From 391e43da797a96aeb65410281891f6d0b0e9611c Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Tue, 15 Nov 2011 17:14:39 +0100
Subject: sched: Move all scheduler bits into kernel/sched/
There's too many sched*.[ch] files in kernel/, give them their own
directory.
(No code changed, other than Makefile glue added.)
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/sched.c | 8101 --------------------------------------------------------
1 file changed, 8101 deletions(-)
delete mode 100644 kernel/sched.c
(limited to 'kernel/sched.c')
diff --git a/kernel/sched.c b/kernel/sched.c
deleted file mode 100644
index 2ffcceed8862..000000000000
--- a/kernel/sched.c
+++ /dev/null
@@ -1,8101 +0,0 @@
-/*
- * kernel/sched.c
- *
- * Kernel scheduler and related syscalls
- *
- * Copyright (C) 1991-2002 Linus Torvalds
- *
- * 1996-12-23 Modified by Dave Grothe to fix bugs in semaphores and
- * make semaphores SMP safe
- * 1998-11-19 Implemented schedule_timeout() and related stuff
- * by Andrea Arcangeli
- * 2002-01-04 New ultra-scalable O(1) scheduler by Ingo Molnar:
- * hybrid priority-list and round-robin design with
- * an array-switch method of distributing timeslices
- * and per-CPU runqueues. Cleanups and useful suggestions
- * by Davide Libenzi, preemptible kernel bits by Robert Love.
- * 2003-09-03 Interactivity tuning by Con Kolivas.
- * 2004-04-02 Scheduler domains code by Nick Piggin
- * 2007-04-15 Work begun on replacing all interactivity tuning with a
- * fair scheduling design by Con Kolivas.
- * 2007-05-05 Load balancing (smp-nice) and other improvements
- * by Peter Williams
- * 2007-05-06 Interactivity improvements to CFS by Mike Galbraith
- * 2007-07-01 Group scheduling enhancements by Srivatsa Vaddagiri
- * 2007-11-29 RT balancing improvements by Steven Rostedt, Gregory Haskins,
- * Thomas Gleixner, Mike Kravetz
- */
-
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/nmi.h>
-#include <linux/init.h>
-#include <linux/uaccess.h>
-#include <linux/highmem.h>
-#include <asm/mmu_context.h>
-#include <linux/interrupt.h>
-#include <linux/capability.h>
-#include <linux/completion.h>
-#include <linux/kernel_stat.h>
-#include <linux/debug_locks.h>
-#include <linux/perf_event.h>
-#include <linux/security.h>
-#include <linux/notifier.h>
-#include <linux/profile.h>
-#include <linux/freezer.h>
-#include <linux/vmalloc.h>
-#include <linux/blkdev.h>
-#include <linux/delay.h>
-#include <linux/pid_namespace.h>
-#include <linux/smp.h>
-#include <linux/threads.h>
-#include <linux/timer.h>
-#include <linux/rcupdate.h>
-#include <linux/cpu.h>
-#include <linux/cpuset.h>
-#include <linux/percpu.h>
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
-#include <linux/sysctl.h>
-#include <linux/syscalls.h>
-#include <linux/times.h>
-#include <linux/tsacct_kern.h>
-#include <linux/kprobes.h>
-#include <linux/delayacct.h>
-#include <linux/unistd.h>
-#include <linux/pagemap.h>
-#include <linux/hrtimer.h>
-#include <linux/tick.h>
-#include <linux/debugfs.h>
-#include <linux/ctype.h>
-#include <linux/ftrace.h>
-#include <linux/slab.h>
-#include <linux/init_task.h>
-
-#include <asm/tlb.h>
-#include <asm/irq_regs.h>
-#ifdef CONFIG_PARAVIRT
-#include <asm/paravirt.h>
-#endif
-
-#include "sched.h"
-#include "workqueue_sched.h"
-
-#define CREATE_TRACE_POINTS
-#include <trace/events/sched.h>
-
-void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period)
-{
- unsigned long delta;
- ktime_t soft, hard, now;
-
- for (;;) {
- if (hrtimer_active(period_timer))
- break;
-
- now = hrtimer_cb_get_time(period_timer);
- hrtimer_forward(period_timer, now, period);
-
- soft = hrtimer_get_softexpires(period_timer);
- hard = hrtimer_get_expires(period_timer);
- delta = ktime_to_ns(ktime_sub(hard, soft));
- __hrtimer_start_range_ns(period_timer, soft, delta,
- HRTIMER_MODE_ABS_PINNED, 0);
- }
-}
-
-DEFINE_MUTEX(sched_domains_mutex);
-DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
-
-static void update_rq_clock_task(struct rq *rq, s64 delta);
-
-void update_rq_clock(struct rq *rq)
-{
- s64 delta;
-
- if (rq->skip_clock_update > 0)
- return;
-
- delta = sched_clock_cpu(cpu_of(rq)) - rq->clock;
- rq->clock += delta;
- update_rq_clock_task(rq, delta);
-}
-
-/*
- * Debugging: various feature bits
- */
-
-#define SCHED_FEAT(name, enabled) \
- (1UL << __SCHED_FEAT_##name) * enabled |
-
-const_debug unsigned int sysctl_sched_features =
-#include "sched_features.h"
- 0;
-
-#undef SCHED_FEAT
-
-#ifdef CONFIG_SCHED_DEBUG
-#define SCHED_FEAT(name, enabled) \
- #name ,
-
-static __read_mostly char *sched_feat_names[] = {
-#include "sched_features.h"
- NULL
-};
-
-#undef SCHED_FEAT
-
-static int sched_feat_show(struct seq_file *m, void *v)
-{
- int i;
-
- for (i = 0; sched_feat_names[i]; i++) {
- if (!(sysctl_sched_features & (1UL << i)))
- seq_puts(m, "NO_");
- seq_printf(m, "%s ", sched_feat_names[i]);
- }
- seq_puts(m, "\n");
-
- return 0;
-}
-
-static ssize_t
-sched_feat_write(struct file *filp, const char __user *ubuf,
- size_t cnt, loff_t *ppos)
-{
- char buf[64];
- char *cmp;
- int neg = 0;
- int i;
-
- if (cnt > 63)
- cnt = 63;
-
- if (copy_from_user(&buf, ubuf, cnt))
- return -EFAULT;
-
- buf[cnt] = 0;
- cmp = strstrip(buf);
-
- if (strncmp(cmp, "NO_", 3) == 0) {
- neg = 1;
- cmp += 3;
- }
-
- for (i = 0; sched_feat_names[i]; i++) {
- if (strcmp(cmp, sched_feat_names[i]) == 0) {
- if (neg)
- sysctl_sched_features &= ~(1UL << i);
- else
- sysctl_sched_features |= (1UL << i);
- break;
- }
- }
-
- if (!sched_feat_names[i])
- return -EINVAL;
-
- *ppos += cnt;
-
- return cnt;
-}
-
-static int sched_feat_open(struct inode *inode, struct file *filp)
-{
- return single_open(filp, sched_feat_show, NULL);
-}
-
-static const struct file_operations sched_feat_fops = {
- .open = sched_feat_open,
- .write = sched_feat_write,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
-};
-
-static __init int sched_init_debug(void)
-{
- debugfs_create_file("sched_features", 0644, NULL, NULL,
- &sched_feat_fops);
-
- return 0;
-}
-late_initcall(sched_init_debug);
-
-#endif
-
-/*
- * Number of tasks to iterate in a single balance run.
- * Limited because this is done with IRQs disabled.
- */
-const_debug unsigned int sysctl_sched_nr_migrate = 32;
-
-/*
- * period over which we average the RT time consumption, measured
- * in ms.
- *
- * default: 1s
- */
-const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC;
-
-/*
- * period over which we measure -rt task cpu usage in us.
- * default: 1s
- */
-unsigned int sysctl_sched_rt_period = 1000000;
-
-__read_mostly int scheduler_running;
-
-/*
- * part of the period that we allow rt tasks to run in us.
- * default: 0.95s
- */
-int sysctl_sched_rt_runtime = 950000;
-
-
-
-/*
- * __task_rq_lock - lock the rq @p resides on.
- */
-static inline struct rq *__task_rq_lock(struct task_struct *p)
- __acquires(rq->lock)
-{
- struct rq *rq;
-
- lockdep_assert_held(&p->pi_lock);
-
- for (;;) {
- rq = task_rq(p);
- raw_spin_lock(&rq->lock);
- if (likely(rq == task_rq(p)))
- return rq;
- raw_spin_unlock(&rq->lock);
- }
-}
-
-/*
- * task_rq_lock - lock p->pi_lock and lock the rq @p resides on.
- */
-static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags)
- __acquires(p->pi_lock)
- __acquires(rq->lock)
-{
- struct rq *rq;
-
- for (;;) {
- raw_spin_lock_irqsave(&p->pi_lock, *flags);
- rq = task_rq(p);
- raw_spin_lock(&rq->lock);
- if (likely(rq == task_rq(p)))
- return rq;
- raw_spin_unlock(&rq->lock);
- raw_spin_unlock_irqrestore(&p->pi_lock, *flags);
- }
-}
-
-static void __task_rq_unlock(struct rq *rq)
- __releases(rq->lock)
-{
- raw_spin_unlock(&rq->lock);
-}
-
-static inline void
-task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags)
- __releases(rq->lock)
- __releases(p->pi_lock)
-{
- raw_spin_unlock(&rq->lock);
- raw_spin_unlock_irqrestore(&p->pi_lock, *flags);
-}
-
-/*
- * this_rq_lock - lock this runqueue and disable interrupts.
- */
-static struct rq *this_rq_lock(void)
- __acquires(rq->lock)
-{
- struct rq *rq;
-
- local_irq_disable();
- rq = this_rq();
- raw_spin_lock(&rq->lock);
-
- return rq;
-}
-
-#ifdef CONFIG_SCHED_HRTICK
-/*
- * Use HR-timers to deliver accurate preemption points.
- *
- * Its all a bit involved since we cannot program an hrt while holding the
- * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a
- * reschedule event.
- *
- * When we get rescheduled we reprogram the hrtick_timer outside of the
- * rq->lock.
- */
-
-static void hrtick_clear(struct rq *rq)
-{
- if (hrtimer_active(&rq->hrtick_timer))
- hrtimer_cancel(&rq->hrtick_timer);
-}
-
-/*
- * High-resolution timer tick.
- * Runs from hardirq context with interrupts disabled.
- */
-static enum hrtimer_restart hrtick(struct hrtimer *timer)
-{
- struct rq *rq = container_of(timer, struct rq, hrtick_timer);
-
- WARN_ON_ONCE(cpu_of(rq) != smp_processor_id());
-
- raw_spin_lock(&rq->lock);
- update_rq_clock(rq);
- rq->curr->sched_class->task_tick(rq, rq->curr, 1);
- raw_spin_unlock(&rq->lock);
-
- return HRTIMER_NORESTART;
-}
-
-#ifdef CONFIG_SMP
-/*
- * called from hardirq (IPI) context
- */
-static void __hrtick_start(void *arg)
-{
- struct rq *rq = arg;
-
- raw_spin_lock(&rq->lock);
- hrtimer_restart(&rq->hrtick_timer);
- rq->hrtick_csd_pending = 0;
- raw_spin_unlock(&rq->lock);
-}
-
-/*
- * Called to set the hrtick timer state.
- *
- * called with rq->lock held and irqs disabled
- */
-void hrtick_start(struct rq *rq, u64 delay)
-{
- struct hrtimer *timer = &rq->hrtick_timer;
- ktime_t time = ktime_add_ns(timer->base->get_time(), delay);
-
- hrtimer_set_expires(timer, time);
-
- if (rq == this_rq()) {
- hrtimer_restart(timer);
- } else if (!rq->hrtick_csd_pending) {
- __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0);
- rq->hrtick_csd_pending = 1;
- }
-}
-
-static int
-hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu)
-{
- int cpu = (int)(long)hcpu;
-
- switch (action) {
- case CPU_UP_CANCELED:
- case CPU_UP_CANCELED_FROZEN:
- case CPU_DOWN_PREPARE:
- case CPU_DOWN_PREPARE_FROZEN:
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- hrtick_clear(cpu_rq(cpu));
- return NOTIFY_OK;
- }
-
- return NOTIFY_DONE;
-}
-
-static __init void init_hrtick(void)
-{
- hotcpu_notifier(hotplug_hrtick, 0);
-}
-#else
-/*
- * Called to set the hrtick timer state.
- *
- * called with rq->lock held and irqs disabled
- */
-void hrtick_start(struct rq *rq, u64 delay)
-{
- __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0,
- HRTIMER_MODE_REL_PINNED, 0);
-}
-
-static inline void init_hrtick(void)
-{
-}
-#endif /* CONFIG_SMP */
-
-static void init_rq_hrtick(struct rq *rq)
-{
-#ifdef CONFIG_SMP
- rq->hrtick_csd_pending = 0;
-
- rq->hrtick_csd.flags = 0;
- rq->hrtick_csd.func = __hrtick_start;
- rq->hrtick_csd.info = rq;
-#endif
-
- hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
- rq->hrtick_timer.function = hrtick;
-}
-#else /* CONFIG_SCHED_HRTICK */
-static inline void hrtick_clear(struct rq *rq)
-{
-}
-
-static inline void init_rq_hrtick(struct rq *rq)
-{
-}
-
-static inline void init_hrtick(void)
-{
-}
-#endif /* CONFIG_SCHED_HRTICK */
-
-/*
- * resched_task - mark a task 'to be rescheduled now'.
- *
- * On UP this means the setting of the need_resched flag, on SMP it
- * might also involve a cross-CPU call to trigger the scheduler on
- * the target CPU.
- */
-#ifdef CONFIG_SMP
-
-#ifndef tsk_is_polling
-#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
-#endif
-
-void resched_task(struct task_struct *p)
-{
- int cpu;
-
- assert_raw_spin_locked(&task_rq(p)->lock);
-
- if (test_tsk_need_resched(p))
- return;
-
- set_tsk_need_resched(p);
-
- cpu = task_cpu(p);
- if (cpu == smp_processor_id())
- return;
-
- /* NEED_RESCHED must be visible before we test polling */
- smp_mb();
- if (!tsk_is_polling(p))
- smp_send_reschedule(cpu);
-}
-
-void resched_cpu(int cpu)
-{
- struct rq *rq = cpu_rq(cpu);
- unsigned long flags;
-
- if (!raw_spin_trylock_irqsave(&rq->lock, flags))
- return;
- resched_task(cpu_curr(cpu));
- raw_spin_unlock_irqrestore(&rq->lock, flags);
-}
-
-#ifdef CONFIG_NO_HZ
-/*
- * In the semi idle case, use the nearest busy cpu for migrating timers
- * from an idle cpu. This is good for power-savings.
- *
- * We don't do similar optimization for completely idle system, as
- * selecting an idle cpu will add more delays to the timers than intended
- * (as that cpu's timer base may not be uptodate wrt jiffies etc).
- */
-int get_nohz_timer_target(void)
-{
- int cpu = smp_processor_id();
- int i;
- struct sched_domain *sd;
-
- rcu_read_lock();
- for_each_domain(cpu, sd) {
- for_each_cpu(i, sched_domain_span(sd)) {
- if (!idle_cpu(i)) {
- cpu = i;
- goto unlock;
- }
- }
- }
-unlock:
- rcu_read_unlock();
- return cpu;
-}
-/*
- * When add_timer_on() enqueues a timer into the timer wheel of an
- * idle CPU then this timer might expire before the next timer event
- * which is scheduled to wake up that CPU. In case of a completely
- * idle system the next event might even be infinite time into the
- * future. wake_up_idle_cpu() ensures that the CPU is woken up and
- * leaves the inner idle loop so the newly added timer is taken into
- * account when the CPU goes back to idle and evaluates the timer
- * wheel for the next timer event.
- */
-void wake_up_idle_cpu(int cpu)
-{
- struct rq *rq = cpu_rq(cpu);
-
- if (cpu == smp_processor_id())
- return;
-
- /*
- * This is safe, as this function is called with the timer
- * wheel base lock of (cpu) held. When the CPU is on the way
- * to idle and has not yet set rq->curr to idle then it will
- * be serialized on the timer wheel base lock and take the new
- * timer into account automatically.
- */
- if (rq->curr != rq->idle)
- return;
-
- /*
- * We can set TIF_RESCHED on the idle task of the other CPU
- * lockless. The worst case is that the other CPU runs the
- * idle task through an additional NOOP schedule()
- */
- set_tsk_need_resched(rq->idle);
-
- /* NEED_RESCHED must be visible before we test polling */
- smp_mb();
- if (!tsk_is_polling(rq->idle))
- smp_send_reschedule(cpu);
-}
-
-static inline bool got_nohz_idle_kick(void)
-{
- return idle_cpu(smp_processor_id()) && this_rq()->nohz_balance_kick;
-}
-
-#else /* CONFIG_NO_HZ */
-
-static inline bool got_nohz_idle_kick(void)
-{
- return false;
-}
-
-#endif /* CONFIG_NO_HZ */
-
-void sched_avg_update(struct rq *rq)
-{
- s64 period = sched_avg_period();
-
- while ((s64)(rq->clock - rq->age_stamp) > period) {
- /*
- * Inline assembly required to prevent the compiler
- * optimising this loop into a divmod call.
- * See __iter_div_u64_rem() for another example of this.
- */
- asm("" : "+rm" (rq->age_stamp));
- rq->age_stamp += period;
- rq->rt_avg /= 2;
- }
-}
-
-#else /* !CONFIG_SMP */
-void resched_task(struct task_struct *p)
-{
- assert_raw_spin_locked(&task_rq(p)->lock);
- set_tsk_need_resched(p);
-}
-#endif /* CONFIG_SMP */
-
-#if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \
- (defined(CONFIG_SMP) || defined(CONFIG_CFS_BANDWIDTH)))
-/*
- * Iterate task_group tree rooted at *from, calling @down when first entering a
- * node and @up when leaving it for the final time.
- *
- * Caller must hold rcu_lock or sufficient equivalent.
- */
-int walk_tg_tree_from(struct task_group *from,
- tg_visitor down, tg_visitor up, void *data)
-{
- struct task_group *parent, *child;
- int ret;
-
- parent = from;
-
-down:
- ret = (*down)(parent, data);
- if (ret)
- goto out;
- list_for_each_entry_rcu(child, &parent->children, siblings) {
- parent = child;
- goto down;
-
-up:
- continue;
- }
- ret = (*up)(parent, data);
- if (ret || parent == from)
- goto out;
-
- child = parent;
- parent = parent->parent;
- if (parent)
- goto up;
-out:
- return ret;
-}
-
-int tg_nop(struct task_group *tg, void *data)
-{
- return 0;
-}
-#endif
-
-void update_cpu_load(struct rq *this_rq);
-
-static void set_load_weight(struct task_struct *p)
-{
- int prio = p->static_prio - MAX_RT_PRIO;
- struct load_weight *load = &p->se.load;
-
- /*
- * SCHED_IDLE tasks get minimal weight:
- */
- if (p->policy == SCHED_IDLE) {
- load->weight = scale_load(WEIGHT_IDLEPRIO);
- load->inv_weight = WMULT_IDLEPRIO;
- return;
- }
-
- load->weight = scale_load(prio_to_weight[prio]);
- load->inv_weight = prio_to_wmult[prio];
-}
-
-static void enqueue_task(struct rq *rq, struct task_struct *p, int flags)
-{
- update_rq_clock(rq);
- sched_info_queued(p);
- p->sched_class->enqueue_task(rq, p, flags);
-}
-
-static void dequeue_task(struct rq *rq, struct task_struct *p, int flags)
-{
- update_rq_clock(rq);
- sched_info_dequeued(p);
- p->sched_class->dequeue_task(rq, p, flags);
-}
-
-/*
- * activate_task - move a task to the runqueue.
- */
-void activate_task(struct rq *rq, struct task_struct *p, int flags)
-{
- if (task_contributes_to_load(p))
- rq->nr_uninterruptible--;
-
- enqueue_task(rq, p, flags);
-}
-
-/*
- * deactivate_task - remove a task from the runqueue.
- */
-void deactivate_task(struct rq *rq, struct task_struct *p, int flags)
-{
- if (task_contributes_to_load(p))
- rq->nr_uninterruptible++;
-
- dequeue_task(rq, p, flags);
-}
-
-#ifdef CONFIG_IRQ_TIME_ACCOUNTING
-
-/*
- * There are no locks covering percpu hardirq/softirq time.
- * They are only modified in account_system_vtime, on corresponding CPU
- * with interrupts disabled. So, writes are safe.
- * They are read and saved off onto struct rq in update_rq_clock().
- * This may result in other CPU reading this CPU's irq time and can
- * race with irq/account_system_vtime on this CPU. We would either get old
- * or new value with a side effect of accounting a slice of irq time to wrong
- * task when irq is in progress while we read rq->clock. That is a worthy
- * compromise in place of having locks on each irq in account_system_time.
- */
-static DEFINE_PER_CPU(u64, cpu_hardirq_time);
-static DEFINE_PER_CPU(u64, cpu_softirq_time);
-
-static DEFINE_PER_CPU(u64, irq_start_time);
-static int sched_clock_irqtime;
-
-void enable_sched_clock_irqtime(void)
-{
- sched_clock_irqtime = 1;
-}
-
-void disable_sched_clock_irqtime(void)
-{
- sched_clock_irqtime = 0;
-}
-
-#ifndef CONFIG_64BIT
-static DEFINE_PER_CPU(seqcount_t, irq_time_seq);
-
-static inline void irq_time_write_begin(void)
-{
- __this_cpu_inc(irq_time_seq.sequence);
- smp_wmb();
-}
-
-static inline void irq_time_write_end(void)
-{
- smp_wmb();
- __this_cpu_inc(irq_time_seq.sequence);
-}
-
-static inline u64 irq_time_read(int cpu)
-{
- u64 irq_time;
- unsigned seq;
-
- do {
- seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu));
- irq_time = per_cpu(cpu_softirq_time, cpu) +
- per_cpu(cpu_hardirq_time, cpu);
- } while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq));
-
- return irq_time;
-}
-#else /* CONFIG_64BIT */
-static inline void irq_time_write_begin(void)
-{
-}
-
-static inline void irq_time_write_end(void)
-{
-}
-
-static inline u64 irq_time_read(int cpu)
-{
- return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu);
-}
-#endif /* CONFIG_64BIT */
-
-/*
- * Called before incrementing preempt_count on {soft,}irq_enter
- * and before decrementing preempt_count on {soft,}irq_exit.
- */
-void account_system_vtime(struct task_struct *curr)
-{
- unsigned long flags;
- s64 delta;
- int cpu;
-
- if (!sched_clock_irqtime)
- return;
-
- local_irq_save(flags);
-
- cpu = smp_processor_id();
- delta = sched_clock_cpu(cpu) - __this_cpu_read(irq_start_time);
- __this_cpu_add(irq_start_time, delta);
-
- irq_time_write_begin();
- /*
- * We do not account for softirq time from ksoftirqd here.
- * We want to continue accounting softirq time to ksoftirqd thread
- * in that case, so as not to confuse scheduler with a special task
- * that do not consume any time, but still wants to run.
- */
- if (hardirq_count())
- __this_cpu_add(cpu_hardirq_time, delta);
- else if (in_serving_softirq() && curr != this_cpu_ksoftirqd())
- __this_cpu_add(cpu_softirq_time, delta);
-
- irq_time_write_end();
- local_irq_restore(flags);
-}
-EXPORT_SYMBOL_GPL(account_system_vtime);
-
-#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
-
-#ifdef CONFIG_PARAVIRT
-static inline u64 steal_ticks(u64 steal)
-{
- if (unlikely(steal > NSEC_PER_SEC))
- return div_u64(steal, TICK_NSEC);
-
- return __iter_div_u64_rem(steal, TICK_NSEC, &steal);
-}
-#endif
-
-static void update_rq_clock_task(struct rq *rq, s64 delta)
-{
-/*
- * In theory, the compile should just see 0 here, and optimize out the call
- * to sched_rt_avg_update. But I don't trust it...
- */
-#if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING)
- s64 steal = 0, irq_delta = 0;
-#endif
-#ifdef CONFIG_IRQ_TIME_ACCOUNTING
- irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time;
-
- /*
- * Since irq_time is only updated on {soft,}irq_exit, we might run into
- * this case when a previous update_rq_clock() happened inside a
- * {soft,}irq region.
- *
- * When this happens, we stop ->clock_task and only update the
- * prev_irq_time stamp to account for the part that fit, so that a next
- * update will consume the rest. This ensures ->clock_task is
- * monotonic.
- *
- * It does however cause some slight miss-attribution of {soft,}irq
- * time, a more accurate solution would be to update the irq_time using
- * the current rq->clock timestamp, except that would require using
- * atomic ops.
- */
- if (irq_delta > delta)
- irq_delta = delta;
-
- rq->prev_irq_time += irq_delta;
- delta -= irq_delta;
-#endif
-#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
- if (static_branch((¶virt_steal_rq_enabled))) {
- u64 st;
-
- steal = paravirt_steal_clock(cpu_of(rq));
- steal -= rq->prev_steal_time_rq;
-
- if (unlikely(steal > delta))
- steal = delta;
-
- st = steal_ticks(steal);
- steal = st * TICK_NSEC;
-
- rq->prev_steal_time_rq += steal;
-
- delta -= steal;
- }
-#endif
-
- rq->clock_task += delta;
-
-#if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING)
- if ((irq_delta + steal) && sched_feat(NONTASK_POWER))
- sched_rt_avg_update(rq, irq_delta + steal);
-#endif
-}
-
-#ifdef CONFIG_IRQ_TIME_ACCOUNTING
-static int irqtime_account_hi_update(void)
-{
- struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
- unsigned long flags;
- u64 latest_ns;
- int ret = 0;
-
- local_irq_save(flags);
- latest_ns = this_cpu_read(cpu_hardirq_time);
- if (cputime64_gt(nsecs_to_cputime64(latest_ns), cpustat->irq))
- ret = 1;
- local_irq_restore(flags);
- return ret;
-}
-
-static int irqtime_account_si_update(void)
-{
- struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
- unsigned long flags;
- u64 latest_ns;
- int ret = 0;
-
- local_irq_save(flags);
- latest_ns = this_cpu_read(cpu_softirq_time);
- if (cputime64_gt(nsecs_to_cputime64(latest_ns), cpustat->softirq))
- ret = 1;
- local_irq_restore(flags);
- return ret;
-}
-
-#else /* CONFIG_IRQ_TIME_ACCOUNTING */
-
-#define sched_clock_irqtime (0)
-
-#endif
-
-void sched_set_stop_task(int cpu, struct task_struct *stop)
-{
- struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
- struct task_struct *old_stop = cpu_rq(cpu)->stop;
-
- if (stop) {
- /*
- * Make it appear like a SCHED_FIFO task, its something
- * userspace knows about and won't get confused about.
- *
- * Also, it will make PI more or less work without too
- * much confusion -- but then, stop work should not
- * rely on PI working anyway.
- */
- sched_setscheduler_nocheck(stop, SCHED_FIFO, ¶m);
-
- stop->sched_class = &stop_sched_class;
- }
-
- cpu_rq(cpu)->stop = stop;
-
- if (old_stop) {
- /*
- * Reset it back to a normal scheduling class so that
- * it can die in pieces.
- */
- old_stop->sched_class = &rt_sched_class;
- }
-}
-
-/*
- * __normal_prio - return the priority that is based on the static prio
- */
-static inline int __normal_prio(struct task_struct *p)
-{
- return p->static_prio;
-}
-
-/*
- * Calculate the expected normal priority: i.e. priority
- * without taking RT-inheritance into account. Might be
- * boosted by interactivity modifiers. Changes upon fork,
- * setprio syscalls, and whenever the interactivity
- * estimator recalculates.
- */
-static inline int normal_prio(struct task_struct *p)
-{
- int prio;
-
- if (task_has_rt_policy(p))
- prio = MAX_RT_PRIO-1 - p->rt_priority;
- else
- prio = __normal_prio(p);
- return prio;
-}
-
-/*
- * Calculate the current priority, i.e. the priority
- * taken into account by the scheduler. This value might
- * be boosted by RT tasks, or might be boosted by
- * interactivity modifiers. Will be RT if the task got
- * RT-boosted. If not then it returns p->normal_prio.
