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authorLinus Torvalds <torvalds@linux-foundation.org>2014-03-31 11:21:19 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-03-31 11:21:19 -0700
commit971eae7c99212dd67b425a603f1fe3b763359907 (patch)
tree2ff002ecc759275cbecee123a230f90ea7452b18 /kernel
parent8c292f11744297dfb3a69f4a0bccbe4a6417b50d (diff)
parent6037dd1a49f95092824fa8ba75c717ff7805e317 (diff)
downloadlinux-971eae7c99212dd67b425a603f1fe3b763359907.tar.gz
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler changes from Ingo Molnar: "Bigger changes: - sched/idle restructuring: they are WIP preparation for deeper integration between the scheduler and idle state selection, by Nicolas Pitre. - add NUMA scheduling pseudo-interleaving, by Rik van Riel. - optimize cgroup context switches, by Peter Zijlstra. - RT scheduling enhancements, by Thomas Gleixner. The rest is smaller changes, non-urgnt fixes and cleanups" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (68 commits) sched: Clean up the task_hot() function sched: Remove double calculation in fix_small_imbalance() sched: Fix broken setscheduler() sparc64, sched: Remove unused sparc64_multi_core sched: Remove unused mc_capable() and smt_capable() sched/numa: Move task_numa_free() to __put_task_struct() sched/fair: Fix endless loop in idle_balance() sched/core: Fix endless loop in pick_next_task() sched/fair: Push down check for high priority class task into idle_balance() sched/rt: Fix picking RT and DL tasks from empty queue trace: Replace hardcoding of 19 with MAX_NICE sched: Guarantee task priority in pick_next_task() sched/idle: Remove stale old file sched: Put rq's sched_avg under CONFIG_FAIR_GROUP_SCHED cpuidle/arm64: Remove redundant cpuidle_idle_call() cpuidle/powernv: Remove redundant cpuidle_idle_call() sched, nohz: Exclude isolated cores from load balancing sched: Fix select_task_rq_fair() description comments workqueue: Replace hardcoding of -20 and 19 with MIN_NICE and MAX_NICE sys: Replace hardcoding of -20 and 19 with MIN_NICE and MAX_NICE ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/Makefile1
-rw-r--r--kernel/cpu/Makefile1
-rw-r--r--kernel/fork.c1
-rw-r--r--kernel/locking/rtmutex.c12
-rw-r--r--kernel/rcu/rcutorture.c8
-rw-r--r--kernel/sched/Makefile2
-rw-r--r--kernel/sched/auto_group.c2
-rw-r--r--kernel/sched/core.c207
-rw-r--r--kernel/sched/cputime.c4
-rw-r--r--kernel/sched/deadline.c56
-rw-r--r--kernel/sched/debug.c7
-rw-r--r--kernel/sched/fair.c600
-rw-r--r--kernel/sched/idle.c (renamed from kernel/cpu/idle.c)7
-rw-r--r--kernel/sched/idle_task.c25
-rw-r--r--kernel/sched/rt.c102
-rw-r--r--kernel/sched/sched.h65
-rw-r--r--kernel/sched/stop_task.c15
-rw-r--r--kernel/sys.c8
-rw-r--r--kernel/sysctl.c7
-rw-r--r--kernel/trace/ring_buffer_benchmark.c6
-rw-r--r--kernel/workqueue.c2
21 files changed, 788 insertions, 350 deletions
diff --git a/kernel/Makefile b/kernel/Makefile
index 5c0e7666811..4fd847488b7 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -22,7 +22,6 @@ obj-y += sched/
obj-y += locking/
obj-y += power/
obj-y += printk/
-obj-y += cpu/
obj-y += irq/
obj-y += rcu/
diff --git a/kernel/cpu/Makefile b/kernel/cpu/Makefile
deleted file mode 100644
index 59ab052ef7a..00000000000
--- a/kernel/cpu/Makefile
+++ /dev/null
@@ -1 +0,0 @@
-obj-y = idle.o
diff --git a/kernel/fork.c b/kernel/fork.c
index a17621c6cd4..332688e5e7b 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -237,6 +237,7 @@ void __put_task_struct(struct task_struct *tsk)
WARN_ON(atomic_read(&tsk->usage));
WARN_ON(tsk == current);
+ task_numa_free(tsk);
security_task_free(tsk);
exit_creds(tsk);
delayacct_tsk_free(tsk);
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 2e960a2bab8..aa4dff04b59 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -213,6 +213,18 @@ struct task_struct *rt_mutex_get_top_task(struct task_struct *task)
}
/*
+ * Called by sched_setscheduler() to check whether the priority change
+ * is overruled by a possible priority boosting.
+ */
+int rt_mutex_check_prio(struct task_struct *task, int newprio)
+{
+ if (!task_has_pi_waiters(task))
+ return 0;
+
+ return task_top_pi_waiter(task)->task->prio <= newprio;
+}
+
+/*
* Adjust the priority of a task, after its pi_waiters got modified.
*
* This can be both boosting and unboosting. task->pi_lock must be held.
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index f59d48597dd..bd30bc61bc0 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -696,7 +696,7 @@ rcu_torture_writer(void *arg)
static DEFINE_TORTURE_RANDOM(rand);
VERBOSE_TOROUT_STRING("rcu_torture_writer task started");
- set_user_nice(current, 19);
+ set_user_nice(current, MAX_NICE);
do {
schedule_timeout_uninterruptible(1);
@@ -759,7 +759,7 @@ rcu_torture_fakewriter(void *arg)
DEFINE_TORTURE_RANDOM(rand);
VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started");
- set_user_nice(current, 19);
+ set_user_nice(current, MAX_NICE);
do {
schedule_timeout_uninterruptible(1 + torture_random(&rand)%10);
@@ -872,7 +872,7 @@ rcu_torture_reader(void *arg)
unsigned long long ts;
VERBOSE_TOROUT_STRING("rcu_torture_reader task started");
- set_user_nice(current, 19);
+ set_user_nice(current, MAX_NICE);
if (irqreader && cur_ops->irq_capable)
setup_timer_on_stack(&t, rcu_torture_timer, 0);
@@ -1161,7 +1161,7 @@ static int rcu_torture_barrier_cbs(void *arg)
init_rcu_head_on_stack(&rcu);
VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started");
- set_user_nice(current, 19);
+ set_user_nice(current, MAX_NICE);
do {
wait_event(barrier_cbs_wq[myid],
(newphase =
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index 9a95c8c2af2..ab32b7b0db5 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -13,7 +13,7 @@ endif
obj-y += core.o proc.o clock.o cputime.o
obj-y += idle_task.o fair.o rt.o deadline.o stop_task.o
-obj-y += wait.o completion.o
+obj-y += wait.o completion.o idle.o
obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o
obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o
obj-$(CONFIG_SCHEDSTATS) += stats.o
diff --git a/kernel/sched/auto_group.c b/kernel/sched/auto_group.c
index 4a073539c58..e73efba9830 100644
--- a/kernel/sched/auto_group.c
+++ b/kernel/sched/auto_group.c
@@ -203,7 +203,7 @@ int proc_sched_autogroup_set_nice(struct task_struct *p, int nice)
struct autogroup *ag;
int err;
- if (nice < -20 || nice > 19)
+ if (nice < MIN_NICE || nice > MAX_NICE)
return -EINVAL;
err = security_task_setnice(current, nice);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index f5c6635b806..ae365aaa818 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1745,8 +1745,10 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
p->numa_scan_seq = p->mm ? p->mm->numa_scan_seq : 0;
p->numa_scan_period = sysctl_numa_balancing_scan_delay;
p->numa_work.next = &p->numa_work;
- p->numa_faults = NULL;
- p->numa_faults_buffer = NULL;
+ p->numa_faults_memory = NULL;
+ p->numa_faults_buffer_memory = NULL;
+ p->last_task_numa_placement = 0;
+ p->last_sum_exec_runtime = 0;
INIT_LIST_HEAD(&p->numa_entry);
p->numa_group = NULL;
@@ -2149,8 +2151,6 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
if (mm)
mmdrop(mm);
if (unlikely(prev_state == TASK_DEAD)) {
- task_numa_free(prev);
-
if (prev->sched_class->task_dead)
prev->sched_class->task_dead(prev);
@@ -2167,13 +2167,6 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
#ifdef CONFIG_SMP
-/* assumes rq->lock is held */
-static inline void pre_schedule(struct rq *rq, struct task_struct *prev)
-{
- if (prev->sched_class->pre_schedule)
- prev->sched_class->pre_schedule(rq, prev);
-}
-
/* rq->lock is NOT held, but preemption is disabled */
static inline void post_schedule(struct rq *rq)
{
@@ -2191,10 +2184,6 @@ static inline void post_schedule(struct rq *rq)
#else
-static inline void pre_schedule(struct rq *rq, struct task_struct *p)
-{
-}
-
static inline void post_schedule(struct rq *rq)
{
}
@@ -2510,8 +2499,13 @@ void __kprobes preempt_count_add(int val)
DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >=
PREEMPT_MASK - 10);
#endif
- if (preempt_count() == val)
- trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
+ if (preempt_count() == val) {
+ unsigned long ip = get_parent_ip(CALLER_ADDR1);
+#ifdef CONFIG_DEBUG_PREEMPT
+ current->preempt_disable_ip = ip;
+#endif
+ trace_preempt_off(CALLER_ADDR0, ip);
+ }
}
EXPORT_SYMBOL(preempt_count_add);
@@ -2554,6 +2548,13 @@ static noinline void __schedule_bug(struct task_struct *prev)
print_modules();
if (irqs_disabled())
print_irqtrace_events(prev);
+#ifdef CONFIG_DEBUG_PREEMPT
+ if (in_atomic_preempt_off()) {
+ pr_err("Preemption disabled at:");
+ print_ip_sym(current->preempt_disable_ip);
+ pr_cont("\n");
+ }
+#endif
dump_stack();
add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
}
@@ -2577,36 +2578,34 @@ static inline void schedule_debug(struct task_struct *prev)
schedstat_inc(this_rq(), sched_count);
}
-static void put_prev_task(struct rq *rq, struct task_struct *prev)
-{
- if (prev->on_rq || rq->skip_clock_update < 0)
- update_rq_clock(rq);
- prev->sched_class->put_prev_task(rq, prev);
-}
-
/*
* Pick up the highest-prio task:
*/
static inline struct task_struct *
-pick_next_task(struct rq *rq)
+pick_next_task(struct rq *rq, struct task_struct *prev)
{
- const struct sched_class *class;
+ const struct sched_class *class = &fair_sched_class;
struct task_struct *p;
/*
* Optimization: we know that if all tasks are in
* the fair class we can call that function directly:
*/
- if (likely(rq->nr_running == rq->cfs.h_nr_running)) {
- p = fair_sched_class.pick_next_task(rq);
- if (likely(p))
+ if (likely(prev->sched_class == class &&
+ rq->nr_running == rq->cfs.h_nr_running)) {
+ p = fair_sched_class.pick_next_task(rq, prev);
+ if (likely(p && p != RETRY_TASK))
return p;
}
+again:
for_each_class(class) {
- p = class->pick_next_task(rq);
- if (p)
+ p = class->pick_next_task(rq, prev);
+ if (p) {
+ if (unlikely(p == RETRY_TASK))
+ goto again;
return p;
+ }
}
BUG(); /* the idle class will always have a runnable task */
@@ -2700,13 +2699,10 @@ need_resched:
switch_count = &prev->nvcsw;
}
- pre_schedule(rq, prev);
-
- if (unlikely(!rq->nr_running))
- idle_balance(cpu, rq);
+ if (prev->on_rq || rq->skip_clock_update < 0)
+ update_rq_clock(rq);
- put_prev_task(rq, prev);
- next = pick_next_task(rq);
+ next = pick_next_task(rq, prev);
clear_tsk_need_resched(prev);
clear_preempt_need_resched();
rq->skip_clock_update = 0;
@@ -2908,7 +2904,8 @@ EXPORT_SYMBOL(sleep_on_timeout);
* This function changes the 'effective' priority of a task. It does
* not touch ->normal_prio like __setscheduler().
