slice >>= 1;
p->timestamp = sched_clock();
if (unlikely(!current->time_slice)) {
/*
* This case is rare, it happens when the parent has only
* a single jiffy left from its timeslice. Taking the
* runqueue lock is not a problem.
*/
current->time_slice = 1;
task_running_tick(cpu_rq(cpu), current);
}
local_irq_enable();
put_cpu();
}
/*
* After fork, child runs first. (default) If set to 0 then
* parent will (try to) run first.
*/
unsigned int __read_mostly sysctl_sched_child_runs_first = 1;
/*
* wake_up_new_task - wake up a newly created task for the first time.
*
......@@ -1671,77 +1696,28 @@ void fastcall sched_fork(struct task_struct *p, int clone_flags)
*/
void fastcall wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
{
struct rq *rq, *this_rq;
unsigned long flags;
int this_cpu, cpu;
struct rq *rq;
int this_cpu;
rq = task_rq_lock(p, &flags);
BUG_ON(p->state != TASK_RUNNING);
this_cpu = smp_processor_id();
cpu = task_cpu(p);
/*
* We decrease the sleep average of forking parents
* and children as well, to keep max-interactive tasks
* from forking tasks that are max-interactive. The parent
* (current) is done further down, under its lock.
*/
p->sleep_avg = JIFFIES_TO_NS(CURRENT_BONUS(p) *
CHILD_PENALTY / 100 * MAX_SLEEP_AVG / MAX_BONUS);
this_cpu = smp_processor_id(); /* parent's CPU */
p->prio = effective_prio(p);
if (likely(cpu == this_cpu)) {
if (!(clone_flags & CLONE_VM)) {
/*
* The VM isn't cloned, so we're in a good position to
* do child-runs-first in anticipation of an exec. This
* usually avoids a lot of COW overhead.
*/
if (unlikely(!current->array))
__activate_task(p, rq);
else {
p->prio = current->prio;
p->normal_prio = current->normal_prio;
list_add_tail(&p->run_list, &current->run_list);
p->array = current->array;
p->array->nr_active++;
inc_nr_running(p, rq);
}
set_need_resched();
} else
/* Run child last */
__activate_task(p, rq);
/*
* We skip the following code due to cpu == this_cpu
*
* task_rq_unlock(rq, &flags);
* this_rq = task_rq_lock(current, &flags);
*/
this_rq = rq;
if (!sysctl_sched_child_runs_first || (clone_flags & CLONE_VM) ||
task_cpu(p) != this_cpu || !current->se.on_rq) {
activate_task(rq, p, 0);
} else {
this_rq = cpu_rq(this_cpu);
/*
* Not the local CPU - must adjust timestamp. This should
* get optimised away in the !CONFIG_SMP case.
* Let the scheduling class do new task startup
* management (if any):
*/
p->timestamp = (p->timestamp - this_rq->most_recent_timestamp)
+ rq->most_recent_timestamp;
__activate_task(p, rq);
if (TASK_PREEMPTS_CURR(p, rq))
resched_task(rq->curr);
/*
* Parent and child are on different CPUs, now get the
* parent runqueue to update the parent's ->sleep_avg:
*/
task_rq_unlock(rq, &flags);
this_rq = task_rq_lock(current, &flags);
p->sched_class->task_new(rq, p);
}
current->sleep_avg = JIFFIES_TO_NS(CURRENT_BONUS(current) *
PARENT_PENALTY / 100 * MAX_SLEEP_AVG / MAX_BONUS);
task_rq_unlock(this_rq, &flags);
check_preempt_curr(rq, p);
task_rq_unlock(rq, &flags);
}
/**
......@@ -1833,13 +1809,15 @@ asmlinkage void schedule_tail(struct task_struct *prev)
* context_switch - switch to the new MM and the new
* thread's register state.
*/
static inline struct task_struct *
static inline void
context_switch(struct rq *rq, struct task_struct *prev,
struct task_struct *next)
{
struct mm_struct *mm = next->mm;
struct mm_struct *oldmm = prev->active_mm;
struct mm_struct *mm, *oldmm;
prepare_task_switch(rq, next);
mm = next->mm;
oldmm = prev->active_mm;
/*
* For paravirt, this is coupled with an exit in switch_to to
* combine the page table reload and the switch backend into
......@@ -1847,16 +1825,15 @@ context_switch(struct rq *rq, struct task_struct *prev,
*/
arch_enter_lazy_cpu_mode();
if (!mm) {
if (unlikely(!mm)) {
next->active_mm = oldmm;
atomic_inc(&oldmm->mm_count);
enter_lazy_tlb(oldmm, next);
} else
switch_mm(oldmm, mm, next);
if (!prev->mm) {
if (unlikely(!prev->mm)) {
prev->active_mm = NULL;
WARN_ON(rq->prev_mm);
rq->prev_mm = oldmm;
}
/*
......@@ -1872,7 +1849,13 @@ context_switch(struct rq *rq, struct task_struct *prev,
/* Here we just switch the register state and the stack. */
switch_to(prev, next, prev);
return prev;
barrier();
/*
* this_rq must be evaluated again because prev may have moved
* CPUs since it called schedule(), thus the 'rq' on its stack
* frame will be invalid.
*/
finish_task_switch(this_rq(), prev);
}
/*
......@@ -1945,17 +1928,65 @@ unsigned long nr_active(void)
return running + uninterruptible;
}
#ifdef CONFIG_SMP
/*
* Is this task likely cache-hot:
* Update rq->cpu_load[] statistics. This function is usually called every
* scheduler tick (TICK_NSEC).
*/
static inline int
task_hot(struct task_struct *p, unsigned long long now, struct sched_domain *sd)
static void update_cpu_load(struct rq *this_rq)
{
return (long long)(now - p->last_ran) < (long long)sd->cache_hot_time;
u64 fair_delta64, exec_delta64, idle_delta64, sample_interval64, tmp64;
unsigned long total_load = this_rq->ls.load.weight;
unsigned long this_load = total_load;
struct load_stat *ls = &this_rq->ls;
u64 now = __rq_clock(this_rq);
int i, scale;
this_rq->nr_load_updates++;
if (unlikely(!(sysctl_sched_features & SCHED_FEAT_PRECISE_CPU_LOAD)))
goto do_avg;
/* Update delta_fair/delta_exec fields first */
update_curr_load(this_rq, now);
fair_delta64 = ls->delta_fair + 1;
ls->delta_fair = 0;
exec_delta64 = ls->delta_exec + 1;
ls->delta_exec = 0;
sample_interval64 = now - ls->load_update_last;
ls->load_update_last = now;
if ((s64)sample_interval64 < (s64)TICK_NSEC)
sample_interval64 = TICK_NSEC;
if (exec_delta64 > sample_interval64)
exec_delta64 = sample_interval64;
idle_delta64 = sample_interval64 - exec_delta64;
tmp64 = div64_64(SCHED_LOAD_SCALE * exec_delta64, fair_delta64);
tmp64 = div64_64(tmp64 * exec_delta64, sample_interval64);
this_load = (unsigned long)tmp64;
do_avg:
/* Update our load: */
for (i = 0, scale = 1; i < CPU_LOAD_IDX_MAX; i++, scale += scale) {
unsigned long old_load, new_load;
/* scale is effectively 1 << i now, and >> i divides by scale */
old_load = this_rq->cpu_load[i];
new_load = this_load;
this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i;
}
}
#ifdef CONFIG_SMP
/*
* double_rq_lock - safely lock two runqueues
*
......@@ -2072,23 +2103,17 @@ void sched_exec(void)
* pull_task - move a task from a remote runqueue to the local runqueue.