- */
-static int effective_prio(struct task_struct *p)
-{
- p->normal_prio = normal_prio(p);
- /*
- * If we are RT tasks or we were boosted to RT priority,
- * keep the priority unchanged. Otherwise, update priority
- * to the normal priority:
- */
- if (!rt_prio(p->prio))
- return p->normal_prio;
- return p->prio;
-}
-
-/**
- * task_curr - is this task currently executing on a CPU?
- * @p: the task in question.
- */
-inline int task_curr(const struct task_struct *p)
-{
- return cpu_curr(task_cpu(p)) == p;
-}
-
-static inline void check_class_changed(struct rq *rq, struct task_struct *p,
- const struct sched_class *prev_class,
- int oldprio)
-{
- if (prev_class != p->sched_class) {
- if (prev_class->switched_from)
- prev_class->switched_from(rq, p);
- p->sched_class->switched_to(rq, p);
- } else if (oldprio != p->prio)
- p->sched_class->prio_changed(rq, p, oldprio);
-}
-
-void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
-{
- const struct sched_class *class;
-
- if (p->sched_class == rq->curr->sched_class) {
- rq->curr->sched_class->check_preempt_curr(rq, p, flags);
- } else {
- for_each_class(class) {
- if (class == rq->curr->sched_class)
- break;
- if (class == p->sched_class) {
- resched_task(rq->curr);
- break;
- }
- }
- }
-
- /*
- * A queue event has occurred, and we're going to schedule. In
- * this case, we can save a useless back to back clock update.
- */
- if (rq->curr->on_rq && test_tsk_need_resched(rq->curr))
- rq->skip_clock_update = 1;
-}
-
-#ifdef CONFIG_SMP
-void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
-{
-#ifdef CONFIG_SCHED_DEBUG
- /*
- * We should never call set_task_cpu() on a blocked task,
- * ttwu() will sort out the placement.
- */
- WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING &&
- !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE));
-
-#ifdef CONFIG_LOCKDEP
- /*
- * The caller should hold either p->pi_lock or rq->lock, when changing
- * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks.
- *
- * sched_move_task() holds both and thus holding either pins the cgroup,
- * see set_task_rq().
- *
- * Furthermore, all task_rq users should acquire both locks, see
- * task_rq_lock().
- */
- WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) ||
- lockdep_is_held(&task_rq(p)->lock)));
-#endif
-#endif
-
- trace_sched_migrate_task(p, new_cpu);
-
- if (task_cpu(p) != new_cpu) {
- p->se.nr_migrations++;
- perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, NULL, 0);
- }
-
- __set_task_cpu(p, new_cpu);
-}
-
-struct migration_arg {
- struct task_struct *task;
- int dest_cpu;
-};
-
-static int migration_cpu_stop(void *data);
-
-/*
- * wait_task_inactive - wait for a thread to unschedule.
- *
- * If @match_state is nonzero, it's the @p->state value just checked and
- * not expected to change. If it changes, i.e. @p might have woken up,
- * then return zero. When we succeed in waiting for @p to be off its CPU,
- * we return a positive number (its total switch count). If a second call
- * a short while later returns the same number, the caller can be sure that
- * @p has remained unscheduled the whole time.
- *
- * The caller must ensure that the task *will* unschedule sometime soon,
- * else this function might spin for a *long* time. This function can't
- * be called with interrupts off, or it may introduce deadlock with
- * smp_call_function() if an IPI is sent by the same process we are
- * waiting to become inactive.
- */
-unsigned long wait_task_inactive(struct task_struct *p, long match_state)
-{
- unsigned long flags;
- int running, on_rq;
- unsigned long ncsw;
- struct rq *rq;
-
- for (;;) {
- /*
- * We do the initial early heuristics without holding
- * any task-queue locks at all. We'll only try to get
- * the runqueue lock when things look like they will
- * work out!
- */
- rq = task_rq(p);
-
- /*
- * If the task is actively running on another CPU
- * still, just relax and busy-wait without holding
- * any locks.
- *
- * NOTE! Since we don't hold any locks, it's not
- * even sure that "rq" stays as the right runqueue!
- * But we don't care, since "task_running()" will
- * return false if the runqueue has changed and p
- * is actually now running somewhere else!
- */
- while (task_running(rq, p)) {
- if (match_state && unlikely(p->state != match_state))
- return 0;
- cpu_relax();
- }
-
- /*
- * Ok, time to look more closely! We need the rq
- * lock now, to be *sure*. If we're wrong, we'll
- * just go back and repeat.
- */
- rq = task_rq_lock(p, &flags);
- trace_sched_wait_task(p);
- running = task_running(rq, p);
- on_rq = p->on_rq;
- ncsw = 0;
- if (!match_state || p->state == match_state)
- ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
- task_rq_unlock(rq, p, &flags);
-
- /*
- * If it changed from the expected state, bail out now.
- */
- if (unlikely(!ncsw))
- break;
-
- /*
- * Was it really running after all now that we
- * checked with the proper locks actually held?
- *
- * Oops. Go back and try again..
- */
- if (unlikely(running)) {
- cpu_relax();
- continue;
- }
-
- /*
- * It's not enough that it's not actively running,
- * it must be off the runqueue _entirely_, and not
- * preempted!
- *
- * So if it was still runnable (but just not actively
- * running right now), it's preempted, and we should
- * yield - it could be a while.
- */
- if (unlikely(on_rq)) {
- ktime_t to = ktime_set(0, NSEC_PER_SEC/HZ);
-
- set_current_state(TASK_UNINTERRUPTIBLE);
- schedule_hrtimeout(&to, HRTIMER_MODE_REL);
- continue;
- }
-
- /*
- * Ahh, all good. It wasn't running, and it wasn't
- * runnable, which means that it will never become
- * running in the future either. We're all done!
- */
- break;
- }
-
- return ncsw;
-}
-
-/***
- * kick_process - kick a running thread to enter/exit the kernel
- * @p: the to-be-kicked thread
- *
- * Cause a process which is running on another CPU to enter
- * kernel-mode, without any delay. (to get signals handled.)
- *
- * NOTE: this function doesn't have to take the runqueue lock,
- * because all it wants to ensure is that the remote task enters
- * the kernel. If the IPI races and the task has been migrated
- * to another CPU then no harm is done and the purpose has been
- * achieved as well.
- */
-void kick_process(struct task_struct *p)
-{
- int cpu;
-
- preempt_disable();
- cpu = task_cpu(p);
- if ((cpu != smp_processor_id()) && task_curr(p))
- smp_send_reschedule(cpu);
- preempt_enable();
-}
-EXPORT_SYMBOL_GPL(kick_process);
-#endif /* CONFIG_SMP */
-
-#ifdef CONFIG_SMP
-/*
- * ->cpus_allowed is protected by both rq->lock and p->pi_lock
- */
-static int select_fallback_rq(int cpu, struct task_struct *p)
-{
- int dest_cpu;
- const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu));
-
- /* Look for allowed, online CPU in same node. */
- for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask)
- if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
- return dest_cpu;
-
- /* Any allowed, online CPU? */
- dest_cpu = cpumask_any_and(tsk_cpus_allowed(p), cpu_active_mask);
- if (dest_cpu < nr_cpu_ids)
- return dest_cpu;
-
- /* No more Mr. Nice Guy. */
- dest_cpu = cpuset_cpus_allowed_fallback(p);
- /*
- * Don't tell them about moving exiting tasks or
- * kernel threads (both mm NULL), since they never
- * leave kernel.
- */
- if (p->mm && printk_ratelimit()) {
- printk(KERN_INFO "process %d (%s) no longer affine to cpu%d\n",
- task_pid_nr(p), p->comm, cpu);
- }
-
- return dest_cpu;
-}
-
-/*
- * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable.
- */
-static inline
-int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags)
-{
- int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags);
-
- /*
- * In order not to call set_task_cpu() on a blocking task we need
- * to rely on ttwu() to place the task on a valid ->cpus_allowed
- * cpu.
- *
- * Since this is common to all placement strategies, this lives here.
- *
- * [ this allows ->select_task() to simply return task_cpu(p) and
- * not worry about this generic constraint ]
- */
- if (unlikely(!cpumask_test_cpu(cpu, tsk_cpus_allowed(p)) ||
- !cpu_online(cpu)))
- cpu = select_fallback_rq(task_cpu(p), p);
-
- return cpu;
-}
-
-static void update_avg(u64 *avg, u64 sample)
-{
- s64 diff = sample - *avg;
- *avg += diff >> 3;
-}
-#endif
-
-static void
-ttwu_stat(struct task_struct *p, int cpu, int wake_flags)
-{
-#ifdef CONFIG_SCHEDSTATS
- struct rq *rq = this_rq();
-
-#ifdef CONFIG_SMP
- int this_cpu = smp_processor_id();
-
- if (cpu == this_cpu) {
- schedstat_inc(rq, ttwu_local);
- schedstat_inc(p, se.statistics.nr_wakeups_local);
- } else {
- struct sched_domain *sd;
-
- schedstat_inc(p, se.statistics.nr_wakeups_remote);
- rcu_read_lock();
- for_each_domain(this_cpu, sd) {
- if (cpumask_test_cpu(cpu, sched_domain_span(sd))) {
- schedstat_inc(sd, ttwu_wake_remote);
- break;
- }
- }
- rcu_read_unlock();
- }
-
- if (wake_flags & WF_MIGRATED)
- schedstat_inc(p, se.statistics.nr_wakeups_migrate);
-
-#endif /* CONFIG_SMP */
-
- schedstat_inc(rq, ttwu_count);
- schedstat_inc(p, se.statistics.nr_wakeups);
-
- if (wake_flags & WF_SYNC)
- schedstat_inc(p, se.statistics.nr_wakeups_sync);
-
-#endif /* CONFIG_SCHEDSTATS */
-}
-
-static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags)
-{
- activate_task(rq, p, en_flags);
- p->on_rq = 1;
-
- /* if a worker is waking up, notify workqueue */
- if (p->flags & PF_WQ_WORKER)
- wq_worker_waking_up(p, cpu_of(rq));
-}
-
-/*
- * Mark the task runnable and perform wakeup-preemption.
- */
-static void
-ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags)
-{
- trace_sched_wakeup(p, true);
- check_preempt_curr(rq, p, wake_flags);
-
- p->state = TASK_RUNNING;
-#ifdef CONFIG_SMP
- if (p->sched_class->task_woken)
- p->sched_class->task_woken(rq, p);
-
- if (rq->idle_stamp) {
- u64 delta = rq->clock - rq->idle_stamp;
- u64 max = 2*sysctl_sched_migration_cost;
-
- if (delta > max)
- rq->avg_idle = max;
- else
- update_avg(&rq->avg_idle, delta);
- rq->idle_stamp = 0;
- }
-#endif
-}
-
-static void
-ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags)
-{
-#ifdef CONFIG_SMP
- if (p->sched_contributes_to_load)
- rq->nr_uninterruptible--;
-#endif
-
- ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_WAKING);
- ttwu_do_wakeup(rq, p, wake_flags);
-}
-
-/*
- * Called in case the task @p isn't fully descheduled from its runqueue,
- * in this case we must do a remote wakeup. Its a 'light' wakeup though,
- * since all we need to do is flip p->state to TASK_RUNNING, since
- * the task is still ->on_rq.
- */
-static int ttwu_remote(struct task_struct *p, int wake_flags)
-{
- struct rq *rq;
- int ret = 0;
-
- rq = __task_rq_lock(p);
- if (p->on_rq) {
- ttwu_do_wakeup(rq, p, wake_flags);
- ret = 1;
- }
- __task_rq_unlock(rq);
-
- return ret;
-}
-
-#ifdef CONFIG_SMP
-static void sched_ttwu_pending(void)
-{
- struct rq *rq = this_rq();
- struct llist_node *llist = llist_del_all(&rq->wake_list);
- struct task_struct *p;
-
- raw_spin_lock(&rq->lock);
-
- while (llist) {
- p = llist_entry(llist, struct task_struct, wake_entry);
- llist = llist_next(llist);
- ttwu_do_activate(rq, p, 0);
- }
-
- raw_spin_unlock(&rq->lock);
-}
-
-void scheduler_ipi(void)
-{
- if (llist_empty(&this_rq()->wake_list) && !got_nohz_idle_kick())
- return;
-
- /*
- * Not all reschedule IPI handlers call irq_enter/irq_exit, since
- * traditionally all their work was done from the interrupt return
- * path. Now that we actually do some work, we need to make sure
- * we do call them.
- *
- * Some archs already do call them, luckily irq_enter/exit nest
- * properly.
- *
- * Arguably we should visit all archs and update all handlers,
- * however a fair share of IPIs are still resched only so this would
- * somewhat pessimize the simple resched case.
- */
- irq_enter();
- sched_ttwu_pending();
-
- /*
- * Check if someone kicked us for doing the nohz idle load balance.
- */
- if (unlikely(got_nohz_idle_kick() && !need_resched())) {
- this_rq()->idle_balance = 1;
- raise_softirq_irqoff(SCHED_SOFTIRQ);
- }
- irq_exit();
-}
-
-static void ttwu_queue_remote(struct task_struct *p, int cpu)
-{
- if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list))
- smp_send_reschedule(cpu);
-}
-
-#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
-static int ttwu_activate_remote(struct task_struct *p, int wake_flags)
-{
- struct rq *rq;
- int ret = 0;
-
- rq = __task_rq_lock(p);
- if (p->on_cpu) {
- ttwu_activate(rq, p, ENQUEUE_WAKEUP);
- ttwu_do_wakeup(rq, p, wake_flags);
- ret = 1;
- }
- __task_rq_unlock(rq);
-
- return ret;
-
-}
-#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
-#endif /* CONFIG_SMP */
-
-static void ttwu_queue(struct task_struct *p, int cpu)
-{
- struct rq *rq = cpu_rq(cpu);
-
-#if defined(CONFIG_SMP)
- if (sched_feat(TTWU_QUEUE) && cpu != smp_processor_id()) {
- sched_clock_cpu(cpu); /* sync clocks x-cpu */
- ttwu_queue_remote(p, cpu);
- return;
- }
-#endif
-
- raw_spin_lock(&rq->lock);
- ttwu_do_activate(rq, p, 0);
- raw_spin_unlock(&rq->lock);
-}
-
-/**
- * try_to_wake_up - wake up a thread
- * @p: the thread to be awakened
- * @state: the mask of task states that can be woken
- * @wake_flags: wake modifier flags (WF_*)
- *
- * Put it on the run-queue if it's not already there. The "current"
- * thread is always on the run-queue (except when the actual
- * re-schedule is in progress), and as such you're allowed to do
- * the simpler "current->state = TASK_RUNNING" to mark yourself
- * runnable without the overhead of this.
- *
- * Returns %true if @p was woken up, %false if it was already running
- * or @state didn't match @p's state.
- */
-static int
-try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
-{
- unsigned long flags;
- int cpu, success = 0;
-
- smp_wmb();
- raw_spin_lock_irqsave(&p->pi_lock, flags);
- if (!(p->state & state))
- goto out;
-
- success = 1; /* we're going to change ->state */
- cpu = task_cpu(p);
-
- if (p->on_rq && ttwu_remote(p, wake_flags))
- goto stat;
-
-#ifdef CONFIG_SMP
- /*
- * If the owning (remote) cpu is still in the middle of schedule() with
- * this task as prev, wait until its done referencing the task.
- */
- while (p->on_cpu) {
-#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
- /*
- * In case the architecture enables interrupts in
- * context_switch(), we cannot busy wait, since that
- * would lead to deadlocks when an interrupt hits and
- * tries to wake up @prev. So bail and do a complete
- * remote wakeup.
- */
- if (ttwu_activate_remote(p, wake_flags))
- goto stat;
-#else
- cpu_relax();
-#endif
- }
- /*
- * Pairs with the smp_wmb() in finish_lock_switch().
- */
- smp_rmb();
-
- p->sched_contributes_to_load = !!task_contributes_to_load(p);
- p->state = TASK_WAKING;
-
- if (p->sched_class->task_waking)
- p->sched_class->task_waking(p);
-
- cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
- if (task_cpu(p) != cpu) {
- wake_flags |= WF_MIGRATED;
- set_task_cpu(p, cpu);
- }
-#endif /* CONFIG_SMP */
-
- ttwu_queue(p, cpu);
-stat:
- ttwu_stat(p, cpu, wake_flags);
-out:
- raw_spin_unlock_irqrestore(&p->pi_lock, flags);
-
- return success;
-}
-
-/**
- * try_to_wake_up_local - try to wake up a local task with rq lock held
- * @p: the thread to be awakened
- *
- * Put @p on the run-queue if it's not already there. The caller must
- * ensure that this_rq() is locked, @p is bound to this_rq() and not
- * the current task.
- */
-static void try_to_wake_up_local(struct task_struct *p)
-{
- struct rq *rq = task_rq(p);
-
- BUG_ON(rq != this_rq());
- BUG_ON(p == current);
- lockdep_assert_held(&rq->lock);
-
- if (!raw_spin_trylock(&p->pi_lock)) {
- raw_spin_unlock(&rq->lock);
- raw_spin_lock(&p->pi_lock);
- raw_spin_lock(&rq->lock);
- }
-
- if (!(p->state & TASK_NORMAL))
- goto out;
-
- if (!p->on_rq)
- ttwu_activate(rq, p, ENQUEUE_WAKEUP);
-
- ttwu_do_wakeup(rq, p, 0);
- ttwu_stat(p, smp_processor_id(), 0);
-out:
- raw_spin_unlock(&p->pi_lock);
-}
-
-/**
- * wake_up_process - Wake up a specific process
- * @p: The process to be woken up.
- *
- * Attempt to wake up the nominated process and move it to the set of runnable
- * processes. Returns 1 if the process was woken up, 0 if it was already
- * running.
- *
- * It may be assumed that this function implies a write memory barrier before
- * changing the task state if and only if any tasks are woken up.
- */
-int wake_up_process(struct task_struct *p)
-{
- return try_to_wake_up(p, TASK_ALL, 0);
-}
-EXPORT_SYMBOL(wake_up_process);
-
-int wake_up_state(struct task_struct *p, unsigned int state)
-{
- return try_to_wake_up(p, state, 0);
-}
-
-/*
- * Perform scheduler related setup for a newly forked process p.
- * p is forked by current.
- *
- * __sched_fork() is basic setup used by init_idle() too:
- */
-static void __sched_fork(struct task_struct *p)
-{
- p->on_rq = 0;
-
- p->se.on_rq = 0;
- p->se.exec_start = 0;
- p->se.sum_exec_runtime = 0;
- p->se.prev_sum_exec_runtime = 0;
- p->se.nr_migrations = 0;
- p->se.vruntime = 0;
- INIT_LIST_HEAD(&p->se.group_node);
-
-#ifdef CONFIG_SCHEDSTATS
- memset(&p->se.statistics, 0, sizeof(p->se.statistics));
-#endif
-
- INIT_LIST_HEAD(&p->rt.run_list);
-
-#ifdef CONFIG_PREEMPT_NOTIFIERS
- INIT_HLIST_HEAD(&p->preempt_notifiers);
-#endif
-}
-
-/*
- * fork()/clone()-time setup:
- */
-void sched_fork(struct task_struct *p)
-{
- unsigned long flags;
- int cpu = get_cpu();
-
- __sched_fork(p);
- /*
- * We mark the process as running here. This guarantees that
- * nobody will actually run it, and a signal or other external
- * event cannot wake it up and insert it on the runqueue either.
- */
- p->state = TASK_RUNNING;
-
- /*
- * Make sure we do not leak PI boosting priority to the child.
- */
- p->prio = current->normal_prio;
-
- /*
- * Revert to default priority/policy on fork if requested.
- */
- if (unlikely(p->sched_reset_on_fork)) {
- if (task_has_rt_policy(p)) {
- p->policy = SCHED_NORMAL;
- p->static_prio = NICE_TO_PRIO(0);
- p->rt_priority = 0;
- } else if (PRIO_TO_NICE(p->static_prio) < 0)
- p->static_prio = NICE_TO_PRIO(0);
-
- p->prio = p->normal_prio = __normal_prio(p);
- set_load_weight(p);
-
- /*
- * We don't need the reset flag anymore after the fork. It has
- * fulfilled its duty:
- */
- p->sched_reset_on_fork = 0;
- }
-
- if (!rt_prio(p->prio))
- p->sched_class = &fair_sched_class;
-
- if (p->sched_class->task_fork)
- p->sched_class->task_fork(p);
-
- /*
- * The child is not yet in the pid-hash so no cgroup attach races,
- * and the cgroup is pinned to this child due to cgroup_fork()
- * is ran before sched_fork().
- *
- * Silence PROVE_RCU.
- */
- raw_spin_lock_irqsave(&p->pi_lock, flags);
- set_task_cpu(p, cpu);
- raw_spin_unlock_irqrestore(&p->pi_lock, flags);
-
-#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
- if (likely(sched_info_on()))
- memset(&p->sched_info, 0, sizeof(p->sched_info));
-#endif
-#if defined(CONFIG_SMP)
- p->on_cpu = 0;
-#endif
-#ifdef CONFIG_PREEMPT_COUNT
- /* Want to start with kernel preemption disabled. */
- task_thread_info(p)->preempt_count = 1;
-#endif
-#ifdef CONFIG_SMP
- plist_node_init(&p->pushable_tasks, MAX_PRIO);
-#endif
-
- put_cpu();
-}
-
-/*
- * wake_up_new_task - wake up a newly created task for the first time.
- *
- * This function will do some initial scheduler statistics housekeeping
- * that must be done for every newly created context, then puts the task
- * on the runqueue and wakes it.
- */
-void wake_up_new_task(struct task_struct *p)
-{
- unsigned long flags;
- struct rq *rq;
-
- raw_spin_lock_irqsave(&p->pi_lock, flags);
-#ifdef CONFIG_SMP
- /*
- * Fork balancing, do it here and not earlier because:
- * - cpus_allowed can change in the fork path
- * - any previously selected cpu might disappear through hotplug
- */
- set_task_cpu(p, select_task_rq(p, SD_BALANCE_FORK, 0));
-#endif
-
- rq = __task_rq_lock(p);
- activate_task(rq, p, 0);
- p->on_rq = 1;
- trace_sched_wakeup_new(p, true);
- check_preempt_curr(rq, p, WF_FORK);
-#ifdef CONFIG_SMP
- if (p->sched_class->task_woken)
- p->sched_class->task_woken(rq, p);
-#endif
- task_rq_unlock(rq, p, &flags);
-}
-
-#ifdef CONFIG_PREEMPT_NOTIFIERS
-
-/**
- * preempt_notifier_register - tell me when current is being preempted & rescheduled
- * @notifier: notifier struct to register
- */
-void preempt_notifier_register(struct preempt_notifier *notifier)
-{
- hlist_add_head(¬ifier->link, ¤t->preempt_notifiers);
-}
-EXPORT_SYMBOL_GPL(preempt_notifier_register);
-
-/**
- * preempt_notifier_unregister - no longer interested in preemption notifications
- * @notifier: notifier struct to unregister
- *
- * This is safe to call from within a preemption notifier.
- */
-void preempt_notifier_unregister(struct preempt_notifier *notifier)
-{
- hlist_del(¬ifier->link);
-}
-EXPORT_SYMBOL_GPL(preempt_notifier_unregister);
-
-static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
-{
- struct preempt_notifier *notifier;
- struct hlist_node *node;
-
- hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link)
- notifier->ops->sched_in(notifier, raw_smp_processor_id());
-}
-
-static void
-fire_sched_out_preempt_notifiers(struct task_struct *curr,
- struct task_struct *next)
-{
- struct preempt_notifier *notifier;
- struct hlist_node *node;
-
- hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link)
- notifier->ops->sched_out(notifier, next);
-}
-
-#else /* !CONFIG_PREEMPT_NOTIFIERS */
-
-static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
-{
-}
-
-static void
-fire_sched_out_preempt_notifiers(struct task_struct *curr,
- struct task_struct *next)
-{
-}
-
-#endif /* CONFIG_PREEMPT_NOTIFIERS */
-
-/**
- * prepare_task_switch - prepare to switch tasks
- * @rq: the runqueue preparing to switch
- * @prev: the current task that is being switched out
- * @next: the task we are going to switch to.
- *
- * This is called with the rq lock held and interrupts off. It must
- * be paired with a subsequent finish_task_switch after the context
- * switch.
- *
- * prepare_task_switch sets up locking and calls architecture specific
- * hooks.
- */
-static inline void
-prepare_task_switch(struct rq *rq, struct task_struct *prev,
- struct task_struct *next)
-{
- sched_info_switch(prev, next);
- perf_event_task_sched_out(prev, next);
- fire_sched_out_preempt_notifiers(prev, next);
- prepare_lock_switch(rq, next);
- prepare_arch_switch(next);
- trace_sched_switch(prev, next);
-}
-
-/**
- * finish_task_switch - clean up after a task-switch
- * @rq: runqueue associated with task-switch
- * @prev: the thread we just switched away from.
- *
- * finish_task_switch must be called after the context switch, paired
- * with a prepare_task_switch call before the context switch.
- * finish_task_switch will reconcile locking set up by prepare_task_switch,
- * and do any other architecture-specific cleanup actions.
- *
- * Note that we may have delayed dropping an mm in context_switch(). If
- * so, we finish that here outside of the runqueue lock. (Doing it
- * with the lock held can cause deadlocks; see schedule() for
- * details.)
- */
-static void finish_task_switch(struct rq *rq, struct task_struct *prev)
- __releases(rq->lock)
-{
- struct mm_struct *mm = rq->prev_mm;
- long prev_state;
-
- rq->prev_mm = NULL;
-
- /*
- * A task struct has one reference for the use as "current".
- * If a task dies, then it sets TASK_DEAD in tsk->state and calls
- * schedule one last time. The schedule call will never return, and
- * the scheduled task must drop that reference.
- * The test for TASK_DEAD must occur while the runqueue locks are
- * still held, otherwise prev could be scheduled on another cpu, die
- * there before we look at prev->state, and then the reference would
- * be dropped twice.
- * Manfred Spraul <manfred@colorfullife.com>
- */
- prev_state = prev->state;
- finish_arch_switch(prev);
-#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
- local_irq_disable();
-#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
- perf_event_task_sched_in(prev, current);
-#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
- local_irq_enable();
-#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
- finish_lock_switch(rq, prev);
-
- fire_sched_in_preempt_notifiers(current);
- if (mm)
- mmdrop(mm);
- if (unlikely(prev_state == TASK_DEAD)) {
- /*
- * Remove function-return probe instances associated with this
- * task and put them back on the free list.
- */
- kprobe_flush_task(prev);
- put_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)
-{
- if (rq->post_schedule) {
- unsigned long flags;
-
- raw_spin_lock_irqsave(&rq->lock, flags);
- if (rq->curr->sched_class->post_schedule)
- rq->curr->sched_class->post_schedule(rq);
- raw_spin_unlock_irqrestore(&rq->lock, flags);
-
- rq->post_schedule = 0;
- }
-}
-
-#else
-
-static inline void pre_schedule(struct rq *rq, struct task_struct *p)
-{
-}
-
-static inline void post_schedule(struct rq *rq)
-{
-}
-
-#endif
-
-/**
- * schedule_tail - first thing a freshly forked thread must call.
- * @prev: the thread we just switched away from.
- */
-asmlinkage void schedule_tail(struct task_struct *prev)
- __releases(rq->lock)
-{
- struct rq *rq = this_rq();
-
- finish_task_switch(rq, prev);
-
- /*
- * FIXME: do we need to worry about rq being invalidated by the
- * task_switch?
- */
- post_schedule(rq);
-
-#ifdef __ARCH_WANT_UNLOCKED_CTXSW
- /* In this case, finish_task_switch does not reenable preemption */
- preempt_enable();
-#endif
- if (current->set_child_tid)
- put_user(task_pid_vnr(current), current->set_child_tid);
-}
-
-/*
- * context_switch - switch to the new MM and the new
- * thread's register state.
- */
-static inline void
-context_switch(struct rq *rq, struct task_struct *prev,
- struct task_struct *next)
-{
- struct mm_struct *mm, *oldmm;
-
- prepare_task_switch(rq, prev, 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
- * one hypercall.