*
- * Used by the rt_mutex code to implement priority inheritance logic.
+ * Used by the rt_mutex code to implement priority inheritance
+ * logic. Call site only calls if the priority of the task changed.
*/
void rt_mutex_setprio(struct task_struct *p, int prio)
{
@@ -2998,7 +2995,7 @@ void set_user_nice(struct task_struct *p, long nice)
unsigned long flags;
struct rq *rq;
- if (TASK_NICE(p) == nice || nice < -20 || nice > 19)
+ if (task_nice(p) == nice || nice < MIN_NICE || nice > MAX_NICE)
return;
/*
* We have to be careful, if called from sys_setpriority(),
@@ -3076,11 +3073,11 @@ SYSCALL_DEFINE1(nice, int, increment)
if (increment > 40)
increment = 40;
- nice = TASK_NICE(current) + increment;
- if (nice < -20)
- nice = -20;
- if (nice > 19)
- nice = 19;
+ nice = task_nice(current) + increment;
+ if (nice < MIN_NICE)
+ nice = MIN_NICE;
+ if (nice > MAX_NICE)
+ nice = MAX_NICE;
if (increment < 0 && !can_nice(current, nice))
return -EPERM;
@@ -3109,18 +3106,6 @@ int task_prio(const struct task_struct *p)
}
/**
- * task_nice - return the nice value of a given task.
- * @p: the task in question.
- *
- * Return: The nice value [ -20 ... 0 ... 19 ].
- */
-int task_nice(const struct task_struct *p)
-{
- return TASK_NICE(p);
-}
-EXPORT_SYMBOL(task_nice);
-
-/**
* idle_cpu - is a given cpu idle currently?
* @cpu: the processor in question.
*
@@ -3189,9 +3174,8 @@ __setparam_dl(struct task_struct *p, const struct sched_attr *attr)
dl_se->dl_new = 1;
}
-/* Actually do priority change: must hold pi & rq lock. */
-static void __setscheduler(struct rq *rq, struct task_struct *p,
- const struct sched_attr *attr)
+static void __setscheduler_params(struct task_struct *p,
+ const struct sched_attr *attr)
{
int policy = attr->sched_policy;
@@ -3211,9 +3195,21 @@ static void __setscheduler(struct rq *rq, struct task_struct *p,
* getparam()/getattr() don't report silly values for !rt tasks.
*/
p->rt_priority = attr->sched_priority;
-
p->normal_prio = normal_prio(p);
- p->prio = rt_mutex_getprio(p);
+ set_load_weight(p);
+}
+
+/* Actually do priority change: must hold pi & rq lock. */
+static void __setscheduler(struct rq *rq, struct task_struct *p,
+ const struct sched_attr *attr)
+{
+ __setscheduler_params(p, attr);
+
+ /*
+ * If we get here, there was no pi waiters boosting the
+ * task. It is safe to use the normal prio.
+ */
+ p->prio = normal_prio(p);
if (dl_prio(p->prio))
p->sched_class = &dl_sched_class;
@@ -3221,8 +3217,6 @@ static void __setscheduler(struct rq *rq, struct task_struct *p,
p->sched_class = &rt_sched_class;
else
p->sched_class = &fair_sched_class;
-
- set_load_weight(p);
}
static void
@@ -3275,6 +3269,8 @@ static int __sched_setscheduler(struct task_struct *p,
const struct sched_attr *attr,
bool user)
{
+ int newprio = dl_policy(attr->sched_policy) ? MAX_DL_PRIO - 1 :
+ MAX_RT_PRIO - 1 - attr->sched_priority;
int retval, oldprio, oldpolicy = -1, on_rq, running;
int policy = attr->sched_policy;
unsigned long flags;
@@ -3319,7 +3315,7 @@ recheck:
*/
if (user && !capable(CAP_SYS_NICE)) {
if (fair_policy(policy)) {
- if (attr->sched_nice < TASK_NICE(p) &&
+ if (attr->sched_nice < task_nice(p) &&
!can_nice(p, attr->sched_nice))
return -EPERM;
}
@@ -3352,7 +3348,7 @@ recheck:
* SCHED_NORMAL if the RLIMIT_NICE would normally permit it.
*/
if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) {
- if (!can_nice(p, TASK_NICE(p)))
+ if (!can_nice(p, task_nice(p)))
return -EPERM;
}
@@ -3389,16 +3385,18 @@ recheck:
}
/*
- * If not changing anything there's no need to proceed further:
+ * If not changing anything there's no need to proceed further,
+ * but store a possible modification of reset_on_fork.
*/
if (unlikely(policy == p->policy)) {
- if (fair_policy(policy) && attr->sched_nice != TASK_NICE(p))
+ if (fair_policy(policy) && attr->sched_nice != task_nice(p))
goto change;
if (rt_policy(policy) && attr->sched_priority != p->rt_priority)
goto change;
if (dl_policy(policy))
goto change;
+ p->sched_reset_on_fork = reset_on_fork;
task_rq_unlock(rq, p, &flags);
return 0;
}
@@ -3452,6 +3450,24 @@ change:
return -EBUSY;
}
+ p->sched_reset_on_fork = reset_on_fork;
+ oldprio = p->prio;
+
+ /*
+ * Special case for priority boosted tasks.
+ *
+ * If the new priority is lower or equal (user space view)
+ * than the current (boosted) priority, we just store the new
+ * normal parameters and do not touch the scheduler class and
+ * the runqueue. This will be done when the task deboost
+ * itself.
+ */
+ if (rt_mutex_check_prio(p, newprio)) {
+ __setscheduler_params(p, attr);
+ task_rq_unlock(rq, p, &flags);
+ return 0;
+ }
+
on_rq = p->on_rq;
running = task_current(rq, p);
if (on_rq)
@@ -3459,16 +3475,18 @@ change:
if (running)
p->sched_class->put_prev_task(rq, p);
- p->sched_reset_on_fork = reset_on_fork;
-
- oldprio = p->prio;
prev_class = p->sched_class;
__setscheduler(rq, p, attr);
if (running)
p->sched_class->set_curr_task(rq);
- if (on_rq)
- enqueue_task(rq, p, 0);
+ if (on_rq) {
+ /*
+ * We enqueue to tail when the priority of a task is
+ * increased (user space view).
+ */
+ enqueue_task(rq, p, oldprio <= p->prio ? ENQUEUE_HEAD : 0);
+ }
check_class_changed(rq, p, prev_class, oldprio);
task_rq_unlock(rq, p, &flags);
@@ -3624,7 +3642,7 @@ static int sched_copy_attr(struct sched_attr __user *uattr,
* XXX: do we want to be lenient like existing syscalls; or do we want
* to be strict and return an error on out-of-bounds values?
*/
- attr->sched_nice = clamp(attr->sched_nice, -20, 19);
+ attr->sched_nice = clamp(attr->sched_nice, MIN_NICE, MAX_NICE);
out:
return ret;
@@ -3845,7 +3863,7 @@ SYSCALL_DEFINE4(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr,
else if (task_has_rt_policy(p))
attr.sched_priority = p->rt_priority;
else
- attr.sched_nice = TASK_NICE(p);
+ attr.sched_nice = task_nice(p);
rcu_read_unlock();
@@ -4483,6 +4501,7 @@ void init_idle(struct task_struct *idle, int cpu)
rcu_read_unlock();
rq->curr = rq->idle = idle;
+ idle->on_rq = 1;
#if defined(CONFIG_SMP)
idle->on_cpu = 1;
#endif
@@ -4721,6 +4740,22 @@ static void calc_load_migrate(struct rq *rq)
atomic_long_add(delta, &calc_load_tasks);
}
+static void put_prev_task_fake(struct rq *rq, struct task_struct *prev)
+{
+}
+
+static const struct sched_class fake_sched_class = {
+ .put_prev_task = put_prev_task_fake,
+};
+
+static struct task_struct fake_task = {
+ /*
+ * Avoid pull_{rt,dl}_task()
+ */
+ .prio = MAX_PRIO + 1,
+ .sched_class = &fake_sched_class,
+};
+
/*
* Migrate all tasks from the rq, sleeping tasks will be migrated by
* try_to_wake_up()->select_task_rq().