* Both runqueues must be locked.
*/
static void pull_task(struct rq *src_rq, struct prio_array *src_array,
struct task_struct *p, struct rq *this_rq,
struct prio_array *this_array, int this_cpu)
static void pull_task(struct rq *src_rq, struct task_struct *p,
struct rq *this_rq, int this_cpu)
{
dequeue_task(p, src_array);
dec_nr_running(p, src_rq);
deactivate_task(src_rq, p, 0);
set_task_cpu(p, this_cpu);
inc_nr_running(p, this_rq);
enqueue_task(p, this_array);
p->timestamp = (p->timestamp - src_rq->most_recent_timestamp)
+ this_rq->most_recent_timestamp;
activate_task(this_rq, p, 0);
/*
* Note that idle threads have a prio of MAX_PRIO, for this test
* to be always true for them.
*/
if (TASK_PREEMPTS_CURR(p, this_rq))
resched_task(this_rq->curr);
check_preempt_curr(this_rq, p);
}
/*
......@@ -2113,132 +2138,67 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
return 0;
/*
* Aggressive migration if:
* 1) task is cache cold, or
* 2) too many balance attempts have failed.
* Aggressive migration if too many balance attempts have failed:
*/
if (sd->nr_balance_failed > sd->cache_nice_tries) {
#ifdef CONFIG_SCHEDSTATS
if (task_hot(p, rq->most_recent_timestamp, sd))
schedstat_inc(sd, lb_hot_gained[idle]);
#endif
if (sd->nr_balance_failed > sd->cache_nice_tries)
return 1;
}
if (task_hot(p, rq->most_recent_timestamp, sd))
return 0;
return 1;
}
#define rq_best_prio(rq) min((rq)->curr->prio, (rq)->best_expired_prio)
/*
* move_tasks tries to move up to max_nr_move tasks and max_load_move weighted
* load from busiest to this_rq, as part of a balancing operation within
* "domain". Returns the number of tasks moved.
*
* Called with both runqueues locked.
*/
static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
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)
int *all_pinned, unsigned long *load_moved,
int this_best_prio, int best_prio, int best_prio_seen,
struct rq_iterator *iterator)
{
int idx, pulled = 0, pinned = 0, this_best_prio, best_prio,
best_prio_seen, skip_for_load;
struct prio_array *array, *dst_array;
struct list_head *head, *curr;
struct task_struct *tmp;
long rem_load_move;
int 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)
goto out;
rem_load_move = max_load_move;
pinned = 1;
this_best_prio = rq_best_prio(this_rq);
best_prio = rq_best_prio(busiest);
/*
* Enable handling of the case where there is more than one task
* with the best priority. If the current running task is one
* of those with prio==best_prio we know it won't be moved
* and therefore it's safe to override the skip (based on load) of
* any task we find with that prio.
*/
best_prio_seen = best_prio == busiest->curr->prio;
/*
* We first consider expired tasks. Those will likely not be
* executed in the near future, and they are most likely to
* be cache-cold, thus switching CPUs has the least effect
* on them.
* Start the load-balancing iterator:
*/
if (busiest->expired->nr_active) {
array = busiest->expired;
dst_array = this_rq->expired;
} else {
array = busiest->active;
dst_array = this_rq->active;
}
new_array:
/* Start searching at priority 0: */
idx = 0;
skip_bitmap:
if (!idx)
idx = sched_find_first_bit(array->bitmap);
else
idx = find_next_bit(array->bitmap, MAX_PRIO, idx);
if (idx >= MAX_PRIO) {
if (array == busiest->expired && busiest->active->nr_active) {
array = busiest->active;
dst_array = this_rq->active;
goto new_array;
}
p = iterator->start(iterator->arg);
next:
if (!p)
goto out;
}
head = array->queue + idx;
curr = head->prev;
skip_queue:
tmp = list_entry(curr, struct task_struct, run_list);
curr = curr->prev;
/*
* To help distribute high priority tasks accross 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
*/
skip_for_load = tmp->load_weight > rem_load_move;
if (skip_for_load && idx < this_best_prio)
skip_for_load = !best_prio_seen && idx == best_prio;
skip_for_load = (p->se.load.weight >> 1) > rem_load_move +
SCHED_LOAD_SCALE_FUZZ;
if (skip_for_load && p->prio < this_best_prio)
skip_for_load = !best_prio_seen && p->prio == best_prio;
if (skip_for_load ||
!can_migrate_task(tmp, busiest, this_cpu, sd, idle, &pinned)) {
!can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) {
best_prio_seen |= idx == best_prio;
if (curr != head)
goto skip_queue;
idx++;
goto skip_bitmap;
best_prio_seen |= p->prio == best_prio;
p = iterator->next(iterator->arg);
goto next;
}
pull_task(busiest, array, tmp, this_rq, dst_array, this_cpu);
pull_task(busiest, p, this_rq, this_cpu);
pulled++;
rem_load_move -= tmp->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.
*/
if (pulled < max_nr_move && rem_load_move > 0) {
if (idx < this_best_prio)
this_best_prio = idx;
if (curr != head)
goto skip_queue;
idx++;
goto skip_bitmap;
if (p->prio < this_best_prio)
this_best_prio = p->prio;
p = iterator->next(iterator->arg);
goto next;
}
out:
/*
......@@ -2250,9 +2210,39 @@ static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
if (all_pinned)
*all_pinned = pinned;
*load_moved = max_load_move - rem_load_move;
return pulled;
}
/*
* move_tasks tries to move up to max_nr_move tasks and max_load_move weighted
* load from busiest to this_rq, as part of a balancing operation within
* "domain". Returns the number of tasks moved.
*
* Called with both runqueues locked.
*/
static int move_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)
{
struct sched_class *class = sched_class_highest;
unsigned long load_moved, total_nr_moved = 0, nr_moved;
long rem_load_move = max_load_move;
do {
nr_moved = class->load_balance(this_rq, this_cpu, busiest,
max_nr_move, (unsigned long)rem_load_move,
sd, idle, all_pinned, &load_moved);
total_nr_moved += nr_moved;
max_nr_move -= nr_moved;
rem_load_move -= load_moved;
class = class->next;
} while (class && max_nr_move && rem_load_move > 0);
return total_nr_moved;
}
/*
* find_busiest_group finds and returns the busiest CPU group within the
* domain. It calculates and returns the amount of weighted load which
......@@ -2260,8 +2250,8 @@ static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
*/
static struct sched_group *
find_busiest_group(struct sched_domain *sd, int this_cpu,
unsigned long *imbalance, enum cpu_idle_type idle, int *sd_idle,
cpumask_t *cpus, int *balance)
unsigned long *imbalance, enum cpu_idle_type idle,
int *sd_idle, cpumask_t *cpus, int *balance)
{
struct sched_group *busiest = NULL, *this = NULL, *group = sd->groups;
unsigned long max_load, avg_load, total_load, this_load, total_pwr;
......@@ -2325,7 +2315,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
avg_load += load;
sum_nr_running += rq->nr_running;
sum_weighted_load += rq->raw_weighted_load;
sum_weighted_load += weighted_cpuload(i);
}
/*
......@@ -2365,8 +2355,9 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
* Busy processors will not participate in power savings
* balance.