- */
- arch_start_context_switch(prev);
-
- if (!mm) {
- next->active_mm = oldmm;
- atomic_inc(&oldmm->mm_count);
- enter_lazy_tlb(oldmm, next);
- } else
- switch_mm(oldmm, mm, next);
-
- if (!prev->mm) {
- prev->active_mm = NULL;
- rq->prev_mm = oldmm;
- }
- /*
- * Since the runqueue lock will be released by the next
- * task (which is an invalid locking op but in the case
- * of the scheduler it's an obvious special-case), so we
- * do an early lockdep release here:
- */
-#ifndef __ARCH_WANT_UNLOCKED_CTXSW
- spin_release(&rq->lock.dep_map, 1, _THIS_IP_);
-#endif
-
- /* Here we just switch the register state and the stack. */
- switch_to(prev, next, 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);
-}
-
-/*
- * nr_running, nr_uninterruptible and nr_context_switches:
- *
- * externally visible scheduler statistics: current number of runnable
- * threads, current number of uninterruptible-sleeping threads, total
- * number of context switches performed since bootup.
- */
-unsigned long nr_running(void)
-{
- unsigned long i, sum = 0;
-
- for_each_online_cpu(i)
- sum += cpu_rq(i)->nr_running;
-
- return sum;
-}
-
-unsigned long nr_uninterruptible(void)
-{
- unsigned long i, sum = 0;
-
- for_each_possible_cpu(i)
- sum += cpu_rq(i)->nr_uninterruptible;
-
- /*
- * Since we read the counters lockless, it might be slightly
- * inaccurate. Do not allow it to go below zero though:
- */
- if (unlikely((long)sum < 0))
- sum = 0;
-
- return sum;
-}
-
-unsigned long long nr_context_switches(void)
-{
- int i;
- unsigned long long sum = 0;
-
- for_each_possible_cpu(i)
- sum += cpu_rq(i)->nr_switches;
-
- return sum;
-}
-
-unsigned long nr_iowait(void)
-{
- unsigned long i, sum = 0;
-
- for_each_possible_cpu(i)
- sum += atomic_read(&cpu_rq(i)->nr_iowait);
-
- return sum;
-}
-
-unsigned long nr_iowait_cpu(int cpu)
-{
- struct rq *this = cpu_rq(cpu);
- return atomic_read(&this->nr_iowait);
-}
-
-unsigned long this_cpu_load(void)
-{
- struct rq *this = this_rq();
- return this->cpu_load[0];
-}
-
-
-/* Variables and functions for calc_load */
-static atomic_long_t calc_load_tasks;
-static unsigned long calc_load_update;
-unsigned long avenrun[3];
-EXPORT_SYMBOL(avenrun);
-
-static long calc_load_fold_active(struct rq *this_rq)
-{
- long nr_active, delta = 0;
-
- nr_active = this_rq->nr_running;
- nr_active += (long) this_rq->nr_uninterruptible;
-
- if (nr_active != this_rq->calc_load_active) {
- delta = nr_active - this_rq->calc_load_active;
- this_rq->calc_load_active = nr_active;
- }
-
- return delta;
-}
-
-static unsigned long
-calc_load(unsigned long load, unsigned long exp, unsigned long active)
-{
- load *= exp;
- load += active * (FIXED_1 - exp);
- load += 1UL << (FSHIFT - 1);
- return load >> FSHIFT;
-}
-
-#ifdef CONFIG_NO_HZ
-/*
- * For NO_HZ we delay the active fold to the next LOAD_FREQ update.
- *
- * When making the ILB scale, we should try to pull this in as well.
- */
-static atomic_long_t calc_load_tasks_idle;
-
-void calc_load_account_idle(struct rq *this_rq)
-{
- long delta;
-
- delta = calc_load_fold_active(this_rq);
- if (delta)
- atomic_long_add(delta, &calc_load_tasks_idle);
-}
-
-static long calc_load_fold_idle(void)
-{
- long delta = 0;
-
- /*
- * Its got a race, we don't care...
- */
- if (atomic_long_read(&calc_load_tasks_idle))
- delta = atomic_long_xchg(&calc_load_tasks_idle, 0);
-
- return delta;
-}
-
-/**
- * fixed_power_int - compute: x^n, in O(log n) time
- *
- * @x: base of the power
- * @frac_bits: fractional bits of @x
- * @n: power to raise @x to.
- *
- * By exploiting the relation between the definition of the natural power
- * function: x^n := x*x*...*x (x multiplied by itself for n times), and
- * the binary encoding of numbers used by computers: n := \Sum n_i * 2^i,
- * (where: n_i \elem {0, 1}, the binary vector representing n),
- * we find: x^n := x^(\Sum n_i * 2^i) := \Prod x^(n_i * 2^i), which is
- * of course trivially computable in O(log_2 n), the length of our binary
- * vector.
- */
-static unsigned long
-fixed_power_int(unsigned long x, unsigned int frac_bits, unsigned int n)
-{
- unsigned long result = 1UL << frac_bits;
-
- if (n) for (;;) {
- if (n & 1) {
- result *= x;
- result += 1UL << (frac_bits - 1);
- result >>= frac_bits;
- }
- n >>= 1;
- if (!n)
- break;
- x *= x;
- x += 1UL << (frac_bits - 1);
- x >>= frac_bits;
- }
-
- return result;
-}
-
-/*
- * a1 = a0 * e + a * (1 - e)
- *
- * a2 = a1 * e + a * (1 - e)
- * = (a0 * e + a * (1 - e)) * e + a * (1 - e)
- * = a0 * e^2 + a * (1 - e) * (1 + e)
- *
- * a3 = a2 * e + a * (1 - e)
- * = (a0 * e^2 + a * (1 - e) * (1 + e)) * e + a * (1 - e)
- * = a0 * e^3 + a * (1 - e) * (1 + e + e^2)
- *
- * ...
- *
- * an = a0 * e^n + a * (1 - e) * (1 + e + ... + e^n-1) [1]
- * = a0 * e^n + a * (1 - e) * (1 - e^n)/(1 - e)
- * = a0 * e^n + a * (1 - e^n)
- *
- * [1] application of the geometric series:
- *
- * n 1 - x^(n+1)
- * S_n := \Sum x^i = -------------
- * i=0 1 - x
- */
-static unsigned long
-calc_load_n(unsigned long load, unsigned long exp,
- unsigned long active, unsigned int n)
-{
-
- return calc_load(load, fixed_power_int(exp, FSHIFT, n), active);
-}
-
-/*
- * NO_HZ can leave us missing all per-cpu ticks calling
- * calc_load_account_active(), but since an idle CPU folds its delta into
- * calc_load_tasks_idle per calc_load_account_idle(), all we need to do is fold
- * in the pending idle delta if our idle period crossed a load cycle boundary.
- *
- * Once we've updated the global active value, we need to apply the exponential
- * weights adjusted to the number of cycles missed.
- */
-static void calc_global_nohz(unsigned long ticks)
-{
- long delta, active, n;
-
- if (time_before(jiffies, calc_load_update))
- return;
-
- /*
- * If we crossed a calc_load_update boundary, make sure to fold
- * any pending idle changes, the respective CPUs might have
- * missed the tick driven calc_load_account_active() update
- * due to NO_HZ.
- */
- delta = calc_load_fold_idle();
- if (delta)
- atomic_long_add(delta, &calc_load_tasks);
-
- /*
- * If we were idle for multiple load cycles, apply them.
- */
- if (ticks >= LOAD_FREQ) {
- n = ticks / LOAD_FREQ;
-
- active = atomic_long_read(&calc_load_tasks);
- active = active > 0 ? active * FIXED_1 : 0;
-
- avenrun[0] = calc_load_n(avenrun[0], EXP_1, active, n);
- avenrun[1] = calc_load_n(avenrun[1], EXP_5, active, n);
- avenrun[2] = calc_load_n(avenrun[2], EXP_15, active, n);
-
- calc_load_update += n * LOAD_FREQ;
- }
-
- /*
- * Its possible the remainder of the above division also crosses
- * a LOAD_FREQ period, the regular check in calc_global_load()
- * which comes after this will take care of that.
- *
- * Consider us being 11 ticks before a cycle completion, and us
- * sleeping for 4*LOAD_FREQ + 22 ticks, then the above code will
- * age us 4 cycles, and the test in calc_global_load() will
- * pick up the final one.
- */
-}
-#else
-void calc_load_account_idle(struct rq *this_rq)
-{
-}
-
-static inline long calc_load_fold_idle(void)
-{
- return 0;
-}
-
-static void calc_global_nohz(unsigned long ticks)
-{
-}
-#endif
-
-/**
- * get_avenrun - get the load average array
- * @loads: pointer to dest load array
- * @offset: offset to add
- * @shift: shift count to shift the result left
- *
- * These values are estimates at best, so no need for locking.
- */
-void get_avenrun(unsigned long *loads, unsigned long offset, int shift)
-{
- loads[0] = (avenrun[0] + offset) << shift;
- loads[1] = (avenrun[1] + offset) << shift;
- loads[2] = (avenrun[2] + offset) << shift;
-}
-
-/*
- * calc_load - update the avenrun load estimates 10 ticks after the
- * CPUs have updated calc_load_tasks.
- */
-void calc_global_load(unsigned long ticks)
-{
- long active;
-
- calc_global_nohz(ticks);
-
- if (time_before(jiffies, calc_load_update + 10))
- return;
-
- active = atomic_long_read(&calc_load_tasks);
- active = active > 0 ? active * FIXED_1 : 0;
-
- avenrun[0] = calc_load(avenrun[0], EXP_1, active);
- avenrun[1] = calc_load(avenrun[1], EXP_5, active);
- avenrun[2] = calc_load(avenrun[2], EXP_15, active);
-
- calc_load_update += LOAD_FREQ;
-}
-
-/*
- * Called from update_cpu_load() to periodically update this CPU's
- * active count.
- */
-static void calc_load_account_active(struct rq *this_rq)
-{
- long delta;
-
- if (time_before(jiffies, this_rq->calc_load_update))
- return;
-
- delta = calc_load_fold_active(this_rq);
- delta += calc_load_fold_idle();
- if (delta)
- atomic_long_add(delta, &calc_load_tasks);
-
- this_rq->calc_load_update += LOAD_FREQ;
-}
-
-/*
- * The exact cpuload at various idx values, calculated at every tick would be
- * load = (2^idx - 1) / 2^idx * load + 1 / 2^idx * cur_load
- *
- * If a cpu misses updates for n-1 ticks (as it was idle) and update gets called
- * on nth tick when cpu may be busy, then we have:
- * load = ((2^idx - 1) / 2^idx)^(n-1) * load
- * load = (2^idx - 1) / 2^idx) * load + 1 / 2^idx * cur_load
- *
- * decay_load_missed() below does efficient calculation of
- * load = ((2^idx - 1) / 2^idx)^(n-1) * load
- * avoiding 0..n-1 loop doing load = ((2^idx - 1) / 2^idx) * load
- *
- * The calculation is approximated on a 128 point scale.
- * degrade_zero_ticks is the number of ticks after which load at any
- * particular idx is approximated to be zero.
- * degrade_factor is a precomputed table, a row for each load idx.
- * Each column corresponds to degradation factor for a power of two ticks,
- * based on 128 point scale.
- * Example:
- * row 2, col 3 (=12) says that the degradation at load idx 2 after
- * 8 ticks is 12/128 (which is an approximation of exact factor 3^8/4^8).
- *
- * With this power of 2 load factors, we can degrade the load n times
- * by looking at 1 bits in n and doing as many mult/shift instead of
- * n mult/shifts needed by the exact degradation.
- */
-#define DEGRADE_SHIFT 7
-static const unsigned char
- degrade_zero_ticks[CPU_LOAD_IDX_MAX] = {0, 8, 32, 64, 128};
-static const unsigned char
- degrade_factor[CPU_LOAD_IDX_MAX][DEGRADE_SHIFT + 1] = {
- {0, 0, 0, 0, 0, 0, 0, 0},
- {64, 32, 8, 0, 0, 0, 0, 0},
- {96, 72, 40, 12, 1, 0, 0},
- {112, 98, 75, 43, 15, 1, 0},
- {120, 112, 98, 76, 45, 16, 2} };
-
-/*
- * Update cpu_load for any missed ticks, due to tickless idle. The backlog
- * would be when CPU is idle and so we just decay the old load without
- * adding any new load.
- */
-static unsigned long
-decay_load_missed(unsigned long load, unsigned long missed_updates, int idx)
-{
- int j = 0;
-
- if (!missed_updates)
- return load;
-
- if (missed_updates >= degrade_zero_ticks[idx])
- return 0;
-
- if (idx == 1)
- return load >> missed_updates;
-
- while (missed_updates) {
- if (missed_updates % 2)
- load = (load * degrade_factor[idx][j]) >> DEGRADE_SHIFT;
-
- missed_updates >>= 1;
- j++;
- }
- return load;
-}
-
-/*
- * Update rq->cpu_load[] statistics. This function is usually called every
- * scheduler tick (TICK_NSEC). With tickless idle this will not be called
- * every tick. We fix it up based on jiffies.
- */
-void update_cpu_load(struct rq *this_rq)
-{
- unsigned long this_load = this_rq->load.weight;
- unsigned long curr_jiffies = jiffies;
- unsigned long pending_updates;
- int i, scale;
-
- this_rq->nr_load_updates++;
-
- /* Avoid repeated calls on same jiffy, when moving in and out of idle */
- if (curr_jiffies == this_rq->last_load_update_tick)
- return;
-
- pending_updates = curr_jiffies - this_rq->last_load_update_tick;
- this_rq->last_load_update_tick = curr_jiffies;
-
- /* Update our load: */
- this_rq->cpu_load[0] = this_load; /* Fasttrack for idx 0 */
- for (i = 1, scale = 2; 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];
- old_load = decay_load_missed(old_load, pending_updates - 1, 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;
- }
-
- sched_avg_update(this_rq);
-}
-
-static void update_cpu_load_active(struct rq *this_rq)
-{
- update_cpu_load(this_rq);
-
- calc_load_account_active(this_rq);
-}
-
-#ifdef CONFIG_SMP
-
-/*
- * sched_exec - execve() is a valuable balancing opportunity, because at
- * this point the task has the smallest effective memory and cache footprint.
- */
-void sched_exec(void)
-{
- struct task_struct *p = current;
- unsigned long flags;
- int dest_cpu;
-
- raw_spin_lock_irqsave(&p->pi_lock, flags);
- dest_cpu = p->sched_class->select_task_rq(p, SD_BALANCE_EXEC, 0);
- if (dest_cpu == smp_processor_id())
- goto unlock;
-
- if (likely(cpu_active(dest_cpu))) {
- struct migration_arg arg = { p, dest_cpu };
-
- raw_spin_unlock_irqrestore(&p->pi_lock, flags);
- stop_one_cpu(task_cpu(p), migration_cpu_stop, &arg);
- return;
- }
-unlock:
- raw_spin_unlock_irqrestore(&p->pi_lock, flags);
-}
-
-#endif
-
-DEFINE_PER_CPU(struct kernel_stat, kstat);
-
-EXPORT_PER_CPU_SYMBOL(kstat);
-
-/*
- * Return any ns on the sched_clock that have not yet been accounted in
- * @p in case that task is currently running.
- *
- * Called with task_rq_lock() held on @rq.
- */
-static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq)
-{
- u64 ns = 0;
-
- if (task_current(rq, p)) {
- update_rq_clock(rq);
- ns = rq->clock_task - p->se.exec_start;
- if ((s64)ns < 0)
- ns = 0;
- }
-
- return ns;
-}
-
-unsigned long long task_delta_exec(struct task_struct *p)
-{
- unsigned long flags;
- struct rq *rq;
- u64 ns = 0;
-
- rq = task_rq_lock(p, &flags);
- ns = do_task_delta_exec(p, rq);
- task_rq_unlock(rq, p, &flags);
-
- return ns;
-}
-
-/*
- * Return accounted runtime for the task.
- * In case the task is currently running, return the runtime plus current's
- * pending runtime that have not been accounted yet.
- */
-unsigned long long task_sched_runtime(struct task_struct *p)
-{
- unsigned long flags;
- struct rq *rq;
- u64 ns = 0;
-
- rq = task_rq_lock(p, &flags);
- ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq);
- task_rq_unlock(rq, p, &flags);
-
- return ns;
-}
-
-/*
- * Account user cpu time to a process.
- * @p: the process that the cpu time gets accounted to
- * @cputime: the cpu time spent in user space since the last update
- * @cputime_scaled: cputime scaled by cpu frequency
- */
-void account_user_time(struct task_struct *p, cputime_t cputime,
- cputime_t cputime_scaled)
-{
- struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
- cputime64_t tmp;
-
- /* Add user time to process. */
- p->utime = cputime_add(p->utime, cputime);
- p->utimescaled = cputime_add(p->utimescaled, cputime_scaled);
- account_group_user_time(p, cputime);
-
- /* Add user time to cpustat. */
- tmp = cputime_to_cputime64(cputime);
- if (TASK_NICE(p) > 0)
- cpustat->nice = cputime64_add(cpustat->nice, tmp);
- else
- cpustat->user = cputime64_add(cpustat->user, tmp);
-
- cpuacct_update_stats(p, CPUACCT_STAT_USER, cputime);
- /* Account for user time used */
- acct_update_integrals(p);
-}
-
-/*
- * Account guest cpu time to a process.
- * @p: the process that the cpu time gets accounted to
- * @cputime: the cpu time spent in virtual machine since the last update
- * @cputime_scaled: cputime scaled by cpu frequency
- */
-static void account_guest_time(struct task_struct *p, cputime_t cputime,
- cputime_t cputime_scaled)
-{
- cputime64_t tmp;
- struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
-
- tmp = cputime_to_cputime64(cputime);
-
- /* Add guest time to process. */
- p->utime = cputime_add(p->utime, cputime);
- p->utimescaled = cputime_add(p->utimescaled, cputime_scaled);
- account_group_user_time(p, cputime);
- p->gtime = cputime_add(p->gtime, cputime);
-
- /* Add guest time to cpustat. */
- if (TASK_NICE(p) > 0) {
- cpustat->nice = cputime64_add(cpustat->nice, tmp);
- cpustat->guest_nice = cputime64_add(cpustat->guest_nice, tmp);
- } else {
- cpustat->user = cputime64_add(cpustat->user, tmp);
- cpustat->guest = cputime64_add(cpustat->guest, tmp);
- }
-}
-
-/*
- * Account system cpu time to a process and desired cpustat field
- * @p: the process that the cpu time gets accounted to
- * @cputime: the cpu time spent in kernel space since the last update
- * @cputime_scaled: cputime scaled by cpu frequency
- * @target_cputime64: pointer to cpustat field that has to be updated
- */
-static inline
-void __account_system_time(struct task_struct *p, cputime_t cputime,
- cputime_t cputime_scaled, cputime64_t *target_cputime64)
-{
- cputime64_t tmp = cputime_to_cputime64(cputime);
-
- /* Add system time to process. */
- p->stime = cputime_add(p->stime, cputime);
- p->stimescaled = cputime_add(p->stimescaled, cputime_scaled);
- account_group_system_time(p, cputime);
-
- /* Add system time to cpustat. */
- *target_cputime64 = cputime64_add(*target_cputime64, tmp);
- cpuacct_update_stats(p, CPUACCT_STAT_SYSTEM, cputime);
-
- /* Account for system time used */
- acct_update_integrals(p);
-}
-
-/*
- * Account system cpu time to a process.
- * @p: the process that the cpu time gets accounted to
- * @hardirq_offset: the offset to subtract from hardirq_count()
- * @cputime: the cpu time spent in kernel space since the last update
- * @cputime_scaled: cputime scaled by cpu frequency
- */
-void account_system_time(struct task_struct *p, int hardirq_offset,
- cputime_t cputime, cputime_t cputime_scaled)
-{
- struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
- cputime64_t *target_cputime64;
-
- if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) {
- account_guest_time(p, cputime, cputime_scaled);
- return;
- }
-
- if (hardirq_count() - hardirq_offset)
- target_cputime64 = &cpustat->irq;
- else if (in_serving_softirq())
- target_cputime64 = &cpustat->softirq;
- else
- target_cputime64 = &cpustat->system;
-
- __account_system_time(p, cputime, cputime_scaled, target_cputime64);
-}
-
-/*
- * Account for involuntary wait time.
- * @cputime: the cpu time spent in involuntary wait
- */
-void account_steal_time(cputime_t cputime)
-{
- struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
- cputime64_t cputime64 = cputime_to_cputime64(cputime);
-
- cpustat->steal = cputime64_add(cpustat->steal, cputime64);
-}
-
-/*
- * Account for idle time.
- * @cputime: the cpu time spent in idle wait
- */
-void account_idle_time(cputime_t cputime)
-{
- struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
- cputime64_t cputime64 = cputime_to_cputime64(cputime);
- struct rq *rq = this_rq();
-
- if (atomic_read(&rq->nr_iowait) > 0)
- cpustat->iowait = cputime64_add(cpustat->iowait, cputime64);
- else
- cpustat->idle = cputime64_add(cpustat->idle, cputime64);
-}
-
-static __always_inline bool steal_account_process_tick(void)
-{
-#ifdef CONFIG_PARAVIRT
- if (static_branch(¶virt_steal_enabled)) {
- u64 steal, st = 0;
-
- steal = paravirt_steal_clock(smp_processor_id());
- steal -= this_rq()->prev_steal_time;
-
- st = steal_ticks(steal);
- this_rq()->prev_steal_time += st * TICK_NSEC;
-
- account_steal_time(st);
- return st;
- }
-#endif
- return false;
-}
-
-#ifndef CONFIG_VIRT_CPU_ACCOUNTING
-
-#ifdef CONFIG_IRQ_TIME_ACCOUNTING
-/*
- * Account a tick to a process and cpustat
- * @p: the process that the cpu time gets accounted to
- * @user_tick: is the tick from userspace
- * @rq: the pointer to rq
- *
- * Tick demultiplexing follows the order
- * - pending hardirq update
- * - pending softirq update
- * - user_time
- * - idle_time
- * - system time
- * - check for guest_time
- * - else account as system_time
- *
- * Check for hardirq is done both for system and user time as there is
- * no timer going off while we are on hardirq and hence we may never get an
- * opportunity to update it solely in system time.
- * p->stime and friends are only updated on system time and not on irq
- * softirq as those do not count in task exec_runtime any more.
- */
-static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
- struct rq *rq)
-{
- cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
- cputime64_t tmp = cputime_to_cputime64(cputime_one_jiffy);
- struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
-
- if (steal_account_process_tick())
- return;
-
- if (irqtime_account_hi_update()) {
- cpustat->irq = cputime64_add(cpustat->irq, tmp);
- } else if (irqtime_account_si_update()) {
- cpustat->softirq = cputime64_add(cpustat->softirq, tmp);
- } else if (this_cpu_ksoftirqd() == p) {
- /*
- * ksoftirqd time do not get accounted in cpu_softirq_time.
- * So, we have to handle it separately here.
- * Also, p->stime needs to be updated for ksoftirqd.
- */
- __account_system_time(p, cputime_one_jiffy, one_jiffy_scaled,
- &cpustat->softirq);
- } else if (user_tick) {
- account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
- } else if (p == rq->idle) {
- account_idle_time(cputime_one_jiffy);
- } else if (p->flags & PF_VCPU) { /* System time or guest time */
- account_guest_time(p, cputime_one_jiffy, one_jiffy_scaled);
- } else {
- __account_system_time(p, cputime_one_jiffy, one_jiffy_scaled,
- &cpustat->system);
- }
-}
-
-static void irqtime_account_idle_ticks(int ticks)
-{
- int i;
- struct rq *rq = this_rq();
-
- for (i = 0; i < ticks; i++)
- irqtime_account_process_tick(current, 0, rq);
-}
-#else /* CONFIG_IRQ_TIME_ACCOUNTING */
-static void irqtime_account_idle_ticks(int ticks) {}
-static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
- struct rq *rq) {}
-#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
-
-/*
- * Account a single tick of cpu time.
- * @p: the process that the cpu time gets accounted to
- * @user_tick: indicates if the tick is a user or a system tick
- */
-void account_process_tick(struct task_struct *p, int user_tick)
-{
- cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
- struct rq *rq = this_rq();
-
- if (sched_clock_irqtime) {
- irqtime_account_process_tick(p, user_tick, rq);
- return;
- }
-
- if (steal_account_process_tick())
- return;
-
- if (user_tick)
- account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
- else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))
- account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy,
- one_jiffy_scaled);
- else
- account_idle_time(cputime_one_jiffy);
-}
-
-/*
- * Account multiple ticks of steal time.
- * @p: the process from which the cpu time has been stolen
- * @ticks: number of stolen ticks
- */
-void account_steal_ticks(unsigned long ticks)
-{
- account_steal_time(jiffies_to_cputime(ticks));
-}
-
-/*
- * Account multiple ticks of idle time.
- * @ticks: number of stolen ticks
- */
-void account_idle_ticks(unsigned long ticks)
-{
-
- if (sched_clock_irqtime) {
- irqtime_account_idle_ticks(ticks);
- return;
- }
-
- account_idle_time(jiffies_to_cputime(ticks));
-}
-
-#endif
-
-/*
- * Use precise platform statistics if available:
- */
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
-void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
-{
- *ut = p->utime;
- *st = p->stime;
-}
-
-void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
-{
- struct task_cputime cputime;
-
- thread_group_cputime(p, &cputime);
-
- *ut = cputime.utime;
- *st = cputime.stime;
-}
-#else
-
-#ifndef nsecs_to_cputime
-# define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs)
-#endif
-
-void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
-{
- cputime_t rtime, utime = p->utime, total = cputime_add(utime, p->stime);
-
- /*
- * Use CFS's precise accounting:
- */
- rtime = nsecs_to_cputime(p->se.sum_exec_runtime);
-
- if (total) {
- u64 temp = rtime;
-
- temp *= utime;
- do_div(temp, total);
- utime = (cputime_t)temp;
- } else
- utime = rtime;
-
- /*
- * Compare with previous values, to keep monotonicity:
- */
- p->prev_utime = max(p->prev_utime, utime);
- p->prev_stime = max(p->prev_stime, cputime_sub(rtime, p->prev_utime));
-
- *ut = p->prev_utime;
- *st = p->prev_stime;
-}
-
-/*
- * Must be called with siglock held.
- */
-void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
-{
- struct signal_struct *sig = p->signal;
- struct task_cputime cputime;
- cputime_t rtime, utime, total;
-
- thread_group_cputime(p, &cputime);
-
- total = cputime_add(cputime.utime, cputime.stime);
- rtime = nsecs_to_cputime(cputime.sum_exec_runtime);
-
- if (total) {
- u64 temp = rtime;
-
- temp *= cputime.utime;
- do_div(temp, total);
- utime = (cputime_t)temp;
- } else
- utime = rtime;
-
- sig->prev_utime = max(sig->prev_utime, utime);
- sig->prev_stime = max(sig->prev_stime,
- cputime_sub(rtime, sig->prev_utime));
-
- *ut = sig->prev_utime;
- *st = sig->prev_stime;
-}
-#endif
-
-/*
- * This function gets called by the timer code, with HZ frequency.
- * We call it with interrupts disabled.
- */
-void scheduler_tick(void)
-{
- int cpu = smp_processor_id();
- struct rq *rq = cpu_rq(cpu);
- struct task_struct *curr = rq->curr;
-
- sched_clock_tick();
-
- raw_spin_lock(&rq->lock);
- update_rq_clock(rq);
- update_cpu_load_active(rq);
- curr->sched_class->task_tick(rq, curr, 0);
- raw_spin_unlock(&rq->lock);
-
- perf_event_task_tick();
-
-#ifdef CONFIG_SMP
- rq->idle_balance = idle_cpu(cpu);
- trigger_load_balance(rq, cpu);
-#endif
-}
-
-notrace unsigned long get_parent_ip(unsigned long addr)
-{
- if (in_lock_functions(addr)) {
- addr = CALLER_ADDR2;
- if (in_lock_functions(addr))
- addr = CALLER_ADDR3;
- }
- return addr;
-}
-
-#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
- defined(CONFIG_PREEMPT_TRACER))
-
-void __kprobes add_preempt_count(int val)
-{
-#ifdef CONFIG_DEBUG_PREEMPT
- /*
- * Underflow?