@@ -4761,7 +4796,7 @@ static void migrate_tasks(unsigned int dead_cpu)
if (rq->nr_running == 1)
break;
- next = pick_next_task(rq);
+ next = pick_next_task(rq, &fake_task);
BUG_ON(!next);
next->sched_class->put_prev_task(rq, next);
@@ -4851,7 +4886,7 @@ set_table_entry(struct ctl_table *entry,
static struct ctl_table *
sd_alloc_ctl_domain_table(struct sched_domain *sd)
{
- struct ctl_table *table = sd_alloc_ctl_entry(13);
+ struct ctl_table *table = sd_alloc_ctl_entry(14);
if (table == NULL)
return NULL;
@@ -4879,9 +4914,12 @@ sd_alloc_ctl_domain_table(struct sched_domain *sd)
sizeof(int), 0644, proc_dointvec_minmax, false);
set_table_entry(&table[10], "flags", &sd->flags,
sizeof(int), 0644, proc_dointvec_minmax, false);
- set_table_entry(&table[11], "name", sd->name,
+ set_table_entry(&table[11], "max_newidle_lb_cost",
+ &sd->max_newidle_lb_cost,
+ sizeof(long), 0644, proc_doulongvec_minmax, false);
+ set_table_entry(&table[12], "name", sd->name,
CORENAME_MAX_SIZE, 0444, proc_dostring, false);
- /* &table[12] is terminator */
+ /* &table[13] is terminator */
return table;
}
@@ -6858,7 +6896,6 @@ void __init sched_init(void)
rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime;
#ifdef CONFIG_RT_GROUP_SCHED
- INIT_LIST_HEAD(&rq->leaf_rt_rq_list);
init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, NULL);
#endif
@@ -6947,7 +6984,8 @@ void __might_sleep(const char *file, int line, int preempt_offset)
static unsigned long prev_jiffy; /* ratelimiting */
rcu_sleep_check(); /* WARN_ON_ONCE() by default, no rate limit reqd. */
- if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) ||
+ if ((preempt_count_equals(preempt_offset) && !irqs_disabled() &&
+ !is_idle_task(current)) ||
system_state != SYSTEM_RUNNING || oops_in_progress)
return;
if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
@@ -6965,6 +7003,13 @@ void __might_sleep(const char *file, int line, int preempt_offset)
debug_show_held_locks(current);
if (irqs_disabled())
print_irqtrace_events(current);
+#ifdef CONFIG_DEBUG_PREEMPT
+ if (!preempt_count_equals(preempt_offset)) {
+ pr_err("Preemption disabled at:");
+ print_ip_sym(current->preempt_disable_ip);
+ pr_cont("\n");
+ }
+#endif
dump_stack();
}
EXPORT_SYMBOL(__might_sleep);
@@ -7018,7 +7063,7 @@ void normalize_rt_tasks(void)
* Renice negative nice level userspace
* tasks back to 0:
*/
- if (TASK_NICE(p) < 0 && p->mm)
+ if (task_nice(p) < 0 && p->mm)
set_user_nice(p, 0);
continue;
}
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 99947919e30..58624a65f12 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -142,7 +142,7 @@ void account_user_time(struct task_struct *p, cputime_t cputime,
p->utimescaled += cputime_scaled;
account_group_user_time(p, cputime);
- index = (TASK_NICE(p) > 0) ? CPUTIME_NICE : CPUTIME_USER;
+ index = (task_nice(p) > 0) ? CPUTIME_NICE : CPUTIME_USER;
/* Add user time to cpustat. */
task_group_account_field(p, index, (__force u64) cputime);
@@ -169,7 +169,7 @@ static void account_guest_time(struct task_struct *p, cputime_t cputime,
p->gtime += cputime;
/* Add guest time to cpustat. */
- if (TASK_NICE(p) > 0) {
+ if (task_nice(p) > 0) {
cpustat[CPUTIME_NICE] += (__force u64) cputime;
cpustat[CPUTIME_GUEST_NICE] += (__force u64) cputime;
} else {
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 6e79b3faa4c..27ef4092552 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -210,6 +210,16 @@ static inline int has_pushable_dl_tasks(struct rq *rq)
static int push_dl_task(struct rq *rq);
+static inline bool need_pull_dl_task(struct rq *rq, struct task_struct *prev)
+{
+ return dl_task(prev);
+}
+
+static inline void set_post_schedule(struct rq *rq)
+{
+ rq->post_schedule = has_pushable_dl_tasks(rq);
+}
+
#else
static inline
@@ -232,6 +242,19 @@ void dec_dl_migration(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq)
{
}
+static inline bool need_pull_dl_task(struct rq *rq, struct task_struct *prev)
+{
+ return false;
+}
+
+static inline int pull_dl_task(struct rq *rq)
+{
+ return 0;
+}
+
+static inline void set_post_schedule(struct rq *rq)
+{
+}
#endif /* CONFIG_SMP */
static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags);
@@ -586,8 +609,8 @@ static void update_curr_dl(struct rq *rq)
* approach need further study.
*/
delta_exec = rq_clock_task(rq) - curr->se.exec_start;
- if (unlikely((s64)delta_exec < 0))
- delta_exec = 0;
+ if (unlikely((s64)delta_exec <= 0))
+ return;
schedstat_set(curr->se.statistics.exec_max,
max(curr->se.statistics.exec_max, delta_exec));
@@ -942,6 +965,8 @@ static void check_preempt_equal_dl(struct rq *rq, struct task_struct *p)
resched_task(rq->curr);
}
+static int pull_dl_task(struct rq *this_rq);
+
#endif /* CONFIG_SMP */
/*
@@ -988,7 +1013,7 @@ static struct sched_dl_entity *pick_next_dl_entity(struct rq *rq,
return rb_entry(left, struct sched_dl_entity, rb_node);
}
-struct task_struct *pick_next_task_dl(struct rq *rq)
+struct task_struct *pick_next_task_dl(struct rq *rq, struct task_struct *prev)
{
struct sched_dl_entity *dl_se;
struct task_struct *p;
@@ -996,9 +1021,20 @@ struct task_struct *pick_next_task_dl(struct rq *rq)
dl_rq = &rq->dl;
+ if (need_pull_dl_task(rq, prev))
+ pull_dl_task(rq);
+ /*
+ * When prev is DL, we may throttle it in put_prev_task().
+ * So, we update time before we check for dl_nr_running.
+ */
+ if (prev->sched_class == &dl_sched_class)
+ update_curr_dl(rq);
+
if (unlikely(!dl_rq->dl_nr_running))
return NULL;
+ put_prev_task(rq, prev);
+
dl_se = pick_next_dl_entity(rq, dl_rq);
BUG_ON(!dl_se);
@@ -1013,9 +1049,7 @@ struct task_struct *pick_next_task_dl(struct rq *rq)
start_hrtick_dl(rq, p);
#endif
-#ifdef CONFIG_SMP
- rq->post_schedule = has_pushable_dl_tasks(rq);
-#endif /* CONFIG_SMP */
+ set_post_schedule(rq);
return p;
}
@@ -1424,13 +1458,6 @@ skip:
return ret;
}
-static void pre_schedule_dl(struct rq *rq, struct task_struct *prev)
-{
- /* Try to pull other tasks here */
- if (dl_task(prev))
- pull_dl_task(rq);
-}
-
static void post_schedule_dl(struct rq *rq)
{
push_dl_tasks(rq);
@@ -1558,7 +1585,7 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p)
if (unlikely(p->dl.dl_throttled))
return;
- if (p->on_rq || rq->curr != p) {
+ if (p->on_rq && rq->curr != p) {
#ifdef CONFIG_SMP
if (rq->dl.overloaded && push_dl_task(rq) && rq != task_rq(p))
/* Only reschedule if pushing failed */
@@ -1623,7 +1650,6 @@ const struct sched_class dl_sched_class = {
.set_cpus_allowed = set_cpus_allowed_dl,
.rq_online = rq_online_dl,
.rq_offline = rq_offline_dl,
- .pre_schedule = pre_schedule_dl,
.post_schedule = post_schedule_dl,
.task_woken = task_woken_dl,
#endif
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index dd52e7ffb10..f3344c31632 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -321,6 +321,7 @@ do { \
P(sched_goidle);
#ifdef CONFIG_SMP
P64(avg_idle);
+ P64(max_idle_balance_cost);
#endif
P(ttwu_count);
@@ -533,15 +534,15 @@ static void sched_show_numa(struct task_struct *p, struct seq_file *m)
unsigned long nr_faults = -1;
int cpu_current, home_node;
- if (p->numa_faults)
- nr_faults = p->numa_faults[2*node + i];
+ if (p->numa_faults_memory)
+ nr_faults = p->numa_faults_memory[2*node + i];
cpu_current = !i ? (task_node(p) == node) :
(pol && node_isset(node, pol->v.nodes));
home_node = (p->numa_preferred_nid == node);
- SEQ_printf(m, "numa_faults, %d, %d, %d, %d, %ld\n",
+ SEQ_printf(m, "numa_faults_memory, %d, %d, %d, %d, %ld\n",
i, node, cpu_current, home_node, nr_faults);
}
}
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 9b4c4f32013..7e9bd0b1fa9 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -322,13 +322,13 @@ static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq)
list_for_each_entry_rcu(cfs_rq, &rq->leaf_cfs_rq_list, leaf_cfs_rq_list)
/* Do the two (enqueued) entities belong to the same group ? */
-static inline int
+static inline struct cfs_rq *
is_same_group(struct sched_entity *se, struct sched_entity *pse)
{
if (se->cfs_rq == pse->cfs_rq)
- return 1;
+ return se->cfs_rq;
- return 0;
+ return NULL;
}
static inline struct sched_entity *parent_entity(struct sched_entity *se)
@@ -336,17 +336,6 @@ static inline struct sched_entity *parent_entity(struct sched_entity *se)
return se->parent;
}
-/* return depth at which a sched entity is present in the hierarchy */
-static inline int depth_se(struct sched_entity *se)
-{
- int depth = 0;
-
- for_each_sched_entity(se)
- depth++;
-
- return depth;
-}
-
static void
find_matching_se(struct sched_entity **se, struct sched_entity **pse)
{
@@ -360,8 +349,8 @@ find_matching_se(struct sched_entity **se, struct sched_entity **pse)
*/
/* First walk up until both entities are at same depth */
- se_depth = depth_se(*se);
- pse_depth = depth_se(*pse);
+ se_depth = (*se)->depth;
+ pse_depth = (*pse)->depth;
while (se_depth > pse_depth) {
se_depth--;
@@ -426,12 +415,6 @@ static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq)
#define for_each_leaf_cfs_rq(rq, cfs_rq) \
for (cfs_rq = &rq->cfs; cfs_rq; cfs_rq = NULL)
-static inline int
-is_same_group(struct sched_entity *se, struct sched_entity *pse)
-{
- return 1;
-}
-
static inline struct sched_entity *parent_entity(struct sched_entity *se)
{
return NULL;
@@ -819,14 +802,6 @@ unsigned int sysctl_numa_balancing_scan_size = 256;
/* Scan @scan_size MB every @scan_period after an initial @scan_delay in ms */
unsigned int sysctl_numa_balancing_scan_delay = 1000;
-/*
- * After skipping a page migration on a shared page, skip N more numa page
- * migrations unconditionally. This reduces the number of NUMA migrations
- * in shared memory workloads, and has the effect of pulling tasks towards
- * where their memory lives, over pulling the memory towards the task.