*/
if (idle == CPU_NOT_IDLE || !(sd->flags & SD_POWERSAVINGS_BALANCE))
goto group_next;
if (idle == CPU_NOT_IDLE ||
!(sd->flags & SD_POWERSAVINGS_BALANCE))
goto group_next;
/*
* If the local group is idle or completely loaded
......@@ -2376,42 +2367,42 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
!this_nr_running))
power_savings_balance = 0;
/*
/*
* If a group is already running at full capacity or idle,
* don't include that group in power savings calculations
*/
if (!power_savings_balance || sum_nr_running >= group_capacity
*/
if (!power_savings_balance || sum_nr_running >= group_capacity
|| !sum_nr_running)
goto group_next;
goto group_next;
/*
/*
* Calculate the group which has the least non-idle load.
* This is the group from where we need to pick up the load
* for saving power
*/
if ((sum_nr_running < min_nr_running) ||
(sum_nr_running == min_nr_running &&
* This is the group from where we need to pick up the load
* for saving power
*/
if ((sum_nr_running < min_nr_running) ||
(sum_nr_running == min_nr_running &&
first_cpu(group->cpumask) <
first_cpu(group_min->cpumask))) {
group_min = group;
min_nr_running = sum_nr_running;
group_min = group;
min_nr_running = sum_nr_running;
min_load_per_task = sum_weighted_load /
sum_nr_running;
}
}
/*
/*
* Calculate the group which is almost near its
* capacity but still has some space to pick up some load
* from other group and save more power
*/
if (sum_nr_running <= group_capacity - 1) {
if (sum_nr_running > leader_nr_running ||
(sum_nr_running == leader_nr_running &&
first_cpu(group->cpumask) >
first_cpu(group_leader->cpumask))) {
group_leader = group;
leader_nr_running = sum_nr_running;
}
* capacity but still has some space to pick up some load
* from other group and save more power
*/
if (sum_nr_running <= group_capacity - 1) {
if (sum_nr_running > leader_nr_running ||
(sum_nr_running == leader_nr_running &&
first_cpu(group->cpumask) >
first_cpu(group_leader->cpumask))) {
group_leader = group;
leader_nr_running = sum_nr_running;
}
}
group_next:
#endif
......@@ -2466,7 +2457,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
* a think about bumping its value to force at least one task to be
* moved
*/
if (*imbalance < busiest_load_per_task) {
if (*imbalance + SCHED_LOAD_SCALE_FUZZ < busiest_load_per_task/2) {
unsigned long tmp, pwr_now, pwr_move;
unsigned int imbn;
......@@ -2480,7 +2471,8 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
} else
this_load_per_task = SCHED_LOAD_SCALE;
if (max_load - this_load >= busiest_load_per_task * imbn) {
if (max_load - this_load + SCHED_LOAD_SCALE_FUZZ >=
busiest_load_per_task * imbn) {
*imbalance = busiest_load_per_task;
return busiest;
}
......@@ -2552,17 +2544,19 @@ find_busiest_queue(struct sched_group *group, enum cpu_idle_type idle,
int i;
for_each_cpu_mask(i, group->cpumask) {
unsigned long wl;
if (!cpu_isset(i, *cpus))
continue;
rq = cpu_rq(i);
wl = weighted_cpuload(i);
if (rq->nr_running == 1 && rq->raw_weighted_load > imbalance)
if (rq->nr_running == 1 && wl > imbalance)
continue;
if (rq->raw_weighted_load > max_load) {
max_load = rq->raw_weighted_load;
if (wl > max_load) {
max_load = wl;
busiest = rq;
}
}
......@@ -2599,7 +2593,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
/*
* When power savings policy is enabled for the parent domain, idle
* sibling can pick up load irrespective of busy siblings. In this case,
* let the state of idle sibling percolate up as IDLE, instead of
* let the state of idle sibling percolate up as CPU_IDLE, instead of
* portraying it as CPU_NOT_IDLE.
*/
if (idle != CPU_NOT_IDLE && sd->flags & SD_SHARE_CPUPOWER &&
......@@ -2822,8 +2816,8 @@ load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd)
static void idle_balance(int this_cpu, struct rq *this_rq)
{
struct sched_domain *sd;
int pulled_task = 0;
unsigned long next_balance = jiffies + 60 * HZ;
int pulled_task = -1;
unsigned long next_balance = jiffies + HZ;
for_each_domain(this_cpu, sd) {
unsigned long interval;
......@@ -2842,12 +2836,13 @@ static void idle_balance(int this_cpu, struct rq *this_rq)
if (pulled_task)
break;
}
if (!pulled_task)
if (pulled_task || time_after(jiffies, this_rq->next_balance)) {
/*
* We are going idle. next_balance may be set based on
* a busy processor. So reset next_balance.
*/
this_rq->next_balance = next_balance;
}
}
/*
......@@ -2900,32 +2895,6 @@ static void active_load_balance(struct rq *busiest_rq, int busiest_cpu)
spin_unlock(&target_rq->lock);
}
static void update_load(struct rq *this_rq)
{
unsigned long this_load;
unsigned int i, scale;
this_load = this_rq->raw_weighted_load;
/* Update our load: */
for (i = 0, scale = 1; i < 3; i++, scale += scale) {
unsigned long old_load, new_load;
/* scale is effectively 1 << i now, and >> i divides by scale */
old_load = this_rq->cpu_load[i];
new_load = this_load;
/*
* Round up the averaging division if load is increasing. This
* prevents us from getting stuck on 9 if the load is 10, for
* example.
*/
if (new_load > old_load)
new_load += scale-1;
this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i;
}
}
#ifdef CONFIG_NO_HZ
static struct {
atomic_t load_balancer;
......@@ -3029,6 +2998,9 @@ static inline void rebalance_domains(int cpu, enum cpu_idle_type idle)
interval = msecs_to_jiffies(interval);
if (unlikely(!interval))
interval = 1;
if (interval > HZ*NR_CPUS/10)
interval = HZ*NR_CPUS/10;
if (sd->flags & SD_SERIALIZE) {
if (!spin_trylock(&balancing))
......@@ -3070,11 +3042,12 @@ static inline void rebalance_domains(int cpu, enum cpu_idle_type idle)
*/
static void run_rebalance_domains(struct softirq_action *h)
{
int local_cpu = smp_processor_id();
struct rq *local_rq = cpu_rq(local_cpu);
enum cpu_idle_type idle = local_rq->idle_at_tick ? CPU_IDLE : CPU_NOT_IDLE;
int this_cpu = smp_processor_id();
struct rq *this_rq = cpu_rq(this_cpu);
enum cpu_idle_type idle = this_rq->idle_at_tick ?