- */
- if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0)))
- return;
-#endif
- preempt_count() += val;
-#ifdef CONFIG_DEBUG_PREEMPT
- /*
- * Spinlock count overflowing soon?
- */
- 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));
-}
-EXPORT_SYMBOL(add_preempt_count);
-
-void __kprobes sub_preempt_count(int val)
-{
-#ifdef CONFIG_DEBUG_PREEMPT
- /*
- * Underflow?
- */
- if (DEBUG_LOCKS_WARN_ON(val > preempt_count()))
- return;
- /*
- * Is the spinlock portion underflowing?
- */
- if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) &&
- !(preempt_count() & PREEMPT_MASK)))
- return;
-#endif
-
- if (preempt_count() == val)
- trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
- preempt_count() -= val;
-}
-EXPORT_SYMBOL(sub_preempt_count);
-
-#endif
-
-/*
- * Print scheduling while atomic bug:
- */
-static noinline void __schedule_bug(struct task_struct *prev)
-{
- struct pt_regs *regs = get_irq_regs();
-
- printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n",
- prev->comm, prev->pid, preempt_count());
-
- debug_show_held_locks(prev);
- print_modules();
- if (irqs_disabled())
- print_irqtrace_events(prev);
-
- if (regs)
- show_regs(regs);
- else
- 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_preempt_off() && !prev->exit_state))
- __schedule_bug(prev);
- rcu_sleep_check();
-
- profile_hit(SCHED_PROFILING, __builtin_return_address(0));
-
- 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)
-{
- const struct sched_class *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))
- return p;
- }
-
- for_each_class(class) {
- p = class->pick_next_task(rq);
- if (p)
- return p;
- }
-
- BUG(); /* the idle class will always have a runnable task */
-}
-
-/*
- * __schedule() is the main scheduler function.
- */
-static void __sched __schedule(void)
-{
- struct task_struct *prev, *next;
- unsigned long *switch_count;
- struct rq *rq;
- int cpu;
-
-need_resched:
- preempt_disable();
- cpu = smp_processor_id();
- rq = cpu_rq(cpu);
- rcu_note_context_switch(cpu);
- prev = rq->curr;
-
- schedule_debug(prev);
-
- if (sched_feat(HRTICK))
- hrtick_clear(rq);
-
- raw_spin_lock_irq(&rq->lock);
-
- switch_count = &prev->nivcsw;
- if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
- if (unlikely(signal_pending_state(prev->state, prev))) {
- prev->state = TASK_RUNNING;
- } else {
- deactivate_task(rq, prev, DEQUEUE_SLEEP);
- prev->on_rq = 0;
-
- /*
- * If a worker went to sleep, notify and ask workqueue
- * whether it wants to wake up a task to maintain
- * concurrency.
- */
- if (prev->flags & PF_WQ_WORKER) {
- struct task_struct *to_wakeup;
-
- to_wakeup = wq_worker_sleeping(prev, cpu);
- if (to_wakeup)
- try_to_wake_up_local(to_wakeup);
- }
- }
- switch_count = &prev->nvcsw;
- }
-
- pre_schedule(rq, prev);
-
- if (unlikely(!rq->nr_running))
- idle_balance(cpu, rq);
-
- put_prev_task(rq, prev);
- next = pick_next_task(rq);
- clear_tsk_need_resched(prev);
- rq->skip_clock_update = 0;
-
- if (likely(prev != next)) {
- rq->nr_switches++;
- rq->curr = next;
- ++*switch_count;
-
- context_switch(rq, prev, next); /* unlocks the rq */
- /*
- * The context switch have flipped the stack from under us
- * and restored the local variables which were saved when
- * this task called schedule() in the past. prev == current
- * is still correct, but it can be moved to another cpu/rq.
- */
- cpu = smp_processor_id();
- rq = cpu_rq(cpu);
- } else
- raw_spin_unlock_irq(&rq->lock);
-
- post_schedule(rq);
-
- preempt_enable_no_resched();
- if (need_resched())
- goto need_resched;
-}
-
-static inline void sched_submit_work(struct task_struct *tsk)
-{
- if (!tsk->state)
- return;
- /*
- * If we are going to sleep and we have plugged IO queued,
- * make sure to submit it to avoid deadlocks.
- */
- if (blk_needs_flush_plug(tsk))
- blk_schedule_flush_plug(tsk);
-}
-
-asmlinkage void __sched schedule(void)
-{
- struct task_struct *tsk = current;
-
- sched_submit_work(tsk);
- __schedule();
-}
-EXPORT_SYMBOL(schedule);
-
-#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
-
-static inline bool owner_running(struct mutex *lock, struct task_struct *owner)
-{
- if (lock->owner != owner)
- return false;
-
- /*
- * Ensure we emit the owner->on_cpu, dereference _after_ checking
- * lock->owner still matches owner, if that fails, owner might
- * point to free()d memory, if it still matches, the rcu_read_lock()
- * ensures the memory stays valid.
- */
- barrier();
-
- return owner->on_cpu;
-}
-
-/*
- * Look out! "owner" is an entirely speculative pointer
- * access and not reliable.
- */
-int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner)
-{
- if (!sched_feat(OWNER_SPIN))
- return 0;
-
- rcu_read_lock();
- while (owner_running(lock, owner)) {
- if (need_resched())
- break;
-
- arch_mutex_cpu_relax();
- }
- rcu_read_unlock();
-
- /*
- * We break out the loop above on need_resched() and when the
- * owner changed, which is a sign for heavy contention. Return
- * success only when lock->owner is NULL.
- */
- return lock->owner == NULL;
-}
-#endif
-
-#ifdef CONFIG_PREEMPT
-/*
- * this is the entry point to schedule() from in-kernel preemption
- * off of preempt_enable. Kernel preemptions off return from interrupt
- * occur there and call schedule directly.
- */
-asmlinkage void __sched notrace preempt_schedule(void)
-{
- struct thread_info *ti = current_thread_info();
-
- /*
- * If there is a non-zero preempt_count or interrupts are disabled,
- * we do not want to preempt the current task. Just return..
- */
- if (likely(ti->preempt_count || irqs_disabled()))
- return;
-
- do {
- add_preempt_count_notrace(PREEMPT_ACTIVE);
- __schedule();
- sub_preempt_count_notrace(PREEMPT_ACTIVE);
-
- /*
- * Check again in case we missed a preemption opportunity
- * between schedule and now.
- */
- barrier();
- } while (need_resched());
-}
-EXPORT_SYMBOL(preempt_schedule);
-
-/*
- * this is the entry point to schedule() from kernel preemption
- * off of irq context.
- * Note, that this is called and return with irqs disabled. This will
- * protect us against recursive calling from irq.
- */
-asmlinkage void __sched preempt_schedule_irq(void)
-{
- struct thread_info *ti = current_thread_info();
-
- /* Catch callers which need to be fixed */
- BUG_ON(ti->preempt_count || !irqs_disabled());
-
- do {
- add_preempt_count(PREEMPT_ACTIVE);
- local_irq_enable();
- __schedule();
- local_irq_disable();
- sub_preempt_count(PREEMPT_ACTIVE);
-
- /*
- * Check again in case we missed a preemption opportunity
- * between schedule and now.
- */
- barrier();
- } while (need_resched());
-}
-
-#endif /* CONFIG_PREEMPT */
-
-int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags,
- void *key)
-{
- return try_to_wake_up(curr->private, mode, wake_flags);
-}
-EXPORT_SYMBOL(default_wake_function);
-
-/*
- * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just
- * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve
- * number) then we wake all the non-exclusive tasks and one exclusive task.
- *
- * There are circumstances in which we can try to wake a task which has already
- * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns
- * zero in this (rare) case, and we handle it by continuing to scan the queue.
- */
-static void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
- int nr_exclusive, int wake_flags, void *key)
-{
- wait_queue_t *curr, *next;
-
- list_for_each_entry_safe(curr, next, &q->task_list, task_list) {
- unsigned flags = curr->flags;
-
- if (curr->func(curr, mode, wake_flags, key) &&
- (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive)
- break;
- }
-}
-
-/**
- * __wake_up - wake up threads blocked on a waitqueue.
- * @q: the waitqueue
- * @mode: which threads
- * @nr_exclusive: how many wake-one or wake-many threads to wake up
- * @key: is directly passed to the wakeup function
- *
- * It may be assumed that this function implies a write memory barrier before
- * changing the task state if and only if any tasks are woken up.
- */
-void __wake_up(wait_queue_head_t *q, unsigned int mode,
- int nr_exclusive, void *key)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&q->lock, flags);
- __wake_up_common(q, mode, nr_exclusive, 0, key);
- spin_unlock_irqrestore(&q->lock, flags);
-}
-EXPORT_SYMBOL(__wake_up);
-
-/*
- * Same as __wake_up but called with the spinlock in wait_queue_head_t held.
- */
-void __wake_up_locked(wait_queue_head_t *q, unsigned int mode)
-{
- __wake_up_common(q, mode, 1, 0, NULL);
-}
-EXPORT_SYMBOL_GPL(__wake_up_locked);
-
-void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key)
-{
- __wake_up_common(q, mode, 1, 0, key);
-}
-EXPORT_SYMBOL_GPL(__wake_up_locked_key);
-
-/**
- * __wake_up_sync_key - wake up threads blocked on a waitqueue.
- * @q: the waitqueue
- * @mode: which threads
- * @nr_exclusive: how many wake-one or wake-many threads to wake up
- * @key: opaque value to be passed to wakeup targets
- *
- * The sync wakeup differs that the waker knows that it will schedule
- * away soon, so while the target thread will be woken up, it will not
- * be migrated to another CPU - ie. the two threads are 'synchronized'
- * with each other. This can prevent needless bouncing between CPUs.
- *
- * On UP it can prevent extra preemption.
- *
- * It may be assumed that this function implies a write memory barrier before
- * changing the task state if and only if any tasks are woken up.
- */
-void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
- int nr_exclusive, void *key)
-{
- unsigned long flags;
- int wake_flags = WF_SYNC;
-
- if (unlikely(!q))
- return;
-
- if (unlikely(!nr_exclusive))
- wake_flags = 0;
-
- spin_lock_irqsave(&q->lock, flags);
- __wake_up_common(q, mode, nr_exclusive, wake_flags, key);
- spin_unlock_irqrestore(&q->lock, flags);
-}
-EXPORT_SYMBOL_GPL(__wake_up_sync_key);
-
-/*
- * __wake_up_sync - see __wake_up_sync_key()
- */
-void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
-{
- __wake_up_sync_key(q, mode, nr_exclusive, NULL);
-}
-EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */
-
-/**
- * complete: - signals a single thread waiting on this completion
- * @x: holds the state of this particular completion
- *
- * This will wake up a single thread waiting on this completion. Threads will be
- * awakened in the same order in which they were queued.
- *
- * See also complete_all(), wait_for_completion() and related routines.
- *
- * It may be assumed that this function implies a write memory barrier before
- * changing the task state if and only if any tasks are woken up.
- */
-void complete(struct completion *x)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&x->wait.lock, flags);
- x->done++;
- __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL);
- spin_unlock_irqrestore(&x->wait.lock, flags);
-}
-EXPORT_SYMBOL(complete);
-
-/**
- * complete_all: - signals all threads waiting on this completion
- * @x: holds the state of this particular completion
- *
- * This will wake up all threads waiting on this particular completion event.
- *
- * It may be assumed that this function implies a write memory barrier before
- * changing the task state if and only if any tasks are woken up.
- */
-void complete_all(struct completion *x)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&x->wait.lock, flags);
- x->done += UINT_MAX/2;
- __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL);
- spin_unlock_irqrestore(&x->wait.lock, flags);
-}
-EXPORT_SYMBOL(complete_all);
-
-static inline long __sched
-do_wait_for_common(struct completion *x, long timeout, int state)
-{
- if (!x->done) {
- DECLARE_WAITQUEUE(wait, current);
-
- __add_wait_queue_tail_exclusive(&x->wait, &wait);
- do {
- if (signal_pending_state(state, current)) {
- timeout = -ERESTARTSYS;
- break;
- }
- __set_current_state(state);
- spin_unlock_irq(&x->wait.lock);
- timeout = schedule_timeout(timeout);
- spin_lock_irq(&x->wait.lock);
- } while (!x->done && timeout);
- __remove_wait_queue(&x->wait, &wait);
- if (!x->done)
- return timeout;
- }
- x->done--;
- return timeout ?: 1;
-}
-
-static long __sched
-wait_for_common(struct completion *x, long timeout, int state)
-{
- might_sleep();
-
- spin_lock_irq(&x->wait.lock);
- timeout = do_wait_for_common(x, timeout, state);
- spin_unlock_irq(&x->wait.lock);
- return timeout;
-}
-
-/**
- * wait_for_completion: - waits for completion of a task
- * @x: holds the state of this particular completion
- *
- * This waits to be signaled for completion of a specific task. It is NOT
- * interruptible and there is no timeout.
- *
- * See also similar routines (i.e. wait_for_completion_timeout()) with timeout
- * and interrupt capability. Also see complete().
- */
-void __sched wait_for_completion(struct completion *x)
-{
- wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
-}
-EXPORT_SYMBOL(wait_for_completion);
-
-/**
- * wait_for_completion_timeout: - waits for completion of a task (w/timeout)
- * @x: holds the state of this particular completion
- * @timeout: timeout value in jiffies
- *
- * This waits for either a completion of a specific task to be signaled or for a
- * specified timeout to expire. The timeout is in jiffies. It is not
- * interruptible.
- *
- * The return value is 0 if timed out, and positive (at least 1, or number of
- * jiffies left till timeout) if completed.
- */
-unsigned long __sched
-wait_for_completion_timeout(struct completion *x, unsigned long timeout)
-{
- return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE);
-}
-EXPORT_SYMBOL(wait_for_completion_timeout);
-
-/**
- * wait_for_completion_interruptible: - waits for completion of a task (w/intr)
- * @x: holds the state of this particular completion
- *
- * This waits for completion of a specific task to be signaled. It is
- * interruptible.
- *
- * The return value is -ERESTARTSYS if interrupted, 0 if completed.
- */
-int __sched wait_for_completion_interruptible(struct completion *x)
-{
- long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE);
- if (t == -ERESTARTSYS)
- return t;
- return 0;
-}
-EXPORT_SYMBOL(wait_for_completion_interruptible);
-
-/**
- * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr))
- * @x: holds the state of this particular completion
- * @timeout: timeout value in jiffies
- *
- * This waits for either a completion of a specific task to be signaled or for a
- * specified timeout to expire. It is interruptible. The timeout is in jiffies.
- *
- * The return value is -ERESTARTSYS if interrupted, 0 if timed out,
- * positive (at least 1, or number of jiffies left till timeout) if completed.
- */
-long __sched
-wait_for_completion_interruptible_timeout(struct completion *x,
- unsigned long timeout)
-{
- return wait_for_common(x, timeout, TASK_INTERRUPTIBLE);
-}
-EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
-
-/**
- * wait_for_completion_killable: - waits for completion of a task (killable)
- * @x: holds the state of this particular completion
- *
- * This waits to be signaled for completion of a specific task. It can be
- * interrupted by a kill signal.
- *
- * The return value is -ERESTARTSYS if interrupted, 0 if completed.
- */
-int __sched wait_for_completion_killable(struct completion *x)
-{
- long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE);
- if (t == -ERESTARTSYS)
- return t;
- return 0;
-}
-EXPORT_SYMBOL(wait_for_completion_killable);
-
-/**
- * wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable))
- * @x: holds the state of this particular completion
- * @timeout: timeout value in jiffies
- *
- * This waits for either a completion of a specific task to be
- * signaled or for a specified timeout to expire. It can be
- * interrupted by a kill signal. The timeout is in jiffies.
- *
- * The return value is -ERESTARTSYS if interrupted, 0 if timed out,
- * positive (at least 1, or number of jiffies left till timeout) if completed.
- */
-long __sched
-wait_for_completion_killable_timeout(struct completion *x,
- unsigned long timeout)
-{
- return wait_for_common(x, timeout, TASK_KILLABLE);
-}
-EXPORT_SYMBOL(wait_for_completion_killable_timeout);
-
-/**
- * try_wait_for_completion - try to decrement a completion without blocking
- * @x: completion structure
- *
- * Returns: 0 if a decrement cannot be done without blocking
- * 1 if a decrement succeeded.
- *
- * If a completion is being used as a counting completion,
- * attempt to decrement the counter without blocking. This
- * enables us to avoid waiting if the resource the completion
- * is protecting is not available.
- */
-bool try_wait_for_completion(struct completion *x)
-{
- unsigned long flags;
- int ret = 1;
-
- spin_lock_irqsave(&x->wait.lock, flags);
- if (!x->done)
- ret = 0;
- else
- x->done--;
- spin_unlock_irqrestore(&x->wait.lock, flags);
- return ret;
-}
-EXPORT_SYMBOL(try_wait_for_completion);
-
-/**
- * completion_done - Test to see if a completion has any waiters
- * @x: completion structure
- *
- * Returns: 0 if there are waiters (wait_for_completion() in progress)
- * 1 if there are no waiters.
- *
- */
-bool completion_done(struct completion *x)
-{
- unsigned long flags;
- int ret = 1;
-
- spin_lock_irqsave(&x->wait.lock, flags);
- if (!x->done)
- ret = 0;
- spin_unlock_irqrestore(&x->wait.lock, flags);
- return ret;
-}
-EXPORT_SYMBOL(completion_done);
-
-static long __sched
-sleep_on_common(wait_queue_head_t *q, int state, long timeout)
-{
- unsigned long flags;
- wait_queue_t wait;
-
- init_waitqueue_entry(&wait, current);
-
- __set_current_state(state);
-
- spin_lock_irqsave(&q->lock, flags);
- __add_wait_queue(q, &wait);
- spin_unlock(&q->lock);
- timeout = schedule_timeout(timeout);
- spin_lock_irq(&q->lock);
- __remove_wait_queue(q, &wait);
- spin_unlock_irqrestore(&q->lock, flags);
-
- return timeout;
-}
-
-void __sched interruptible_sleep_on(wait_queue_head_t *q)
-{
- sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
-}
-EXPORT_SYMBOL(interruptible_sleep_on);
-
-long __sched
-interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout)
-{
- return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout);
-}
-EXPORT_SYMBOL(interruptible_sleep_on_timeout);
-
-void __sched sleep_on(wait_queue_head_t *q)
-{
- sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
-}
-EXPORT_SYMBOL(sleep_on);
-
-long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout)
-{
- return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout);
-}
-EXPORT_SYMBOL(sleep_on_timeout);
-
-#ifdef CONFIG_RT_MUTEXES
-
-/*
- * rt_mutex_setprio - set the current priority of a task
- * @p: task
- * @prio: prio value (kernel-internal form)
- *
- * 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.
- */
-void rt_mutex_setprio(struct task_struct *p, int prio)
-{
- int oldprio, on_rq, running;
- struct rq *rq;
- const struct sched_class *prev_class;
-
- BUG_ON(prio < 0 || prio > MAX_PRIO);
-
- rq = __task_rq_lock(p);
-
- trace_sched_pi_setprio(p, prio);
- oldprio = p->prio;
- prev_class = p->sched_class;
- on_rq = p->on_rq;
- running = task_current(rq, p);
- if (on_rq)
- dequeue_task(rq, p, 0);
- if (running)
- p->sched_class->put_prev_task(rq, p);
-
- if (rt_prio(prio))
- p->sched_class = &rt_sched_class;
- else
- p->sched_class = &fair_sched_class;
-
- p->prio = prio;
-
- if (running)
- p->sched_class->set_curr_task(rq);
- if (on_rq)
- enqueue_task(rq, p, oldprio < prio ? ENQUEUE_HEAD : 0);
-
- check_class_changed(rq, p, prev_class, oldprio);
- __task_rq_unlock(rq);
-}
-
-#endif
-
-void set_user_nice(struct task_struct *p, long nice)
-{
- int old_prio, delta, on_rq;
- unsigned long flags;
- struct rq *rq;
-
- if (TASK_NICE(p) == nice || nice < -20 || nice > 19)
- return;
- /*
- * We have to be careful, if called from sys_setpriority(),
- * the task might be in the middle of scheduling on another CPU.
- */
- rq = task_rq_lock(p, &flags);
- /*
- * 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
- * SCHED_FIFO/SCHED_RR:
- */
- if (task_has_rt_policy(p)) {
- p->static_prio = NICE_TO_PRIO(nice);
- goto out_unlock;
- }
- on_rq = p->on_rq;
- if (on_rq)
- dequeue_task(rq, p, 0);
-
- p->static_prio = NICE_TO_PRIO(nice);
- set_load_weight(p);
- old_prio = p->prio;
- p->prio = effective_prio(p);
- delta = p->prio - old_prio;
-
- if (on_rq) {
- enqueue_task(rq, p, 0);
- /*
- * If the task increased its priority or is running and
- * lowered its priority, then reschedule its CPU:
- */
- if (delta < 0 || (delta > 0 && task_running(rq, p)))
- resched_task(rq->curr);
- }
-out_unlock:
- task_rq_unlock(rq, p, &flags);
-}
-EXPORT_SYMBOL(set_user_nice);
-
-/*
- * can_nice - check if a task can reduce its nice value
- * @p: task
- * @nice: nice value
- */
-int can_nice(const struct task_struct *p, const int nice)
-{
- /* convert nice value [19,-20] to rlimit style value [1,40] */
- int nice_rlim = 20 - nice;
-
- return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) ||
- capable(CAP_SYS_NICE));
-}
-
-#ifdef __ARCH_WANT_SYS_NICE
-
-/*
- * sys_nice - change the priority of the current process.
- * @increment: priority increment
- *
- * sys_setpriority is a more generic, but much slower function that
- * does similar things.
- */
-SYSCALL_DEFINE1(nice, int, increment)
-{
- long nice, retval;
-
- /*
- * Setpriority might change our priority at the same moment.
- * We don't have to worry. Conceptually one call occurs first
- * and we have a single winner.
- */
- if (increment < -40)
- increment = -40;
- if (increment > 40)
- increment = 40;
-
- nice = TASK_NICE(current) + increment;
- if (nice < -20)
- nice = -20;
- if (nice > 19)
- nice = 19;
-
- if (increment < 0 && !can_nice(current, nice))
- return -EPERM;
-
- retval = security_task_setnice(current, nice);
- if (retval)
- return retval;
-
- set_user_nice(current, nice);
- return 0;
-}
-
-#endif
-
-/**
- * task_prio - return the priority value of a given task.
- * @p: the task in question.
- *
- * This is the priority value as seen by users in /proc.
- * RT tasks are offset by -200. Normal tasks are centered
- * around 0, value goes from -16 to +15.
- */
-int task_prio(const struct task_struct *p)
-{
- return p->prio - MAX_RT_PRIO;
-}
-
-/**
- * task_nice - return the nice value of a given task.
- * @p: the task in question.
- */
-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.
- */
-int idle_cpu(int cpu)
-{
- struct rq *rq = cpu_rq(cpu);
-
- if (rq->curr != rq->idle)
- return 0;
-
- if (rq->nr_running)
- return 0;
-
-#ifdef CONFIG_SMP
- if (!llist_empty(&rq->wake_list))
- return 0;
-#endif
-
- return 1;
-}
-
-/**
- * idle_task - return the idle task for a given cpu.
- * @cpu: the processor in question.
- */
-struct task_struct *idle_task(int cpu)
-{
- return cpu_rq(cpu)->idle;
-}
-
-/**
- * find_process_by_pid - find a process with a matching PID value.
- * @pid: the pid in question.
- */
-static struct task_struct *find_process_by_pid(pid_t pid)
-{
- return pid ? find_task_by_vpid(pid) : current;
-}
-
-/* Actually do priority change: must hold rq lock. */
-static void
-__setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio)
-{
- p->policy = policy;
- p->rt_priority = prio;
- p->normal_prio = normal_prio(p);
- /* we are holding p->pi_lock already */
- p->prio = rt_mutex_getprio(p);
- if (rt_prio(p->prio))
- p->sched_class = &rt_sched_class;
- else
- p->sched_class = &fair_sched_class;
- set_load_weight(p);
-}
-
-/*
- * check the target process has a UID that matches the current process's
- */
-static bool check_same_owner(struct task_struct *p)
-{
- const struct cred *cred = current_cred(), *pcred;
- bool match;
-
- rcu_read_lock();
- pcred = __task_cred(p);
- if (cred->user->user_ns == pcred->user->user_ns)
- match = (cred->euid == pcred->euid ||
- cred->euid == pcred->uid);
- else
- match = false;
- rcu_read_unlock();
- return match;
-}
-
-static int __sched_setscheduler(struct task_struct *p, int policy,
- const struct sched_param *param, bool user)
-{
- int retval, oldprio, oldpolicy = -1, on_rq, running;
- unsigned long flags;
- const struct sched_class *prev_class;
- struct rq *rq;
- int reset_on_fork;
-
- /* may grab non-irq protected spin_locks */
- BUG_ON(in_interrupt());
-recheck:
- /* double check policy once rq lock held */
- if (policy < 0) {
- reset_on_fork = p->sched_reset_on_fork;
- policy = oldpolicy = p->policy;
- } else {
- reset_on_fork = !!(policy & SCHED_RESET_ON_FORK);
- policy &= ~SCHED_RESET_ON_FORK;
-
- if (policy != SCHED_FIFO && policy != SCHED_RR &&
- 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,
- * SCHED_BATCH and SCHED_IDLE is 0.
- */
- if (param->sched_priority < 0 ||
- (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) ||
- (!p->mm && param->sched_priority > MAX_RT_PRIO-1))
- return -EINVAL;
- if (rt_policy(policy) != (param->sched_priority != 0))
- return -EINVAL;
-
- /*
- * Allow unprivileged RT tasks to decrease priority:
- */
- if (user && !capable(CAP_SYS_NICE)) {
- if (rt_policy(policy)) {
- unsigned long rlim_rtprio =
- task_rlimit(p, RLIMIT_RTPRIO);
-
- /* can't set/change the rt policy */
- if (policy != p->policy && !rlim_rtprio)
- return -EPERM;
-
- /* can't increase priority */
- if (param->sched_priority > p->rt_priority &&
- param->sched_priority > rlim_rtprio)
- return -EPERM;
- }
-
- /*
- * Treat SCHED_IDLE as nice 20. Only allow a switch to
- * 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)))
- return -EPERM;
- }
-
- /* can't change other user's priorities */
- if (!check_same_owner(p))
- return -EPERM;
-
- /* Normal users shall not reset the sched_reset_on_fork flag */
- if (p->sched_reset_on_fork && !reset_on_fork)
- return -EPERM;
- }
-
- if (user) {
- retval = security_task_setscheduler(p);
- if (retval)
- return retval;
- }
-
- /*
- * make sure no PI-waiters arrive (or leave) while we are
- * changing the priority of the task:
- *
- * To be able to change p->policy safely, the appropriate
- * runqueue lock must be held.
- */
- rq = task_rq_lock(p, &flags);
-
- /*
- * Changing the policy of the stop threads its a very bad idea
- */
- if (p == rq->stop) {
- task_rq_unlock(rq, p, &flags);
- return -EINVAL;
- }
-
- /*
- * If not changing anything there's no need to proceed further:
- */
- if (unlikely(policy == p->policy && (!rt_policy(policy) ||
- param->sched_priority == p->rt_priority))) {
-
- __task_rq_unlock(rq);
- raw_spin_unlock_irqrestore(&p->pi_lock, flags);
- return 0;
- }
-
-#ifdef CONFIG_RT_GROUP_SCHED
- if (user) {
- /*
- * Do not allow realtime tasks into groups that have no runtime
- * assigned.