- */
-unsigned int sysctl_numa_balancing_migrate_deferred = 16;
-
static unsigned int task_nr_scan_windows(struct task_struct *p)
{
unsigned long rss = 0;
@@ -893,10 +868,26 @@ struct numa_group {
struct list_head task_list;
struct rcu_head rcu;
+ nodemask_t active_nodes;
unsigned long total_faults;
+ /*
+ * Faults_cpu is used to decide whether memory should move
+ * towards the CPU. As a consequence, these stats are weighted
+ * more by CPU use than by memory faults.
+ */
+ unsigned long *faults_cpu;
unsigned long faults[0];
};
+/* Shared or private faults. */
+#define NR_NUMA_HINT_FAULT_TYPES 2
+
+/* Memory and CPU locality */
+#define NR_NUMA_HINT_FAULT_STATS (NR_NUMA_HINT_FAULT_TYPES * 2)
+
+/* Averaged statistics, and temporary buffers. */
+#define NR_NUMA_HINT_FAULT_BUCKETS (NR_NUMA_HINT_FAULT_STATS * 2)
+
pid_t task_numa_group_id(struct task_struct *p)
{
return p->numa_group ? p->numa_group->gid : 0;
@@ -904,16 +895,16 @@ pid_t task_numa_group_id(struct task_struct *p)
static inline int task_faults_idx(int nid, int priv)
{
- return 2 * nid + priv;
+ return NR_NUMA_HINT_FAULT_TYPES * nid + priv;
}
static inline unsigned long task_faults(struct task_struct *p, int nid)
{
- if (!p->numa_faults)
+ if (!p->numa_faults_memory)
return 0;
- return p->numa_faults[task_faults_idx(nid, 0)] +
- p->numa_faults[task_faults_idx(nid, 1)];
+ return p->numa_faults_memory[task_faults_idx(nid, 0)] +
+ p->numa_faults_memory[task_faults_idx(nid, 1)];
}
static inline unsigned long group_faults(struct task_struct *p, int nid)
@@ -925,6 +916,12 @@ static inline unsigned long group_faults(struct task_struct *p, int nid)
p->numa_group->faults[task_faults_idx(nid, 1)];
}
+static inline unsigned long group_faults_cpu(struct numa_group *group, int nid)
+{
+ return group->faults_cpu[task_faults_idx(nid, 0)] +
+ group->faults_cpu[task_faults_idx(nid, 1)];
+}
+
/*
* These return the fraction of accesses done by a particular task, or
* task group, on a particular numa node. The group weight is given a
@@ -935,7 +932,7 @@ static inline unsigned long task_weight(struct task_struct *p, int nid)
{
unsigned long total_faults;
- if (!p->numa_faults)
+ if (!p->numa_faults_memory)
return 0;
total_faults = p->total_numa_faults;
@@ -954,6 +951,69 @@ static inline unsigned long group_weight(struct task_struct *p, int nid)
return 1000 * group_faults(p, nid) / p->numa_group->total_faults;
}
+bool should_numa_migrate_memory(struct task_struct *p, struct page * page,
+ int src_nid, int dst_cpu)
+{
+ struct numa_group *ng = p->numa_group;
+ int dst_nid = cpu_to_node(dst_cpu);
+ int last_cpupid, this_cpupid;
+
+ this_cpupid = cpu_pid_to_cpupid(dst_cpu, current->pid);
+
+ /*
+ * Multi-stage node selection is used in conjunction with a periodic
+ * migration fault to build a temporal task<->page relation. By using
+ * a two-stage filter we remove short/unlikely relations.
+ *
+ * Using P(p) ~ n_p / n_t as per frequentist probability, we can equate
+ * a task's usage of a particular page (n_p) per total usage of this
+ * page (n_t) (in a given time-span) to a probability.
+ *
+ * Our periodic faults will sample this probability and getting the
+ * same result twice in a row, given these samples are fully
+ * independent, is then given by P(n)^2, provided our sample period
+ * is sufficiently short compared to the usage pattern.
+ *
+ * This quadric squishes small probabilities, making it less likely we
+ * act on an unlikely task<->page relation.
+ */
+ last_cpupid = page_cpupid_xchg_last(page, this_cpupid);
+ if (!cpupid_pid_unset(last_cpupid) &&
+ cpupid_to_nid(last_cpupid) != dst_nid)
+ return false;
+
+ /* Always allow migrate on private faults */
+ if (cpupid_match_pid(p, last_cpupid))
+ return true;
+
+ /* A shared fault, but p->numa_group has not been set up yet. */
+ if (!ng)
+ return true;
+
+ /*
+ * Do not migrate if the destination is not a node that
+ * is actively used by this numa group.
+ */
+ if (!node_isset(dst_nid, ng->active_nodes))
+ return false;
+
+ /*
+ * Source is a node that is not actively used by this
+ * numa group, while the destination is. Migrate.
+ */
+ if (!node_isset(src_nid, ng->active_nodes))
+ return true;
+
+ /*
+ * Both source and destination are nodes in active
+ * use by this numa group. Maximize memory bandwidth
+ * by migrating from more heavily used groups, to less
+ * heavily used ones, spreading the load around.
+ * Use a 1/4 hysteresis to avoid spurious page movement.
+ */
+ return group_faults(p, dst_nid) < (group_faults(p, src_nid) * 3 / 4);
+}
+
static unsigned long weighted_cpuload(const int cpu);
static unsigned long source_load(int cpu, int type);
static unsigned long target_load(int cpu, int type);
@@ -1267,7 +1327,7 @@ static int task_numa_migrate(struct task_struct *p)
static void numa_migrate_preferred(struct task_struct *p)
{
/* This task has no NUMA fault statistics yet */
- if (unlikely(p->numa_preferred_nid == -1 || !p->numa_faults))
+ if (unlikely(p->numa_preferred_nid == -1 || !p->numa_faults_memory))
return;
/* Periodically retry migrating the task to the preferred node */
@@ -1282,6 +1342,38 @@ static void numa_migrate_preferred(struct task_struct *p)
}
/*
+ * Find the nodes on which the workload is actively running. We do this by
+ * tracking the nodes from which NUMA hinting faults are triggered. This can
+ * be different from the set of nodes where the workload's memory is currently
+ * located.
+ *
+ * The bitmask is used to make smarter decisions on when to do NUMA page
+ * migrations, To prevent flip-flopping, and excessive page migrations, nodes
+ * are added when they cause over 6/16 of the maximum number of faults, but
+ * only removed when they drop below 3/16.
+ */
+static void update_numa_active_node_mask(struct numa_group *numa_group)
+{
+ unsigned long faults, max_faults = 0;
+ int nid;
+
+ for_each_online_node(nid) {
+ faults = group_faults_cpu(numa_group, nid);
+ if (faults > max_faults)
+ max_faults = faults;
+ }
+
+ for_each_online_node(nid) {
+ faults = group_faults_cpu(numa_group, nid);
+ if (!node_isset(nid, numa_group->active_nodes)) {
+ if (faults > max_faults * 6 / 16)
+ node_set(nid, numa_group->active_nodes);
+ } else if (faults < max_faults * 3 / 16)
+ node_clear(nid, numa_group->active_nodes);
+ }
+}
+
+/*
* When adapting the scan rate, the period is divided into NUMA_PERIOD_SLOTS
* increments. The more local the fault statistics are, the higher the scan
* period will be for the next scan window. If local/remote ratio is below
@@ -1355,11 +1447,41 @@ static void update_task_scan_period(struct task_struct *p,
memset(p->numa_faults_locality, 0, sizeof(p->numa_faults_locality));
}
+/*
+ * Get the fraction of time the task has been running since the last
+ * NUMA placement cycle. The scheduler keeps similar statistics, but
+ * decays those on a 32ms period, which is orders of magnitude off
+ * from the dozens-of-seconds NUMA balancing period. Use the scheduler
+ * stats only if the task is so new there are no NUMA statistics yet.
+ */
+static u64 numa_get_avg_runtime(struct task_struct *p, u64 *period)
+{
+ u64 runtime, delta, now;
+ /* Use the start of this time slice to avoid calculations. */
+ now = p->se.exec_start;
+ runtime = p->se.sum_exec_runtime;
+
+ if (p->last_task_numa_placement) {
+ delta = runtime - p->last_sum_exec_runtime;
+ *period = now - p->last_task_numa_placement;
+ } else {
+ delta = p->se.avg.runnable_avg_sum;
+ *period = p->se.avg.runnable_avg_period;
+ }
+
+ p->last_sum_exec_runtime = runtime;
+ p->last_task_numa_placement = now;
+
+ return delta;
+}
+
static void task_numa_placement(struct task_struct *p)
{
int seq, nid, max_nid = -1, max_group_nid = -1;
unsigned long max_faults = 0, max_group_faults = 0;
unsigned long fault_types[2] = { 0, 0 };
+ unsigned long total_faults;
+ u64 runtime, period;
spinlock_t *group_lock = NULL;
seq = ACCESS_ONCE(p->mm->numa_scan_seq);
@@ -1368,6 +1490,10 @@ static void task_numa_placement(struct task_struct *p)
p->numa_scan_seq = seq;
p->numa_scan_period_max = task_scan_max(p);
+ total_faults = p->numa_faults_locality[0] +
+ p->numa_faults_locality[1];
+ runtime = numa_get_avg_runtime(p, &period);
+
/* If the task is part of a group prevent parallel updates to group stats */
if (p->numa_group) {
group_lock = &p->numa_group->lock;
@@ -1379,24 +1505,37 @@ static void task_numa_placement(struct task_struct *p)
unsigned long faults = 0, group_faults = 0;
int priv, i;
- for (priv = 0; priv < 2; priv++) {
- long diff;
+ for (priv = 0; priv < NR_NUMA_HINT_FAULT_TYPES; priv++) {
+ long diff, f_diff, f_weight;
i = task_faults_idx(nid, priv);
- diff = -p->numa_faults[i];
/* Decay existing window, copy faults since last scan */
- p->numa_faults[i] >>= 1;
- p->numa_faults[i] += p->numa_faults_buffer[i];
- fault_types[priv] += p->numa_faults_buffer[i];
- p->numa_faults_buffer[i] = 0;
+ diff = p->numa_faults_buffer_memory[i] - p->numa_faults_memory[i] / 2;
+ fault_types[priv] += p->numa_faults_buffer_memory[i];
+ p->numa_faults_buffer_memory[i] = 0;
- faults += p->numa_faults[i];
- diff += p->numa_faults[i];
+ /*
+ * Normalize the faults_from, so all tasks in a group
+ * count according to CPU use, instead of by the raw
+ * number of faults. Tasks with little runtime have
+ * little over-all impact on throughput, and thus their
+ * faults are less important.