CPU_IDLE : CPU_NOT_IDLE;
rebalance_domains(local_cpu, idle);
rebalance_domains(this_cpu, idle);
#ifdef CONFIG_NO_HZ
/*
......@@ -3082,13 +3055,13 @@ static void run_rebalance_domains(struct softirq_action *h)
* balancing on behalf of the other idle cpus whose ticks are
* stopped.
*/
if (local_rq->idle_at_tick &&
atomic_read(&nohz.load_balancer) == local_cpu) {
if (this_rq->idle_at_tick &&
atomic_read(&nohz.load_balancer) == this_cpu) {
cpumask_t cpus = nohz.cpu_mask;
struct rq *rq;
int balance_cpu;
cpu_clear(local_cpu, cpus);
cpu_clear(this_cpu, cpus);
for_each_cpu_mask(balance_cpu, cpus) {
/*
* If this cpu gets work to do, stop the load balancing
......@@ -3098,11 +3071,11 @@ static void run_rebalance_domains(struct softirq_action *h)
if (need_resched())
break;
rebalance_domains(balance_cpu, CPU_IDLE);
rebalance_domains(balance_cpu, SCHED_IDLE);
rq = cpu_rq(balance_cpu);
if (time_after(local_rq->next_balance, rq->next_balance))
local_rq->next_balance = rq->next_balance;
if (time_after(this_rq->next_balance, rq->next_balance))
this_rq->next_balance = rq->next_balance;
}
}
#endif
......@@ -3115,9 +3088,8 @@ static void run_rebalance_domains(struct softirq_action *h)
* idle load balancing owner or decide to stop the periodic load balancing,
* if the whole system is idle.
*/
static inline void trigger_load_balance(int cpu)
static inline void trigger_load_balance(struct rq *rq, int cpu)
{
struct rq *rq = cpu_rq(cpu);
#ifdef CONFIG_NO_HZ
/*
* If we were in the nohz mode recently and busy at the current
......@@ -3169,13 +3141,29 @@ static inline void trigger_load_balance(int cpu)
if (time_after_eq(jiffies, rq->next_balance))
raise_softirq(SCHED_SOFTIRQ);
}
#else
#else /* CONFIG_SMP */
/*
* on UP we do not need to balance between CPUs:
*/
static inline void idle_balance(int cpu, struct rq *rq)
{
}
/* 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, int best_prio, int best_prio_seen,
struct rq_iterator *iterator)
{
*load_moved = 0;
return 0;
}
#endif
DEFINE_PER_CPU(struct kernel_stat, kstat);
......@@ -3277,81 +3265,6 @@ void account_steal_time(struct task_struct *p, cputime_t steal)
cpustat->steal = cputime64_add(cpustat->steal, tmp);
}
static void task_running_tick(struct rq *rq, struct task_struct *p)
{
if (p->array != rq->active) {
/* Task has expired but was not scheduled yet */
set_tsk_need_resched(p);
return;
}
spin_lock(&rq->lock);
/*
* The task was running during this tick - update the
* time slice counter. Note: we do not update a thread's
* priority until it either goes to sleep or uses up its
* timeslice. This makes it possible for interactive tasks
* to use up their timeslices at their highest priority levels.
*/
if (rt_task(p)) {
/*
* RR tasks need a special form of timeslice management.
* FIFO tasks have no timeslices.
*/
if ((p->policy == SCHED_RR) && !--p->time_slice) {
p->time_slice = task_timeslice(p);
p->first_time_slice = 0;
set_tsk_need_resched(p);
/* put it at the end of the queue: */
requeue_task(p, rq->active);
}
goto out_unlock;
}
if (!--p->time_slice) {
dequeue_task(p, rq->active);
set_tsk_need_resched(p);
p->prio = effective_prio(p);
p->time_slice = task_timeslice(p);
p->first_time_slice = 0;
if (!rq->expired_timestamp)
rq->expired_timestamp = jiffies;
if (!TASK_INTERACTIVE(p)) {
enqueue_task(p, rq->expired);
if (p->static_prio < rq->best_expired_prio)
rq->best_expired_prio = p->static_prio;
} else
enqueue_task(p, rq->active);
} else {
/*
* Prevent a too long timeslice allowing a task to monopolize
* the CPU. We do this by splitting up the timeslice into
* smaller pieces.
*
* Note: this does not mean the task's timeslices expire or
* get lost in any way, they just might be preempted by
* another task of equal priority. (one with higher
* priority would have preempted this task already.) We
* requeue this task to the end of the list on this priority
* level, which is in essence a round-robin of tasks with
* equal priority.
*
* This only applies to tasks in the interactive
* delta range with at least TIMESLICE_GRANULARITY to requeue.
*/
if (TASK_INTERACTIVE(p) && !((task_timeslice(p) -
p->time_slice) % TIMESLICE_GRANULARITY(p)) &&
(p->time_slice >= TIMESLICE_GRANULARITY(p)) &&
(p->array == rq->active)) {
requeue_task(p, rq->active);
set_tsk_need_resched(p);
}
}
out_unlock:
spin_unlock(&rq->lock);
}
/*
* This function gets called by the timer code, with HZ frequency.
* We call it with interrupts disabled.
......@@ -3361,17 +3274,19 @@ static void task_running_tick(struct rq *rq, struct task_struct *p)
*/
void scheduler_tick(void)
{
struct task_struct *p = current;
int cpu = smp_processor_id();
int idle_at_tick = idle_cpu(cpu);
struct rq *rq = cpu_rq(cpu);
struct task_struct *curr = rq->curr;
spin_lock(&rq->lock);
if (curr != rq->idle) /* FIXME: needed? */
curr->sched_class->task_tick(rq, curr);
update_cpu_load(rq);
spin_unlock(&rq->lock);
if (!idle_at_tick)
task_running_tick(rq, p);
#ifdef CONFIG_SMP
update_load(rq);
rq->idle_at_tick = idle_at_tick;
trigger_load_balance(cpu);
rq->idle_at_tick = idle_cpu(cpu);
trigger_load_balance(rq, cpu);
#endif
}
......@@ -3414,140 +3329,128 @@ EXPORT_SYMBOL(sub_preempt_count);
#endif
/*
* schedule() is the main scheduler function.
* Print scheduling while atomic bug:
*/
asmlinkage void __sched schedule(void)
static noinline void __schedule_bug(struct task_struct *prev)
{
struct task_struct *prev, *next;
struct prio_array *array;
struct list_head *queue;
unsigned long long now;
unsigned long run_time;
int cpu, idx;
long *switch_count;
struct rq *rq;
printk(KERN_ERR "BUG: scheduling while atomic: %s/0x%08x/%d\n",
prev->comm, preempt_count(), prev->pid);
debug_show_held_locks(prev);
if (irqs_disabled())
print_irqtrace_events(prev);
dump_stack();
}
/*
* Various schedule()-time debugging checks and statistics:
*/
static inline void schedule_debug(struct task_struct *prev)
{
/*
* 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.
