diff options
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 9403 |
1 files changed, 0 insertions, 9403 deletions
diff --git a/kernel/sched.c b/kernel/sched.c deleted file mode 100644 index aa14a56f9d0..00000000000 --- a/kernel/sched.c +++ /dev/null @@ -1,9403 +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 <linux/smp_lock.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/stop_machine.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 <asm/tlb.h> -#include <asm/irq_regs.h> - -#include "sched_cpupri.h" -#include "workqueue_sched.h" - -#define CREATE_TRACE_POINTS -#include <trace/events/sched.h> - -/* - * Convert user-nice values [ -20 ... 0 ... 19 ] - * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], - * and back. - */ -#define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20) -#define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20) -#define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio) - -/* - * 'User priority' is the nice value converted to something we - * can work with better when scaling various scheduler parameters, - * it's a [ 0 ... 39 ] range. - */ -#define USER_PRIO(p) ((p)-MAX_RT_PRIO) -#define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio) -#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO)) - -/* - * Helpers for converting nanosecond timing to jiffy resolution - */ -#define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) - -#define NICE_0_LOAD SCHED_LOAD_SCALE -#define NICE_0_SHIFT SCHED_LOAD_SHIFT - -/* - * These are the 'tuning knobs' of the scheduler: - * - * default timeslice is 100 msecs (used only for SCHED_RR tasks). - * Timeslices get refilled after they expire. - */ -#define DEF_TIMESLICE (100 * HZ / 1000) - -/* - * single value that denotes runtime == period, ie unlimited time. - */ -#define RUNTIME_INF ((u64)~0ULL) - -static inline int rt_policy(int policy) -{ - if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR)) - return 1; - return 0; -} - -static inline int task_has_rt_policy(struct task_struct *p) -{ - return rt_policy(p->policy); -} - -/* - * This is the priority-queue data structure of the RT scheduling class: - */ -struct rt_prio_array { - DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ - struct list_head queue[MAX_RT_PRIO]; -}; - -struct rt_bandwidth { - /* nests inside the rq lock: */ - raw_spinlock_t rt_runtime_lock; - ktime_t rt_period; - u64 rt_runtime; - struct hrtimer rt_period_timer; -}; - -static struct rt_bandwidth def_rt_bandwidth; - -static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); - -static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) -{ - struct rt_bandwidth *rt_b = - container_of(timer, struct rt_bandwidth, rt_period_timer); - ktime_t now; - int overrun; - int idle = 0; - - for (;;) { - now = hrtimer_cb_get_time(timer); - overrun = hrtimer_forward(timer, now, rt_b->rt_period); - - if (!overrun) - break; - - idle = do_sched_rt_period_timer(rt_b, overrun); - } - - return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; -} - -static -void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) -{ - rt_b->rt_period = ns_to_ktime(period); - rt_b->rt_runtime = runtime; - - raw_spin_lock_init(&rt_b->rt_runtime_lock); - - hrtimer_init(&rt_b->rt_period_timer, - CLOCK_MONOTONIC, HRTIMER_MODE_REL); - rt_b->rt_period_timer.function = sched_rt_period_timer; -} - -static inline int rt_bandwidth_enabled(void) -{ - return sysctl_sched_rt_runtime >= 0; -} - -static void start_rt_bandwidth(struct rt_bandwidth *rt_b) -{ - ktime_t now; - - if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) - return; - - if (hrtimer_active(&rt_b->rt_period_timer)) - return; - - raw_spin_lock(&rt_b->rt_runtime_lock); - for (;;) { - unsigned long delta; - ktime_t soft, hard; - - if (hrtimer_active(&rt_b->rt_period_timer)) - break; - - now = hrtimer_cb_get_time(&rt_b->rt_period_timer); - hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period); - - soft = hrtimer_get_softexpires(&rt_b->rt_period_timer); - hard = hrtimer_get_expires(&rt_b->rt_period_timer); - delta = ktime_to_ns(ktime_sub(hard, soft)); - __hrtimer_start_range_ns(&rt_b->rt_period_timer, soft, delta, - HRTIMER_MODE_ABS_PINNED, 0); - } - raw_spin_unlock(&rt_b->rt_runtime_lock); -} - -#ifdef CONFIG_RT_GROUP_SCHED -static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) -{ - hrtimer_cancel(&rt_b->rt_period_timer); -} -#endif - -/* - * sched_domains_mutex serializes calls to arch_init_sched_domains, - * detach_destroy_domains and partition_sched_domains. - */ -static DEFINE_MUTEX(sched_domains_mutex); - -#ifdef CONFIG_CGROUP_SCHED - -#include <linux/cgroup.h> - -struct cfs_rq; - -static LIST_HEAD(task_groups); - -/* task group related information */ -struct task_group { - struct cgroup_subsys_state css; - -#ifdef CONFIG_FAIR_GROUP_SCHED - /* schedulable entities of this group on each cpu */ - struct sched_entity **se; - /* runqueue "owned" by this group on each cpu */ - struct cfs_rq **cfs_rq; - unsigned long shares; -#endif - -#ifdef CONFIG_RT_GROUP_SCHED - struct sched_rt_entity **rt_se; - struct rt_rq **rt_rq; - - struct rt_bandwidth rt_bandwidth; -#endif - - struct rcu_head rcu; - struct list_head list; - - struct task_group *parent; - struct list_head siblings; - struct list_head children; -}; - -#define root_task_group init_task_group - -/* task_group_lock serializes add/remove of task groups and also changes to - * a task group's cpu shares. - */ -static DEFINE_SPINLOCK(task_group_lock); - -#ifdef CONFIG_FAIR_GROUP_SCHED - -#ifdef CONFIG_SMP -static int root_task_group_empty(void) -{ - return list_empty(&root_task_group.children); -} -#endif - -# define INIT_TASK_GROUP_LOAD NICE_0_LOAD - -/* - * A weight of 0 or 1 can cause arithmetics problems. - * A weight of a cfs_rq is the sum of weights of which entities - * are queued on this cfs_rq, so a weight of a entity should not be - * too large, so as the shares value of a task group. - * (The default weight is 1024 - so there's no practical - * limitation from this.) - */ -#define MIN_SHARES 2 -#define MAX_SHARES (1UL << 18) - -static int init_task_group_load = INIT_TASK_GROUP_LOAD; -#endif - -/* Default task group. - * Every task in system belong to this group at bootup. - */ -struct task_group init_task_group; - -#endif /* CONFIG_CGROUP_SCHED */ - -/* CFS-related fields in a runqueue */ -struct cfs_rq { - struct load_weight load; - unsigned long nr_running; - - u64 exec_clock; - u64 min_vruntime; - - struct rb_root tasks_timeline; - struct rb_node *rb_leftmost; - - struct list_head tasks; - struct list_head *balance_iterator; - - /* - * 'curr' points to currently running entity on this cfs_rq. - * It is set to NULL otherwise (i.e when none are currently running). - */ - struct sched_entity *curr, *next, *last; - - unsigned int nr_spread_over; - -#ifdef CONFIG_FAIR_GROUP_SCHED - struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ - - /* - * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in - * a hierarchy). Non-leaf lrqs hold other higher schedulable entities - * (like users, containers etc.) - * - * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This - * list is used during load balance. - */ - struct list_head leaf_cfs_rq_list; - struct task_group *tg; /* group that "owns" this