+ */
+ f_weight = div64_u64(runtime << 16, period + 1);
+ f_weight = (f_weight * p->numa_faults_buffer_cpu[i]) /
+ (total_faults + 1);
+ f_diff = f_weight - p->numa_faults_cpu[i] / 2;
+ p->numa_faults_buffer_cpu[i] = 0;
+
+ p->numa_faults_memory[i] += diff;
+ p->numa_faults_cpu[i] += f_diff;
+ faults += p->numa_faults_memory[i];
p->total_numa_faults += diff;
if (p->numa_group) {
/* safe because we can only change our own group */
p->numa_group->faults[i] += diff;
+ p->numa_group->faults_cpu[i] += f_diff;
p->numa_group->total_faults += diff;
group_faults += p->numa_group->faults[i];
}
@@ -1416,6 +1555,7 @@ static void task_numa_placement(struct task_struct *p)
update_task_scan_period(p, fault_types[0], fault_types[1]);
if (p->numa_group) {
+ update_numa_active_node_mask(p->numa_group);
/*
* If the preferred task and group nids are different,
* iterate over the nodes again to find the best place.
@@ -1465,7 +1605,7 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags,
if (unlikely(!p->numa_group)) {
unsigned int size = sizeof(struct numa_group) +
- 2*nr_node_ids*sizeof(unsigned long);
+ 4*nr_node_ids*sizeof(unsigned long);
grp = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
if (!grp)
@@ -1475,9 +1615,14 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags,
spin_lock_init(&grp->lock);
INIT_LIST_HEAD(&grp->task_list);
grp->gid = p->pid;
+ /* Second half of the array tracks nids where faults happen */
+ grp->faults_cpu = grp->faults + NR_NUMA_HINT_FAULT_TYPES *
+ nr_node_ids;
+
+ node_set(task_node(current), grp->active_nodes);
- for (i = 0; i < 2*nr_node_ids; i++)
- grp->faults[i] = p->numa_faults[i];
+ for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++)
+ grp->faults[i] = p->numa_faults_memory[i];
grp->total_faults = p->total_numa_faults;
@@ -1534,9 +1679,9 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags,
double_lock(&my_grp->lock, &grp->lock);
- for (i = 0; i < 2*nr_node_ids; i++) {
- my_grp->faults[i] -= p->numa_faults[i];
- grp->faults[i] += p->numa_faults[i];
+ for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++) {
+ my_grp->faults[i] -= p->numa_faults_memory[i];
+ grp->faults[i] += p->numa_faults_memory[i];
}
my_grp->total_faults -= p->total_numa_faults;
grp->total_faults += p->total_numa_faults;
@@ -1562,12 +1707,12 @@ void task_numa_free(struct task_struct *p)
{
struct numa_group *grp = p->numa_group;
int i;
- void *numa_faults = p->numa_faults;
+ void *numa_faults = p->numa_faults_memory;
if (grp) {
spin_lock(&grp->lock);
- for (i = 0; i < 2*nr_node_ids; i++)
- grp->faults[i] -= p->numa_faults[i];
+ for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++)
+ grp->faults[i] -= p->numa_faults_memory[i];
grp->total_faults -= p->total_numa_faults;
list_del(&p->numa_entry);
@@ -1577,18 +1722,21 @@ void task_numa_free(struct task_struct *p)
put_numa_group(grp);
}
- p->numa_faults = NULL;
- p->numa_faults_buffer = NULL;
+ p->numa_faults_memory = NULL;
+ p->numa_faults_buffer_memory = NULL;
+ p->numa_faults_cpu= NULL;
+ p->numa_faults_buffer_cpu = NULL;
kfree(numa_faults);
}
/*
* Got a PROT_NONE fault for a page on @node.
*/
-void task_numa_fault(int last_cpupid, int node, int pages, int flags)
+void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags)
{
struct task_struct *p = current;
bool migrated = flags & TNF_MIGRATED;
+ int cpu_node = task_node(current);
int priv;
if (!numabalancing_enabled)
@@ -1603,16 +1751,24 @@ void task_numa_fault(int last_cpupid, int node, int pages, int flags)
return;
/* Allocate buffer to track faults on a per-node basis */
- if (unlikely(!p->numa_faults)) {
- int size = sizeof(*p->numa_faults) * 2 * nr_node_ids;
+ if (unlikely(!p->numa_faults_memory)) {
+ int size = sizeof(*p->numa_faults_memory) *
+ NR_NUMA_HINT_FAULT_BUCKETS * nr_node_ids;
- /* numa_faults and numa_faults_buffer share the allocation */
- p->numa_faults = kzalloc(size * 2, GFP_KERNEL|__GFP_NOWARN);
- if (!p->numa_faults)
+ p->numa_faults_memory = kzalloc(size, GFP_KERNEL|__GFP_NOWARN);
+ if (!p->numa_faults_memory)
return;
- BUG_ON(p->numa_faults_buffer);
- p->numa_faults_buffer = p->numa_faults + (2 * nr_node_ids);
+ BUG_ON(p->numa_faults_buffer_memory);
+ /*
+ * The averaged statistics, shared & private, memory & cpu,
+ * occupy the first half of the array. The second half of the
+ * array is for current counters, which are averaged into the
+ * first set by task_numa_placement.
+ */
+ p->numa_faults_cpu = p->numa_faults_memory + (2 * nr_node_ids);
+ p->numa_faults_buffer_memory = p->numa_faults_memory + (4 * nr_node_ids);
+ p->numa_faults_buffer_cpu = p->numa_faults_memory + (6 * nr_node_ids);
p->total_numa_faults = 0;
memset(p->numa_faults_locality, 0, sizeof(p->numa_faults_locality));
}
@@ -1641,7 +1797,8 @@ void task_numa_fault(int last_cpupid, int node, int pages, int flags)
if (migrated)
p->numa_pages_migrated += pages;
- p->numa_faults_buffer[task_faults_idx(node, priv)] += pages;
+ p->numa_faults_buffer_memory[task_faults_idx(mem_node, priv)] += pages;
+ p->numa_faults_buffer_cpu[task_faults_idx(cpu_node, priv)] += pages;
p->numa_faults_locality[!!(flags & TNF_FAULT_LOCAL)] += pages;
}
@@ -2219,13 +2376,20 @@ static inline void __update_group_entity_contrib(struct sched_entity *se)
se->avg.load_avg_contrib >>= NICE_0_SHIFT;
}
}
-#else
+
+static inline void update_rq_runnable_avg(struct rq *rq, int runnable)
+{
+ __update_entity_runnable_avg(rq_clock_task(rq), &rq->avg, runnable);
+ __update_tg_runnable_avg(&rq->avg, &rq->cfs);
+}
+#else /* CONFIG_FAIR_GROUP_SCHED */
static inline void __update_cfs_rq_tg_load_contrib(struct cfs_rq *cfs_rq,
int force_update) {}
static inline void __update_tg_runnable_avg(struct sched_avg *sa,
struct cfs_rq *cfs_rq) {}
static inline void __update_group_entity_contrib(struct sched_entity *se) {}
-#endif
+static inline void update_rq_runnable_avg(struct rq *rq, int runnable) {}
+#endif /* CONFIG_FAIR_GROUP_SCHED */
static inline void __update_task_entity_contrib(struct sched_entity *se)
{
@@ -2323,12 +2487,6 @@ static void update_cfs_rq_blocked_load(struct cfs_rq *cfs_rq, int force_update)
__update_cfs_rq_tg_load_contrib(cfs_rq, force_update);
}
-static inline void update_rq_runnable_avg(struct rq *rq, int runnable)
-{
- __update_entity_runnable_avg(rq_clock_task(rq), &rq->avg, runnable);
- __update_tg_runnable_avg(&rq->avg, &rq->cfs);
-}
-
/* Add the load generated by se into cfs_rq's child load-average */
static inline void enqueue_entity_load_avg(struct cfs_rq *cfs_rq,
struct sched_entity *se,
@@ -2416,7 +2574,10 @@ void idle_exit_fair(struct rq *this_rq)
update_rq_runnable_avg(this_rq, 0);
}
-#else
+static int idle_balance(struct rq *this_rq);
+
+#else /* CONFIG_SMP */
+
static inline void update_entity_load_avg(struct sched_entity *se,
int update_cfs_rq) {}
static inline void update_rq_runnable_avg(struct rq *rq, int runnable) {}
@@ -2428,7 +2589,13 @@ static inline void dequeue_entity_load_avg(struct cfs_rq *cfs_rq,
int sleep) {}
static inline void update_cfs_rq_blocked_load(struct cfs_rq *cfs_rq,
int force_update) {}
-#endif
+
+static inline int idle_balance(struct rq *rq)
+{
+ return 0;
+}
+
+#endif /* CONFIG_SMP */
static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
@@ -2578,10 +2745,10 @@ static void __clear_buddies_last(struct sched_entity *se)
{
for_each_sched_entity(se) {
struct cfs_rq *cfs_rq = cfs_rq_of(se);
- if (cfs_rq->last == se)
- cfs_rq->last = NULL;
- else
+ if (cfs_rq->last != se)
break;
+
+ cfs_rq->last = NULL;
}
}
@@ -2589,10 +2756,10 @@ static void __clear_buddies_next(struct sched_entity *se)
{
for_each_sched_entity(se) {
struct cfs_rq *cfs_rq = cfs_rq_of(se);
- if (cfs_rq->next == se)
- cfs_rq->next = NULL;
- else
+ if (cfs_rq->next != se)
break;
+
+ cfs_rq->next = NULL;
}
}
@@ -2600,10 +2767,10 @@ static void __clear_buddies_skip(struct sched_entity *se)
{
for_each_sched_entity(se) {
struct cfs_rq *cfs_rq = cfs_rq_of(se);
- if (cfs_rq->skip == se)
- cfs_rq->skip = NULL;
- else
+ if (cfs_rq->skip != se)
break;
+
+ cfs_rq->skip = NULL;
}
}
@@ -2746,17 +2913,36 @@ wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se);
* 3) pick the "last" process, for cache locality
* 4) do not run the "skip" process, if something else is available
*/
-static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq)
+static struct sched_entity *
+pick_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *curr)
{
- struct sched_entity *se = __pick_first_entity(cfs_rq);
- struct sched_entity *left = se;
+ struct sched_entity *left = __pick_first_entity(cfs_rq);
+ struct sched_entity *se;
+
+ /*
+ * If curr is set we have to see if its left of the leftmost entity
+ * still in the tree, provided there was anything in the tree at all.
+ */
+ if (!left || (curr && entity_before(curr, left)))
+ left = curr;
+
+ se = left; /* ideally we run the leftmost entity */
/*
* Avoid running the skip buddy, if running something else can
* be done without getting too unfair.