- */
- if (rt_bandwidth_enabled() && rt_policy(policy) &&
- task_group(p)->rt_bandwidth.rt_runtime == 0 &&
- !task_group_is_autogroup(task_group(p))) {
- task_rq_unlock(rq, p, &flags);
- return -EPERM;
- }
- }
-#endif
-
- /* recheck policy now with rq lock held */
- if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) {
- policy = oldpolicy = -1;
- task_rq_unlock(rq, p, &flags);
- goto recheck;
- }
- on_rq = p->on_rq;
- running = task_current(rq, p);
- if (on_rq)
- deactivate_task(rq, p, 0);
- 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, policy, param->sched_priority);
-
- if (running)
- p->sched_class->set_curr_task(rq);
- if (on_rq)
- activate_task(rq, p, 0);
-
- check_class_changed(rq, p, prev_class, oldprio);
- task_rq_unlock(rq, p, &flags);
-
- rt_mutex_adjust_pi(p);
-
- return 0;
-}
-
-/**
- * sched_setscheduler - change the scheduling policy and/or RT priority of a thread.
- * @p: the task in question.
- * @policy: new policy.
- * @param: structure containing the new RT priority.
- *
- * NOTE that the task may be already dead.
- */
-int sched_setscheduler(struct task_struct *p, int policy,
- const struct sched_param *param)
-{
- return __sched_setscheduler(p, policy, param, true);
-}
-EXPORT_SYMBOL_GPL(sched_setscheduler);
-
-/**
- * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace.
- * @p: the task in question.
- * @policy: new policy.
- * @param: structure containing the new RT priority.
- *
- * Just like sched_setscheduler, only don't bother checking if the
- * current context has permission. For example, this is needed in
- * stop_machine(): we create temporary high priority worker threads,
- * but our caller might not have that capability.
- */
-int sched_setscheduler_nocheck(struct task_struct *p, int policy,
- const struct sched_param *param)
-{
- return __sched_setscheduler(p, policy, param, false);
-}
-
-static int
-do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param)
-{
- struct sched_param lparam;
- struct task_struct *p;
- int retval;
-
- if (!param || pid < 0)
- return -EINVAL;
- if (copy_from_user(&lparam, param, sizeof(struct sched_param)))
- return -EFAULT;
-
- rcu_read_lock();
- retval = -ESRCH;
- p = find_process_by_pid(pid);
- if (p != NULL)
- retval = sched_setscheduler(p, policy, &lparam);
- rcu_read_unlock();
-
- return retval;
-}
-
-/**
- * sys_sched_setscheduler - set/change the scheduler policy and RT priority
- * @pid: the pid in question.
- * @policy: new policy.
- * @param: structure containing the new RT priority.
- */
-SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy,
- struct sched_param __user *, param)
-{
- /* negative values for policy are not valid */
- if (policy < 0)
- return -EINVAL;
-
- return do_sched_setscheduler(pid, policy, param);
-}
-
-/**
- * sys_sched_setparam - set/change the RT priority of a thread
- * @pid: the pid in question.
- * @param: structure containing the new RT priority.
- */
-SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param)
-{
- return do_sched_setscheduler(pid, -1, param);
-}
-
-/**
- * sys_sched_getscheduler - get the policy (scheduling class) of a thread
- * @pid: the pid in question.
- */
-SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
-{
- struct task_struct *p;
- int retval;
-
- if (pid < 0)
- return -EINVAL;
-
- retval = -ESRCH;
- rcu_read_lock();
- p = find_process_by_pid(pid);
- if (p) {
- retval = security_task_getscheduler(p);
- if (!retval)
- retval = p->policy
- | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0);
- }
- rcu_read_unlock();
- return retval;
-}
-
-/**
- * sys_sched_getparam - get the RT priority of a thread
- * @pid: the pid in question.
- * @param: structure containing the RT priority.
- */
-SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
-{
- struct sched_param lp;
- struct task_struct *p;
- int retval;
-
- if (!param || pid < 0)
- return -EINVAL;
-
- rcu_read_lock();
- p = find_process_by_pid(pid);
- retval = -ESRCH;
- if (!p)
- goto out_unlock;
-
- retval = security_task_getscheduler(p);
- if (retval)
- goto out_unlock;
-
- lp.sched_priority = p->rt_priority;
- rcu_read_unlock();
-
- /*
- * This one might sleep, we cannot do it with a spinlock held ...
- */
- retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0;
-
- return retval;
-
-out_unlock:
- rcu_read_unlock();
- return retval;
-}
-
-long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
-{
- cpumask_var_t cpus_allowed, new_mask;
- struct task_struct *p;
- int retval;
-
- get_online_cpus();
- rcu_read_lock();
-
- p = find_process_by_pid(pid);
- if (!p) {
- rcu_read_unlock();
- put_online_cpus();
- return -ESRCH;
- }
-
- /* Prevent p going away */
- get_task_struct(p);
- rcu_read_unlock();
-
- if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) {
- retval = -ENOMEM;
- goto out_put_task;
- }
- if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) {
- retval = -ENOMEM;
- goto out_free_cpus_allowed;
- }
- retval = -EPERM;
- if (!check_same_owner(p) && !task_ns_capable(p, CAP_SYS_NICE))
- goto out_unlock;
-
- retval = security_task_setscheduler(p);
- if (retval)
- goto out_unlock;
-
- cpuset_cpus_allowed(p, cpus_allowed);
- cpumask_and(new_mask, in_mask, cpus_allowed);
-again:
- retval = set_cpus_allowed_ptr(p, new_mask);
-
- if (!retval) {
- cpuset_cpus_allowed(p, cpus_allowed);
- if (!cpumask_subset(new_mask, cpus_allowed)) {
- /*
- * We must have raced with a concurrent cpuset
- * update. Just reset the cpus_allowed to the
- * cpuset's cpus_allowed
- */
- cpumask_copy(new_mask, cpus_allowed);
- goto again;
- }
- }
-out_unlock:
- free_cpumask_var(new_mask);
-out_free_cpus_allowed:
- free_cpumask_var(cpus_allowed);
-out_put_task:
- put_task_struct(p);
- put_online_cpus();
- return retval;
-}
-
-static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len,
- struct cpumask *new_mask)
-{
- if (len < cpumask_size())
- cpumask_clear(new_mask);
- else if (len > cpumask_size())
- len = cpumask_size();
-
- return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0;
-}
-
-/**
- * sys_sched_setaffinity - set the cpu affinity of a process
- * @pid: pid of the process
- * @len: length in bytes of the bitmask pointed to by user_mask_ptr
- * @user_mask_ptr: user-space pointer to the new cpu mask
- */
-SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len,
- unsigned long __user *, user_mask_ptr)
-{
- cpumask_var_t new_mask;
- int retval;
-
- if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
- return -ENOMEM;
-
- retval = get_user_cpu_mask(user_mask_ptr, len, new_mask);
- if (retval == 0)
- retval = sched_setaffinity(pid, new_mask);
- free_cpumask_var(new_mask);
- return retval;
-}
-
-long sched_getaffinity(pid_t pid, struct cpumask *mask)
-{
- struct task_struct *p;
- unsigned long flags;
- int retval;
-
- get_online_cpus();
- rcu_read_lock();
-
- retval = -ESRCH;
- p = find_process_by_pid(pid);
- if (!p)
- goto out_unlock;
-
- retval = security_task_getscheduler(p);
- if (retval)
- goto out_unlock;
-
- raw_spin_lock_irqsave(&p->pi_lock, flags);
- cpumask_and(mask, &p->cpus_allowed, cpu_online_mask);
- raw_spin_unlock_irqrestore(&p->pi_lock, flags);
-
-out_unlock:
- rcu_read_unlock();
- put_online_cpus();
-
- return retval;
-}
-
-/**
- * sys_sched_getaffinity - get the cpu affinity of a process
- * @pid: pid of the process
- * @len: length in bytes of the bitmask pointed to by user_mask_ptr
- * @user_mask_ptr: user-space pointer to hold the current cpu mask
- */
-SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
- unsigned long __user *, user_mask_ptr)
-{
- int ret;
- cpumask_var_t mask;
-
- if ((len * BITS_PER_BYTE) < nr_cpu_ids)
- return -EINVAL;
- if (len & (sizeof(unsigned long)-1))
- return -EINVAL;
-
- if (!alloc_cpumask_var(&mask, GFP_KERNEL))
- return -ENOMEM;
-
- ret = sched_getaffinity(pid, mask);
- if (ret == 0) {
- size_t retlen = min_t(size_t, len, cpumask_size());
-
- if (copy_to_user(user_mask_ptr, mask, retlen))
- ret = -EFAULT;
- else
- ret = retlen;
- }
- free_cpumask_var(mask);
-
- return ret;
-}
-
-/**
- * sys_sched_yield - yield the current processor to other threads.
- *
- * This function yields the current CPU to other tasks. If there are no
- * other threads running on this CPU then this function will return.
- */
-SYSCALL_DEFINE0(sched_yield)
-{
- struct rq *rq = this_rq_lock();
-
- schedstat_inc(rq, yld_count);
- current->sched_class->yield_task(rq);
-
- /*
- * Since we are going to call schedule() anyway, there's
- * no need to preempt or enable interrupts:
- */
- __release(rq->lock);
- spin_release(&rq->lock.dep_map, 1, _THIS_IP_);
- do_raw_spin_unlock(&rq->lock);
- preempt_enable_no_resched();
-
- schedule();
-
- return 0;
-}
-
-static inline int should_resched(void)
-{
- return need_resched() && !(preempt_count() & PREEMPT_ACTIVE);
-}
-
-static void __cond_resched(void)
-{
- add_preempt_count(PREEMPT_ACTIVE);
- __schedule();
- sub_preempt_count(PREEMPT_ACTIVE);
-}
-
-int __sched _cond_resched(void)
-{
- if (should_resched()) {
- __cond_resched();
- return 1;
- }
- return 0;
-}
-EXPORT_SYMBOL(_cond_resched);
-
-/*
- * __cond_resched_lock() - if a reschedule is pending, drop the given lock,
- * call schedule, and on return reacquire the lock.
- *
- * This works OK both with and without CONFIG_PREEMPT. We do strange low-level
- * operations here to prevent schedule() from being called twice (once via
- * spin_unlock(), once by hand).
- */
-int __cond_resched_lock(spinlock_t *lock)
-{
- int resched = should_resched();
- int ret = 0;
-
- lockdep_assert_held(lock);
-
- if (spin_needbreak(lock) || resched) {
- spin_unlock(lock);
- if (resched)
- __cond_resched();
- else
- cpu_relax();
- ret = 1;
- spin_lock(lock);
- }
- return ret;
-}
-EXPORT_SYMBOL(__cond_resched_lock);
-
-int __sched __cond_resched_softirq(void)
-{
- BUG_ON(!in_softirq());
-
- if (should_resched()) {
- local_bh_enable();
- __cond_resched();
- local_bh_disable();
- return 1;
- }
- return 0;
-}
-EXPORT_SYMBOL(__cond_resched_softirq);
-
-/**
- * yield - yield the current processor to other threads.
- *
- * This is a shortcut for kernel-space yielding - it marks the
- * thread runnable and calls sys_sched_yield().
- */
-void __sched yield(void)
-{
- set_current_state(TASK_RUNNING);
- sys_sched_yield();
-}
-EXPORT_SYMBOL(yield);
-
-/**
- * yield_to - yield the current processor to another thread in
- * your thread group, or accelerate that thread toward the
- * processor it's on.
- * @p: target task
- * @preempt: whether task preemption is allowed or not
- *
- * It's the caller's job to ensure that the target task struct
- * can't go away on us before we can do any checks.
- *
- * Returns true if we indeed boosted the target task.
- */
-bool __sched yield_to(struct task_struct *p, bool preempt)
-{
- struct task_struct *curr = current;
- struct rq *rq, *p_rq;
- unsigned long flags;
- bool yielded = 0;
-
- local_irq_save(flags);
- rq = this_rq();
-
-again:
- p_rq = task_rq(p);
- double_rq_lock(rq, p_rq);
- while (task_rq(p) != p_rq) {
- double_rq_unlock(rq, p_rq);
- goto again;
- }
-
- if (!curr->sched_class->yield_to_task)
- goto out;
-
- if (curr->sched_class != p->sched_class)
- goto out;
-
- if (task_running(p_rq, p) || p->state)
- goto out;
-
- yielded = curr->sched_class->yield_to_task(rq, p, preempt);
- if (yielded) {
- schedstat_inc(rq, yld_count);
- /*
- * Make p's CPU reschedule; pick_next_entity takes care of
- * fairness.
- */
- if (preempt && rq != p_rq)
- resched_task(p_rq->curr);
- }
-
-out:
- double_rq_unlock(rq, p_rq);
- local_irq_restore(flags);
-
- if (yielded)
- schedule();
-
- return yielded;
-}
-EXPORT_SYMBOL_GPL(yield_to);
-
-/*
- * This task is about to go to sleep on IO. Increment rq->nr_iowait so
- * that process accounting knows that this is a task in IO wait state.
- */
-void __sched io_schedule(void)
-{
- struct rq *rq = raw_rq();
-
- delayacct_blkio_start();
- atomic_inc(&rq->nr_iowait);
- blk_flush_plug(current);
- current->in_iowait = 1;
- schedule();
- current->in_iowait = 0;
- atomic_dec(&rq->nr_iowait);
- delayacct_blkio_end();
-}
-EXPORT_SYMBOL(io_schedule);
-
-long __sched io_schedule_timeout(long timeout)
-{
- struct rq *rq = raw_rq();
- long ret;
-
- delayacct_blkio_start();
- atomic_inc(&rq->nr_iowait);
- blk_flush_plug(current);
- current->in_iowait = 1;
- ret = schedule_timeout(timeout);
- current->in_iowait = 0;
- atomic_dec(&rq->nr_iowait);
- delayacct_blkio_end();
- return ret;
-}
-
-/**
- * sys_sched_get_priority_max - return maximum RT priority.
- * @policy: scheduling class.
- *
- * this syscall returns the maximum rt_priority that can be used
- * by a given scheduling class.
- */
-SYSCALL_DEFINE1(sched_get_priority_max, int, policy)
-{
- int ret = -EINVAL;
-
- switch (policy) {
- case SCHED_FIFO:
- case SCHED_RR:
- ret = MAX_USER_RT_PRIO-1;
- break;
- case SCHED_NORMAL:
- case SCHED_BATCH:
- case SCHED_IDLE:
- ret = 0;
- break;
- }
- return ret;
-}
-
-/**
- * sys_sched_get_priority_min - return minimum RT priority.
- * @policy: scheduling class.
- *
- * this syscall returns the minimum rt_priority that can be used
- * by a given scheduling class.
- */
-SYSCALL_DEFINE1(sched_get_priority_min, int, policy)
-{
- int ret = -EINVAL;
-
- switch (policy) {
- case SCHED_FIFO:
- case SCHED_RR:
- ret = 1;
- break;
- case SCHED_NORMAL:
- case SCHED_BATCH:
- case SCHED_IDLE:
- ret = 0;
- }
- return ret;
-}
-
-/**
- * sys_sched_rr_get_interval - return the default timeslice of a process.
- * @pid: pid of the process.
- * @interval: userspace pointer to the timeslice value.
- *
- * this syscall writes the default timeslice value of a given process
- * into the user-space timespec buffer. A value of '0' means infinity.
- */
-SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
- struct timespec __user *, interval)
-{
- struct task_struct *p;
- unsigned int time_slice;
- unsigned long flags;
- struct rq *rq;
- int retval;
- struct timespec t;
-
- if (pid < 0)
- return -EINVAL;
-
- retval = -ESRCH;
- rcu_read_lock();
- p = find_process_by_pid(pid);
- if (!p)
- goto out_unlock;
-
- retval = security_task_getscheduler(p);
- if (retval)
- goto out_unlock;
-
- rq = task_rq_lock(p, &flags);
- time_slice = p->sched_class->get_rr_interval(rq, p);
- task_rq_unlock(rq, p, &flags);
-
- rcu_read_unlock();
- jiffies_to_timespec(time_slice, &t);
- retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
- return retval;
-
-out_unlock:
- rcu_read_unlock();
- return retval;
-}
-
-static const char stat_nam[] = TASK_STATE_TO_CHAR_STR;
-
-void sched_show_task(struct task_struct *p)
-{
- unsigned long free = 0;
- unsigned state;
-
- state = p->state ? __ffs(p->state) + 1 : 0;
- printk(KERN_INFO "%-15.15s %c", p->comm,
- state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
-#if BITS_PER_LONG == 32
- if (state == TASK_RUNNING)
- printk(KERN_CONT " running ");
- else
- printk(KERN_CONT " %08lx ", thread_saved_pc(p));
-#else
- if (state == TASK_RUNNING)
- printk(KERN_CONT " running task ");
- else
- printk(KERN_CONT " %016lx ", thread_saved_pc(p));
-#endif
-#ifdef CONFIG_DEBUG_STACK_USAGE
- free = stack_not_used(p);
-#endif
- printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free,
- task_pid_nr(p), task_pid_nr(p->real_parent),
- (unsigned long)task_thread_info(p)->flags);
-
- show_stack(p, NULL);
-}
-
-void show_state_filter(unsigned long state_filter)
-{
- struct task_struct *g, *p;
-
-#if BITS_PER_LONG == 32
- printk(KERN_INFO
- " task PC stack pid father\n");
-#else
- printk(KERN_INFO
- " task PC stack pid father\n");
-#endif
- rcu_read_lock();
- do_each_thread(g, p) {
- /*
- * reset the NMI-timeout, listing all files on a slow
- * console might take a lot of time:
- */
- touch_nmi_watchdog();
- if (!state_filter || (p->state & state_filter))
- sched_show_task(p);
- } while_each_thread(g, p);
-
- touch_all_softlockup_watchdogs();
-
-#ifdef CONFIG_SCHED_DEBUG
- sysrq_sched_debug_show();
-#endif
- rcu_read_unlock();
- /*
- * Only show locks if all tasks are dumped:
- */
- if (!state_filter)
- debug_show_all_locks();
-}
-
-void __cpuinit init_idle_bootup_task(struct task_struct *idle)
-{
- idle->sched_class = &idle_sched_class;
-}
-
-/**
- * init_idle - set up an idle thread for a given CPU
- * @idle: task in question
- * @cpu: cpu the idle task belongs to
- *
- * NOTE: this function does not set the idle thread's NEED_RESCHED
- * flag, to make booting more robust.
- */
-void __cpuinit init_idle(struct task_struct *idle, int cpu)
-{
- struct rq *rq = cpu_rq(cpu);
- unsigned long flags;
-
- raw_spin_lock_irqsave(&rq->lock, flags);
-
- __sched_fork(idle);
- idle->state = TASK_RUNNING;
- idle->se.exec_start = sched_clock();
-
- do_set_cpus_allowed(idle, cpumask_of(cpu));
- /*
- * We're having a chicken and egg problem, even though we are
- * holding rq->lock, the cpu isn't yet set to this cpu so the
- * lockdep check in task_group() will fail.
- *
- * Similar case to sched_fork(). / Alternatively we could
- * use task_rq_lock() here and obtain the other rq->lock.
- *
- * Silence PROVE_RCU
- */
- rcu_read_lock();
- __set_task_cpu(idle, cpu);
- rcu_read_unlock();
-
- rq->curr = rq->idle = idle;
-#if defined(CONFIG_SMP)
- idle->on_cpu = 1;
-#endif
- raw_spin_unlock_irqrestore(&rq->lock, flags);
-
- /* Set the preempt count _outside_ the spinlocks! */
- task_thread_info(idle)->preempt_count = 0;
-
- /*
- * The idle tasks have their own, simple scheduling class:
- */
- idle->sched_class = &idle_sched_class;
- ftrace_graph_init_idle_task(idle, cpu);
-#if defined(CONFIG_SMP)
- sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu);
-#endif
-}
-
-#ifdef CONFIG_SMP
-void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
-{
- if (p->sched_class && p->sched_class->set_cpus_allowed)
- p->sched_class->set_cpus_allowed(p, new_mask);
-
- cpumask_copy(&p->cpus_allowed, new_mask);
- p->rt.nr_cpus_allowed = cpumask_weight(new_mask);
-}
-
-/*
- * This is how migration works:
- *
- * 1) we invoke migration_cpu_stop() on the target CPU using
- * stop_one_cpu().
- * 2) stopper starts to run (implicitly forcing the migrated thread
- * off the CPU)
- * 3) it checks whether the migrated task is still in the wrong runqueue.
- * 4) if it's in the wrong runqueue then the migration thread removes
- * it and puts it into the right queue.
- * 5) stopper completes and stop_one_cpu() returns and the migration
- * is done.
- */
-
-/*
- * Change a given task's CPU affinity. Migrate the thread to a
- * proper CPU and schedule it away if the CPU it's executing on
- * is removed from the allowed bitmask.
- *
- * NOTE: the caller must have a valid reference to the task, the
- * task must not exit() & deallocate itself prematurely. The
- * call is not atomic; no spinlocks may be held.
- */
-int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
-{
- unsigned long flags;
- struct rq *rq;
- unsigned int dest_cpu;
- int ret = 0;
-
- rq = task_rq_lock(p, &flags);
-
- if (cpumask_equal(&p->cpus_allowed, new_mask))
- goto out;
-
- if (!cpumask_intersects(new_mask, cpu_active_mask)) {
- ret = -EINVAL;
- goto out;
- }
-
- if (unlikely((p->flags & PF_THREAD_BOUND) && p != current)) {
- ret = -EINVAL;
- goto out;
- }
-
- do_set_cpus_allowed(p, new_mask);
-
- /* Can the task run on the task's current CPU? If so, we're done */
- if (cpumask_test_cpu(task_cpu(p), new_mask))
- goto out;
-
- dest_cpu = cpumask_any_and(cpu_active_mask, new_mask);
- if (p->on_rq) {
- struct migration_arg arg = { p, dest_cpu };
- /* Need help from migration thread: drop lock and wait. */
- task_rq_unlock(rq, p, &flags);
- stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg);
- tlb_migrate_finish(p->mm);
- return 0;
- }
-out:
- task_rq_unlock(rq, p, &flags);
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr);
-
-/*
- * Move (not current) task off this cpu, onto dest cpu. We're doing
- * this because either it can't run here any more (set_cpus_allowed()
- * away from this CPU, or CPU going down), or because we're
- * attempting to rebalance this task on exec (sched_exec).
- *
- * So we race with normal scheduler movements, but that's OK, as long
- * as the task is no longer on this CPU.
- *
- * Returns non-zero if task was successfully migrated.
- */
-static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
-{
- struct rq *rq_dest, *rq_src;
- int ret = 0;
-
- if (unlikely(!cpu_active(dest_cpu)))
- return ret;
-
- rq_src = cpu_rq(src_cpu);
- rq_dest = cpu_rq(dest_cpu);
-
- raw_spin_lock(&p->pi_lock);
- double_rq_lock(rq_src, rq_dest);
- /* Already moved. */
- if (task_cpu(p) != src_cpu)
- goto done;
- /* Affinity changed (again). */
- if (!cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
- goto fail;
-
- /*
- * If we're not on a rq, the next wake-up will ensure we're
- * placed properly.
- */
- if (p->on_rq) {
- deactivate_task(rq_src, p, 0);
- set_task_cpu(p, dest_cpu);
- activate_task(rq_dest, p, 0);
- check_preempt_curr(rq_dest, p, 0);
- }
-done:
- ret = 1;
-fail:
- double_rq_unlock(rq_src, rq_dest);
- raw_spin_unlock(&p->pi_lock);
- return ret;
-}
-
-/*
- * migration_cpu_stop - this will be executed by a highprio stopper thread
- * and performs thread migration by bumping thread off CPU then
- * 'pushing' onto another runqueue.
- */
-static int migration_cpu_stop(void *data)
-{
- struct migration_arg *arg = data;
-
- /*
- * The original target cpu might have gone down and we might
- * be on another cpu but it doesn't matter.
- */
- local_irq_disable();
- __migrate_task(arg->task, raw_smp_processor_id(), arg->dest_cpu);
- local_irq_enable();
- return 0;
-}
-
-#ifdef CONFIG_HOTPLUG_CPU
-
-/*
- * Ensures that the idle task is using init_mm right before its cpu goes
- * offline.
- */
-void idle_task_exit(void)
-{
- struct mm_struct *mm = current->active_mm;
-
- BUG_ON(cpu_online(smp_processor_id()));
-
- if (mm != &init_mm)
- switch_mm(mm, &init_mm, current);
- mmdrop(mm);
-}
-
-/*
- * While a dead CPU has no uninterruptible tasks queued at this point,
- * it might still have a nonzero ->nr_uninterruptible counter, because
- * for performance reasons the counter is not stricly tracking tasks to
- * their home CPUs. So we just add the counter to another CPU's counter,
- * to keep the global sum constant after CPU-down:
- */
-static void migrate_nr_uninterruptible(struct rq *rq_src)
-{
- struct rq *rq_dest = cpu_rq(cpumask_any(cpu_active_mask));
-
- rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible;
- rq_src->nr_uninterruptible = 0;
-}
-
-/*
- * remove the tasks which were accounted by rq from calc_load_tasks.
- */
-static void calc_global_load_remove(struct rq *rq)
-{
- atomic_long_sub(rq->calc_load_active, &calc_load_tasks);
- rq->calc_load_active = 0;
-}
-
-/*
- * Migrate all tasks from the rq, sleeping tasks will be migrated by
- * try_to_wake_up()->select_task_rq().
- *
- * Called with rq->lock held even though we'er in stop_machine() and
- * there's no concurrency possible, we hold the required locks anyway
- * because of lock validation efforts.
- */
-static void migrate_tasks(unsigned int dead_cpu)
-{
- struct rq *rq = cpu_rq(dead_cpu);
- struct task_struct *next, *stop = rq->stop;
- int dest_cpu;
-
- /*
- * Fudge the rq selection such that the below task selection loop
- * doesn't get stuck on the currently eligible stop task.
- *
- * We're currently inside stop_machine() and the rq is either stuck
- * in the stop_machine_cpu_stop() loop, or we're executing this code,
- * either way we should never end up calling schedule() until we're
- * done here.
- */
- rq->stop = NULL;
-
- /* Ensure any throttled groups are reachable by pick_next_task */
- unthrottle_offline_cfs_rqs(rq);
-
- for ( ; ; ) {
- /*
- * There's this thread running, bail when that's the only
- * remaining thread.
- */
- if (rq->nr_running == 1)
- break;
-
- next = pick_next_task(rq);
- BUG_ON(!next);
- next->sched_class->put_prev_task(rq, next);
-
- /* Find suitable destination for @next, with force if needed. */
- dest_cpu = select_fallback_rq(dead_cpu, next);
- raw_spin_unlock(&rq->lock);
-
- __migrate_task(next, dead_cpu, dest_cpu);
-
- raw_spin_lock(&rq->lock);
- }
-
- rq->stop = stop;
-}
-
-#endif /* CONFIG_HOTPLUG_CPU */
-
-#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
-
-static struct ctl_table sd_ctl_dir[] = {
- {
- .procname = "sched_domain",
- .mode = 0555,
- },
- {}
-};
-
-static struct ctl_table sd_ctl_root[] = {
- {
- .procname = "kernel",
- .mode = 0555,
- .child = sd_ctl_dir,
- },
- {}
-};
-
-static struct ctl_table *sd_alloc_ctl_entry(int n)
-{
- struct ctl_table *entry =
- kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL);
-
- return entry;
-}
-
-static void sd_free_ctl_entry(struct ctl_table **tablep)
-{
- struct ctl_table *entry;
-
- /*
- * In the intermediate directories, both the child directory and
- * procname are dynamically allocated and could fail but the mode
- * will always be set. In the lowest directory the names are
- * static strings and all have proc handlers.