runqueue */ - -#ifdef CONFIG_SMP - /* - * the part of load.weight contributed by tasks - */ - unsigned long task_weight; - - /* - * h_load = weight * f(tg) - * - * Where f(tg) is the recursive weight fraction assigned to - * this group. - */ - unsigned long h_load; - - /* - * this cpu's part of tg->shares - */ - unsigned long shares; - - /* - * load.weight at the time we set shares - */ - unsigned long rq_weight; -#endif -#endif -}; - -/* Real-Time classes' related field in a runqueue: */ -struct rt_rq { - struct rt_prio_array active; - unsigned long rt_nr_running; -#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED - struct { - int curr; /* highest queued rt task prio */ -#ifdef CONFIG_SMP - int next; /* next highest */ -#endif - } highest_prio; -#endif -#ifdef CONFIG_SMP - unsigned long rt_nr_migratory; - unsigned long rt_nr_total; - int overloaded; - struct plist_head pushable_tasks; -#endif - int rt_throttled; - u64 rt_time; - u64 rt_runtime; - /* Nests inside the rq lock: */ - raw_spinlock_t rt_runtime_lock; - -#ifdef CONFIG_RT_GROUP_SCHED - unsigned long rt_nr_boosted; - - struct rq *rq; - struct list_head leaf_rt_rq_list; - struct task_group *tg; -#endif -}; - -#ifdef CONFIG_SMP - -/* - * We add the notion of a root-domain which will be used to define per-domain - * variables. Each exclusive cpuset essentially defines an island domain by - * fully partitioning the member cpus from any other cpuset. Whenever a new - * exclusive cpuset is created, we also create and attach a new root-domain - * object. - * - */ -struct root_domain { - atomic_t refcount; - cpumask_var_t span; - cpumask_var_t online; - - /* - * The "RT overload" flag: it gets set if a CPU has more than - * one runnable RT task. - */ - cpumask_var_t rto_mask; - atomic_t rto_count; - struct cpupri cpupri; -}; - -/* - * By default the system creates a single root-domain with all cpus as - * members (mimicking the global state we have today). - */ -static struct root_domain def_root_domain; - -#endif /* CONFIG_SMP */ - -/* - * This is the main, per-CPU runqueue data structure. - * - * Locking rule: those places that want to lock multiple runqueues - * (such as the load balancing or the thread migration code), lock - * acquire operations must be ordered by ascending &runqueue. - */ -struct rq { - /* runqueue lock: */ - raw_spinlock_t lock; - - /* - * nr_running and cpu_load should be in the same cacheline because - * remote CPUs use both these fields when doing load calculation. - */ - unsigned long nr_running; - #define CPU_LOAD_IDX_MAX 5 - unsigned long cpu_load[CPU_LOAD_IDX_MAX]; - unsigned long last_load_update_tick; -#ifdef CONFIG_NO_HZ - u64 nohz_stamp; - unsigned char nohz_balance_kick; -#endif - unsigned int skip_clock_update; - - /* capture load from *all* tasks on this cpu: */ - struct load_weight load; - unsigned long nr_load_updates; - u64 nr_switches; - - struct cfs_rq cfs; - struct rt_rq rt; - -#ifdef CONFIG_FAIR_GROUP_SCHED - /* list of leaf cfs_rq on this cpu: */ - struct list_head leaf_cfs_rq_list; -#endif -#ifdef CONFIG_RT_GROUP_SCHED - struct list_head leaf_rt_rq_list; -#endif - - /* - * This is part of a global counter where only the total sum - * over all CPUs matters. A task can increase this counter on - * one CPU and if it got migrated afterwards it may decrease - * it on another CPU. Always updated under the runqueue lock: - */ - unsigned long nr_uninterruptible; - - struct task_struct *curr, *idle, *stop; - unsigned long next_balance; - struct mm_struct *prev_mm; - - u64 clock; - u64 clock_task; - - atomic_t nr_iowait; - -#ifdef CONFIG_SMP - struct root_domain *rd; - struct sched_domain *sd; - - unsigned long cpu_power; - - unsigned char idle_at_tick; - /* For active balancing */ - int post_schedule; - int active_balance; - int push_cpu; - struct cpu_stop_work active_balance_work; - /* cpu of this runqueue: */ - int cpu; - int online; - - unsigned long avg_load_per_task; - - u64 rt_avg; - u64 age_stamp; - u64 idle_stamp; - u64 avg_idle; -#endif - -#ifdef CONFIG_IRQ_TIME_ACCOUNTING - u64 prev_irq_time; -#endif - - /* calc_load related fields */ - unsigned long calc_load_update; - long calc_load_active; - -#ifdef CONFIG_SCHED_HRTICK -#ifdef CONFIG_SMP - int hrtick_csd_pending; - struct call_single_data hrtick_csd; -#endif - struct hrtimer hrtick_timer; -#endif - -#ifdef CONFIG_SCHEDSTATS - /* latency stats */ - struct sched_info rq_sched_info; - unsigned long long rq_cpu_time; - /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ - - /* sys_sched_yield() stats */ - unsigned int yld_count; - - /* schedule() stats */ - unsigned int sched_switch; - unsigned int sched_count; - unsigned int sched_goidle; - - /* try_to_wake_up() stats */ - unsigned int ttwu_count; - unsigned int ttwu_local; - - /* BKL stats */ - unsigned int bkl_count; -#endif -}; - -static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); - -static inline -void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) -{ - rq->curr->sched_class->check_preempt_curr(rq, p, flags); - - /* - * 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 (test_tsk_need_resched(p)) - rq->skip_clock_update = 1; -} - -static inline int cpu_of(struct rq *rq) -{ -#ifdef CONFIG_SMP - return rq->cpu; -#else - return 0; -#endif -} - -#define rcu_dereference_check_sched_domain(p) \ - rcu_dereference_check((p), \ - rcu_read_lock_sched_held() || \ - lockdep_is_held(&sched_domains_mutex)) - -/* - * The domain tree (rq->sd) is protected by RCU's quiescent state transition. - * See detach_destroy_domains: synchronize_sched for details. - * - * The domain tree of any CPU may only be accessed from within - * preempt-disabled sections. - */ -#define for_each_domain(cpu, __sd) \ - for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent) - -#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) -#define this_rq() (&__get_cpu_var(runqueues)) -#define task_rq(p) cpu_rq(task_cpu(p)) -#define cpu_curr(cpu) (cpu_rq(cpu)->curr) -#define raw_rq() (&__raw_get_cpu_var(runqueues)) - -#ifdef CONFIG_CGROUP_SCHED - -/* - * Return the group to which this tasks belongs. - * - * We use task_subsys_state_check() and extend the RCU verification - * with lockdep_is_held(&task_rq(p)->lock) because cpu_cgroup_attach() - * holds that lock for each task it moves into the cgroup. Therefore - * by holding that lock, we pin the task to the current cgroup. - */ -static inline struct task_group *task_group(struct task_struct *p) -{ - struct cgroup_subsys_state *css; - - css = task_subsys_state_check(p, cpu_cgroup_subsys_id, - lockdep_is_held(&task_rq(p)->lock)); - return container_of(css, struct task_group, css); -} - -/* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ -static inline void set_task_rq(struct task_struct *p, unsigned int cpu) -{ -#ifdef CONFIG_FAIR_GROUP_SCHED - p->se.cfs_rq = task_group(p)->cfs_rq[cpu]; - p->se.parent = task_group(p)->se[cpu]; -#endif - -#ifdef CONFIG_RT_GROUP_SCHED - p->rt.rt_rq = task_group(p)->rt_rq[cpu]; - p->rt.parent = task_group(p)->rt_se[cpu]; -#endif -} - -#else /* CONFIG_CGROUP_SCHED */ - -static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } -static inline struct task_group *task_group(struct task_struct *p) -{ - return NULL; -} - -#endif /* CONFIG_CGROUP_SCHED */ - -static u64 