*/
if (cfs_rq->skip == se) {
- struct sched_entity *second = __pick_next_entity(se);
+ struct sched_entity *second;
+
+ if (se == curr) {
+ second = __pick_first_entity(cfs_rq);
+ } else {
+ second = __pick_next_entity(se);
+ if (!second || (curr && entity_before(curr, second)))
+ second = curr;
+ }
+
if (second && wakeup_preempt_entity(second, left) < 1)
se = second;
}
@@ -2778,7 +2964,7 @@ static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq)
return se;
}
-static void check_cfs_rq_runtime(struct cfs_rq *cfs_rq);
+static bool check_cfs_rq_runtime(struct cfs_rq *cfs_rq);
static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev)
{
@@ -3433,22 +3619,23 @@ static void check_enqueue_throttle(struct cfs_rq *cfs_rq)
}
/* conditionally throttle active cfs_rq's from put_prev_entity() */
-static void check_cfs_rq_runtime(struct cfs_rq *cfs_rq)
+static bool check_cfs_rq_runtime(struct cfs_rq *cfs_rq)
{
if (!cfs_bandwidth_used())
- return;
+ return false;
if (likely(!cfs_rq->runtime_enabled || cfs_rq->runtime_remaining > 0))
- return;
+ return false;
/*
* it's possible for a throttled entity to be forced into a running
* state (e.g. set_curr_task), in this case we're finished.
*/
if (cfs_rq_throttled(cfs_rq))
- return;
+ return true;
throttle_cfs_rq(cfs_rq);
+ return true;
}
static enum hrtimer_restart sched_cfs_slack_timer(struct hrtimer *timer)
@@ -3558,7 +3745,7 @@ static inline u64 cfs_rq_clock_task(struct cfs_rq *cfs_rq)
}
static void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, u64 delta_exec) {}
-static void check_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
+static bool check_cfs_rq_runtime(struct cfs_rq *cfs_rq) { return false; }
static void check_enqueue_throttle(struct cfs_rq *cfs_rq) {}
static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
@@ -4213,13 +4400,14 @@ done:
}
/*
- * sched_balance_self: balance the current task (running on cpu) in domains
- * that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and
- * SD_BALANCE_EXEC.
+ * select_task_rq_fair: Select target runqueue for the waking task in domains
+ * that have the 'sd_flag' flag set. In practice, this is SD_BALANCE_WAKE,
+ * SD_BALANCE_FORK, or SD_BALANCE_EXEC.
*
- * Balance, ie. select the least loaded group.
+ * Balances load by selecting the idlest cpu in the idlest group, or under
+ * certain conditions an idle sibling cpu if the domain has SD_WAKE_AFFINE set.
*
- * Returns the target CPU number, or the same CPU if no balancing is needed.
+ * Returns the target cpu number.
*
* preempt must be disabled.
*/
@@ -4494,26 +4682,124 @@ preempt:
set_last_buddy(se);
}
-static struct task_struct *pick_next_task_fair(struct rq *rq)
+static struct task_struct *
+pick_next_task_fair(struct rq *rq, struct task_struct *prev)
{
- struct task_struct *p;
struct cfs_rq *cfs_rq = &rq->cfs;
struct sched_entity *se;
+ struct task_struct *p;
+ int new_tasks;
+again:
+#ifdef CONFIG_FAIR_GROUP_SCHED
if (!cfs_rq->nr_running)
- return NULL;
+ goto idle;
+
+ if (prev->sched_class != &fair_sched_class)
+ goto simple;
+
+ /*
+ * Because of the set_next_buddy() in dequeue_task_fair() it is rather
+ * likely that a next task is from the same cgroup as the current.
+ *
+ * Therefore attempt to avoid putting and setting the entire cgroup
+ * hierarchy, only change the part that actually changes.
+ */
+
+ do {
+ struct sched_entity *curr = cfs_rq->curr;
+
+ /*
+ * Since we got here without doing put_prev_entity() we also
+ * have to consider cfs_rq->curr. If it is still a runnable
+ * entity, update_curr() will update its vruntime, otherwise
+ * forget we've ever seen it.
+ */
+ if (curr && curr->on_rq)
+ update_curr(cfs_rq);
+ else
+ curr = NULL;
+
+ /*
+ * This call to check_cfs_rq_runtime() will do the throttle and
+ * dequeue its entity in the parent(s). Therefore the 'simple'
+ * nr_running test will indeed be correct.
+ */
+ if (unlikely(check_cfs_rq_runtime(cfs_rq)))
+ goto simple;
+
+ se = pick_next_entity(cfs_rq, curr);
+ cfs_rq = group_cfs_rq(se);
+ } while (cfs_rq);
+
+ p = task_of(se);
+
+ /*
+ * Since we haven't yet done put_prev_entity and if the selected task
+ * is a different task than we started out with, try and touch the
+ * least amount of cfs_rqs.
+ */
+ if (prev != p) {
+ struct sched_entity *pse = &prev->se;
+
+ while (!(cfs_rq = is_same_group(se, pse))) {
+ int se_depth = se->depth;
+ int pse_depth = pse->depth;
+
+ if (se_depth <= pse_depth) {
+ put_prev_entity(cfs_rq_of(pse), pse);
+ pse = parent_entity(pse);
+ }
+ if (se_depth >= pse_depth) {
+ set_next_entity(cfs_rq_of(se), se);
+ se = parent_entity(se);
+ }
+ }
+
+ put_prev_entity(cfs_rq, pse);
+ set_next_entity(cfs_rq, se);
+ }
+
+ if (hrtick_enabled(rq))
+ hrtick_start_fair(rq, p);
+
+ return p;
+simple:
+ cfs_rq = &rq->cfs;
+#endif
+
+ if (!cfs_rq->nr_running)
+ goto idle;
+
+ put_prev_task(rq, prev);
do {
- se = pick_next_entity(cfs_rq);
+ se = pick_next_entity(cfs_rq, NULL);
set_next_entity(cfs_rq, se);
cfs_rq = group_cfs_rq(se);
} while (cfs_rq);
p = task_of(se);
+
if (hrtick_enabled(rq))
hrtick_start_fair(rq, p);
return p;
+
+idle:
+ new_tasks = idle_balance(rq);
+ /*
+ * Because idle_balance() releases (and re-acquires) rq->lock, it is
+ * possible for any higher priority task to appear. In that case we
+ * must re-start the pick_next_entity() loop.
+ */
+ if (new_tasks < 0)
+ return RETRY_TASK;
+
+ if (new_tasks > 0)
+ goto again;
+
+ return NULL;
}
/*
@@ -4751,7 +5037,7 @@ static void move_task(struct task_struct *p, struct lb_env *env)
* Is this task likely cache-hot:
*/
static int
-task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
+task_hot(struct task_struct *p, u64 now)
{
s64 delta;
@@ -4785,7 +5071,7 @@ static bool migrate_improves_locality(struct task_struct *p, struct lb_env *env)
{
int src_nid, dst_nid;
- if (!sched_feat(NUMA_FAVOUR_HIGHER) || !p->numa_faults ||
+ if (!sched_feat(NUMA_FAVOUR_HIGHER) || !p->numa_faults_memory ||
!(env->sd->flags & SD_NUMA)) {
return false;
}
@@ -4816,7 +5102,7 @@ static bool migrate_degrades_locality(struct task_struct *p, struct lb_env *env)
if (!sched_feat(NUMA) || !sched_feat(NUMA_RESIST_LOWER))
return false;
- if (!p->numa_faults || !(env->sd->flags & SD_NUMA))
+ if (!p->numa_faults_memory || !(env->sd->flags & SD_NUMA))
return false;
src_nid = cpu_to_node(env->src_cpu);
@@ -4912,7 +5198,7 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env)
* 2) task is cache cold, or
* 3) too many balance attempts have failed.
*/
- tsk_cache_hot = task_hot(p, rq_clock_task(env->src_rq), env->sd);
+ tsk_cache_hot = task_hot(p, rq_clock_task(env->src_rq));
if (!tsk_cache_hot)
tsk_cache_hot = migrate_degrades_locality(p, env);
@@ -5775,12 +6061,10 @@ void fix_small_imbalance(struct lb_env *env, struct sd_lb_stats *sds)
pwr_now /= SCHED_POWER_SCALE;
/* Amount of load we'd subtract */
- tmp = (busiest->load_per_task * SCHED_POWER_SCALE) /
- busiest->group_power;
- if (busiest->avg_load > tmp) {
+ if (busiest->avg_load > scaled_busy_load_per_task) {
pwr_move += busiest->group_power *
min(busiest->load_per_task,
- busiest->avg_load - tmp);
+ busiest->avg_load - scaled_busy_load_per_task);
}
/* Amount of load we'd add */
@@ -6359,17 +6643,23 @@ out:
* idle_balance is called by schedule() if this_cpu is about to become
* idle. Attempts to pull tasks from other CPUs.
*/
-void idle_balance(int this_cpu, struct rq *this_rq)
+static int idle_balance(struct rq *this_rq)
{
struct sched_domain *sd;
int pulled_task = 0;
unsigned long next_balance = jiffies + HZ;
u64 curr_cost = 0;
+ int this_cpu = this_rq->cpu;
+ idle_enter_fair(this_rq);
+ /*
+ * We must set idle_stamp _before_ calling idle_balance(), such that we
+ * measure the duration of idle_balance() as idle time.
+ */
this_rq->idle_stamp = rq_clock(this_rq);
if (this_rq->avg_idle < sysctl_sched_migration_cost)
- return;
+ goto out;
/*
* Drop the rq->lock, but keep IRQ/preempt disabled.
@@ -6407,15 +6697,22 @@ void idle_balance(int this_cpu, struct rq *this_rq)
interval = msecs_to_jiffies(sd->balance_interval);
if (time_after(next_balance, sd->last_balance + interval))
next_balance = sd->last_balance + interval;
- if (pulled_task) {
- this_rq->idle_stamp = 0;
+ if (pulled_task)
break;
- }
}
rcu_read_unlock();
raw_spin_lock(&this_rq->lock);
+ /*
+ * While browsing the domains, we released the rq lock.