- */
- for (entry = *tablep; entry->mode; entry++) {
- if (entry->child)
- sd_free_ctl_entry(&entry->child);
- if (entry->proc_handler == NULL)
- kfree(entry->procname);
- }
-
- kfree(*tablep);
- *tablep = NULL;
-}
-
-static void
-set_table_entry(struct ctl_table *entry,
- const char *procname, void *data, int maxlen,
- mode_t mode, proc_handler *proc_handler)
-{
- entry->procname = procname;
- entry->data = data;
- entry->maxlen = maxlen;
- entry->mode = mode;
- entry->proc_handler = proc_handler;
-}
-
-static struct ctl_table *
-sd_alloc_ctl_domain_table(struct sched_domain *sd)
-{
- struct ctl_table *table = sd_alloc_ctl_entry(13);
-
- if (table == NULL)
- return NULL;
-
- set_table_entry(&table[0], "min_interval", &sd->min_interval,
- sizeof(long), 0644, proc_doulongvec_minmax);
- set_table_entry(&table[1], "max_interval", &sd->max_interval,
- sizeof(long), 0644, proc_doulongvec_minmax);
- set_table_entry(&table[2], "busy_idx", &sd->busy_idx,
- sizeof(int), 0644, proc_dointvec_minmax);
- set_table_entry(&table[3], "idle_idx", &sd->idle_idx,
- sizeof(int), 0644, proc_dointvec_minmax);
- set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx,
- sizeof(int), 0644, proc_dointvec_minmax);
- set_table_entry(&table[5], "wake_idx", &sd->wake_idx,
- sizeof(int), 0644, proc_dointvec_minmax);
- set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx,
- sizeof(int), 0644, proc_dointvec_minmax);
- set_table_entry(&table[7], "busy_factor", &sd->busy_factor,
- sizeof(int), 0644, proc_dointvec_minmax);
- set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct,
- sizeof(int), 0644, proc_dointvec_minmax);
- set_table_entry(&table[9], "cache_nice_tries",
- &sd->cache_nice_tries,
- sizeof(int), 0644, proc_dointvec_minmax);
- set_table_entry(&table[10], "flags", &sd->flags,
- sizeof(int), 0644, proc_dointvec_minmax);
- set_table_entry(&table[11], "name", sd->name,
- CORENAME_MAX_SIZE, 0444, proc_dostring);
- /* &table[12] is terminator */
-
- return table;
-}
-
-static ctl_table *sd_alloc_ctl_cpu_table(int cpu)
-{
- struct ctl_table *entry, *table;
- struct sched_domain *sd;
- int domain_num = 0, i;
- char buf[32];
-
- for_each_domain(cpu, sd)
- domain_num++;
- entry = table = sd_alloc_ctl_entry(domain_num + 1);
- if (table == NULL)
- return NULL;
-
- i = 0;
- for_each_domain(cpu, sd) {
- snprintf(buf, 32, "domain%d", i);
- entry->procname = kstrdup(buf, GFP_KERNEL);
- entry->mode = 0555;
- entry->child = sd_alloc_ctl_domain_table(sd);
- entry++;
- i++;
- }
- return table;
-}
-
-static struct ctl_table_header *sd_sysctl_header;
-static void register_sched_domain_sysctl(void)
-{
- int i, cpu_num = num_possible_cpus();
- struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
- char buf[32];
-
- WARN_ON(sd_ctl_dir[0].child);
- sd_ctl_dir[0].child = entry;
-
- if (entry == NULL)
- return;
-
- for_each_possible_cpu(i) {
- snprintf(buf, 32, "cpu%d", i);
- entry->procname = kstrdup(buf, GFP_KERNEL);
- entry->mode = 0555;
- entry->child = sd_alloc_ctl_cpu_table(i);
- entry++;
- }
-
- WARN_ON(sd_sysctl_header);
- sd_sysctl_header = register_sysctl_table(sd_ctl_root);
-}
-
-/* may be called multiple times per register */
-static void unregister_sched_domain_sysctl(void)
-{
- if (sd_sysctl_header)
- unregister_sysctl_table(sd_sysctl_header);
- sd_sysctl_header = NULL;
- if (sd_ctl_dir[0].child)
- sd_free_ctl_entry(&sd_ctl_dir[0].child);
-}
-#else
-static void register_sched_domain_sysctl(void)
-{
-}
-static void unregister_sched_domain_sysctl(void)
-{
-}
-#endif
-
-static void set_rq_online(struct rq *rq)
-{
- if (!rq->online) {
- const struct sched_class *class;
-
- cpumask_set_cpu(rq->cpu, rq->rd->online);
- rq->online = 1;
-
- for_each_class(class) {
- if (class->rq_online)
- class->rq_online(rq);
- }
- }
-}
-
-static void set_rq_offline(struct rq *rq)
-{
- if (rq->online) {
- const struct sched_class *class;
-
- for_each_class(class) {
- if (class->rq_offline)
- class->rq_offline(rq);
- }
-
- cpumask_clear_cpu(rq->cpu, rq->rd->online);
- rq->online = 0;
- }
-}
-
-/*
- * migration_call - callback that gets triggered when a CPU is added.
- * Here we can start up the necessary migration thread for the new CPU.
- */
-static int __cpuinit
-migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
-{
- int cpu = (long)hcpu;
- unsigned long flags;
- struct rq *rq = cpu_rq(cpu);
-
- switch (action & ~CPU_TASKS_FROZEN) {
-
- case CPU_UP_PREPARE:
- rq->calc_load_update = calc_load_update;
- break;
-
- case CPU_ONLINE:
- /* Update our root-domain */
- raw_spin_lock_irqsave(&rq->lock, flags);
- if (rq->rd) {
- BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
-
- set_rq_online(rq);
- }
- raw_spin_unlock_irqrestore(&rq->lock, flags);
- break;
-
-#ifdef CONFIG_HOTPLUG_CPU
- case CPU_DYING:
- sched_ttwu_pending();
- /* Update our root-domain */
- raw_spin_lock_irqsave(&rq->lock, flags);
- if (rq->rd) {
- BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
- set_rq_offline(rq);
- }
- migrate_tasks(cpu);
- BUG_ON(rq->nr_running != 1); /* the migration thread */
- raw_spin_unlock_irqrestore(&rq->lock, flags);
-
- migrate_nr_uninterruptible(rq);
- calc_global_load_remove(rq);
- break;
-#endif
- }
-
- update_max_interval();
-
- return NOTIFY_OK;
-}
-
-/*
- * Register at high priority so that task migration (migrate_all_tasks)
- * happens before everything else. This has to be lower priority than
- * the notifier in the perf_event subsystem, though.
- */
-static struct notifier_block __cpuinitdata migration_notifier = {
- .notifier_call = migration_call,
- .priority = CPU_PRI_MIGRATION,
-};
-
-static int __cpuinit sched_cpu_active(struct notifier_block *nfb,
- unsigned long action, void *hcpu)
-{
- switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_ONLINE:
- case CPU_DOWN_FAILED:
- set_cpu_active((long)hcpu, true);
- return NOTIFY_OK;
- default:
- return NOTIFY_DONE;
- }
-}
-
-static int __cpuinit sched_cpu_inactive(struct notifier_block *nfb,
- unsigned long action, void *hcpu)
-{
- switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_DOWN_PREPARE:
- set_cpu_active((long)hcpu, false);
- return NOTIFY_OK;
- default:
- return NOTIFY_DONE;
- }
-}
-
-static int __init migration_init(void)
-{
- void *cpu = (void *)(long)smp_processor_id();
- int err;
-
- /* Initialize migration for the boot CPU */
- err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu);
- BUG_ON(err == NOTIFY_BAD);
- migration_call(&migration_notifier, CPU_ONLINE, cpu);
- register_cpu_notifier(&migration_notifier);
-
- /* Register cpu active notifiers */
- cpu_notifier(sched_cpu_active, CPU_PRI_SCHED_ACTIVE);
- cpu_notifier(sched_cpu_inactive, CPU_PRI_SCHED_INACTIVE);
-
- return 0;
-}
-early_initcall(migration_init);
-#endif
-
-#ifdef CONFIG_SMP
-
-static cpumask_var_t sched_domains_tmpmask; /* sched_domains_mutex */
-
-#ifdef CONFIG_SCHED_DEBUG
-
-static __read_mostly int sched_domain_debug_enabled;
-
-static int __init sched_domain_debug_setup(char *str)
-{
- sched_domain_debug_enabled = 1;
-
- return 0;
-}
-early_param("sched_debug", sched_domain_debug_setup);
-
-static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
- struct cpumask *groupmask)
-{
- struct sched_group *group = sd->groups;
- char str[256];
-
- cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd));
- cpumask_clear(groupmask);
-
- printk(KERN_DEBUG "%*s domain %d: ", level, "", level);
-
- if (!(sd->flags & SD_LOAD_BALANCE)) {
- printk("does not load-balance\n");
- if (sd->parent)
- printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain"
- " has parent");
- return -1;
- }
-
- printk(KERN_CONT "span %s level %s\n", str, sd->name);
-
- if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) {
- printk(KERN_ERR "ERROR: domain->span does not contain "
- "CPU%d\n", cpu);
- }
- if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) {
- printk(KERN_ERR "ERROR: domain->groups does not contain"
- " CPU%d\n", cpu);
- }
-
- printk(KERN_DEBUG "%*s groups:", level + 1, "");
- do {
- if (!group) {
- printk("\n");
- printk(KERN_ERR "ERROR: group is NULL\n");
- break;
- }
-
- if (!group->sgp->power) {
- printk(KERN_CONT "\n");
- printk(KERN_ERR "ERROR: domain->cpu_power not "
- "set\n");
- break;
- }
-
- if (!cpumask_weight(sched_group_cpus(group))) {
- printk(KERN_CONT "\n");
- printk(KERN_ERR "ERROR: empty group\n");
- break;
- }
-
- if (cpumask_intersects(groupmask, sched_group_cpus(group))) {
- printk(KERN_CONT "\n");
- printk(KERN_ERR "ERROR: repeated CPUs\n");
- break;
- }
-
- cpumask_or(groupmask, groupmask, sched_group_cpus(group));
-
- cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group));
-
- printk(KERN_CONT " %s", str);
- if (group->sgp->power != SCHED_POWER_SCALE) {
- printk(KERN_CONT " (cpu_power = %d)",
- group->sgp->power);
- }
-
- group = group->next;
- } while (group != sd->groups);
- printk(KERN_CONT "\n");
-
- if (!cpumask_equal(sched_domain_span(sd), groupmask))
- printk(KERN_ERR "ERROR: groups don't span domain->span\n");
-
- if (sd->parent &&
- !cpumask_subset(groupmask, sched_domain_span(sd->parent)))
- printk(KERN_ERR "ERROR: parent span is not a superset "
- "of domain->span\n");
- return 0;
-}
-
-static void sched_domain_debug(struct sched_domain *sd, int cpu)
-{
- int level = 0;
-
- if (!sched_domain_debug_enabled)
- return;
-
- if (!sd) {
- printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu);
- return;
- }
-
- printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu);
-
- for (;;) {
- if (sched_domain_debug_one(sd, cpu, level, sched_domains_tmpmask))
- break;
- level++;
- sd = sd->parent;
- if (!sd)
- break;
- }
-}
-#else /* !CONFIG_SCHED_DEBUG */
-# define sched_domain_debug(sd, cpu) do { } while (0)
-#endif /* CONFIG_SCHED_DEBUG */
-
-static int sd_degenerate(struct sched_domain *sd)
-{
- if (cpumask_weight(sched_domain_span(sd)) == 1)
- return 1;
-
- /* Following flags need at least 2 groups */
- if (sd->flags & (SD_LOAD_BALANCE |
- SD_BALANCE_NEWIDLE |
- SD_BALANCE_FORK |
- SD_BALANCE_EXEC |
- SD_SHARE_CPUPOWER |
- SD_SHARE_PKG_RESOURCES)) {
- if (sd->groups != sd->groups->next)
- return 0;
- }
-
- /* Following flags don't use groups */
- if (sd->flags & (SD_WAKE_AFFINE))
- return 0;
-
- return 1;
-}
-
-static int
-sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
-{
- unsigned long cflags = sd->flags, pflags = parent->flags;
-
- if (sd_degenerate(parent))
- return 1;
-
- if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent)))
- return 0;
-
- /* Flags needing groups don't count if only 1 group in parent */
- if (parent->groups == parent->groups->next) {
- pflags &= ~(SD_LOAD_BALANCE |
- SD_BALANCE_NEWIDLE |
- SD_BALANCE_FORK |
- SD_BALANCE_EXEC |
- SD_SHARE_CPUPOWER |
- SD_SHARE_PKG_RESOURCES);
- if (nr_node_ids == 1)
- pflags &= ~SD_SERIALIZE;
- }
- if (~cflags & pflags)
- return 0;
-
- return 1;
-}
-
-static void free_rootdomain(struct rcu_head *rcu)
-{
- struct root_domain *rd = container_of(rcu, struct root_domain, rcu);
-
- cpupri_cleanup(&rd->cpupri);
- free_cpumask_var(rd->rto_mask);
- free_cpumask_var(rd->online);
- free_cpumask_var(rd->span);
- kfree(rd);
-}
-
-static void rq_attach_root(struct rq *rq, struct root_domain *rd)
-{
- struct root_domain *old_rd = NULL;
- unsigned long flags;
-
- raw_spin_lock_irqsave(&rq->lock, flags);
-
- if (rq->rd) {
- old_rd = rq->rd;
-
- if (cpumask_test_cpu(rq->cpu, old_rd->online))
- set_rq_offline(rq);
-
- cpumask_clear_cpu(rq->cpu, old_rd->span);
-
- /*
- * If we dont want to free the old_rt yet then
- * set old_rd to NULL to skip the freeing later
- * in this function:
- */
- if (!atomic_dec_and_test(&old_rd->refcount))
- old_rd = NULL;
- }
-
- atomic_inc(&rd->refcount);
- rq->rd = rd;
-
- cpumask_set_cpu(rq->cpu, rd->span);
- if (cpumask_test_cpu(rq->cpu, cpu_active_mask))
- set_rq_online(rq);
-
- raw_spin_unlock_irqrestore(&rq->lock, flags);
-
- if (old_rd)
- call_rcu_sched(&old_rd->rcu, free_rootdomain);
-}
-
-static int init_rootdomain(struct root_domain *rd)
-{
- memset(rd, 0, sizeof(*rd));
-
- if (!alloc_cpumask_var(&rd->span, GFP_KERNEL))
- goto out;
- if (!alloc_cpumask_var(&rd->online, GFP_KERNEL))
- goto free_span;
- if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL))
- goto free_online;
-
- if (cpupri_init(&rd->cpupri) != 0)
- goto free_rto_mask;
- return 0;
-
-free_rto_mask:
- free_cpumask_var(rd->rto_mask);
-free_online:
- free_cpumask_var(rd->online);
-free_span:
- free_cpumask_var(rd->span);
-out:
- return -ENOMEM;
-}
-
-/*
- * By default the system creates a single root-domain with all cpus as
- * members (mimicking the global state we have today).
- */
-struct root_domain def_root_domain;
-
-static void init_defrootdomain(void)
-{
- init_rootdomain(&def_root_domain);
-
- atomic_set(&def_root_domain.refcount, 1);
-}
-
-static struct root_domain *alloc_rootdomain(void)
-{
- struct root_domain *rd;
-
- rd = kmalloc(sizeof(*rd), GFP_KERNEL);
- if (!rd)
- return NULL;
-
- if (init_rootdomain(rd) != 0) {
- kfree(rd);
- return NULL;
- }
-
- return rd;
-}
-
-static void free_sched_groups(struct sched_group *sg, int free_sgp)
-{
- struct sched_group *tmp, *first;
-
- if (!sg)
- return;
-
- first = sg;
- do {
- tmp = sg->next;
-
- if (free_sgp && atomic_dec_and_test(&sg->sgp->ref))
- kfree(sg->sgp);
-
- kfree(sg);
- sg = tmp;
- } while (sg != first);
-}
-
-static void free_sched_domain(struct rcu_head *rcu)
-{
- struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu);
-
- /*
- * If its an overlapping domain it has private groups, iterate and
- * nuke them all.
- */
- if (sd->flags & SD_OVERLAP) {
- free_sched_groups(sd->groups, 1);
- } else if (atomic_dec_and_test(&sd->groups->ref)) {
- kfree(sd->groups->sgp);
- kfree(sd->groups);
- }
- kfree(sd);
-}
-
-static void destroy_sched_domain(struct sched_domain *sd, int cpu)
-{
- call_rcu(&sd->rcu, free_sched_domain);
-}
-
-static void destroy_sched_domains(struct sched_domain *sd, int cpu)
-{
- for (; sd; sd = sd->parent)
- destroy_sched_domain(sd, cpu);
-}
-
-/*
- * Attach the domain 'sd' to 'cpu' as its base domain. Callers must
- * hold the hotplug lock.
- */
-static void
-cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
-{
- struct rq *rq = cpu_rq(cpu);
- struct sched_domain *tmp;
-
- /* Remove the sched domains which do not contribute to scheduling. */
- for (tmp = sd; tmp; ) {
- struct sched_domain *parent = tmp->parent;
- if (!parent)
- break;
-
- if (sd_parent_degenerate(tmp, parent)) {
- tmp->parent = parent->parent;
- if (parent->parent)
- parent->parent->child = tmp;
- destroy_sched_domain(parent, cpu);
- } else
- tmp = tmp->parent;
- }
-
- if (sd && sd_degenerate(sd)) {
- tmp = sd;
- sd = sd->parent;
- destroy_sched_domain(tmp, cpu);
- if (sd)
- sd->child = NULL;
- }
-
- sched_domain_debug(sd, cpu);
-
- rq_attach_root(rq, rd);
- tmp = rq->sd;
- rcu_assign_pointer(rq->sd, sd);
- destroy_sched_domains(tmp, cpu);
-}
-
-/* cpus with isolated domains */
-static cpumask_var_t cpu_isolated_map;
-
-/* Setup the mask of cpus configured for isolated domains */
-static int __init isolated_cpu_setup(char *str)
-{
- alloc_bootmem_cpumask_var(&cpu_isolated_map);
- cpulist_parse(str, cpu_isolated_map);
- return 1;
-}
-
-__setup("isolcpus=", isolated_cpu_setup);
-
-#ifdef CONFIG_NUMA
-
-/**
- * find_next_best_node - find the next node to include in a sched_domain
- * @node: node whose sched_domain we're building
- * @used_nodes: nodes already in the sched_domain
- *
- * Find the next node to include in a given scheduling domain. Simply
- * finds the closest node not already in the @used_nodes map.
- *
- * Should use nodemask_t.
- */
-static int find_next_best_node(int node, nodemask_t *used_nodes)
-{
- int i, n, val, min_val, best_node = -1;
-
- min_val = INT_MAX;
-
- for (i = 0; i < nr_node_ids; i++) {
- /* Start at @node */
- n = (node + i) % nr_node_ids;
-
- if (!nr_cpus_node(n))
- continue;
-
- /* Skip already used nodes */
- if (node_isset(n, *used_nodes))
- continue;
-
- /* Simple min distance search */
- val = node_distance(node, n);
-
- if (val < min_val) {
- min_val = val;
- best_node = n;
- }
- }
-
- if (best_node != -1)
- node_set(best_node, *used_nodes);
- return best_node;
-}
-
-/**
- * sched_domain_node_span - get a cpumask for a node's sched_domain
- * @node: node whose cpumask we're constructing
- * @span: resulting cpumask
- *
- * Given a node, construct a good cpumask for its sched_domain to span. It
- * should be one that prevents unnecessary balancing, but also spreads tasks
- * out optimally.
- */
-static void sched_domain_node_span(int node, struct cpumask *span)
-{
- nodemask_t used_nodes;
- int i;
-
- cpumask_clear(span);
- nodes_clear(used_nodes);
-
- cpumask_or(span, span, cpumask_of_node(node));
- node_set(node, used_nodes);
-
- for (i = 1; i < SD_NODES_PER_DOMAIN; i++) {
- int next_node = find_next_best_node(node, &used_nodes);
- if (next_node < 0)
- break;
- cpumask_or(span, span, cpumask_of_node(next_node));
- }
-}
-
-static const struct cpumask *cpu_node_mask(int cpu)
-{
- lockdep_assert_held(&sched_domains_mutex);
-
- sched_domain_node_span(cpu_to_node(cpu), sched_domains_tmpmask);
-
- return sched_domains_tmpmask;
-}
-
-static const struct cpumask *cpu_allnodes_mask(int cpu)
-{
- return cpu_possible_mask;
-}
-#endif /* CONFIG_NUMA */
-
-static const struct cpumask *cpu_cpu_mask(int cpu)
-{
- return cpumask_of_node(cpu_to_node(cpu));
-}
-
-int sched_smt_power_savings = 0, sched_mc_power_savings = 0;
-
-struct sd_data {
- struct sched_domain **__percpu sd;
- struct sched_group **__percpu sg;
- struct sched_group_power **__percpu sgp;
-};
-
-struct s_data {
- struct sched_domain ** __percpu sd;
- struct root_domain *rd;
-};
-
-enum s_alloc {
- sa_rootdomain,
- sa_sd,
- sa_sd_storage,
- sa_none,
-};
-
-struct sched_domain_topology_level;
-
-typedef struct sched_domain *(*sched_domain_init_f)(struct sched_domain_topology_level *tl, int cpu);
-typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
-
-#define SDTL_OVERLAP 0x01
-
-struct sched_domain_topology_level {
- sched_domain_init_f init;
- sched_domain_mask_f mask;
- int flags;
- struct sd_data data;
-};
-
-static int
-build_overlap_sched_groups(struct sched_domain *sd, int cpu)
-{
- struct sched_group *first = NULL, *last = NULL, *groups = NULL, *sg;
- const struct cpumask *span = sched_domain_span(sd);
- struct cpumask *covered = sched_domains_tmpmask;
- struct sd_data *sdd = sd->private;
- struct sched_domain *child;
- int i;
-
- cpumask_clear(covered);
-
- for_each_cpu(i, span) {
- struct cpumask *sg_span;
-
- if (cpumask_test_cpu(i, covered))
- continue;
-
- sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(),
- GFP_KERNEL, cpu_to_node(i));
-
- if (!sg)
- goto fail;
-
- sg_span = sched_group_cpus(sg);
-
- child = *per_cpu_ptr(sdd->sd, i);
- if (child->child) {
- child = child->child;
- cpumask_copy(sg_span, sched_domain_span(child));
- } else
- cpumask_set_cpu(i, sg_span);
-
- cpumask_or(covered, covered, sg_span);
-
- sg->sgp = *per_cpu_ptr(sdd->sgp, cpumask_first(sg_span));
- atomic_inc(&sg->sgp->ref);
-
- if (cpumask_test_cpu(cpu, sg_span))
- groups = sg;
-
- if (!first)
- first = sg;
- if (last)
- last->next = sg;
- last = sg;
- last->next = first;
- }
- sd->groups = groups;
-
- return 0;
-
-fail:
- free_sched_groups(first, 0);
-
- return -ENOMEM;
-}
-
-static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg)
-{
- struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu);
- struct sched_domain *child = sd->child;
-
- if (child)
- cpu = cpumask_first(sched_domain_span(child));
-
- if (sg) {
- *sg = *per_cpu_ptr(sdd->sg, cpu);
- (*sg)->sgp = *per_cpu_ptr(sdd->sgp, cpu);
- atomic_set(&(*sg)->sgp->ref, 1); /* for claim_allocations */
- }
-
- return cpu;
-}
-
-/*
- * build_sched_groups will build a circular linked list of the groups
- * covered by the given span, and will set each group's ->cpumask correctly,
- * and ->cpu_power to 0.
- *
- * Assumes the sched_domain tree is fully constructed
- */
-static int
-build_sched_groups(struct sched_domain *sd, int cpu)
-{
- struct sched_group *first = NULL, *last = NULL;
- struct sd_data *sdd = sd->private;
- const struct cpumask *span = sched_domain_span(sd);
- struct cpumask *covered;
- int i;
-
- get_group(cpu, sdd, &sd->groups);
- atomic_inc(&sd->groups->ref);
-
- if (cpu != cpumask_first(sched_domain_span(sd)))
- return 0;
-
- lockdep_assert_held(&sched_domains_mutex);
- covered = sched_domains_tmpmask;
-
- cpumask_clear(covered);
-
- for_each_cpu(i, span) {
- struct sched_group *sg;
- int group = get_group(i, sdd, &sg);
- int j;
-
- if (cpumask_test_cpu(i, covered))
- continue;
-
- cpumask_clear(sched_group_cpus(sg));
- sg->sgp->power = 0;
-
- for_each_cpu(j, span) {
- if (get_group(j, sdd, NULL) != group)
- continue;
-
- cpumask_set_cpu(j, covered);
- cpumask_set_cpu(j, sched_group_cpus(sg));
- }
-
- if (!first)
- first = sg;
- if (last)
- last->next = sg;
- last = sg;
- }
- last->next = first;
-
- return 0;
-}
-
-/*
- * Initialize sched groups cpu_power.
- *
- * cpu_power indicates the capacity of sched group, which is used while
- * distributing the load between different sched groups in a sched domain.
- * Typically cpu_power for all the groups in a sched domain will be same unless
- * there are asymmetries in the topology. If there are asymmetries, group
- * having more cpu_power will pickup more load compared to the group having
- * less cpu_power.
- */
-static void init_sched_groups_power(int cpu, struct sched_domain *sd)
-{
- struct sched_group *sg = sd->groups;
-
- WARN_ON(!sd || !sg);
-
- do {
- sg->group_weight = cpumask_weight(sched_group_cpus(sg));
- sg = sg->next;
- } while (sg != sd->groups);
-
- if (cpu != group_first_cpu(sg))
- return;
-
- update_group_power(sd, cpu);
-}
-
-int __weak arch_sd_sibling_asym_packing(void)
-{
- return 0*SD_ASYM_PACKING;
-}
-
-/*
- * Initializers for schedule domains
- * Non-inlined to reduce accumulated stack pressure in build_sched_domains()
- */
-
-#ifdef CONFIG_SCHED_DEBUG
-# define SD_INIT_NAME(sd, type) sd->name = #type
-#else
-# define SD_INIT_NAME(sd, type) do { } while (0)
-#endif
-
-#define SD_INIT_FUNC(type) \
-static noinline struct sched_domain * \
-sd_init_##type(struct sched_domain_topology_level *tl, int cpu) \
-{ \
- struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu); \
- *sd = SD_##type##_INIT; \
- SD_INIT_NAME(sd, type); \
- sd->private = &tl->data; \
- return sd; \
-}
-
-SD_INIT_FUNC(CPU)
-#ifdef CONFIG_NUMA
- SD_INIT_FUNC(ALLNODES)
- SD_INIT_FUNC(NODE)
-#endif
-#ifdef CONFIG_SCHED_SMT
- SD_INIT_FUNC(SIBLING)
-#endif
-#ifdef CONFIG_SCHED_MC
- SD_INIT_FUNC(MC)
-#endif
-#ifdef CONFIG_SCHED_BOOK
- SD_INIT_FUNC(BOOK)
-#endif
-
-static int default_relax_domain_level = -1;
-int sched_domain_level_max;
-
-static int __init setup_relax_domain_level(char *str)
-{
- unsigned long val;
-
- val = simple_strtoul(str, NULL, 0);
- if (val < sched_domain_level_max)
- default_relax_domain_level = val;
-
- return 1;
-}
-__setup("relax_domain_level=", setup_relax_domain_level);
-
-static void set_domain_attribute(struct sched_domain *sd,
- struct sched_domain_attr *attr)
-{
- int request;
-
- if (!attr || attr->relax_domain_level < 0) {
- if (default_relax_domain_level < 0)
- return;
- else
- request = default_relax_domain_level;
- } else
- request = attr->relax_domain_level;
- if (request < sd->level) {
- /* turn off idle balance on this domain */
- sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
- } else {
- /* turn on idle balance on this domain */
- sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
- }
-}
-
-static void __sdt_free(const struct cpumask *cpu_map);
-static int __sdt_alloc(const struct cpumask *cpu_map);
-
-static void __free_domain_allocs(struct s_data *d, enum s_alloc what,
- const struct cpumask *cpu_map)
-{
- switch (what) {
- case sa_rootdomain:
- if (!atomic_read(&d->rd->refcount))
- free_rootdomain(&d->rd->rcu); /* fall through */
- case sa_sd:
- free_percpu(d->sd); /* fall through */
- case sa_sd_storage:
- __sdt_free(cpu_map); /* fall through */
- case sa_none:
- break;
- }
-}
-
-static enum s_alloc __visit_domain_allocation_hell(struct s_data *d,
- const struct cpumask *cpu_map)
-{
- memset(d, 0, sizeof(*d));
-
- if (__sdt_alloc(cpu_map))
- return sa_sd_storage;
- d->sd = alloc_percpu(struct sched_domain *);
- if (!d->sd)
- return sa_sd_storage;
- d->rd = alloc_rootdomain();
- if (!d->rd)
- return sa_sd;
- return sa_rootdomain;
-}
-
-/*
- * NULL the sd_data elements we've used to build the sched_domain and
- * sched_group structure so that the subsequent __free_domain_allocs()
- * will not free the data we're using.