irq_time_cpu(int cpu); -static void sched_irq_time_avg_update(struct rq *rq, u64 irq_time); - -inline void update_rq_clock(struct rq *rq) -{ - if (!rq->skip_clock_update) { - int cpu = cpu_of(rq); - u64 irq_time; - - rq->clock = sched_clock_cpu(cpu); - irq_time = irq_time_cpu(cpu); - if (rq->clock - irq_time > rq->clock_task) - rq->clock_task = rq->clock - irq_time; - - sched_irq_time_avg_update(rq, irq_time); - } -} - -/* - * Tunables that become constants when CONFIG_SCHED_DEBUG is off: - */ -#ifdef CONFIG_SCHED_DEBUG -# define const_debug __read_mostly -#else -# define const_debug static const -#endif - -/** - * runqueue_is_locked - * @cpu: the processor in question. - * - * Returns true if the current cpu runqueue is locked. - * This interface allows printk to be called with the runqueue lock - * held and know whether or not it is OK to wake up the klogd. - */ -int runqueue_is_locked(int cpu) -{ - return raw_spin_is_locked(&cpu_rq(cpu)->lock); -} - -/* - * Debugging: various feature bits - */ - -#define SCHED_FEAT(name, enabled) \ - __SCHED_FEAT_##name , - -enum { -#include "sched_features.h" -}; - -#undef SCHED_FEAT - -#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(buf, "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 - -#define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) - -/* - * Number of tasks to iterate in a single balance run. - * Limited because this is done with IRQs disabled. - */ -const_debug unsigned int sysctl_sched_nr_migrate = 32; - -/* - * ratelimit for updating the group shares. - * default: 0.25ms - */ -unsigned int sysctl_sched_shares_ratelimit = 250000; -unsigned int normalized_sysctl_sched_shares_ratelimit = 250000; - -/* - * Inject some fuzzyness into changing the per-cpu group shares - * this avoids remote rq-locks at the expense of fairness. - * default: 4 - */ -unsigned int sysctl_sched_shares_thresh = 4; - -/* - * 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; - -static __read_mostly int scheduler_running; - -/* - * part of the period that we allow rt tasks to run in us. - * default: 0.95s - */ -int sysctl_sched_rt_runtime = 950000; - -static inline u64 global_rt_period(void) -{ - return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; -} - -static inline u64 global_rt_runtime(void) -{ - if (sysctl_sched_rt_runtime < 0) - return RUNTIME_INF; - - return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; -} - -#ifndef prepare_arch_switch -# define prepare_arch_switch(next) do { } while (0) -#endif -#ifndef finish_arch_switch -# define finish_arch_switch(prev) do { } while (0) -#endif - -static inline int task_current(struct rq *rq, struct task_struct *p) -{ - return rq->curr == p; -} - -#ifndef __ARCH_WANT_UNLOCKED_CTXSW -static inline int task_running(struct rq *rq, struct task_struct *p) -{ - return task_current(rq, p); -} - -static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) -{ -} - -static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) -{ -#ifdef CONFIG_DEBUG_SPINLOCK - /* this is a valid case when another task releases the spinlock */ - rq->lock.owner = current; -#endif - /* - * If we are tracking spinlock dependencies then we have to - * fix up the runqueue lock - which gets 'carried over' from - * prev into current: - */ - spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); - - raw_spin_unlock_irq(&rq->lock); -} - -#else /* __ARCH_WANT_UNLOCKED_CTXSW */ -static inline int task_running(struct rq *rq, struct task_struct *p) -{ -#ifdef CONFIG_SMP - return p->oncpu; -#else - return task_current(rq, p); -#endif -} - -static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) -{ -#ifdef CONFIG_SMP - /* - * We can optimise this out completely for !SMP, because the - * SMP rebalancing from interrupt is the only thing that cares - * here. - */ - next->oncpu = 1; -#endif -#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW - raw_spin_unlock_irq(&rq->lock); -#else - raw_spin_unlock(&rq->lock); -#endif -} - -static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) -{ -#ifdef CONFIG_SMP - /* - * After ->oncpu is cleared, the task can be moved to a different CPU. - * We must ensure this doesn't happen until the switch is completely - * finished. - */ - smp_wmb(); - prev->oncpu = 0; -#endif -#ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW - local_irq_enable(); -#endif -} -#endif /* __ARCH_WANT_UNLOCKED_CTXSW */ - -/* - * Check whether the task is waking, we use this to synchronize ->cpus_allowed - * against ttwu(). - */ -static inline int task_is_waking(struct task_struct *p) -{ - return unlikely(p->state == TASK_WAKING); -} - -/* - * __task_rq_lock - lock the runqueue a given task resides on. - * Must be called interrupts disabled. - */ -static inline struct rq *__task_rq_lock(struct task_struct *p) - __acquires(rq->lock) -{ - struct rq *rq; - - 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 the runqueue a given task resides on and disable - * interrupts. Note the ordering: we can safely lookup the task_rq without - * explicitly disabling preemption. - */ -static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) - __acquires(rq->lock) -{ - struct rq *rq; - - for (;;) { - local_irq_save(*flags); - rq = task_rq(p); - raw_spin_lock(&rq->lock); - if (likely(rq == task_rq(p))) - return rq; - raw_spin_unlock_irqrestore(&rq->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, unsigned long *flags) - __releases(rq->lock) -{ - raw_spin_unlock_irqrestore(&rq->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. - */ - -/* - * Use hrtick when: - * - enabled by features - * - hrtimer is actually high res - */ -static inline int hrtick_enabled(struct rq *rq) -{ - if (!sched_feat(HRTICK)) - return 0; - if (!cpu_active(cpu_of(rq))) - return 0; - return hrtimer_is_hres_active(&rq->hrtick_timer); -} - -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 - */ -static 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 - */ -static 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 - -static 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); -} - -static 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; - - for_each_domain(cpu, sd) { - for_each_cpu(i, sched_domain_span(sd)) - if (!idle_cpu(i)) - return i; - } - 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); -} - -#endif /* CONFIG_NO_HZ */ - -static u64 sched_avg_period(void) -{ - return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2; -} - -static 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; - } -} - -static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) -{ - rq->rt_avg += rt_delta; - sched_avg_update(rq); -} - -#else /* !CONFIG_SMP */ -static void resched_task(struct task_struct *p) -{ - assert_raw_spin_locked(&task_rq(p)->lock); - set_tsk_need_resched(p); -} - -static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) -{ -} - -static void sched_avg_update(struct rq *rq) -{ -} -#endif /* CONFIG_SMP */ - -#if BITS_PER_LONG == 32 -# define WMULT_CONST (~0UL) -#else -# define WMULT_CONST (1UL << 32) -#endif - -#define WMULT_SHIFT 32 - -/* - * Shift right and round: - */ -#define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y)) - -/* - * delta *= weight / lw - */ -static unsigned long -calc_delta_mine(unsigned long delta_exec, unsigned long