*/
if (unlikely(in_atomic() && !current->exit_state)) {
printk(KERN_ERR "BUG: scheduling while atomic: "
"%s/0x%08x/%d\n",
current->comm, preempt_count(), current->pid);
debug_show_held_locks(current);
if (irqs_disabled())
print_irqtrace_events(current);
dump_stack();
}
if (unlikely(in_atomic_preempt_off()) && unlikely(!prev->exit_state))
__schedule_bug(prev);
profile_hit(SCHED_PROFILING, __builtin_return_address(0));
need_resched:
preempt_disable();
prev = current;
release_kernel_lock(prev);
need_resched_nonpreemptible:
rq = this_rq();
schedstat_inc(this_rq(), sched_cnt);
}
/*
* Pick up the highest-prio task:
*/
static inline struct task_struct *
pick_next_task(struct rq *rq, struct task_struct *prev, u64 now)
{
struct sched_class *class;
struct task_struct *p;
/*
* The idle thread is not allowed to schedule!
* Remove this check after it has been exercised a bit.
* Optimization: we know that if all tasks are in
* the fair class we can call that function directly:
*/
if (unlikely(prev == rq->idle) && prev->state != TASK_RUNNING) {
printk(KERN_ERR "bad: scheduling from the idle thread!\n");
dump_stack();
if (likely(rq->nr_running == rq->cfs.nr_running)) {
p = fair_sched_class.pick_next_task(rq, now);
if (likely(p))
return p;
}
schedstat_inc(rq, sched_cnt);
now = sched_clock();
if (likely((long long)(now - prev->timestamp) < NS_MAX_SLEEP_AVG)) {
run_time = now - prev->timestamp;
if (unlikely((long long)(now - prev->timestamp) < 0))
run_time = 0;
} else
run_time = NS_MAX_SLEEP_AVG;
class = sched_class_highest;
for ( ; ; ) {
p = class->pick_next_task(rq, now);
if (p)
return p;
/*
* Will never be NULL as the idle class always
* returns a non-NULL p:
*/
class = class->next;
}
}
/*
* Tasks charged proportionately less run_time at high sleep_avg to
* delay them losing their interactive status
*/
run_time /= (CURRENT_BONUS(prev) ? : 1);
/*
* schedule() is the main scheduler function.
*/
asmlinkage void __sched schedule(void)
{
struct task_struct *prev, *next;
long *switch_count;
struct rq *rq;
u64 now;
int cpu;
need_resched:
preempt_disable();
cpu = smp_processor_id();
rq = cpu_rq(cpu);
rcu_qsctr_inc(cpu);
prev = rq->curr;
switch_count = &prev->nivcsw;
release_kernel_lock(prev);
need_resched_nonpreemptible:
schedule_debug(prev);
spin_lock_irq(&rq->lock);
clear_tsk_need_resched(prev);
switch_count = &prev->nivcsw;
if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
switch_count = &prev->nvcsw;
if (unlikely((prev->state & TASK_INTERRUPTIBLE) &&
unlikely(signal_pending(prev))))
unlikely(signal_pending(prev)))) {
prev->state = TASK_RUNNING;
else {
if (prev->state == TASK_UNINTERRUPTIBLE)
rq->nr_uninterruptible++;
deactivate_task(prev, rq);
} else {
deactivate_task(rq, prev, 1);
}
switch_count = &prev->nvcsw;
}
cpu = smp_processor_id();
if (unlikely(!rq->nr_running)) {
if (unlikely(!rq->nr_running))
idle_balance(cpu, rq);
if (!rq->nr_running) {
next = rq->idle;
rq->expired_timestamp = 0;
goto switch_tasks;
}
}
array = rq->active;
if (unlikely(!array->nr_active)) {
/*
* Switch the active and expired arrays.
*/
schedstat_inc(rq, sched_switch);
rq->active = rq->expired;
rq->expired = array;
array = rq->active;
rq->expired_timestamp = 0;
rq->best_expired_prio = MAX_PRIO;
}
idx = sched_find_first_bit(array->bitmap);
queue = array->queue + idx;
next = list_entry(queue->next, struct task_struct, run_list);
switch_tasks:
if (next == rq->idle)
schedstat_inc(rq, sched_goidle);
prefetch(next);
prefetch_stack(next);
clear_tsk_need_resched(prev);
rcu_qsctr_inc(task_cpu(prev));
prev->timestamp = prev->last_ran = now;
now = __rq_clock(rq);
prev->sched_class->put_prev_task(rq, prev, now);
next = pick_next_task(rq, prev, now);
sched_info_switch(prev, next);
if (likely(prev != next)) {
next->timestamp = next->last_ran = now;
rq->nr_switches++;
rq->curr = next;
++*switch_count;
prepare_task_switch(rq, next);
prev = context_switch(rq, prev, next);
barrier();
/*
* this_rq must be evaluated again because prev may have moved
* CPUs since it called schedule(), thus the 'rq' on its stack
* frame will be invalid.
*/
finish_task_switch(this_rq(), prev);
context_switch(rq, prev, next); /* unlocks the rq */
} else
spin_unlock_irq(&rq->lock);
prev = current;
if (unlikely(reacquire_kernel_lock(prev) < 0))
if (unlikely(reacquire_kernel_lock(current) < 0)) {
cpu = smp_processor_id();
rq = cpu_rq(cpu);
goto need_resched_nonpreemptible;
}
preempt_enable_no_resched();
if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
goto need_resched;
......@@ -3959,29 +3862,30 @@ EXPORT_SYMBOL(sleep_on_timeout);
*/
void rt_mutex_setprio(struct task_struct *p, int prio)
{
struct prio_array *array;
unsigned long flags;
int oldprio, on_rq;
struct rq *rq;
int oldprio;
u64 now;
BUG_ON(prio < 0 || prio > MAX_PRIO);
rq = task_rq_lock(p, &flags);
now = rq_clock(rq);
oldprio = p->prio;
array = p->array;
if (array)
dequeue_task(p, array);
on_rq = p->se.on_rq;
if (on_rq)
dequeue_task(rq, p, 0, now);
if (rt_prio(prio))
p->sched_class = &rt_sched_class;
else
p->sched_class = &fair_sched_class;
p->prio = prio;
if (array) {
/*
* If changing to an RT priority then queue it
* in the active array!
*/
if (rt_task(p))
array = rq->active;
enqueue_task(p, array);
if (on_rq) {
enqueue_task(rq, p, 0, now);
/*
* Reschedule if we are currently running on this runqueue and
* our priority decreased, or if we are not currently running on
......@@ -3990,8 +3894,9 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
if (task_running(rq, p)) {
if (p->prio > oldprio)
resched_task(rq->curr);
} else if (TASK_PREEMPTS_CURR(p, rq))
resched_task(rq->curr);
} else {
check_preempt_curr(rq, p);
}
}
task_rq_unlock(rq, &flags);
}
......@@ -4000,10 +3905,10 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
void set_user_nice(struct task_struct *p, long nice)
{
struct prio_array *array;
int old_prio, delta;
int old_prio, delta, on_rq;
unsigned long flags;
struct rq *rq;
u64 now;
if (TASK_NICE(p) == nice || nice < -20 || nice > 19)
return;
......@@ -4012,20 +3917,21 @@ void set_user_nice(struct task_struct *p, long nice)
* the task might be in the middle of scheduling on another CPU.