- */
-static void claim_allocations(int cpu, struct sched_domain *sd)
-{
- struct sd_data *sdd = sd->private;
-
- WARN_ON_ONCE(*per_cpu_ptr(sdd->sd, cpu) != sd);
- *per_cpu_ptr(sdd->sd, cpu) = NULL;
-
- if (atomic_read(&(*per_cpu_ptr(sdd->sg, cpu))->ref))
- *per_cpu_ptr(sdd->sg, cpu) = NULL;
-
- if (atomic_read(&(*per_cpu_ptr(sdd->sgp, cpu))->ref))
- *per_cpu_ptr(sdd->sgp, cpu) = NULL;
-}
-
-#ifdef CONFIG_SCHED_SMT
-static const struct cpumask *cpu_smt_mask(int cpu)
-{
- return topology_thread_cpumask(cpu);
-}
-#endif
-
-/*
- * Topology list, bottom-up.
- */
-static struct sched_domain_topology_level default_topology[] = {
-#ifdef CONFIG_SCHED_SMT
- { sd_init_SIBLING, cpu_smt_mask, },
-#endif
-#ifdef CONFIG_SCHED_MC
- { sd_init_MC, cpu_coregroup_mask, },
-#endif
-#ifdef CONFIG_SCHED_BOOK
- { sd_init_BOOK, cpu_book_mask, },
-#endif
- { sd_init_CPU, cpu_cpu_mask, },
-#ifdef CONFIG_NUMA
- { sd_init_NODE, cpu_node_mask, SDTL_OVERLAP, },
- { sd_init_ALLNODES, cpu_allnodes_mask, },
-#endif
- { NULL, },
-};
-
-static struct sched_domain_topology_level *sched_domain_topology = default_topology;
-
-static int __sdt_alloc(const struct cpumask *cpu_map)
-{
- struct sched_domain_topology_level *tl;
- int j;
-
- for (tl = sched_domain_topology; tl->init; tl++) {
- struct sd_data *sdd = &tl->data;
-
- sdd->sd = alloc_percpu(struct sched_domain *);
- if (!sdd->sd)
- return -ENOMEM;
-
- sdd->sg = alloc_percpu(struct sched_group *);
- if (!sdd->sg)
- return -ENOMEM;
-
- sdd->sgp = alloc_percpu(struct sched_group_power *);
- if (!sdd->sgp)
- return -ENOMEM;
-
- for_each_cpu(j, cpu_map) {
- struct sched_domain *sd;
- struct sched_group *sg;
- struct sched_group_power *sgp;
-
- sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(),
- GFP_KERNEL, cpu_to_node(j));
- if (!sd)
- return -ENOMEM;
-
- *per_cpu_ptr(sdd->sd, j) = sd;
-
- sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(),
- GFP_KERNEL, cpu_to_node(j));
- if (!sg)
- return -ENOMEM;
-
- *per_cpu_ptr(sdd->sg, j) = sg;
-
- sgp = kzalloc_node(sizeof(struct sched_group_power),
- GFP_KERNEL, cpu_to_node(j));
- if (!sgp)
- return -ENOMEM;
-
- *per_cpu_ptr(sdd->sgp, j) = sgp;
- }
- }
-
- return 0;
-}
-
-static void __sdt_free(const struct cpumask *cpu_map)
-{
- struct sched_domain_topology_level *tl;
- int j;
-
- for (tl = sched_domain_topology; tl->init; tl++) {
- struct sd_data *sdd = &tl->data;
-
- for_each_cpu(j, cpu_map) {
- struct sched_domain *sd = *per_cpu_ptr(sdd->sd, j);
- if (sd && (sd->flags & SD_OVERLAP))
- free_sched_groups(sd->groups, 0);
- kfree(*per_cpu_ptr(sdd->sd, j));
- kfree(*per_cpu_ptr(sdd->sg, j));
- kfree(*per_cpu_ptr(sdd->sgp, j));
- }
- free_percpu(sdd->sd);
- free_percpu(sdd->sg);
- free_percpu(sdd->sgp);
- }
-}
-
-struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl,
- struct s_data *d, const struct cpumask *cpu_map,
- struct sched_domain_attr *attr, struct sched_domain *child,
- int cpu)
-{
- struct sched_domain *sd = tl->init(tl, cpu);
- if (!sd)
- return child;
-
- set_domain_attribute(sd, attr);
- cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu));
- if (child) {
- sd->level = child->level + 1;
- sched_domain_level_max = max(sched_domain_level_max, sd->level);
- child->parent = sd;
- }
- sd->child = child;
-
- return sd;
-}
-
-/*
- * Build sched domains for a given set of cpus and attach the sched domains
- * to the individual cpus
- */
-static int build_sched_domains(const struct cpumask *cpu_map,
- struct sched_domain_attr *attr)
-{
- enum s_alloc alloc_state = sa_none;
- struct sched_domain *sd;
- struct s_data d;
- int i, ret = -ENOMEM;
-
- alloc_state = __visit_domain_allocation_hell(&d, cpu_map);
- if (alloc_state != sa_rootdomain)
- goto error;
-
- /* Set up domains for cpus specified by the cpu_map. */
- for_each_cpu(i, cpu_map) {
- struct sched_domain_topology_level *tl;
-
- sd = NULL;
- for (tl = sched_domain_topology; tl->init; tl++) {
- sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i);
- if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP))
- sd->flags |= SD_OVERLAP;
- if (cpumask_equal(cpu_map, sched_domain_span(sd)))
- break;
- }
-
- while (sd->child)
- sd = sd->child;
-
- *per_cpu_ptr(d.sd, i) = sd;
- }
-
- /* Build the groups for the domains */
- for_each_cpu(i, cpu_map) {
- for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) {
- sd->span_weight = cpumask_weight(sched_domain_span(sd));
- if (sd->flags & SD_OVERLAP) {
- if (build_overlap_sched_groups(sd, i))
- goto error;
- } else {
- if (build_sched_groups(sd, i))
- goto error;
- }
- }
- }
-
- /* Calculate CPU power for physical packages and nodes */
- for (i = nr_cpumask_bits-1; i >= 0; i--) {
- if (!cpumask_test_cpu(i, cpu_map))
- continue;
-
- for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) {
- claim_allocations(i, sd);
- init_sched_groups_power(i, sd);
- }
- }
-
- /* Attach the domains */
- rcu_read_lock();
- for_each_cpu(i, cpu_map) {
- sd = *per_cpu_ptr(d.sd, i);
- cpu_attach_domain(sd, d.rd, i);
- }
- rcu_read_unlock();
-
- ret = 0;
-error:
- __free_domain_allocs(&d, alloc_state, cpu_map);
- return ret;
-}
-
-static cpumask_var_t *doms_cur; /* current sched domains */
-static int ndoms_cur; /* number of sched domains in 'doms_cur' */
-static struct sched_domain_attr *dattr_cur;
- /* attribues of custom domains in 'doms_cur' */
-
-/*
- * Special case: If a kmalloc of a doms_cur partition (array of
- * cpumask) fails, then fallback to a single sched domain,
- * as determined by the single cpumask fallback_doms.
- */
-static cpumask_var_t fallback_doms;
-
-/*
- * arch_update_cpu_topology lets virtualized architectures update the
- * cpu core maps. It is supposed to return 1 if the topology changed
- * or 0 if it stayed the same.
- */
-int __attribute__((weak)) arch_update_cpu_topology(void)
-{
- return 0;
-}
-
-cpumask_var_t *alloc_sched_domains(unsigned int ndoms)
-{
- int i;
- cpumask_var_t *doms;
-
- doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL);
- if (!doms)
- return NULL;
- for (i = 0; i < ndoms; i++) {
- if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) {
- free_sched_domains(doms, i);
- return NULL;
- }
- }
- return doms;
-}
-
-void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms)
-{
- unsigned int i;
- for (i = 0; i < ndoms; i++)
- free_cpumask_var(doms[i]);
- kfree(doms);
-}
-
-/*
- * Set up scheduler domains and groups. Callers must hold the hotplug lock.
- * For now this just excludes isolated cpus, but could be used to
- * exclude other special cases in the future.
- */
-static int init_sched_domains(const struct cpumask *cpu_map)
-{
- int err;
-
- arch_update_cpu_topology();
- ndoms_cur = 1;
- doms_cur = alloc_sched_domains(ndoms_cur);
- if (!doms_cur)
- doms_cur = &fallback_doms;
- cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map);
- dattr_cur = NULL;
- err = build_sched_domains(doms_cur[0], NULL);
- register_sched_domain_sysctl();
-
- return err;
-}
-
-/*
- * Detach sched domains from a group of cpus specified in cpu_map
- * These cpus will now be attached to the NULL domain
- */
-static void detach_destroy_domains(const struct cpumask *cpu_map)
-{
- int i;
-
- rcu_read_lock();
- for_each_cpu(i, cpu_map)
- cpu_attach_domain(NULL, &def_root_domain, i);
- rcu_read_unlock();
-}
-
-/* handle null as "default" */
-static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
- struct sched_domain_attr *new, int idx_new)
-{
- struct sched_domain_attr tmp;
-
- /* fast path */
- if (!new && !cur)
- return 1;
-
- tmp = SD_ATTR_INIT;
- return !memcmp(cur ? (cur + idx_cur) : &tmp,
- new ? (new + idx_new) : &tmp,
- sizeof(struct sched_domain_attr));
-}
-
-/*
- * Partition sched domains as specified by the 'ndoms_new'
- * cpumasks in the array doms_new[] of cpumasks. This compares
- * doms_new[] to the current sched domain partitioning, doms_cur[].
- * It destroys each deleted domain and builds each new domain.
- *
- * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'.
- * The masks don't intersect (don't overlap.) We should setup one
- * sched domain for each mask. CPUs not in any of the cpumasks will
- * not be load balanced. If the same cpumask appears both in the
- * current 'doms_cur' domains and in the new 'doms_new', we can leave
- * it as it is.
- *
- * The passed in 'doms_new' should be allocated using
- * alloc_sched_domains. This routine takes ownership of it and will
- * free_sched_domains it when done with it. If the caller failed the
- * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1,
- * and partition_sched_domains() will fallback to the single partition
- * 'fallback_doms', it also forces the domains to be rebuilt.
- *
- * If doms_new == NULL it will be replaced with cpu_online_mask.
- * ndoms_new == 0 is a special case for destroying existing domains,
- * and it will not create the default domain.
- *
- * Call with hotplug lock held
- */
-void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
- struct sched_domain_attr *dattr_new)
-{
- int i, j, n;
- int new_topology;
-
- mutex_lock(&sched_domains_mutex);
-
- /* always unregister in case we don't destroy any domains */
- unregister_sched_domain_sysctl();
-
- /* Let architecture update cpu core mappings. */
- new_topology = arch_update_cpu_topology();
-
- n = doms_new ? ndoms_new : 0;
-
- /* Destroy deleted domains */
- for (i = 0; i < ndoms_cur; i++) {
- for (j = 0; j < n && !new_topology; j++) {
- if (cpumask_equal(doms_cur[i], doms_new[j])
- && dattrs_equal(dattr_cur, i, dattr_new, j))
- goto match1;
- }
- /* no match - a current sched domain not in new doms_new[] */
- detach_destroy_domains(doms_cur[i]);
-match1:
- ;
- }
-
- if (doms_new == NULL) {
- ndoms_cur = 0;
- doms_new = &fallback_doms;
- cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map);
- WARN_ON_ONCE(dattr_new);
- }
-
- /* Build new domains */
- for (i = 0; i < ndoms_new; i++) {
- for (j = 0; j < ndoms_cur && !new_topology; j++) {
- if (cpumask_equal(doms_new[i], doms_cur[j])
- && dattrs_equal(dattr_new, i, dattr_cur, j))
- goto match2;
- }
- /* no match - add a new doms_new */
- build_sched_domains(doms_new[i], dattr_new ? dattr_new + i : NULL);
-match2:
- ;
- }
-
- /* Remember the new sched domains */
- if (doms_cur != &fallback_doms)
- free_sched_domains(doms_cur, ndoms_cur);
- kfree(dattr_cur); /* kfree(NULL) is safe */
- doms_cur = doms_new;
- dattr_cur = dattr_new;
- ndoms_cur = ndoms_new;
-
- register_sched_domain_sysctl();
-
- mutex_unlock(&sched_domains_mutex);
-}
-
-#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
-static void reinit_sched_domains(void)
-{
- get_online_cpus();
-
- /* Destroy domains first to force the rebuild */
- partition_sched_domains(0, NULL, NULL);
-
- rebuild_sched_domains();
- put_online_cpus();
-}
-
-static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt)
-{
- unsigned int level = 0;
-
- if (sscanf(buf, "%u", &level) != 1)
- return -EINVAL;
-
- /*
- * level is always be positive so don't check for
- * level < POWERSAVINGS_BALANCE_NONE which is 0
- * What happens on 0 or 1 byte write,
- * need to check for count as well?
- */
-
- if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS)
- return -EINVAL;
-
- if (smt)
- sched_smt_power_savings = level;
- else
- sched_mc_power_savings = level;
-
- reinit_sched_domains();
-
- return count;
-}
-
-#ifdef CONFIG_SCHED_MC
-static ssize_t sched_mc_power_savings_show(struct sysdev_class *class,
- struct sysdev_class_attribute *attr,
- char *page)
-{
- return sprintf(page, "%u\n", sched_mc_power_savings);
-}
-static ssize_t sched_mc_power_savings_store(struct sysdev_class *class,
- struct sysdev_class_attribute *attr,
- const char *buf, size_t count)
-{
- return sched_power_savings_store(buf, count, 0);
-}
-static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644,
- sched_mc_power_savings_show,
- sched_mc_power_savings_store);
-#endif
-
-#ifdef CONFIG_SCHED_SMT
-static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev,
- struct sysdev_class_attribute *attr,
- char *page)
-{
- return sprintf(page, "%u\n", sched_smt_power_savings);
-}
-static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev,
- struct sysdev_class_attribute *attr,
- const char *buf, size_t count)
-{
- return sched_power_savings_store(buf, count, 1);
-}
-static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644,
- sched_smt_power_savings_show,
- sched_smt_power_savings_store);
-#endif
-
-int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls)
-{
- int err = 0;
-
-#ifdef CONFIG_SCHED_SMT
- if (smt_capable())
- err = sysfs_create_file(&cls->kset.kobj,
- &attr_sched_smt_power_savings.attr);
-#endif
-#ifdef CONFIG_SCHED_MC
- if (!err && mc_capable())
- err = sysfs_create_file(&cls->kset.kobj,
- &attr_sched_mc_power_savings.attr);
-#endif
- return err;
-}
-#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
-
-/*
- * Update cpusets according to cpu_active mask. If cpusets are
- * disabled, cpuset_update_active_cpus() becomes a simple wrapper
- * around partition_sched_domains().
- */
-static int cpuset_cpu_active(struct notifier_block *nfb, unsigned long action,
- void *hcpu)
-{
- switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_ONLINE:
- case CPU_DOWN_FAILED:
- cpuset_update_active_cpus();
- return NOTIFY_OK;
- default:
- return NOTIFY_DONE;
- }
-}
-
-static int cpuset_cpu_inactive(struct notifier_block *nfb, unsigned long action,
- void *hcpu)
-{
- switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_DOWN_PREPARE:
- cpuset_update_active_cpus();
- return NOTIFY_OK;
- default:
- return NOTIFY_DONE;
- }
-}
-
-void __init sched_init_smp(void)
-{
- cpumask_var_t non_isolated_cpus;
-
- alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL);
- alloc_cpumask_var(&fallback_doms, GFP_KERNEL);
-
- get_online_cpus();
- mutex_lock(&sched_domains_mutex);
- init_sched_domains(cpu_active_mask);
- cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map);
- if (cpumask_empty(non_isolated_cpus))
- cpumask_set_cpu(smp_processor_id(), non_isolated_cpus);
- mutex_unlock(&sched_domains_mutex);
- put_online_cpus();
-
- hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE);
- hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE);
-
- /* RT runtime code needs to handle some hotplug events */
- hotcpu_notifier(update_runtime, 0);
-
- init_hrtick();
-
- /* Move init over to a non-isolated CPU */
- if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0)
- BUG();
- sched_init_granularity();
- free_cpumask_var(non_isolated_cpus);
-
- init_sched_rt_class();
-}
-#else
-void __init sched_init_smp(void)
-{
- sched_init_granularity();
-}
-#endif /* CONFIG_SMP */
-
-const_debug unsigned int sysctl_timer_migration = 1;
-
-int in_sched_functions(unsigned long addr)
-{
- return in_lock_functions(addr) ||
- (addr >= (unsigned long)__sched_text_start
- && addr < (unsigned long)__sched_text_end);
-}
-
-#ifdef CONFIG_CGROUP_SCHED
-struct task_group root_task_group;
-#endif
-
-DECLARE_PER_CPU(cpumask_var_t, load_balance_tmpmask);
-
-void __init sched_init(void)
-{
- int i, j;
- unsigned long alloc_size = 0, ptr;
-
-#ifdef CONFIG_FAIR_GROUP_SCHED
- alloc_size += 2 * nr_cpu_ids * sizeof(void **);
-#endif
-#ifdef CONFIG_RT_GROUP_SCHED
- alloc_size += 2 * nr_cpu_ids * sizeof(void **);
-#endif
-#ifdef CONFIG_CPUMASK_OFFSTACK
- alloc_size += num_possible_cpus() * cpumask_size();
-#endif
- if (alloc_size) {
- ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT);
-
-#ifdef CONFIG_FAIR_GROUP_SCHED
- root_task_group.se = (struct sched_entity **)ptr;
- ptr += nr_cpu_ids * sizeof(void **);
-
- root_task_group.cfs_rq = (struct cfs_rq **)ptr;
- ptr += nr_cpu_ids * sizeof(void **);
-
-#endif /* CONFIG_FAIR_GROUP_SCHED */
-#ifdef CONFIG_RT_GROUP_SCHED
- root_task_group.rt_se = (struct sched_rt_entity **)ptr;
- ptr += nr_cpu_ids * sizeof(void **);
-
- root_task_group.rt_rq = (struct rt_rq **)ptr;
- ptr += nr_cpu_ids * sizeof(void **);
-
-#endif /* CONFIG_RT_GROUP_SCHED */
-#ifdef CONFIG_CPUMASK_OFFSTACK
- for_each_possible_cpu(i) {
- per_cpu(load_balance_tmpmask, i) = (void *)ptr;
- ptr += cpumask_size();
- }
-#endif /* CONFIG_CPUMASK_OFFSTACK */
- }
-
-#ifdef CONFIG_SMP
- init_defrootdomain();
-#endif
-
- init_rt_bandwidth(&def_rt_bandwidth,
- global_rt_period(), global_rt_runtime());
-
-#ifdef CONFIG_RT_GROUP_SCHED
- init_rt_bandwidth(&root_task_group.rt_bandwidth,
- global_rt_period(), global_rt_runtime());
-#endif /* CONFIG_RT_GROUP_SCHED */
-
-#ifdef CONFIG_CGROUP_SCHED
- list_add(&root_task_group.list, &task_groups);
- INIT_LIST_HEAD(&root_task_group.children);
- INIT_LIST_HEAD(&root_task_group.siblings);
- autogroup_init(&init_task);
-#endif /* CONFIG_CGROUP_SCHED */
-
- for_each_possible_cpu(i) {
- struct rq *rq;
-
- rq = cpu_rq(i);
- raw_spin_lock_init(&rq->lock);
- rq->nr_running = 0;
- rq->calc_load_active = 0;
- rq->calc_load_update = jiffies + LOAD_FREQ;
- init_cfs_rq(&rq->cfs);
- init_rt_rq(&rq->rt, rq);
-#ifdef CONFIG_FAIR_GROUP_SCHED
- root_task_group.shares = ROOT_TASK_GROUP_LOAD;
- INIT_LIST_HEAD(&rq->leaf_cfs_rq_list);
- /*
- * How much cpu bandwidth does root_task_group get?
- *
- * In case of task-groups formed thr' the cgroup filesystem, it
- * gets 100% of the cpu resources in the system. This overall
- * system cpu resource is divided among the tasks of
- * root_task_group and its child task-groups in a fair manner,
- * based on each entity's (task or task-group's) weight
- * (se->load.weight).
- *
- * In other words, if root_task_group has 10 tasks of weight
- * 1024) and two child groups A0 and A1 (of weight 1024 each),
- * then A0's share of the cpu resource is:
- *
- * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33%
- *
- * We achieve this by letting root_task_group's tasks sit
- * directly in rq->cfs (i.e root_task_group->se[] = NULL).
- */
- init_cfs_bandwidth(&root_task_group.cfs_bandwidth);
- init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, NULL);
-#endif /* CONFIG_FAIR_GROUP_SCHED */
-
- 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
-
- for (j = 0; j < CPU_LOAD_IDX_MAX; j++)
- rq->cpu_load[j] = 0;
-
- rq->last_load_update_tick = jiffies;
-
-#ifdef CONFIG_SMP
- rq->sd = NULL;
- rq->rd = NULL;
- rq->cpu_power = SCHED_POWER_SCALE;
- rq->post_schedule = 0;
- rq->active_balance = 0;
- rq->next_balance = jiffies;
- rq->push_cpu = 0;
- rq->cpu = i;
- rq->online = 0;
- rq->idle_stamp = 0;
- rq->avg_idle = 2*sysctl_sched_migration_cost;
- rq_attach_root(rq, &def_root_domain);
-#ifdef CONFIG_NO_HZ
- rq->nohz_balance_kick = 0;
-#endif
-#endif
- init_rq_hrtick(rq);
- atomic_set(&rq->nr_iowait, 0);
- }
-
- set_load_weight(&init_task);
-
-#ifdef CONFIG_PREEMPT_NOTIFIERS
- INIT_HLIST_HEAD(&init_task.preempt_notifiers);
-#endif
-
-#ifdef CONFIG_RT_MUTEXES
- plist_head_init(&init_task.pi_waiters);
-#endif
-
- /*
- * The boot idle thread does lazy MMU switching as well:
- */
- atomic_inc(&init_mm.mm_count);
- enter_lazy_tlb(&init_mm, current);
-
- /*
- * Make us the idle thread. Technically, schedule() should not be
- * called from this thread, however somewhere below it might be,
- * but because we are the idle thread, we just pick up running again
- * when this runqueue becomes "idle".
- */
- init_idle(current, smp_processor_id());
-
- calc_load_update = jiffies + LOAD_FREQ;
-
- /*
- * During early bootup we pretend to be a normal task:
- */
- current->sched_class = &fair_sched_class;
-
-#ifdef CONFIG_SMP
- zalloc_cpumask_var(&sched_domains_tmpmask, GFP_NOWAIT);
- /* May be allocated at isolcpus cmdline parse time */
- if (cpu_isolated_map == NULL)
- zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
-#endif
- init_sched_fair_class();
-
- scheduler_running = 1;
-}
-
-#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
-static inline int preempt_count_equals(int preempt_offset)
-{
- int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth();
-
- return (nested == preempt_offset);
-}
-
-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()) ||
- system_state != SYSTEM_RUNNING || oops_in_progress)
- return;
- if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
- return;
- prev_jiffy = jiffies;
-
- printk(KERN_ERR
- "BUG: sleeping function called from invalid context at %s:%d\n",
- file, line);
- printk(KERN_ERR
- "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n",
- in_atomic(), irqs_disabled(),
- current->pid, current->comm);
-
- debug_show_held_locks(current);
- if (irqs_disabled())
- print_irqtrace_events(current);
- dump_stack();
-}
-EXPORT_SYMBOL(__might_sleep);
-#endif
-
-#ifdef CONFIG_MAGIC_SYSRQ
-static void normalize_task(struct rq *rq, struct task_struct *p)
-{
- const struct sched_class *prev_class = p->sched_class;
- int old_prio = p->prio;
- int on_rq;
-
- on_rq = p->on_rq;
- if (on_rq)
- deactivate_task(rq, p, 0);
- __setscheduler(rq, p, SCHED_NORMAL, 0);
- if (on_rq) {
- activate_task(rq, p, 0);
- resched_task(rq->curr);
- }
-
- check_class_changed(rq, p, prev_class, old_prio);
-}
-
-void normalize_rt_tasks(void)
-{
- struct task_struct *g, *p;
- unsigned long flags;
- struct rq *rq;
-
- read_lock_irqsave(&tasklist_lock, flags);
- do_each_thread(g, p) {
- /*
- * Only normalize user tasks:
- */
- if (!p->mm)
- continue;
-
- p->se.exec_start = 0;
-#ifdef CONFIG_SCHEDSTATS
- p->se.statistics.wait_start = 0;
- p->se.statistics.sleep_start = 0;
- p->se.statistics.block_start = 0;
-#endif
-
- 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;
- }
-
- raw_spin_lock(&p->pi_lock);
- rq = __task_rq_lock(p);
-
- normalize_task(rq, p);
-
- __task_rq_unlock(rq);
- raw_spin_unlock(&p->pi_lock);
- } while_each_thread(g, p);
-
- read_unlock_irqrestore(&tasklist_lock, flags);
-}
-
-#endif /* CONFIG_MAGIC_SYSRQ */
-
-#if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB)
-/*
- * These functions are only useful for the IA64 MCA handling, or kdb.
- *
- * They can only be called when the whole system has been
- * stopped - every CPU needs to be quiescent, and no scheduling
- * activity can take place. Using them for anything else would
- * be a serious bug, and as a result, they aren't even visible
- * under any other configuration.
- */
-
-/**
- * curr_task - return the current task for a given cpu.
- * @cpu: the processor in question.
- *
- * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
- */
-struct task_struct *curr_task(int cpu)
-{
- return cpu_curr(cpu);
-}
-
-#endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */
-
-#ifdef CONFIG_IA64
-/**
- * set_curr_task - set the current task for a given cpu.
- * @cpu: the processor in question.
- * @p: the task pointer to set.
- *
- * Description: This function must only be used when non-maskable interrupts
- * are serviced on a separate stack. It allows the architecture to switch the
- * notion of the current task on a cpu in a non-blocking manner. This function
- * must be called with all CPU's synchronized, and interrupts disabled, the
- * and caller must save the original value of the current task (see
- * curr_task() above) and restore that value before reenabling interrupts and
- * re-starting the system.
- *
- * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
- */
-void set_curr_task(int cpu, struct task_struct *p)
-{
- cpu_curr(cpu) = p;
-}
-
-#endif
-
-#ifdef CONFIG_RT_GROUP_SCHED
-#else /* !CONFIG_RT_GROUP_SCHED */
-#endif /* CONFIG_RT_GROUP_SCHED */
-
-#ifdef CONFIG_CGROUP_SCHED
-/* task_group_lock serializes the addition/removal of task groups */
-static DEFINE_SPINLOCK(task_group_lock);
-
-static void free_sched_group(struct task_group *tg)
-{
- free_fair_sched_group(tg);
- free_rt_sched_group(tg);
- autogroup_free(tg);
- kfree(tg);
-}
-
-/* allocate runqueue etc for a new task group */
-struct task_group *sched_create_group(struct task_group *parent)
-{
- struct task_group *tg;
- unsigned long flags;
-
- tg = kzalloc(sizeof(*tg), GFP_KERNEL);
- if (!tg)
- return ERR_PTR(-ENOMEM);
-
- if (!alloc_fair_sched_group(tg, parent))
- goto err;
-
- if (!alloc_rt_sched_group(tg, parent))
- goto err;
-
- spin_lock_irqsave(&task_group_lock, flags);
- list_add_rcu(&tg->list, &task_groups);
-
- WARN_ON(!parent); /* root should already exist */
-
- tg->parent = parent;
- INIT_LIST_HEAD(&tg->children);
- list_add_rcu(&tg->siblings, &parent->children);
- spin_unlock_irqrestore(&task_group_lock, flags);
-
- return tg;
-
-err:
- free_sched_group(tg);
- return ERR_PTR(-ENOMEM);
-}
-
-/* rcu callback to free various structures associated with a task group */
-static void free_sched_group_rcu(struct rcu_head *rhp)
-{
- /* now it should be safe to free those cfs_rqs */
- free_sched_group(container_of(rhp, struct task_group, rcu));
-}
-
-/* Destroy runqueue etc associated with a task group */
-void sched_destroy_group(struct task_group *tg)
-{
- unsigned long flags;
- int i;
-
- /* end participation in shares distribution */
- for_each_possible_cpu(i)
- unregister_fair_sched_group(tg, i);
-
- spin_lock_irqsave(&task_group_lock, flags);
- list_del_rcu(&tg->list);
- list_del_rcu(&tg->siblings);
- spin_unlock_irqrestore(&task_group_lock, flags);
-
- /* wait for possible concurrent references to cfs_rqs complete */
- call_rcu(&tg->rcu, free_sched_group_rcu);
-}
-
-/* change task's runqueue when it moves between groups.