weight, - struct load_weight *lw) -{ - u64 tmp; - - if (!lw->inv_weight) { - if (BITS_PER_LONG > 32 && unlikely(lw->weight >= WMULT_CONST)) - lw->inv_weight = 1; - else - lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2) - / (lw->weight+1); - } - - tmp = (u64)delta_exec * weight; - /* - * Check whether we'd overflow the 64-bit multiplication: - */ - if (unlikely(tmp > WMULT_CONST)) - tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight, - WMULT_SHIFT/2); - else - tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT); - - return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX); -} - -static inline void update_load_add(struct load_weight *lw, unsigned long inc) -{ - lw->weight += inc; - lw->inv_weight = 0; -} - -static inline void update_load_sub(struct load_weight *lw, unsigned long dec) -{ - lw->weight -= dec; - lw->inv_weight = 0; -} - -/* - * To aid in avoiding the subversion of "niceness" due to uneven distribution - * of tasks with abnormal "nice" values across CPUs the contribution that - * each task makes to its run queue's load is weighted according to its - * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a - * scaled version of the new time slice allocation that they receive on time - * slice expiry etc. - */ - -#define WEIGHT_IDLEPRIO 3 -#define WMULT_IDLEPRIO 1431655765 - -/* - * Nice levels are multiplicative, with a gentle 10% change for every - * nice level changed. I.e. when a CPU-bound task goes from nice 0 to - * nice 1, it will get ~10% less CPU time than another CPU-bound task - * that remained on nice 0. - * - * The "10% effect" is relative and cumulative: from _any_ nice level, - * if you go up 1 level, it's -10% CPU usage, if you go down 1 level - * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. - * If a task goes up by ~10% and another task goes down by ~10% then - * the relative distance between them is ~25%.) - */ -static const int prio_to_weight[40] = { - /* -20 */ 88761, 71755, 56483, 46273, 36291, - /* -15 */ 29154, 23254, 18705, 14949, 11916, - /* -10 */ 9548, 7620, 6100, 4904, 3906, - /* -5 */ 3121, 2501, 1991, 1586, 1277, - /* 0 */ 1024, 820, 655, 526, 423, - /* 5 */ 335, 272, 215, 172, 137, - /* 10 */ 110, 87, 70, 56, 45, - /* 15 */ 36, 29, 23, 18, 15, -}; - -/* - * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. - * - * In cases where the weight does not change often, we can use the - * precalculated inverse to speed up arithmetics by turning divisions - * into multiplications: - */ -static const u32 prio_to_wmult[40] = { - /* -20 */ 48388, 59856, 76040, 92818, 118348, - /* -15 */ 147320, 184698, 229616, 287308, 360437, - /* -10 */ 449829, 563644, 704093, 875809, 1099582, - /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, - /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, - /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, - /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, - /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, -}; - -/* Time spent by the tasks of the cpu accounting group executing in ... */ -enum cpuacct_stat_index { - CPUACCT_STAT_USER, /* ... user mode */ - CPUACCT_STAT_SYSTEM, /* ... kernel mode */ - - CPUACCT_STAT_NSTATS, -}; - -#ifdef CONFIG_CGROUP_CPUACCT -static void cpuacct_charge(struct task_struct *tsk, u64 cputime); -static void cpuacct_update_stats(struct task_struct *tsk, - enum cpuacct_stat_index idx, cputime_t val); -#else -static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} -static inline void cpuacct_update_stats(struct task_struct *tsk, - enum cpuacct_stat_index idx, cputime_t val) {} -#endif - -static inline void inc_cpu_load(struct rq *rq, unsigned long load) -{ - update_load_add(&rq->load, load); -} - -static inline void dec_cpu_load(struct rq *rq, unsigned long load) -{ - update_load_sub(&rq->load, load); -} - -#if (defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)) || defined(CONFIG_RT_GROUP_SCHED) -typedef int (*tg_visitor)(struct task_group *, void *); - -/* - * Iterate the full tree, calling @down when first entering a node and @up when - * leaving it for the final time. - */ -static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) -{ - struct task_group *parent, *child; - int ret; - - rcu_read_lock(); - parent = &root_task_group; -down: - ret = (*down)(parent, data); - if (ret) - goto out_unlock; - list_for_each_entry_rcu(child, &parent->children, siblings) { - parent = child; - goto down; - -up: - continue; - } - ret = (*up)(parent, data); - if (ret) - goto out_unlock; - - child = parent; - parent = parent->parent; - if (parent) - goto up; -out_unlock: - rcu_read_unlock(); - - return ret; -} - -static int tg_nop(struct task_group *tg, void *data) -{ - return 0; -} -#endif - -#ifdef CONFIG_SMP -/* Used instead of source_load when we know the type == 0 */ -static unsigned long weighted_cpuload(const int cpu) -{ - return cpu_rq(cpu)->load.weight; -} - -/* - * Return a low guess at the load of a migration-source cpu weighted - * according to the scheduling class and "nice" value. - * - * We want to under-estimate the load of migration sources, to - * balance conservatively. - */ -static unsigned long source_load(int cpu, int type) -{ - struct rq *rq = cpu_rq(cpu); - unsigned long total = weighted_cpuload(cpu); - - if (type == 0 || !sched_feat(LB_BIAS)) - return total; - - return min(rq->cpu_load[type-1], total); -} - -/* - * Return a high guess at the load of a migration-target cpu weighted - * according to the scheduling class and "nice" value. - */ -static unsigned long target_load(int cpu, int type) -{ - struct rq *rq = cpu_rq(cpu); - unsigned long total = weighted_cpuload(cpu); - - if (type == 0 || !sched_feat(LB_BIAS)) - return total; - - return max(rq->cpu_load[type-1], total); -} - -static unsigned long power_of(int cpu) -{ - return cpu_rq(cpu)->cpu_power; -} - -static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); - -static unsigned long cpu_avg_load_per_task(int cpu) -{ - struct rq *rq = cpu_rq(cpu); - unsigned long nr_running = ACCESS_ONCE(rq->nr_running); - - if (nr_running) - rq->avg_load_per_task = rq->load.weight / nr_running; - else - rq->avg_load_per_task = 0; - - return rq->avg_load_per_task; -} - -#ifdef CONFIG_FAIR_GROUP_SCHED - -static __read_mostly unsigned long __percpu *update_shares_data; - -static void __set_se_shares(struct sched_entity *se, unsigned long shares); - -/* - * Calculate and set the cpu's group shares. - */ -static void update_group_shares_cpu(struct task_group *tg, int cpu, - unsigned long sd_shares, - unsigned long sd_rq_weight, - unsigned long *usd_rq_weight) -{ - unsigned long shares, rq_weight; - int boost = 0; - - rq_weight = usd_rq_weight[cpu]; - if (!rq_weight) { - boost = 1; - rq_weight = NICE_0_LOAD; - } - - /* - * \Sum_j shares_j * rq_weight_i - * shares_i = ----------------------------- - * \Sum_j rq_weight_j - */ - shares = (sd_shares * rq_weight) / sd_rq_weight; - shares = clamp_t(unsigned long, shares, MIN_SHARES, MAX_SHARES); - - if (abs(shares - tg->se[cpu]->load.weight) > - sysctl_sched_shares_thresh) { - struct rq *rq = cpu_rq(cpu); - unsigned long flags; - - raw_spin_lock_irqsave(&rq->lock, flags); - tg->cfs_rq[cpu]->rq_weight = boost ? 0 : rq_weight; - tg->cfs_rq[cpu]->shares = boost ? 