+ * A task could have be enqueued in the meantime
+ */
+ if (this_rq->cfs.h_nr_running && !pulled_task) {
+ pulled_task = 1;
+ goto out;
+ }
+
if (pulled_task || time_after(jiffies, this_rq->next_balance)) {
/*
* We are going idle. next_balance may be set based on
@@ -6426,6 +6723,20 @@ void idle_balance(int this_cpu, struct rq *this_rq)
if (curr_cost > this_rq->max_idle_balance_cost)
this_rq->max_idle_balance_cost = curr_cost;
+
+out:
+ /* Is there a task of a high priority class? */
+ if (this_rq->nr_running != this_rq->cfs.h_nr_running &&
+ (this_rq->dl.dl_nr_running ||
+ (this_rq->rt.rt_nr_running && !rt_rq_throttled(&this_rq->rt))))
+ pulled_task = -1;
+
+ if (pulled_task) {
+ idle_exit_fair(this_rq);
+ this_rq->idle_stamp = 0;
+ }
+
+ return pulled_task;
}
/*
@@ -6496,6 +6807,11 @@ out_unlock:
return 0;
}
+static inline int on_null_domain(struct rq *rq)
+{
+ return unlikely(!rcu_dereference_sched(rq->sd));
+}
+
#ifdef CONFIG_NO_HZ_COMMON
/*
* idle load balancing details
@@ -6550,8 +6866,13 @@ static void nohz_balancer_kick(void)
static inline void nohz_balance_exit_idle(int cpu)
{
if (unlikely(test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))) {
- cpumask_clear_cpu(cpu, nohz.idle_cpus_mask);
- atomic_dec(&nohz.nr_cpus);
+ /*
+ * Completely isolated CPUs don't ever set, so we must test.
+ */
+ if (likely(cpumask_test_cpu(cpu, nohz.idle_cpus_mask))) {
+ cpumask_clear_cpu(cpu, nohz.idle_cpus_mask);
+ atomic_dec(&nohz.nr_cpus);
+ }
clear_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
}
}
@@ -6605,6 +6926,12 @@ void nohz_balance_enter_idle(int cpu)
if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
return;
+ /*
+ * If we're a completely isolated CPU, we don't play.
+ */
+ if (on_null_domain(cpu_rq(cpu)))
+ return;
+
cpumask_set_cpu(cpu, nohz.idle_cpus_mask);
atomic_inc(&nohz.nr_cpus);
set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
@@ -6867,11 +7194,6 @@ static void run_rebalance_domains(struct softirq_action *h)
nohz_idle_balance(this_rq, idle);
}
-static inline int on_null_domain(struct rq *rq)
-{
- return !rcu_dereference_sched(rq->sd);
-}
-
/*
* Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing.
*/
@@ -7036,7 +7358,15 @@ static void switched_from_fair(struct rq *rq, struct task_struct *p)
*/
static void switched_to_fair(struct rq *rq, struct task_struct *p)
{
- if (!p->se.on_rq)
+ struct sched_entity *se = &p->se;
+#ifdef CONFIG_FAIR_GROUP_SCHED
+ /*
+ * Since the real-depth could have been changed (only FAIR
+ * class maintain depth value), reset depth properly.
+ */
+ se->depth = se->parent ? se->parent->depth + 1 : 0;
+#endif
+ if (!se->on_rq)
return;
/*
@@ -7084,7 +7414,9 @@ void init_cfs_rq(struct cfs_rq *cfs_rq)
#ifdef CONFIG_FAIR_GROUP_SCHED
static void task_move_group_fair(struct task_struct *p, int on_rq)
{
+ struct sched_entity *se = &p->se;
struct cfs_rq *cfs_rq;
+
/*
* If the task was not on the rq at the time of this cgroup movement
* it must have been asleep, sleeping tasks keep their ->vruntime
@@ -7110,23 +7442,24 @@ static void task_move_group_fair(struct task_struct *p, int on_rq)
* To prevent boost or penalty in the new cfs_rq caused by delta
* min_vruntime between the two cfs_rqs, we skip vruntime adjustment.
*/
- if (!on_rq && (!p->se.sum_exec_runtime || p->state == TASK_WAKING))
+ if (!on_rq && (!se->sum_exec_runtime || p->state == TASK_WAKING))
on_rq = 1;
if (!on_rq)
- p->se.vruntime -= cfs_rq_of(&p->se)->min_vruntime;
+ se->vruntime -= cfs_rq_of(se)->min_vruntime;
set_task_rq(p, task_cpu(p));
+ se->depth = se->parent ? se->parent->depth + 1 : 0;
if (!on_rq) {
- cfs_rq = cfs_rq_of(&p->se);
- p->se.vruntime += cfs_rq->min_vruntime;
+ cfs_rq = cfs_rq_of(se);
+ se->vruntime += cfs_rq->min_vruntime;
#ifdef CONFIG_SMP
/*
* migrate_task_rq_fair() will have removed our previous
* contribution, but we must synchronize for ongoing future
* decay.
*/
- p->se.avg.decay_count = atomic64_read(&cfs_rq->decay_counter);
- cfs_rq->blocked_load_avg += p->se.avg.load_avg_contrib;
+ se->avg.decay_count = atomic64_read(&cfs_rq->decay_counter);
+ cfs_rq->blocked_load_avg += se->avg.load_avg_contrib;
#endif
}
}
@@ -7222,10 +7555,13 @@ void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
if (!se)
return;
- if (!parent)
+ if (!parent) {
se->cfs_rq = &rq->cfs;
- else
+ se->depth = 0;
+ } else {
se->cfs_rq = parent->my_q;
+ se->depth = parent->depth + 1;
+ }
se->my_q = cfs_rq;
/* guarantee group entities always have weight */
diff --git a/kernel/cpu/idle.c b/kernel/sched/idle.c
index 277f494c2a9..b7976a12717 100644
--- a/kernel/cpu/idle.c
+++ b/kernel/sched/idle.c
@@ -3,6 +3,7 @@
*/
#include <linux/sched.h>
#include <linux/cpu.h>
+#include <linux/cpuidle.h>
#include <linux/tick.h>
#include <linux/mm.h>
#include <linux/stackprotector.h>
@@ -95,8 +96,10 @@ static void cpu_idle_loop(void)
if (!current_clr_polling_and_test()) {
stop_critical_timings();
rcu_idle_enter();
- arch_cpu_idle();
- WARN_ON_ONCE(irqs_disabled());
+ if (cpuidle_idle_call())
+ arch_cpu_idle();
+ if (WARN_ON_ONCE(irqs_disabled()))
+ local_irq_enable();
rcu_idle_exit();
start_critical_timings();
} else {
diff --git a/kernel/sched/idle_task.c b/kernel/sched/idle_task.c
index 516c3d9ceea..879f2b75266 100644
--- a/kernel/sched/idle_task.c
+++ b/kernel/sched/idle_task.c
@@ -13,18 +13,8 @@ select_task_rq_idle(struct task_struct *p, int cpu, int sd_flag, int flags)
{
return task_cpu(p); /* IDLE tasks as never migrated */
}
-
-static void pre_schedule_idle(struct rq *rq, struct task_struct *prev)
-{
- idle_exit_fair(rq);
- rq_last_tick_reset(rq);
-}
-
-static void post_schedule_idle(struct rq *rq)
-{
- idle_enter_fair(rq);
-}
#endif /* CONFIG_SMP */
+
/*
* Idle tasks are unconditionally rescheduled:
*/
@@ -33,13 +23,12 @@ static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int fl
resched_task(rq->idle);
}
-static struct task_struct *pick_next_task_idle(struct rq *rq)
+static struct task_struct *
+pick_next_task_idle(struct rq *rq, struct task_struct *prev)
{
+ put_prev_task(rq, prev);
+
schedstat_inc(rq, sched_goidle);
-#ifdef CONFIG_SMP
- /* Trigger the post schedule to do an idle_enter for CFS */
- rq->post_schedule = 1;
-#endif
return rq->idle;
}
@@ -58,6 +47,8 @@ dequeue_task_idle(struct rq *rq, struct task_struct *p, int flags)
static void put_prev_task_idle(struct rq *rq, struct task_struct *prev)
{
+ idle_exit_fair(rq);
+ rq_last_tick_reset(rq);
}
static void task_tick_idle(struct rq *rq, struct task_struct *curr, int queued)
@@ -101,8 +92,6 @@ const struct sched_class idle_sched_class = {
#ifdef CONFIG_SMP
.select_task_rq = select_task_rq_idle,
- .pre_schedule = pre_schedule_idle,
- .post_schedule = post_schedule_idle,
#endif
.set_curr_task = set_curr_task_idle,
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 1999021042c..d8cdf161855 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -229,6 +229,14 @@ int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
#ifdef CONFIG_SMP
+static int pull_rt_task(struct rq *this_rq);
+
+static inline bool need_pull_rt_task(struct rq *rq, struct task_struct *prev)
+{
+ /* Try to pull RT tasks here if we lower this rq's prio */
+ return rq->rt.highest_prio.curr > prev->prio;
+}
+
static inline int rt_overloaded(struct rq *rq)
{
return atomic_read(&rq->rd->rto_count);
@@ -315,6 +323,15 @@ static inline int has_pushable_tasks(struct rq *rq)
return !plist_head_empty(&rq->rt.pushable_tasks);
}
+static inline void set_post_schedule(struct rq *rq)
+{
+ /*
+ * We detect this state here so that we can avoid taking the RQ
+ * lock again later if there is no need to push
+ */
+ rq->post_schedule = has_pushable_tasks(rq);
+}
+
static void enqueue_pushable_task(struct rq *rq, struct task_struct *p)
{
plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks);
@@ -359,6 +376,19 @@ void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
{
}
+static inline bool need_pull_rt_task(struct rq *rq, struct task_struct *prev)
+{
+ return false;
+}
+
+static inline int pull_rt_task(struct rq *this_rq)
+{
+ return 0;
+}
+
+static inline void set_post_schedule(struct rq *rq)
+{
+}
#endif /* CONFIG_SMP */
static inline int on_rt_rq(struct sched_rt_entity *rt_se)
@@ -440,11 +470,6 @@ static void sched_rt_rq_dequeue(struct rt_rq *rt_rq)
dequeue_rt_entity(rt_se);
}
-static inline int rt_rq_throttled(struct rt_rq *rt_rq)
-{
- return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted;
-}
-
static int rt_se_boosted(struct sched_rt_entity *rt_se)
{
struct rt_rq *rt_rq = group_rt_rq(rt_se);
@@ -515,11 +540,6 @@ static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq)
{
}
-static inline int rt_rq_throttled(struct rt_rq *rt_rq)
-{
- return rt_rq->rt_throttled;
-}
-
static inline const struct cpumask *sched_rt_period_mask(void)
{
return cpu_online_mask;
@@ -1318,15 +1338,7 @@ static struct task_struct *_pick_next_task_rt(struct rq *rq)
{
struct sched_rt_entity *rt_se;
struct task_struct *p;
- struct rt_rq *rt_rq;
-
- rt_rq = &rq->rt;
-
- if (!rt_rq->rt_nr_running)
- return NULL;
-
- if (rt_rq_throttled(rt_rq))
- return NULL;
+ struct rt_rq *rt_rq = &rq->rt;
do {
rt_se = pick_next_rt_entity(rq, rt_rq);
@@ -1340,21 +1352,45 @@ static struct task_struct *_pick_next_task_rt(struct rq *rq)
return p;
}
-static struct task_struct *pick_next_task_rt(struct rq *rq)
+static struct task_struct *
+pick_next_task_rt(struct rq *rq, struct task_struct *prev)
{
- struct task_struct *p = _pick_next_task_rt(rq);
+ struct task_struct *p;
+ struct rt_rq *rt_rq = &rq->rt;
+
+ if (need_pull_rt_task(rq, prev)) {
+ pull_rt_task(rq);
+ /*
+ * pull_rt_task() can drop (and re-acquire) rq->lock; this
+ * means a dl task can slip in, in which case we need to
+ * re-start task selection.