- * The caller of this function should have put the task in its new group
- * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to
- * reflect its new group.
- */
-void sched_move_task(struct task_struct *tsk)
-{
- int on_rq, running;
- unsigned long flags;
- struct rq *rq;
-
- rq = task_rq_lock(tsk, &flags);
-
- running = task_current(rq, tsk);
- on_rq = tsk->on_rq;
-
- if (on_rq)
- dequeue_task(rq, tsk, 0);
- if (unlikely(running))
- tsk->sched_class->put_prev_task(rq, tsk);
-
-#ifdef CONFIG_FAIR_GROUP_SCHED
- if (tsk->sched_class->task_move_group)
- tsk->sched_class->task_move_group(tsk, on_rq);
- else
-#endif
- set_task_rq(tsk, task_cpu(tsk));
-
- if (unlikely(running))
- tsk->sched_class->set_curr_task(rq);
- if (on_rq)
- enqueue_task(rq, tsk, 0);
-
- task_rq_unlock(rq, tsk, &flags);
-}
-#endif /* CONFIG_CGROUP_SCHED */
-
-#ifdef CONFIG_FAIR_GROUP_SCHED
-#endif
-
-#if defined(CONFIG_RT_GROUP_SCHED) || defined(CONFIG_CFS_BANDWIDTH)
-static unsigned long to_ratio(u64 period, u64 runtime)
-{
- if (runtime == RUNTIME_INF)
- return 1ULL << 20;
-
- return div64_u64(runtime << 20, period);
-}
-#endif
-
-#ifdef CONFIG_RT_GROUP_SCHED
-/*
- * Ensure that the real time constraints are schedulable.
- */
-static DEFINE_MUTEX(rt_constraints_mutex);
-
-/* Must be called with tasklist_lock held */
-static inline int tg_has_rt_tasks(struct task_group *tg)
-{
- struct task_struct *g, *p;
-
- do_each_thread(g, p) {
- if (rt_task(p) && task_rq(p)->rt.tg == tg)
- return 1;
- } while_each_thread(g, p);
-
- return 0;
-}
-
-struct rt_schedulable_data {
- struct task_group *tg;
- u64 rt_period;
- u64 rt_runtime;
-};
-
-static int tg_rt_schedulable(struct task_group *tg, void *data)
-{
- struct rt_schedulable_data *d = data;
- struct task_group *child;
- unsigned long total, sum = 0;
- u64 period, runtime;
-
- period = ktime_to_ns(tg->rt_bandwidth.rt_period);
- runtime = tg->rt_bandwidth.rt_runtime;
-
- if (tg == d->tg) {
- period = d->rt_period;
- runtime = d->rt_runtime;
- }
-
- /*
- * Cannot have more runtime than the period.
- */
- if (runtime > period && runtime != RUNTIME_INF)
- return -EINVAL;
-
- /*
- * Ensure we don't starve existing RT tasks.
- */
- if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg))
- return -EBUSY;
-
- total = to_ratio(period, runtime);
-
- /*
- * Nobody can have more than the global setting allows.
- */
- if (total > to_ratio(global_rt_period(), global_rt_runtime()))
- return -EINVAL;
-
- /*
- * The sum of our children's runtime should not exceed our own.
- */
- list_for_each_entry_rcu(child, &tg->children, siblings) {
- period = ktime_to_ns(child->rt_bandwidth.rt_period);
- runtime = child->rt_bandwidth.rt_runtime;
-
- if (child == d->tg) {
- period = d->rt_period;
- runtime = d->rt_runtime;
- }
-
- sum += to_ratio(period, runtime);
- }
-
- if (sum > total)
- return -EINVAL;
-
- return 0;
-}
-
-static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
-{
- int ret;
-
- struct rt_schedulable_data data = {
- .tg = tg,
- .rt_period = period,
- .rt_runtime = runtime,
- };
-
- rcu_read_lock();
- ret = walk_tg_tree(tg_rt_schedulable, tg_nop, &data);
- rcu_read_unlock();
-
- return ret;
-}
-
-static int tg_set_rt_bandwidth(struct task_group *tg,
- u64 rt_period, u64 rt_runtime)
-{
- int i, err = 0;
-
- mutex_lock(&rt_constraints_mutex);
- read_lock(&tasklist_lock);
- err = __rt_schedulable(tg, rt_period, rt_runtime);
- if (err)
- goto unlock;
-
- raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock);
- tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period);
- tg->rt_bandwidth.rt_runtime = rt_runtime;
-
- for_each_possible_cpu(i) {
- struct rt_rq *rt_rq = tg->rt_rq[i];
-
- raw_spin_lock(&rt_rq->rt_runtime_lock);
- rt_rq->rt_runtime = rt_runtime;
- raw_spin_unlock(&rt_rq->rt_runtime_lock);
- }
- raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock);
-unlock:
- read_unlock(&tasklist_lock);
- mutex_unlock(&rt_constraints_mutex);
-
- return err;
-}
-
-int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us)
-{
- u64 rt_runtime, rt_period;
-
- rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period);
- rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC;
- if (rt_runtime_us < 0)
- rt_runtime = RUNTIME_INF;
-
- return tg_set_rt_bandwidth(tg, rt_period, rt_runtime);
-}
-
-long sched_group_rt_runtime(struct task_group *tg)
-{
- u64 rt_runtime_us;
-
- if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF)
- return -1;
-
- rt_runtime_us = tg->rt_bandwidth.rt_runtime;
- do_div(rt_runtime_us, NSEC_PER_USEC);
- return rt_runtime_us;
-}
-
-int sched_group_set_rt_period(struct task_group *tg, long rt_period_us)
-{
- u64 rt_runtime, rt_period;
-
- rt_period = (u64)rt_period_us * NSEC_PER_USEC;
- rt_runtime = tg->rt_bandwidth.rt_runtime;
-
- if (rt_period == 0)
- return -EINVAL;
-
- return tg_set_rt_bandwidth(tg, rt_period, rt_runtime);
-}
-
-long sched_group_rt_period(struct task_group *tg)
-{
- u64 rt_period_us;
-
- rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period);
- do_div(rt_period_us, NSEC_PER_USEC);
- return rt_period_us;
-}
-
-static int sched_rt_global_constraints(void)
-{
- u64 runtime, period;
- int ret = 0;
-
- if (sysctl_sched_rt_period <= 0)
- return -EINVAL;
-
- runtime = global_rt_runtime();
- period = global_rt_period();
-
- /*
- * Sanity check on the sysctl variables.
- */
- if (runtime > period && runtime != RUNTIME_INF)
- return -EINVAL;
-
- mutex_lock(&rt_constraints_mutex);
- read_lock(&tasklist_lock);
- ret = __rt_schedulable(NULL, 0, 0);
- read_unlock(&tasklist_lock);
- mutex_unlock(&rt_constraints_mutex);
-
- return ret;
-}
-
-int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk)
-{
- /* Don't accept realtime tasks when there is no way for them to run */
- if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0)
- return 0;
-
- return 1;
-}
-
-#else /* !CONFIG_RT_GROUP_SCHED */
-static int sched_rt_global_constraints(void)
-{
- unsigned long flags;
- int i;
-
- if (sysctl_sched_rt_period <= 0)
- return -EINVAL;
-
- /*
- * There's always some RT tasks in the root group
- * -- migration, kstopmachine etc..
- */
- if (sysctl_sched_rt_runtime == 0)
- return -EBUSY;
-
- raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags);
- for_each_possible_cpu(i) {
- struct rt_rq *rt_rq = &cpu_rq(i)->rt;
-
- raw_spin_lock(&rt_rq->rt_runtime_lock);
- rt_rq->rt_runtime = global_rt_runtime();
- raw_spin_unlock(&rt_rq->rt_runtime_lock);
- }
- raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags);
-
- return 0;
-}
-#endif /* CONFIG_RT_GROUP_SCHED */
-
-int sched_rt_handler(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp,
- loff_t *ppos)
-{
- int ret;
- int old_period, old_runtime;
- static DEFINE_MUTEX(mutex);
-
- mutex_lock(&mutex);
- old_period = sysctl_sched_rt_period;
- old_runtime = sysctl_sched_rt_runtime;
-
- ret = proc_dointvec(table, write, buffer, lenp, ppos);
-
- if (!ret && write) {
- ret = sched_rt_global_constraints();
- if (ret) {
- sysctl_sched_rt_period = old_period;
- sysctl_sched_rt_runtime = old_runtime;
- } else {
- def_rt_bandwidth.rt_runtime = global_rt_runtime();
- def_rt_bandwidth.rt_period =
- ns_to_ktime(global_rt_period());
- }
- }
- mutex_unlock(&mutex);
-
- return ret;
-}
-
-#ifdef CONFIG_CGROUP_SCHED
-
-/* return corresponding task_group object of a cgroup */
-static inline struct task_group *cgroup_tg(struct cgroup *cgrp)
-{
- return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id),
- struct task_group, css);
-}
-
-static struct cgroup_subsys_state *
-cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp)
-{
- struct task_group *tg, *parent;
-
- if (!cgrp->parent) {
- /* This is early initialization for the top cgroup */
- return &root_task_group.css;
- }
-
- parent = cgroup_tg(cgrp->parent);
- tg = sched_create_group(parent);
- if (IS_ERR(tg))
- return ERR_PTR(-ENOMEM);
-
- return &tg->css;
-}
-
-static void
-cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
-{
- struct task_group *tg = cgroup_tg(cgrp);
-
- sched_destroy_group(tg);
-}
-
-static int
-cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
-{
-#ifdef CONFIG_RT_GROUP_SCHED
- if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk))
- return -EINVAL;
-#else
- /* We don't support RT-tasks being in separate groups */
- if (tsk->sched_class != &fair_sched_class)
- return -EINVAL;
-#endif
- return 0;
-}
-
-static void
-cpu_cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
-{
- sched_move_task(tsk);
-}
-
-static void
-cpu_cgroup_exit(struct cgroup_subsys *ss, struct cgroup *cgrp,
- struct cgroup *old_cgrp, struct task_struct *task)
-{
- /*
- * cgroup_exit() is called in the copy_process() failure path.
- * Ignore this case since the task hasn't ran yet, this avoids
- * trying to poke a half freed task state from generic code.
- */
- if (!(task->flags & PF_EXITING))
- return;
-
- sched_move_task(task);
-}
-
-#ifdef CONFIG_FAIR_GROUP_SCHED
-static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype,
- u64 shareval)
-{
- return sched_group_set_shares(cgroup_tg(cgrp), scale_load(shareval));
-}
-
-static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft)
-{
- struct task_group *tg = cgroup_tg(cgrp);
-
- return (u64) scale_load_down(tg->shares);
-}
-
-#ifdef CONFIG_CFS_BANDWIDTH
-static DEFINE_MUTEX(cfs_constraints_mutex);
-
-const u64 max_cfs_quota_period = 1 * NSEC_PER_SEC; /* 1s */
-const u64 min_cfs_quota_period = 1 * NSEC_PER_MSEC; /* 1ms */
-
-static int __cfs_schedulable(struct task_group *tg, u64 period, u64 runtime);
-
-static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota)
-{
- int i, ret = 0, runtime_enabled, runtime_was_enabled;
- struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
-
- if (tg == &root_task_group)
- return -EINVAL;
-
- /*
- * Ensure we have at some amount of bandwidth every period. This is
- * to prevent reaching a state of large arrears when throttled via
- * entity_tick() resulting in prolonged exit starvation.
- */
- if (quota < min_cfs_quota_period || period < min_cfs_quota_period)
- return -EINVAL;
-
- /*
- * Likewise, bound things on the otherside by preventing insane quota
- * periods. This also allows us to normalize in computing quota
- * feasibility.
- */
- if (period > max_cfs_quota_period)
- return -EINVAL;
-
- mutex_lock(&cfs_constraints_mutex);
- ret = __cfs_schedulable(tg, period, quota);
- if (ret)
- goto out_unlock;
-
- runtime_enabled = quota != RUNTIME_INF;
- runtime_was_enabled = cfs_b->quota != RUNTIME_INF;
- account_cfs_bandwidth_used(runtime_enabled, runtime_was_enabled);
- raw_spin_lock_irq(&cfs_b->lock);
- cfs_b->period = ns_to_ktime(period);
- cfs_b->quota = quota;
-
- __refill_cfs_bandwidth_runtime(cfs_b);
- /* restart the period timer (if active) to handle new period expiry */
- if (runtime_enabled && cfs_b->timer_active) {
- /* force a reprogram */
- cfs_b->timer_active = 0;
- __start_cfs_bandwidth(cfs_b);
- }
- raw_spin_unlock_irq(&cfs_b->lock);
-
- for_each_possible_cpu(i) {
- struct cfs_rq *cfs_rq = tg->cfs_rq[i];
- struct rq *rq = cfs_rq->rq;
-
- raw_spin_lock_irq(&rq->lock);
- cfs_rq->runtime_enabled = runtime_enabled;
- cfs_rq->runtime_remaining = 0;
-
- if (cfs_rq->throttled)
- unthrottle_cfs_rq(cfs_rq);
- raw_spin_unlock_irq(&rq->lock);
- }
-out_unlock:
- mutex_unlock(&cfs_constraints_mutex);
-
- return ret;
-}
-
-int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us)
-{
- u64 quota, period;
-
- period = ktime_to_ns(tg->cfs_bandwidth.period);
- if (cfs_quota_us < 0)
- quota = RUNTIME_INF;
- else
- quota = (u64)cfs_quota_us * NSEC_PER_USEC;
-
- return tg_set_cfs_bandwidth(tg, period, quota);
-}
-
-long tg_get_cfs_quota(struct task_group *tg)
-{
- u64 quota_us;
-
- if (tg->cfs_bandwidth.quota == RUNTIME_INF)
- return -1;
-
- quota_us = tg->cfs_bandwidth.quota;
- do_div(quota_us, NSEC_PER_USEC);
-
- return quota_us;
-}
-
-int tg_set_cfs_period(struct task_group *tg, long cfs_period_us)
-{
- u64 quota, period;
-
- period = (u64)cfs_period_us * NSEC_PER_USEC;
- quota = tg->cfs_bandwidth.quota;
-
- if (period <= 0)
- return -EINVAL;
-
- return tg_set_cfs_bandwidth(tg, period, quota);
-}
-
-long tg_get_cfs_period(struct task_group *tg)
-{
- u64 cfs_period_us;
-
- cfs_period_us = ktime_to_ns(tg->cfs_bandwidth.period);
- do_div(cfs_period_us, NSEC_PER_USEC);
-
- return cfs_period_us;
-}
-
-static s64 cpu_cfs_quota_read_s64(struct cgroup *cgrp, struct cftype *cft)
-{
- return tg_get_cfs_quota(cgroup_tg(cgrp));
-}
-
-static int cpu_cfs_quota_write_s64(struct cgroup *cgrp, struct cftype *cftype,
- s64 cfs_quota_us)
-{
- return tg_set_cfs_quota(cgroup_tg(cgrp), cfs_quota_us);
-}
-
-static u64 cpu_cfs_period_read_u64(struct cgroup *cgrp, struct cftype *cft)
-{
- return tg_get_cfs_period(cgroup_tg(cgrp));
-}
-
-static int cpu_cfs_period_write_u64(struct cgroup *cgrp, struct cftype *cftype,
- u64 cfs_period_us)
-{
- return tg_set_cfs_period(cgroup_tg(cgrp), cfs_period_us);
-}
-
-struct cfs_schedulable_data {
- struct task_group *tg;
- u64 period, quota;
-};
-
-/*
- * normalize group quota/period to be quota/max_period
- * note: units are usecs
- */
-static u64 normalize_cfs_quota(struct task_group *tg,
- struct cfs_schedulable_data *d)
-{
- u64 quota, period;
-
- if (tg == d->tg) {
- period = d->period;
- quota = d->quota;
- } else {
- period = tg_get_cfs_period(tg);
- quota = tg_get_cfs_quota(tg);
- }
-
- /* note: these should typically be equivalent */
- if (quota == RUNTIME_INF || quota == -1)
- return RUNTIME_INF;
-
- return to_ratio(period, quota);
-}
-
-static int tg_cfs_schedulable_down(struct task_group *tg, void *data)
-{
- struct cfs_schedulable_data *d = data;
- struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
- s64 quota = 0, parent_quota = -1;
-
- if (!tg->parent) {
- quota = RUNTIME_INF;
- } else {
- struct cfs_bandwidth *parent_b = &tg->parent->cfs_bandwidth;
-
- quota = normalize_cfs_quota(tg, d);
- parent_quota = parent_b->hierarchal_quota;
-
- /*
- * ensure max(child_quota) <= parent_quota, inherit when no
- * limit is set
- */
- if (quota == RUNTIME_INF)
- quota = parent_quota;
- else if (parent_quota != RUNTIME_INF && quota > parent_quota)
- return -EINVAL;
- }
- cfs_b->hierarchal_quota = quota;
-
- return 0;
-}
-
-static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota)
-{
- int ret;
- struct cfs_schedulable_data data = {
- .tg = tg,
- .period = period,
- .quota = quota,
- };
-
- if (quota != RUNTIME_INF) {
- do_div(data.period, NSEC_PER_USEC);
- do_div(data.quota, NSEC_PER_USEC);
- }
-
- rcu_read_lock();
- ret = walk_tg_tree(tg_cfs_schedulable_down, tg_nop, &data);
- rcu_read_unlock();
-
- return ret;
-}
-
-static int cpu_stats_show(struct cgroup *cgrp, struct cftype *cft,
- struct cgroup_map_cb *cb)
-{
- struct task_group *tg = cgroup_tg(cgrp);
- struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
-
- cb->fill(cb, "nr_periods", cfs_b->nr_periods);
- cb->fill(cb, "nr_throttled", cfs_b->nr_throttled);
- cb->fill(cb, "throttled_time", cfs_b->throttled_time);
-
- return 0;
-}
-#endif /* CONFIG_CFS_BANDWIDTH */
-#endif /* CONFIG_FAIR_GROUP_SCHED */
-
-#ifdef CONFIG_RT_GROUP_SCHED
-static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft,
- s64 val)
-{
- return sched_group_set_rt_runtime(cgroup_tg(cgrp), val);
-}
-
-static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft)
-{
- return sched_group_rt_runtime(cgroup_tg(cgrp));
-}
-
-static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype,
- u64 rt_period_us)
-{
- return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us);
-}
-
-static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft)
-{
- return sched_group_rt_period(cgroup_tg(cgrp));
-}
-#endif /* CONFIG_RT_GROUP_SCHED */
-
-static struct cftype cpu_files[] = {
-#ifdef CONFIG_FAIR_GROUP_SCHED
- {
- .name = "shares",
- .read_u64 = cpu_shares_read_u64,
- .write_u64 = cpu_shares_write_u64,
- },
-#endif
-#ifdef CONFIG_CFS_BANDWIDTH
- {
- .name = "cfs_quota_us",
- .read_s64 = cpu_cfs_quota_read_s64,
- .write_s64 = cpu_cfs_quota_write_s64,
- },
- {
- .name = "cfs_period_us",
- .read_u64 = cpu_cfs_period_read_u64,
- .write_u64 = cpu_cfs_period_write_u64,
- },
- {
- .name = "stat",
- .read_map = cpu_stats_show,
- },
-#endif
-#ifdef CONFIG_RT_GROUP_SCHED
- {
- .name = "rt_runtime_us",
- .read_s64 = cpu_rt_runtime_read,
- .write_s64 = cpu_rt_runtime_write,
- },
- {
- .name = "rt_period_us",
- .read_u64 = cpu_rt_period_read_uint,
- .write_u64 = cpu_rt_period_write_uint,
- },
-#endif
-};
-
-static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont)
-{
- return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files));
-}
-
-struct cgroup_subsys cpu_cgroup_subsys = {
- .name = "cpu",
- .create = cpu_cgroup_create,
- .destroy = cpu_cgroup_destroy,
- .can_attach_task = cpu_cgroup_can_attach_task,
- .attach_task = cpu_cgroup_attach_task,
- .exit = cpu_cgroup_exit,
- .populate = cpu_cgroup_populate,
- .subsys_id = cpu_cgroup_subsys_id,
- .early_init = 1,
-};
-
-#endif /* CONFIG_CGROUP_SCHED */
-
-#ifdef CONFIG_CGROUP_CPUACCT
-
-/*
- * CPU accounting code for task groups.
- *
- * Based on the work by Paul Menage (menage@google.com) and Balbir Singh
- * (balbir@in.ibm.com).
- */
-
-/* track cpu usage of a group of tasks and its child groups */
-struct cpuacct {
- struct cgroup_subsys_state css;
- /* cpuusage holds pointer to a u64-type object on every cpu */
- u64 __percpu *cpuusage;
- struct percpu_counter cpustat[CPUACCT_STAT_NSTATS];
- struct cpuacct *parent;
-};
-
-struct cgroup_subsys cpuacct_subsys;
-
-/* return cpu accounting group corresponding to this container */
-static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp)
-{
- return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id),
- struct cpuacct, css);
-}
-
-/* return cpu accounting group to which this task belongs */
-static inline struct cpuacct *task_ca(struct task_struct *tsk)
-{
- return container_of(task_subsys_state(tsk, cpuacct_subsys_id),
- struct cpuacct, css);
-}
-
-/* create a new cpu accounting group */
-static struct cgroup_subsys_state *cpuacct_create(
- struct cgroup_subsys *ss, struct cgroup *cgrp)
-{
- struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL);
- int i;
-
- if (!ca)
- goto out;
-
- ca->cpuusage = alloc_percpu(u64);
- if (!ca->cpuusage)
- goto out_free_ca;
-
- for (i = 0; i < CPUACCT_STAT_NSTATS; i++)
- if (percpu_counter_init(&ca->cpustat[i], 0))
- goto out_free_counters;
-
- if (cgrp->parent)
- ca->parent = cgroup_ca(cgrp->parent);
-
- return &ca->css;
-
-out_free_counters:
- while (--i >= 0)
- percpu_counter_destroy(&ca->cpustat[i]);
- free_percpu(ca->cpuusage);
-out_free_ca:
- kfree(ca);
-out:
- return ERR_PTR(-ENOMEM);
-}
-
-/* destroy an existing cpu accounting group */
-static void
-cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
-{
- struct cpuacct *ca = cgroup_ca(cgrp);
- int i;
-
- for (i = 0; i < CPUACCT_STAT_NSTATS; i++)
- percpu_counter_destroy(&ca->cpustat[i]);
- free_percpu(ca->cpuusage);
- kfree(ca);
-}
-
-static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu)
-{
- u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
- u64 data;
-
-#ifndef CONFIG_64BIT
- /*
- * Take rq->lock to make 64-bit read safe on 32-bit platforms.
- */
- raw_spin_lock_irq(&cpu_rq(cpu)->lock);
- data = *cpuusage;
- raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
-#else
- data = *cpuusage;
-#endif
-
- return data;
-}
-
-static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)
-{
- u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
-
-#ifndef CONFIG_64BIT
- /*
- * Take rq->lock to make 64-bit write safe on 32-bit platforms.
- */
- raw_spin_lock_irq(&cpu_rq(cpu)->lock);
- *cpuusage = val;
- raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
-#else
- *cpuusage = val;
-#endif
-}
-
-/* return total cpu usage (in nanoseconds) of a group */
-static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft)
-{
- struct cpuacct *ca = cgroup_ca(cgrp);
- u64 totalcpuusage = 0;
- int i;
-
- for_each_present_cpu(i)
- totalcpuusage += cpuacct_cpuusage_read(ca, i);
-
- return totalcpuusage;
-}
-
-static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype,
- u64 reset)
-{
- struct cpuacct *ca = cgroup_ca(cgrp);
- int err = 0;
- int i;
-
- if (reset) {
- err = -EINVAL;
- goto out;
- }
-
- for_each_present_cpu(i)
- cpuacct_cpuusage_write(ca, i, 0);
-
-out:
- return err;
-}
-
-static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft,
- struct seq_file *m)
-{
- struct cpuacct *ca = cgroup_ca(cgroup);
- u64 percpu;
- int i;
-
- for_each_present_cpu(i) {
- percpu = cpuacct_cpuusage_read(ca, i);
- seq_printf(m, "%llu ", (unsigned long long) percpu);
- }
- seq_printf(m, "\n");
- return 0;
-}
-
-static const char *cpuacct_stat_desc[] = {
- [CPUACCT_STAT_USER] = "user",
- [CPUACCT_STAT_SYSTEM] = "system",
-};
-
-static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft,
- struct cgroup_map_cb *cb)
-{
- struct cpuacct *ca = cgroup_ca(cgrp);
- int i;
-
- for (i = 0; i < CPUACCT_STAT_NSTATS; i++) {
- s64 val = percpu_counter_read(&ca->cpustat[i]);
- val = cputime64_to_clock_t(val);
- cb->fill(cb, cpuacct_stat_desc[i], val);
- }
- return 0;
-}
-
-static struct cftype files[] = {
- {
- .name = "usage",
- .read_u64 = cpuusage_read,
- .write_u64 = cpuusage_write,
- },
- {
- .name = "usage_percpu",
- .read_seq_string = cpuacct_percpu_seq_read,
- },
- {
- .name = "stat",
- .read_map = cpuacct_stats_show,
- },
-};
-
-static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
-{
- return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files));
-}
-
-/*
- * charge this task's execution time to its accounting group.
- *
- * called with rq->lock held.
- */
-void cpuacct_charge(struct task_struct *tsk, u64 cputime)
-{
- struct cpuacct *ca;
- int cpu;
-
- if (unlikely(!cpuacct_subsys.active))
- return;
-
- cpu = task_cpu(tsk);
-
- rcu_read_lock();
-
- ca = task_ca(tsk);
-
- for (; ca; ca = ca->parent) {
- u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
- *cpuusage += cputime;
- }
-
- rcu_read_unlock();
-}
-
-/*
- * When CONFIG_VIRT_CPU_ACCOUNTING is enabled one jiffy can be very large
- * in cputime_t units. As a result, cpuacct_update_stats calls
- * percpu_counter_add with values large enough to always overflow the
- * per cpu batch limit causing bad SMP scalability.
- *
- * To fix this we scale percpu_counter_batch by cputime_one_jiffy so we
- * batch the same amount of time with CONFIG_VIRT_CPU_ACCOUNTING disabled
- * and enabled. We cap it at INT_MAX which is the largest allowed batch value.
- */
-#ifdef CONFIG_SMP
-#define CPUACCT_BATCH \
- min_t(long, percpu_counter_batch * cputime_one_jiffy, INT_MAX)
-#else
-#define CPUACCT_BATCH 0
-#endif
-
-/*
- * Charge the system/user time to the task's accounting group.
- */
-void cpuacct_update_stats(struct task_struct *tsk,
- enum cpuacct_stat_index idx, cputime_t val)
-{
- struct cpuacct *ca;
- int batch = CPUACCT_BATCH;
-
- if (unlikely(!cpuacct_subsys.active))
- return;
-
- rcu_read_lock();
- ca = task_ca(tsk);
-
- do {
- __percpu_counter_add(&ca->cpustat[idx], val, batch);
- ca = ca->parent;
- } while (ca);
- rcu_read_unlock();
-}
-
-struct cgroup_subsys cpuacct_subsys = {
- .name = "cpuacct",
- .create = cpuacct_create,
- .destroy = cpuacct_destroy,
- .populate = cpuacct_populate,
- .subsys_id = cpuacct_subsys_id,
-};
-#endif /* CONFIG_CGROUP_CPUACCT */
--
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