0 : shares; - __set_se_shares(tg->se[cpu], shares); - raw_spin_unlock_irqrestore(&rq->lock, flags); - } -} - -/* - * Re-compute the task group their per cpu shares over the given domain. - * This needs to be done in a bottom-up fashion because the rq weight of a - * parent group depends on the shares of its child groups. - */ -static int tg_shares_up(struct task_group *tg, void *data) -{ - unsigned long weight, rq_weight = 0, sum_weight = 0, shares = 0; - unsigned long *usd_rq_weight; - struct sched_domain *sd = data; - unsigned long flags; - int i; - - if (!tg->se[0]) - return 0; - - local_irq_save(flags); - usd_rq_weight = per_cpu_ptr(update_shares_data, smp_processor_id()); - - for_each_cpu(i, sched_domain_span(sd)) { - weight = tg->cfs_rq[i]->load.weight; - usd_rq_weight[i] = weight; - - rq_weight += weight; - /* - * If there are currently no tasks on the cpu pretend there - * is one of average load so that when a new task gets to - * run here it will not get delayed by group starvation. - */ - if (!weight) - weight = NICE_0_LOAD; - - sum_weight += weight; - shares += tg->cfs_rq[i]->shares; - } - - if (!rq_weight) - rq_weight = sum_weight; - - if ((!shares && rq_weight) || shares > tg->shares) - shares = tg->shares; - - if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE)) - shares = tg->shares; - - for_each_cpu(i, sched_domain_span(sd)) - update_group_shares_cpu(tg, i, shares, rq_weight, usd_rq_weight); - - local_irq_restore(flags); - - return 0; -} - -/* - * Compute the cpu's hierarchical load factor for each task group. - * This needs to be done in a top-down fashion because the load of a child - * group is a fraction of its parents load. - */ -static int tg_load_down(struct task_group *tg, void *data) -{ - unsigned long load; - long cpu = (long)data; - - if (!tg->parent) { - load = cpu_rq(cpu)->load.weight; - } else { - load = tg->parent->cfs_rq[cpu]->h_load; - load *= tg->cfs_rq[cpu]->shares; - load /= tg->parent->cfs_rq[cpu]->load.weight + 1; - } - - tg->cfs_rq[cpu]->h_load = load; - - return 0; -} - -static void update_shares(struct sched_domain *sd) -{ - s64 elapsed; - u64 now; - - if (root_task_group_empty()) - return; - - now = local_clock(); - elapsed = now - sd->last_update; - - if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) { - sd->last_update = now; - walk_tg_tree(tg_nop, tg_shares_up, sd); - } -} - -static void update_h_load(long cpu) -{ - walk_tg_tree(tg_load_down, tg_nop, (void *)cpu); -} - -#else - -static inline void update_shares(struct sched_domain *sd) -{ -} - -#endif - -#ifdef CONFIG_PREEMPT - -static void double_rq_lock(struct rq *rq1, struct rq *rq2); - -/* - * fair double_lock_balance: Safely acquires both rq->locks in a fair - * way at the expense of forcing extra atomic operations in all - * invocations. This assures that the double_lock is acquired using the - * same underlying policy as the spinlock_t on this architecture, which - * reduces latency compared to the unfair variant below. However, it - * also adds more overhead and therefore may reduce throughput. - */ -static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) - __releases(this_rq->lock) - __acquires(busiest->lock) - __acquires(this_rq->lock) -{ - raw_spin_unlock(&this_rq->lock); - double_rq_lock(this_rq, busiest); - - return 1; -} - -#else -/* - * Unfair double_lock_balance: Optimizes throughput at the expense of - * latency by eliminating extra atomic operations when the locks are - * already in proper order on entry. This favors lower cpu-ids and will - * grant the double lock to lower cpus over higher ids under contention, - * regardless of entry order into the function. - */ -static int _double_lock_balance(struct rq *this_rq, struct rq *busiest) - __releases(this_rq->lock) - __acquires(busiest->lock) - __acquires(this_rq->lock) -{ - int ret = 0; - - if (unlikely(!raw_spin_trylock(&busiest->lock))) { - if (busiest < this_rq) { - raw_spin_unlock(&this_rq->lock); - raw_spin_lock(&busiest->lock); - raw_spin_lock_nested(&this_rq->lock, - SINGLE_DEPTH_NESTING); - ret = 1; - } else - raw_spin_lock_nested(&busiest->lock, - SINGLE_DEPTH_NESTING); - } - return ret; -} - -#endif /* CONFIG_PREEMPT */ - -/* - * double_lock_balance - lock the busiest runqueue, this_rq is locked already. - */ -static int double_lock_balance(struct rq *this_rq, struct rq *busiest) -{ - if (unlikely(!irqs_disabled())) { - /* printk() doesn't work good under rq->lock */ - raw_spin_unlock(&this_rq->lock); - BUG_ON(1); - } - - return _double_lock_balance(this_rq, busiest); -} - -static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) - __releases(busiest->lock) -{ - raw_spin_unlock(&busiest->lock); - lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); -} - -/* - * double_rq_lock - safely lock two runqueues - * - * Note this does not disable interrupts like task_rq_lock, - * you need to do so manually before calling. - */ -static void double_rq_lock(struct rq *rq1, struct rq *rq2) - __acquires(rq1->lock) - __acquires(rq2->lock) -{ - BUG_ON(!irqs_disabled()); - if (rq1 == rq2) { - raw_spin_lock(&rq1->lock); - __acquire(rq2->lock); /* Fake it out ;) */ - } else { - if (rq1 < rq2) { - raw_spin_lock(&rq1->lock); - raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); - } else { - raw_spin_lock(&rq2->lock); - raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); - } - } -} - -/* - * double_rq_unlock - safely unlock two runqueues - * - * Note this does not restore interrupts like task_rq_unlock, - * you need to do so manually after calling. - */ -static void double_rq_unlock(struct rq *rq1, struct rq *rq2) - __releases(rq1->lock) - __releases(rq2->lock) -{ - raw_spin_unlock(&rq1->lock); - if (rq1 != rq2) - raw_spin_unlock(&rq2->lock); - else - __release(rq2->lock); -} - -#endif - -#ifdef CONFIG_FAIR_GROUP_SCHED -static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares) -{ -#ifdef CONFIG_SMP - cfs_rq->shares = shares; -#endif -} -#endif - -static void calc_load_account_idle(struct rq *this_rq); -static void update_sysctl(void); -static int get_update_sysctl_factor(void); -static void update_cpu_load(struct rq *this_rq); - -static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) -{ - set_task_rq(p, cpu); -#ifdef CONFIG_SMP - /* - * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be - * successfuly executed on another CPU. We must ensure that updates of - * per-task data have been completed by this moment. - */ - smp_wmb(); - task_thread_info(p)->cpu = cpu; -#endif -} - -static const struct sched_class rt_sched_class; - -#define sched_class_highest (&stop_sched_class) -#define for_each_class(class) \ - for (class = sched_class_highest; class; class = class->next) - -#include "sched_stats.h" - -static void inc_nr_running(struct rq *rq) -{ - rq->nr_running++; -} - -static void dec_nr_running(struct rq *rq) -{ - rq->nr_running--; -} - -static void set_load_weight(struct task_struct *p) -{ - /* - * SCHED_IDLE tasks get minimal weight: - */ - if (p->policy == SCHED_IDLE) { - p->se.load.weight = WEIGHT_IDLEPRIO; - p->se.load.inv_weight = WMULT_IDLEPRIO; - return; - } - - p->se.load.weight = prio_to_weight[p->static_prio - MAX_RT_PRIO]; - p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO]; -} - -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); - p->se.on_rq = 