*/
rq = task_rq_lock(p, &flags);
now = rq_clock(rq);
/*
* The RT priorities are set via sched_setscheduler(), but we still
* allow the 'normal' nice value to be set - but as expected
* it wont have any effect on scheduling until the task is
* not SCHED_NORMAL/SCHED_BATCH:
* SCHED_FIFO/SCHED_RR:
*/
if (task_has_rt_policy(p)) {
p->static_prio = NICE_TO_PRIO(nice);
goto out_unlock;
}
array = p->array;
if (array) {
dequeue_task(p, array);
dec_raw_weighted_load(rq, p);
on_rq = p->se.on_rq;
if (on_rq) {
dequeue_task(rq, p, 0, now);
dec_load(rq, p, now);
}
p->static_prio = NICE_TO_PRIO(nice);
......@@ -4034,9 +3940,9 @@ void set_user_nice(struct task_struct *p, long nice)
p->prio = effective_prio(p);
delta = p->prio - old_prio;
if (array) {
enqueue_task(p, array);
inc_raw_weighted_load(rq, p);
if (on_rq) {
enqueue_task(rq, p, 0, now);
inc_load(rq, p, now);
/*
* If the task increased its priority or is running and
* lowered its priority, then reschedule its CPU:
......@@ -4156,11 +4062,24 @@ static inline struct task_struct *find_process_by_pid(pid_t pid)
}
/* Actually do priority change: must hold rq lock. */
static void __setscheduler(struct task_struct *p, int policy, int prio)
static void
__setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio)
{
BUG_ON(p->array);
BUG_ON(p->se.on_rq);
p->policy = policy;
switch (p->policy) {
case SCHED_NORMAL:
case SCHED_BATCH:
case SCHED_IDLE:
p->sched_class = &fair_sched_class;
break;
case SCHED_FIFO:
case SCHED_RR:
p->sched_class = &rt_sched_class;
break;
}
p->rt_priority = prio;
p->normal_prio = normal_prio(p);
/* we are holding p->pi_lock already */
......@@ -4179,8 +4098,7 @@ static void __setscheduler(struct task_struct *p, int policy, int prio)
int sched_setscheduler(struct task_struct *p, int policy,
struct sched_param *param)
{
int retval, oldprio, oldpolicy = -1;
struct prio_array *array;
int retval, oldprio, oldpolicy = -1, on_rq;
unsigned long flags;
struct rq *rq;
......@@ -4191,12 +4109,13 @@ int sched_setscheduler(struct task_struct *p, int policy,
if (policy < 0)
policy = oldpolicy = p->policy;
else if (policy != SCHED_FIFO && policy != SCHED_RR &&
policy != SCHED_NORMAL && policy != SCHED_BATCH)
policy != SCHED_NORMAL && policy != SCHED_BATCH &&
policy != SCHED_IDLE)
return -EINVAL;
/*
* Valid priorities for SCHED_FIFO and SCHED_RR are
* 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL and
* SCHED_BATCH is 0.
* 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL,
* SCHED_BATCH and SCHED_IDLE is 0.
*/
if (param->sched_priority < 0 ||
(p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) ||
......@@ -4211,7 +4130,6 @@ int sched_setscheduler(struct task_struct *p, int policy,
if (!capable(CAP_SYS_NICE)) {
if (rt_policy(policy)) {
unsigned long rlim_rtprio;
unsigned long flags;
if (!lock_task_sighand(p, &flags))
return -ESRCH;
......@@ -4227,6 +4145,12 @@ int sched_setscheduler(struct task_struct *p, int policy,
param->sched_priority > rlim_rtprio)
return -EPERM;
}
/*
* Like positive nice levels, dont allow tasks to
* move out of SCHED_IDLE either:
*/
if (p->policy == SCHED_IDLE && policy != SCHED_IDLE)
return -EPERM;
/* can't change other user's priorities */
if ((current->euid != p->euid) &&
......@@ -4254,13 +4178,13 @@ int sched_setscheduler(struct task_struct *p, int policy,
spin_unlock_irqrestore(&p->pi_lock, flags);
goto recheck;
}
array = p->array;
if (array)
deactivate_task(p, rq);
on_rq = p->se.on_rq;
if (on_rq)
deactivate_task(rq, p, 0);
oldprio = p->prio;
__setscheduler(p, policy, param->sched_priority);
if (array) {
__activate_task(p, rq);
__setscheduler(rq, p, policy, param->sched_priority);
if (on_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
......@@ -4269,8 +4193,9 @@ int sched_setscheduler(struct task_struct *p, int policy,
if (task_running(rq, p)) {
if (p->prio > oldprio)
resched_task(rq->curr);
} else if (TASK_PREEMPTS_CURR(p, rq))
resched_task(rq->curr);
} else {
check_preempt_curr(rq, p);
}
}
__task_rq_unlock(rq);
spin_unlock_irqrestore(&p->pi_lock, flags);
......@@ -4542,41 +4467,18 @@ asmlinkage long sys_sched_getaffinity(pid_t pid, unsigned int len,
/**
* sys_sched_yield - yield the current processor to other threads.
*
* This function yields the current CPU by moving the calling thread
* to the expired array. If there are no other threads running on this
* CPU then this function will return.
* This function yields the current CPU to other tasks. If there are no
* other threads running on this CPU then this function will return.
*/
asmlinkage long sys_sched_yield(void)
{
struct rq *rq = this_rq_lock();
struct prio_array *array = current->array, *target = rq->expired;
schedstat_inc(rq, yld_cnt);
/*
* We implement yielding by moving the task into the expired
* queue.
*
* (special rule: RT tasks will just roundrobin in the active
* array.)
*/
if (rt_task(current))
target = rq->active;
if (array->nr_active == 1) {
if (unlikely(rq->nr_running == 1))
schedstat_inc(rq, yld_act_empty);
if (!rq->expired->nr_active)
schedstat_inc(rq, yld_both_empty);
} else if (!rq->expired->nr_active)
schedstat_inc(rq, yld_exp_empty);
if (array != target) {
dequeue_task(current, array);
enqueue_task(current, target);
} else
/*
* requeue_task is cheaper so perform that if possible.
*/
requeue_task(current, array);
else
current->sched_class->yield_task(rq, current);
/*
* Since we are going to call schedule() anyway, there's
......@@ -4727,6 +4629,7 @@ asmlinkage long sys_sched_get_priority_max(int policy)
break;
case SCHED_NORMAL:
case SCHED_BATCH:
case SCHED_IDLE:
ret = 0;
break;
}
......@@ -4751,6 +4654,7 @@ asmlinkage long sys_sched_get_priority_min(int policy)
break;
case SCHED_NORMAL:
case SCHED_BATCH:
case SCHED_IDLE:
ret = 0;
}
return ret;
......@@ -4785,7 +4689,7 @@ long sys_sched_rr_get_interval(pid_t pid, struct timespec __user *interval)
goto out_unlock;
jiffies_to_timespec(p->policy == SCHED_FIFO ?