+ */
+ if (unlikely(rq->dl.dl_nr_running))
+ return RETRY_TASK;
+ }
+
+ /*
+ * We may dequeue prev's rt_rq in put_prev_task().
+ * So, we update time before rt_nr_running check.
+ */
+ if (prev->sched_class == &rt_sched_class)
+ update_curr_rt(rq);
+
+ if (!rt_rq->rt_nr_running)
+ return NULL;
+
+ if (rt_rq_throttled(rt_rq))
+ return NULL;
+
+ put_prev_task(rq, prev);
+
+ p = _pick_next_task_rt(rq);
/* The running task is never eligible for pushing */
if (p)
dequeue_pushable_task(rq, p);
-#ifdef CONFIG_SMP
- /*
- * We detect this state here so that we can avoid taking the RQ
- * lock again later if there is no need to push
- */
- rq->post_schedule = has_pushable_tasks(rq);
-#endif
+ set_post_schedule(rq);
return p;
}
@@ -1724,13 +1760,6 @@ skip:
return ret;
}
-static void pre_schedule_rt(struct rq *rq, struct task_struct *prev)
-{
- /* Try to pull RT tasks here if we lower this rq's prio */
- if (rq->rt.highest_prio.curr > prev->prio)
- pull_rt_task(rq);
-}
-
static void post_schedule_rt(struct rq *rq)
{
push_rt_tasks(rq);
@@ -1833,7 +1862,7 @@ static void switched_from_rt(struct rq *rq, struct task_struct *p)
resched_task(rq->curr);
}
-void init_sched_rt_class(void)
+void __init init_sched_rt_class(void)
{
unsigned int i;
@@ -2007,7 +2036,6 @@ const struct sched_class rt_sched_class = {
.set_cpus_allowed = set_cpus_allowed_rt,
.rq_online = rq_online_rt,
.rq_offline = rq_offline_rt,
- .pre_schedule = pre_schedule_rt,
.post_schedule = post_schedule_rt,
.task_woken = task_woken_rt,
.switched_from = switched_from_rt,
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index f964add50f3..f2de7a17562 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -24,24 +24,6 @@ extern long calc_load_fold_active(struct rq *this_rq);
extern void update_cpu_load_active(struct rq *this_rq);
/*
- * Convert user-nice values [ -20 ... 0 ... 19 ]
- * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
- * and back.
- */
-#define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20)
-#define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20)
-#define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio)
-
-/*
- * 'User priority' is the nice value converted to something we
- * can work with better when scaling various scheduler parameters,
- * it's a [ 0 ... 39 ] range.
- */
-#define USER_PRIO(p) ((p)-MAX_RT_PRIO)
-#define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio)
-#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO))
-
-/*
* Helpers for converting nanosecond timing to jiffy resolution
*/
#define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
@@ -441,6 +423,18 @@ struct rt_rq {
#endif
};
+#ifdef CONFIG_RT_GROUP_SCHED
+static inline int rt_rq_throttled(struct rt_rq *rt_rq)
+{
+ return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted;
+}
+#else
+static inline int rt_rq_throttled(struct rt_rq *rt_rq)
+{
+ return rt_rq->rt_throttled;
+}
+#endif
+
/* Deadline class' related fields in a runqueue */
struct dl_rq {
/* runqueue is an rbtree, ordered by deadline */
@@ -558,11 +552,9 @@ struct rq {
#ifdef CONFIG_FAIR_GROUP_SCHED
/* list of leaf cfs_rq on this cpu: */
struct list_head leaf_cfs_rq_list;
-#endif /* CONFIG_FAIR_GROUP_SCHED */
-#ifdef CONFIG_RT_GROUP_SCHED
- struct list_head leaf_rt_rq_list;
-#endif
+ struct sched_avg avg;
+#endif /* CONFIG_FAIR_GROUP_SCHED */
/*
* This is part of a global counter where only the total sum
@@ -651,8 +643,6 @@ struct rq {
#ifdef CONFIG_SMP
struct llist_head wake_list;
#endif
-
- struct sched_avg avg;
};
static inline int cpu_of(struct rq *rq)
@@ -1112,6 +1102,8 @@ static const u32 prio_to_wmult[40] = {
#define DEQUEUE_SLEEP 1
+#define RETRY_TASK ((void *)-1UL)
+
struct sched_class {
const struct sched_class *next;
@@ -1122,14 +1114,22 @@ struct sched_class {
void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
- struct task_struct * (*pick_next_task) (struct rq *rq);
+ /*
+ * It is the responsibility of the pick_next_task() method that will
+ * return the next task to call put_prev_task() on the @prev task or
+ * something equivalent.
+ *
+ * May return RETRY_TASK when it finds a higher prio class has runnable
+ * tasks.
+ */
+ struct task_struct * (*pick_next_task) (struct rq *rq,
+ struct task_struct *prev);
void (*put_prev_task) (struct rq *rq, struct task_struct *p);
#ifdef CONFIG_SMP
int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags);
void (*migrate_task_rq)(struct task_struct *p, int next_cpu);
- void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
void (*post_schedule) (struct rq *this_rq);
void (*task_waking) (struct task_struct *task);
void (*task_woken) (struct rq *this_rq, struct task_struct *task);
@@ -1159,6 +1159,11 @@ struct sched_class {
#endif
};
+static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
+{
+ prev->sched_class->put_prev_task(rq, prev);
+}
+
#define sched_class_highest (&stop_sched_class)
#define for_each_class(class) \
for (class = sched_class_highest; class; class = class->next)
@@ -1175,16 +1180,14 @@ extern const struct sched_class idle_sched_class;
extern void update_group_power(struct sched_domain *sd, int cpu);
extern void trigger_load_balance(struct rq *rq);
-extern void idle_balance(int this_cpu, struct rq *this_rq);
extern void idle_enter_fair(struct rq *this_rq);
extern void idle_exit_fair(struct rq *this_rq);
-#else /* CONFIG_SMP */
+#else
-static inline void idle_balance(int cpu, struct rq *rq)
-{
-}
+static inline void idle_enter_fair(struct rq *rq) { }
+static inline void idle_exit_fair(struct rq *rq) { }
#endif
diff --git a/kernel/sched/stop_task.c b/kernel/sched/stop_task.c
index fdb6bb0b335..d6ce65dde54 100644
--- a/kernel/sched/stop_task.c
+++ b/kernel/sched/stop_task.c
@@ -23,16 +23,19 @@ check_preempt_curr_stop(struct rq *rq, struct task_struct *p, int flags)
/* we're never preempted */
}
-static struct task_struct *pick_next_task_stop(struct rq *rq)
+static struct task_struct *
+pick_next_task_stop(struct rq *rq, struct task_struct *prev)
{
struct task_struct *stop = rq->stop;
- if (stop && stop->on_rq) {
- stop->se.exec_start = rq_clock_task(rq);
- return stop;
- }
+ if (!stop || !stop->on_rq)
+ return NULL;
- return NULL;
+ put_prev_task(rq, prev);
+
+ stop->se.exec_start = rq_clock_task(rq);
+
+ return stop;
}
static void
diff --git a/kernel/sys.c b/kernel/sys.c
index c0a58be780a..adaeab6f7a8 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -174,10 +174,10 @@ SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
/* normalize: avoid signed division (rounding problems) */
error = -ESRCH;
- if (niceval < -20)
- niceval = -20;
- if (niceval > 19)
- niceval = 19;
+ if (niceval < MIN_NICE)
+ niceval = MIN_NICE;
+ if (niceval > MAX_NICE)
+ niceval = MAX_NICE;
rcu_read_lock();
read_lock(&tasklist_lock);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 49e13e1f8fe..7754ff16f33 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -386,13 +386,6 @@ static struct ctl_table kern_table[] = {
.proc_handler = proc_dointvec,
},
{
- .procname = "numa_balancing_migrate_deferred",
- .data = &sysctl_numa_balancing_migrate_deferred,
- .maxlen = sizeof(unsigned int),
- .mode = 0644,
- .proc_handler = proc_dointvec,
- },
- {
.procname = "numa_balancing",
.data = NULL, /* filled in by handler */
.maxlen = sizeof(unsigned int),
diff --git a/kernel/trace/ring_buffer_benchmark.c b/kernel/trace/ring_buffer_benchmark.c
index a5457d577b9..0434ff1b808 100644
--- a/kernel/trace/ring_buffer_benchmark.c
+++ b/kernel/trace/ring_buffer_benchmark.c
@@ -40,8 +40,8 @@ static int write_iteration = 50;
module_param(write_iteration, uint, 0644);
MODULE_PARM_DESC(write_iteration, "# of writes between timestamp readings");
-static int producer_nice = 19;
-static int consumer_nice = 19;
+static int producer_nice = MAX_NICE;
+static int consumer_nice = MAX_NICE;
static int producer_fifo = -1;
static int consumer_fifo = -1;
@@ -308,7 +308,7 @@ static void ring_buffer_producer(void)
/* Let the user know that the test is running at low priority */
if (producer_fifo < 0 && consumer_fifo < 0 &&
- producer_nice == 19 && consumer_nice == 19)
+ producer_nice == MAX_NICE && consumer_nice == MAX_NICE)
trace_printk("WARNING!!! This test is running at lowest priority.\n");
trace_printk("Time: %lld (usecs)\n", time);
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 193e977a10e..3fa5b8f3aae 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -3225,7 +3225,7 @@ static ssize_t wq_nice_store(struct device *dev, struct device_attribute *attr,
return -ENOMEM;
if (sscanf(buf, "%d", &attrs->nice) == 1 &&
- attrs->nice >= -20 && attrs->nice <= 19)
+ attrs->nice >= MIN_NICE && attrs->nice <= MAX_NICE)
ret = apply_workqueue_attrs(wq, attrs);
else
ret = -EINVAL;