1; -} - -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); - p->se.on_rq = 0; -} - -/* - * activate_task - move a task to the runqueue. - */ -static 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); - inc_nr_running(rq); -} - -/* - * deactivate_task - remove a task from the runqueue. - */ -static 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); - dec_nr_running(rq); -} - -#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 (or semi updated value on 32 bit) 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; -} - -static u64 irq_time_cpu(int cpu) -{ - if (!sched_clock_irqtime) - return 0; - - return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu); -} - -void account_system_vtime(struct task_struct *curr) -{ - unsigned long flags; - int cpu; - u64 now, delta; - - if (!sched_clock_irqtime) - return; - - local_irq_save(flags); - - cpu = smp_processor_id(); - now = sched_clock_cpu(cpu); - delta = now - per_cpu(irq_start_time, cpu); - per_cpu(irq_start_time, cpu) = now; - /* - * 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()) - per_cpu(cpu_hardirq_time, cpu) += delta; - else if (in_serving_softirq() && !(curr->flags & PF_KSOFTIRQD)) - per_cpu(cpu_softirq_time, cpu) += delta; - - local_irq_restore(flags); -} -EXPORT_SYMBOL_GPL(account_system_vtime); - -static void sched_irq_time_avg_update(struct rq *rq, u64 curr_irq_time) -{ - if (sched_clock_irqtime && sched_feat(NONIRQ_POWER)) { - u64 delta_irq = curr_irq_time - rq->prev_irq_time; - rq->prev_irq_time = curr_irq_time; - sched_rt_avg_update(rq, delta_irq); - } -} - -#else - -static u64 irq_time_cpu(int cpu) -{ - return 0; -} - -static void sched_irq_time_avg_update(struct rq *rq, u64 curr_irq_time) { } - -#endif - -#include "sched_idletask.c" -#include "sched_fair.c" -#include "sched_rt.c" -#include "sched_stoptask.c" -#ifdef CONFIG_SCHED_DEBUG -# include "sched_debug.c" -#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, int running) -{ - if (prev_class != p->sched_class) { - if (prev_class->switched_from) - prev_class->switched_from(rq, p, running); - p->sched_class->switched_to(rq, p, running); - } else - p->sched_class->prio_changed(rq, p, oldprio, running); -} - -#ifdef CONFIG_SMP -/* - * Is this task likely cache-hot: - */ -static int -task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) -{ - s64 delta; - - if (p->sched_class != &fair_sched_class) - return 0; - - if (unlikely(p->policy == SCHED_IDLE)) - return 0; - - /* - * Buddy candidates are cache hot: - */ - if (sched_feat(CACHE_HOT_BUDDY) && this_rq()->nr_running && - (&p->se == cfs_rq_of(&p->se)->next || - &p->se == cfs_rq_of(&p->se)->last)) - return 1; - - if (sysctl_sched_migration_cost == -1) - return 1; - if (sysctl_sched_migration_cost == 0) - return 0; - - delta = now - p->se.exec_start; - - return delta < (s64)sysctl_sched_migration_cost; -} - -void set_task_cpu(struct task_struct *p, unsigned int new_cpu) -{ -#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)); -#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, 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); - -/* - * The task's runqueue lock must be held. - * Returns true if you have to wait for migration thread. - */ -static bool migrate_task(struct task_struct *p, int dest_cpu) -{ - struct rq *rq = task_rq(p); - - /* - * If the task is not on a runqueue (and not running), then - * the next wake-up will properly place the task. - */ - return p->se.on_rq || task_running(rq, p); -} - -/* - * 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->se.on_rq; - ncsw = 0; - if (!match_state || p->state == match_state) - ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ - task_rq_unlock(rq, &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)) { - schedule_timeout_uninterruptible(1); - continue; - } - - /* - * Ahh, all good. It wasn't running, and it wasn't - * runnable, which means that it will never become - * running in the future either. We're all done! - */ - 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 doesnt 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 */ - -/** - * task_oncpu_function_call - call a function on the cpu on which a task runs - * @p: the task to evaluate - * @func: the function to be called - * @info: the function call argument - * - * Calls the function @func when the task is currently running. This might - * be on the current CPU, which just calls the function directly - */ -void task_oncpu_function_call(struct task_struct *p, - void (*func) (void *info), void *info) -{ - int cpu; - - preempt_disable(); - cpu = task_cpu(p); - if (task_curr(p)) - smp_call_function_single(cpu, func, info, 1); - preempt_enable(); -} - -#ifdef CONFIG_SMP -/* - * ->cpus_allowed is protected by either TASK_WAKING or rq->lock held. - */ -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, &p->cpus_allowed)) - return dest_cpu; - - /* Any allowed, online CPU? */ - dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_active_mask); - if (dest_cpu < nr_cpu_ids) - return dest_cpu; - - /* No more Mr. Nice Guy. */ - if (unlikely(dest_cpu >= nr_cpu_ids)) { - 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 TASK_WAKING, ->cpus_allowed is stable. - */ -static inline -int select_task_rq(struct rq *rq, struct task_struct *p, int sd_flags, int wake_flags) -{ - int cpu = p->sched_class->select_task_rq(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, &p->cpus_allowed) || - !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 inline void ttwu_activate(struct task_struct *p, struct rq *rq, - bool is_sync, bool is_migrate, bool is_local, - unsigned long en_flags) -{ - schedstat_inc(p, se.statistics.nr_wakeups); - if (is_sync) - schedstat_inc(p, se.statistics.nr_wakeups_sync); - if (is_migrate) - schedstat_inc(p, se.statistics.nr_wakeups_migrate); - if (is_local) - schedstat_inc(p, se.statistics.nr_wakeups_local); - else - schedstat_inc(p, se.statistics.nr_wakeups_remote); - - activate_task(rq, p, en_flags); -} - -static inline void ttwu_post_activation(struct task_struct *p, struct rq *rq, - int wake_flags, bool success) -{ - trace_sched_wakeup(p, success); - 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 (unlikely(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 - /* if a worker is waking up, notify workqueue */ - if ((p->flags & PF_WQ_WORKER) && success) - wq_worker_waking_up(p, cpu_of(rq)); -} - -/** - * 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) -{ - int cpu, orig_cpu, this_cpu, success = 0; - unsigned long flags; - unsigned long en_flags = ENQUEUE_WAKEUP; - struct rq *rq; - - this_cpu = get_cpu(); - - smp_wmb(); - rq = task_rq_lock(p, &flags); - if (!