0 : task_timeslice(p), &t);
0 : static_prio_timeslice(p->static_prio), &t);
read_unlock(&tasklist_lock);
retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
out_nounlock:
......@@ -4860,6 +4764,9 @@ void show_state_filter(unsigned long state_filter)
touch_all_softlockup_watchdogs();
#ifdef CONFIG_SCHED_DEBUG
sysrq_sched_debug_show();
#endif
read_unlock(&tasklist_lock);
/*
* Only show locks if all tasks are dumped:
......@@ -4870,7 +4777,7 @@ void show_state_filter(unsigned long state_filter)
void __cpuinit init_idle_bootup_task(struct task_struct *idle)
{
/* nothing yet */
idle->sched_class = &idle_sched_class;
}
/**
......@@ -4886,12 +4793,12 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
struct rq *rq = cpu_rq(cpu);
unsigned long flags;
idle->timestamp = sched_clock();
idle->array = NULL;
__sched_fork(idle);
idle->se.exec_start = sched_clock();
idle->prio = idle->normal_prio = MAX_PRIO;
idle->state = TASK_RUNNING;
idle->cpus_allowed = cpumask_of_cpu(cpu);
set_task_cpu(idle, cpu);
__set_task_cpu(idle, cpu);
spin_lock_irqsave(&rq->lock, flags);
rq->curr = rq->idle = idle;
......@@ -4906,6 +4813,10 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
#else
task_thread_info(idle)->preempt_count = 0;
#endif
/*
* The idle tasks have their own, simple scheduling class:
*/
idle->sched_class = &idle_sched_class;
}
/*
......@@ -4917,6 +4828,28 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
*/
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 gran_limit = 10000000;
sysctl_sched_granularity *= factor;
if (sysctl_sched_granularity > gran_limit)
sysctl_sched_granularity = gran_limit;
sysctl_sched_runtime_limit = sysctl_sched_granularity * 4;
sysctl_sched_wakeup_granularity = sysctl_sched_granularity / 2;
}
#ifdef CONFIG_SMP
/*
* This is how migration works:
......@@ -4990,7 +4923,7 @@ EXPORT_SYMBOL_GPL(set_cpus_allowed);
static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
{
struct rq *rq_dest, *rq_src;
int ret = 0;
int ret = 0, on_rq;
if (unlikely(cpu_is_offline(dest_cpu)))
return ret;
......@@ -5006,20 +4939,13 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
if (!cpu_isset(dest_cpu, p->cpus_allowed))
goto out;
on_rq = p->se.on_rq;
if (on_rq)
deactivate_task(rq_src, p, 0);
set_task_cpu(p, dest_cpu);
if (p->array) {
/*
* Sync timestamp with rq_dest's before activating.
* The same thing could be achieved by doing this step
* afterwards, and pretending it was a local activate.
* This way is cleaner and logically correct.
*/
p->timestamp = p->timestamp - rq_src->most_recent_timestamp
+ rq_dest->most_recent_timestamp;
deactivate_task(p, rq_src);
__activate_task(p, rq_dest);
if (TASK_PREEMPTS_CURR(p, rq_dest))
resched_task(rq_dest->curr);
if (on_rq) {
activate_task(rq_dest, p, 0);
check_preempt_curr(rq_dest, p);
}
ret = 1;
out:
......@@ -5171,7 +5097,8 @@ static void migrate_live_tasks(int src_cpu)
write_unlock_irq(&tasklist_lock);
}
/* Schedules idle task to be the next runnable task on current CPU.
/*
* 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.
*/
......@@ -5191,10 +5118,10 @@ void sched_idle_next(void)
*/
spin_lock_irqsave(&rq->lock, flags);
__setscheduler(p, SCHED_FIFO, MAX_RT_PRIO-1);
__setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1);
/* Add idle task to the _front_ of its priority queue: */
__activate_idle_task(p, rq);
activate_idle_task(p, rq);
spin_unlock_irqrestore(&rq->lock, flags);
}
......@@ -5244,16 +5171,15 @@ static void migrate_dead(unsigned int dead_cpu, struct task_struct *p)
static void migrate_dead_tasks(unsigned int dead_cpu)
{
struct rq *rq = cpu_rq(dead_cpu);
unsigned int arr, i;
for (arr = 0; arr < 2; arr++) {
for (i = 0; i < MAX_PRIO; i++) {
struct list_head *list = &rq->arrays[arr].queue[i];
struct task_struct *next;
while (!list_empty(list))
migrate_dead(dead_cpu, list_entry(list->next,
struct task_struct, run_list));
}
for ( ; ; ) {
if (!rq->nr_running)
break;
next = pick_next_task(rq, rq->curr, rq_clock(rq));
if (!next)
break;
migrate_dead(dead_cpu, next);
}
}
#endif /* CONFIG_HOTPLUG_CPU */
......@@ -5277,14 +5203,14 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
p = kthread_create(migration_thread, hcpu, "migration/%d",cpu);
p = kthread_create(migration_thread, hcpu, "migration/%d", cpu);
if (IS_ERR(p))
return NOTIFY_BAD;
p->flags |= PF_NOFREEZE;
kthread_bind(p, cpu);
/* Must be high prio: stop_machine expects to yield to it. */
rq = task_rq_lock(p, &flags);
__setscheduler(p, SCHED_FIFO, MAX_RT_PRIO-1);
__setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1);
task_rq_unlock(rq, &flags);
cpu_rq(cpu)->migration_thread = p;
break;
......@@ -5315,9 +5241,10 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
rq->migration_thread = NULL;
/* Idle task back to normal (off runqueue, low prio) */
rq = task_rq_lock(rq->idle, &flags);
deactivate_task(rq->idle, rq);
deactivate_task(rq, rq->idle, 0);
rq->idle->static_prio = MAX_PRIO;
__setscheduler(rq->idle, SCHED_NORMAL, 0);
__setscheduler(rq, rq->idle, SCHED_NORMAL, 0);
rq->idle->sched_class = &idle_sched_class;
migrate_dead_tasks(cpu);
task_rq_unlock(rq, &flags);
migrate_nr_uninterruptible(rq);
......@@ -5926,7 +5853,6 @@ 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 sched_domain *sd;
#ifdef CONFIG_NUMA
struct sched_group **sched_group_nodes = NULL;
int sd_allnodes = 0;
......@@ -5934,7 +5860,7 @@ static int build_sched_domains(const cpumask_t *cpu_map)
/*
* Allocate the per-node list of sched groups
*/
sched_group_nodes = kzalloc(sizeof(struct sched_group*)*MAX_NUMNODES,
sched_group_nodes = kzalloc(sizeof(struct sched_group *)*MAX_NUMNODES,
GFP_KERNEL);
if (!sched_group_nodes) {
printk(KERN_WARNING "Can not alloc sched group node list\n");
......@@ -5953,8 +5879,8 @@ static int build_sched_domains(const cpumask_t *cpu_map)
cpus_and(nodemask, nodemask, *cpu_map);
#ifdef CONFIG_NUMA
if (cpus_weight(*cpu_map)
> SD_NODES_PER_DOMAIN*cpus_weight(nodemask)) {
if (cpus_weight(*cpu_map) >
SD_NODES_PER_DOMAIN*cpus_weight(nodemask)) {
sd = &per_cpu(allnodes_domains, i);
*sd = SD_ALLNODES_INIT;
sd->span = *cpu_map;
......@@ -6013,7 +5939,8 @@ static int build_sched_domains(const cpumask_t *cpu_map)
if (i != first_cpu(this_sibling_map))
continue;
init_sched_build_groups(this_sibling_map, cpu_map, &cpu_to_cpu_group);
init_sched_build_groups(this_sibling_map, cpu_map,
&cpu_to_cpu_group);
}
#endif
......@@ -6024,11 +5951,11 @@ static int build_sched_domains(const cpumask_t *cpu_map)
cpus_and(this_core_map, this_core_map, *cpu_map);
if (i != first_cpu(this_core_map))
continue;
init_sched_build_groups(this_core_map, cpu_map, &cpu_to_core_group);
init_sched_build_groups(this_core_map, cpu_map,
&cpu_to_core_group);
}
#endif
/* Set up physical groups */
for (i = 0; i < MAX_NUMNODES; i++) {
cpumask_t nodemask = node_to_cpumask(i);
......@@ -6043,7 +5970,8 @@ static int build_sched_domains(const cpumask_t *cpu_map)
#ifdef CONFIG_NUMA
/* Set up node groups */
if (sd_allnodes)
init_sched_build_groups(*cpu_map, cpu_map, &cpu_to_allnodes_group);
init_sched_build_groups(*cpu_map, cpu_map,
&cpu_to_allnodes_group);
for (i = 0; i < MAX_NUMNODES; i++) {
/* Set up node groups */
......@@ -6115,19 +6043,22 @@ static int build_sched_domains(const cpumask_t *cpu_map)
/* Calculate CPU power for physical packages and nodes */
#ifdef CONFIG_SCHED_SMT
for_each_cpu_mask(i, *cpu_map) {
sd = &per_cpu(cpu_domains, i);
struct sched_domain *sd = &per_cpu(cpu_domains, i);
init_sched_groups_power(i, sd);
}
#endif
#ifdef CONFIG_SCHED_MC
for_each_cpu_mask(i, *cpu_map) {
sd = &per_cpu(core_domains, i);
struct sched_domain *sd = &per_cpu(core_domains, i);
init_sched_groups_power(i, sd);
}
#endif
for_each_cpu_mask(i, *cpu_map) {
sd = &per_cpu(phys_domains, i);
struct sched_domain *sd = &per_cpu(phys_domains, i);
init_sched_groups_power(i, sd);
}
......@@ -6361,10 +6292,12 @@ void __init sched_init_smp(void)
/* Move init over to a non-isolated CPU */
if (set_cpus_allowed(current, non_isolated_cpus) < 0)
BUG();
sched_init_granularity();
}
#else
void __init sched_init_smp(void)
{
sched_init_granularity();
}
#endif /* CONFIG_SMP */
......@@ -6378,28 +6311,51 @@ int in_sched_functions(unsigned long addr)
&& addr < (unsigned long)__sched_text_end);
}
static inline void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq)
{
cfs_rq->tasks_timeline = RB_ROOT;
cfs_rq->fair_clock = 1;
#ifdef CONFIG_FAIR_GROUP_SCHED
cfs_rq->rq = rq;
#endif
}
void __init sched_init(void)
{
int i, j, k;
u64 now = sched_clock();
int highest_cpu = 0;
int i, j;
/*
* Link up the scheduling class hierarchy:
*/
rt_sched_class.next = &fair_sched_class;
fair_sched_class.next = &idle_sched_class;
idle_sched_class.next = NULL;
for_each_possible_cpu(i) {
struct prio_array *array;
struct rt_prio_array *array;
struct rq *rq;
rq = cpu_rq(i);
spin_lock_init(&rq->lock);
lockdep_set_class(&rq->lock, &rq->rq_lock_key);
rq->nr_running = 0;
rq->active = rq->arrays;
rq->expired = rq->arrays + 1;
rq->best_expired_prio = MAX_PRIO;
rq->clock = 1;
init_cfs_rq(&rq->cfs, rq);
#ifdef CONFIG_FAIR_GROUP_SCHED
INIT_LIST_HEAD(&rq->leaf_cfs_rq_list);
list_add(&rq->cfs.leaf_cfs_rq_list, &rq->leaf_cfs_rq_list);
#endif
rq->ls.load_update_last = now;
rq->ls.load_update_start = now;
for (j = 0; j < CPU_LOAD_IDX_MAX; j++)
rq->cpu_load[j] = 0;
#ifdef CONFIG_SMP
rq->sd = NULL;
for (j = 1; j < 3; j++)
rq->cpu_load[j] = 0;
rq->active_balance = 0;
rq->next_balance = jiffies;
rq->push_cpu = 0;
rq->cpu = i;
rq->migration_thread = NULL;
......@@ -6407,16 +6363,14 @@ void __init sched_init(void)
#endif
atomic_set(&rq->nr_iowait, 0);
for (j = 0; j < 2; j++) {
array = rq->arrays + j;
for (k = 0; k < MAX_PRIO; k++) {
INIT_LIST_HEAD(array->queue + k);
__clear_bit(k, array->bitmap);
}
// delimiter for bitsearch
__set_bit(MAX_PRIO, array->bitmap);
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);
......@@ -6443,6 +6397,10 @@ void __init sched_init(void)
* when this runqueue becomes "idle".
*/
init_idle(current, smp_processor_id());
/*
* During early bootup we pretend to be a normal task:
*/
current->sched_class = &fair_sched_class;
}
#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
......@@ -6473,29 +6431,55 @@ EXPORT_SYMBOL(__might_sleep);
#ifdef CONFIG_MAGIC_SYSRQ
void normalize_rt_tasks(void)
{
struct prio_array *array;
struct task_struct *g, *p;
unsigned long flags;
struct rq *rq;
int on_rq;
read_lock_irq(&tasklist_lock);
do_each_thread(g, p) {
if (!rt_task(p))
p->se.fair_key = 0;
p->se.wait_runtime = 0;
p->se.wait_start_fair = 0;
p->se.wait_start = 0;
p->se.exec_start = 0;
p->se.sleep_start = 0;
p->se.sleep_start_fair = 0;
p->se.block_start = 0;
task_rq(p)->cfs.fair_clock = 0;
task_rq(p)->clock = 0;
if (!rt_task(p)) {
/*
* Renice negative nice level userspace
* tasks back to 0:
*/
if (TASK_NICE(p) < 0 && p->mm)
set_user_nice(p, 0);
continue;
}
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
array = p->array;
if (array)
deactivate_task(p, task_rq(p));
__setscheduler(p, SCHED_NORMAL, 0);
if (array) {
__activate_task(p, task_rq(p));
on_rq = p->se.on_rq;
if (on_rq)
deactivate_task(task_rq(p), p, 0);
__setscheduler(rq, p, SCHED_NORMAL, 0);
if (on_rq) {
activate_task(task_rq(p), p, 0);
resched_task(rq->curr);
}
#ifdef CONFIG_SMP
out_unlock:
#endif
__task_rq_unlock(rq);
spin_unlock_irqrestore(&p->pi_lock, flags);
} while_each_thread(g, p);
......
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