(p->state & state)) - goto out; - - if (p->se.on_rq) - goto out_running; - - cpu = task_cpu(p); - orig_cpu = cpu; - -#ifdef CONFIG_SMP - if (unlikely(task_running(rq, p))) - goto out_activate; - - /* - * In order to handle concurrent wakeups and release the rq->lock - * we put the task in TASK_WAKING state. - * - * First fix up the nr_uninterruptible count: - */ - if (task_contributes_to_load(p)) { - if (likely(cpu_online(orig_cpu))) - rq->nr_uninterruptible--; - else - this_rq()->nr_uninterruptible--; - } - p->state = TASK_WAKING; - - if (p->sched_class->task_waking) { - p->sched_class->task_waking(rq, p); - en_flags |= ENQUEUE_WAKING; - } - - cpu = select_task_rq(rq, p, SD_BALANCE_WAKE, wake_flags); - if (cpu != orig_cpu) - set_task_cpu(p, cpu); - __task_rq_unlock(rq); - - rq = cpu_rq(cpu); - raw_spin_lock(&rq->lock); - - /* - * We migrated the task without holding either rq->lock, however - * since the task is not on the task list itself, nobody else - * will try and migrate the task, hence the rq should match the - * cpu we just moved it to. - */ - WARN_ON(task_cpu(p) != cpu); - WARN_ON(p->state != TASK_WAKING); - -#ifdef CONFIG_SCHEDSTATS - schedstat_inc(rq, ttwu_count); - if (cpu == this_cpu) - schedstat_inc(rq, ttwu_local); - else { - struct sched_domain *sd; - for_each_domain(this_cpu, sd) { - if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { - schedstat_inc(sd, ttwu_wake_remote); - break; - } - } - } -#endif /* CONFIG_SCHEDSTATS */ - -out_activate: -#endif /* CONFIG_SMP */ - ttwu_activate(p, rq, wake_flags & WF_SYNC, orig_cpu != cpu, - cpu == this_cpu, en_flags); - success = 1; -out_running: - ttwu_post_activation(p, rq, wake_flags, success); -out: - task_rq_unlock(rq, &flags); - put_cpu(); - - 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 alredy there. The caller must - * ensure that this_rq() is locked, @p is bound to this_rq() and not - * the current task. this_rq() stays locked over invocation. - */ -static void try_to_wake_up_local(struct task_struct *p) -{ - struct rq *rq = task_rq(p); - bool success = false; - - BUG_ON(rq != this_rq()); - BUG_ON(p == current); - lockdep_assert_held(&rq->lock); - - if (!(p->state & TASK_NORMAL)) - return; - - if (!p->se.on_rq) { - if (likely(!task_running(rq, p))) { - schedstat_inc(rq, ttwu_count); - schedstat_inc(rq, ttwu_local); - } - ttwu_activate(p, rq, false, false, true, ENQUEUE_WAKEUP); - success = true; - } - ttwu_post_activation(p, rq, 0, success); -} - -/** - * 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->se.exec_start = 0; - p->se.sum_exec_runtime = 0; - p->se.prev_sum_exec_runtime = 0; - p->se.nr_migrations = 0; - -#ifdef CONFIG_SCHEDSTATS - memset(&p->se.statistics, 0, sizeof(p->se.statistics)); -#endif - - INIT_LIST_HEAD(&p->rt.run_list); - p->se.on_rq = 0; - INIT_LIST_HEAD(&p->se.group_node); - -#ifdef CONFIG_PREEMPT_NOTIFIERS - INIT_HLIST_HEAD(&p->preempt_notifiers); -#endif -} - -/* - * fork()/clone()-time setup: - */ -void sched_fork(struct task_struct *p, int clone_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; - - /* - * Revert to default priority/policy on fork if requested. - */ - if (unlikely(p->sched_reset_on_fork)) { - if (p->policy == SCHED_FIFO || p->policy == SCHED_RR) { - p->policy = SCHED_NORMAL; - p->normal_prio = p->static_prio; - } - - if (PRIO_TO_NICE(p->static_prio) < 0) { - p->static_prio = NICE_TO_PRIO(0); - p->normal_prio = p->static_prio; - 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; - } - - /* - * Make sure we do not leak PI boosting priority to the child. - */ - p->prio = current->normal_prio; - - 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. - */ - rcu_read_lock(); - set_task_cpu(p, cpu); - rcu_read_unlock(); - -#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) && defined(__ARCH_WANT_UNLOCKED_CTXSW) - p->oncpu = 0; -#endif -#ifdef CONFIG_PREEMPT - /* Want to start with kernel preemption disabled. */ - task_thread_info(p)->preempt_count = 1; -#endif - plist_node_init(&p->pushable_tasks, MAX_PRIO); - - 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 clone_flags) -{ - unsigned long flags; - struct rq *rq; - int cpu __maybe_unused = get_cpu(); - -#ifdef CONFIG_SMP - rq = task_rq_lock(p, &flags); - p->state = TASK_WAKING; - - /* - * 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 - * - * We set TASK_WAKING so that select_task_rq() can drop rq->lock - * without people poking at ->cpus_allowed. - */ - cpu = select_task_rq(rq, p, SD_BALANCE_FORK, 0); - set_task_cpu(p, cpu); - - p->state = TASK_RUNNING; - task_rq_unlock(rq, &flags); -#endif - - rq = task_rq_lock(p, &flags); - activate_task(rq, p, 0); - trace_sched_wakeup_new(p, 1); - 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, &flags); - put_cpu(); -} - -#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) -{ - fire_sched_out_preempt_notifiers(prev, next); - prepare_lock_switch(rq, next); - prepare_arch_switch(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(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); - trace_sched_switch(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; -} - -#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; - -static 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; -} -#else -static void calc_load_account_idle(struct rq *this_rq) -{ -} - -static inline long calc_load_fold_idle(void) -{ - return 0; -} -#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; -} - -static unsigned long -calc_load(unsigned long load, unsigned long exp, unsigned long active) -{ - load *= exp; - load += active * (FIXED_1 - exp); - return load >> FSHIFT; -} - -/* - * calc_load - update the avenrun load estimates 10 ticks after the - * CPUs have updated calc_load_tasks. - */ -void calc_global_load(void) -{ - unsigned long upd = calc_load_update + 10; - long active; - - if (time_before(jiffies, upd)) - 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. - */ -static 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; - struct rq *rq; - int dest_cpu; - - rq = task_rq_lock(p, &flags); - dest_cpu = p->sched_class->select_task_rq(rq, p, SD_BALANCE_EXEC, 0); - if (dest_cpu == smp_processor_id()) - goto unlock; - - /* - * select_task_rq() can race against ->cpus_allowed - */ - if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed) && - likely(cpu_active(dest_cpu)) && migrate_task(p, dest_cpu)) { - struct migration_arg arg = { p, dest_cpu }; - - task_rq_unlock(rq, &flags); - stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); - return; - } -unlock: - task_rq_unlock(rq, &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, &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, &flags); - - return ns; -} - -/* - * Return sum_exec_runtime for the thread group. - * In case the task is currently running, return the sum plus current's - * pending runtime that have not been accounted yet. - * - * Note that the thread group might have other running tasks as well, - * so the return value not includes other pending runtime that other - * running tasks might have. - */ -unsigned long long thread_group_sched_runtime(struct task_struct *p) -{ - struct task_cputime totals; - unsigned long flags; - struct rq *rq; - u64 ns; - - rq = task_rq_lock(p, &flags); - thread_group_cputime(p, &totals); - ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq); - task_rq_unlock(rq, &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. - * @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 tmp; - - if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) { - account_guest_time(p, cputime, cputime_scaled); - return; - } - - /* 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. */ - tmp = cputime_to_cputime64(cputime); - if (hardirq_count() - hardirq_offset) - cpustat->irq = cputime64_add(cpustat->irq, tmp); - else if (in_serving_softirq()) - cpustat->softirq = cputime64_add(cpustat->softirq, tmp); - else - cpustat->system = cputime64_add(cpustat->system, tmp); - - cpuacct_update_stats(p, CPUACCT_STAT_SYSTEM, cputime); - - /* Account for system time used */ - acct_update_integrals(p); -} - -/* - * Account for involuntary wait time. - * @steal: 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); -} - -#ifndef CONFIG_VIRT_CPU_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 (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) -{ - 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. - * - * It also gets called by the fork code, when changing the parent's - * timeslices. - */ -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_at_tick = 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); - - profile_hit(SCHED_PROFILING, __builtin_return_address(0)); - - schedstat_inc(this_rq(), sched_count); -#ifdef CONFIG_SCHEDSTATS - if (unlikely(prev->lock_depth >= 0)) { - schedstat_inc(this_rq(), bkl_count); - schedstat_inc(prev, sched_info.bkl_count); - } -#endif -} - -static void put_prev_task(struct rq *rq, struct task_struct *prev) -{ - if (prev->se.on_rq) - update_rq_clock(rq); - rq->skip_clock_update = 0; - 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.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. - */ -asmlinkage 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; - - release_kernel_lock(prev); -need_resched_nonpreemptible: - - schedule_debug(prev); - - if (sched_feat(HRTICK)) - hrtick_clear(rq); - - raw_spin_lock_irq(&rq->lock); - clear_tsk_need_resched(prev); - - switch_count = &prev->nivcsw; - if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { - if (unlikely(signal_pending_state(prev->state, prev))) { - prev->state = TASK_RUNNING; - } else { - /* - * If a worker is going to sleep, notify and - * ask workqueue whether it wants to wake up a - * task to maintain concurrency. If so, wake - * up the task. - */ - 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); - } - deactivate_task(rq, prev, DEQUEUE_SLEEP); - } - 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); - - if (likely(prev != next)) { - sched_info_switch(prev, next); - perf_event_task_sched_out(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); - - if (unlikely(reacquire_kernel_lock(prev))) - goto need_resched_nonpreemptible; - - preempt_enable_no_resched(); - if (need_resched()) - goto need_resched; -} -EXPORT_SYMBOL(schedule); - -#ifdef CONFIG_MUTEX_SPIN_ON_OWNER -/* - * Look out! "owner" is an entirely speculative pointer - * access and not reliable. - */ -int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner) -{ - unsigned int cpu; - struct rq *rq; - - if (!sched_feat(OWNER_SPIN)) - return 0; - -#ifdef CONFIG_DEBUG_PAGEALLOC - /* - * Need to access the cpu field knowing that - * DEBUG_PAGEALLOC could have unmapped it if - * the mutex owner just released it and exited. - */ - if (probe_kernel_address(&owner->cpu, cpu)) - return 0; -#else - cpu = owner->cpu; -#endif - - /* - * Even if the access succeeded (likely case), - * the cpu field may no longer be valid. - */ - if (cpu >= nr_cpumask_bits) - return 0; - - /* - * We need to validate that we can do a - * get_cpu() and that we have the percpu area. - */ - if (!cpu_online(cpu)) - return 0; - - rq = cpu_rq(cpu); - - for (;;) { - /* - * Owner changed, break to re-assess state. - */ - if (lock->owner != owner) { - /* - * If the lock has switched to a different owner, - * we likely have heavy contention. Return 0 to quit - * optimistic spinning and not contend further: - */ - if (lock->owner) - return 0; - break; - } - - /* - * Is that owner really running on that cpu? - */ - if (task_thread_info(rq->curr) != owner || need_resched()) - return 0; - - cpu_relax(); - } - - return 1; -} -#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); -} - -/** - * __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. - */ -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. - */ -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. - */ -unsigned 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. - */ -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. - */ -unsigned 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) -{ - unsigned long flags; - 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, &flags); - - trace_sched_pi_setprio(p, prio); - oldprio = p->prio; - prev_class = p->sched_class; - on_rq = p->se.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, running); - } - task_rq_unlock(rq, &flags); -} - -#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->se.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, &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) -{ - return cpu_curr(cpu) == cpu_rq(cpu)->idle; -} - -/** - * 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) -{ - BUG_ON(p->se.on_rq); - - 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); - match = (cred->euid == pcred->euid || - cred->euid == pcred->uid); - rcu_read_unlock(); - return match; -} - -static int __sched_setscheduler(struct task_struct *p, int policy, - 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; - } - /* - * Like positive nice levels, dont allow tasks to - * move out of SCHED_IDLE either: - */ - if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) - return -EPERM; - - /* can't change other user's priorities */ - if (!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: - */ - raw_spin_lock_irqsave(&p->pi_lock, flags); - /* - * To be able to change p->policy safely, the apropriate - * runqueue lock must be held. - */ - rq = __task_rq_lock(p); - - /* - * Changing the policy of the stop threads its a very bad idea - */ - if (p == rq->stop) { - __task_rq_unlock(rq); - raw_spin_unlock_irqrestore(&p->pi_lock, flags); - return -EINVAL; - } - -#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_rq_unlock(rq); - raw_spin_unlock_irqrestore(&p->pi_lock, 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); - raw_spin_unlock_irqrestore(&p->pi_lock, flags); - goto recheck; - } - on_rq = p->se.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, running); - } - __task_rq_unlock(rq); - raw_spin_unlock_irqrestore(&p->pi_lock, 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, - 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, - 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) && !capable(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; - struct rq *rq; - 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; - - rq = task_rq_lock(p, &flags); - cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); - task_rq_unlock(rq, &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); - -/* - * 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); - 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); - 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, &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 "%-13.13s %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 - read_lock(&tasklist_lock); - do_each_thread(g, p) { - /* - * reset the NMI-timeout, listing all files on a slow - * console might take alot 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 - read_unlock(&tasklist_lock); - /* - * 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(); - - cpumask_copy(&idle->cpus_allowed, 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) && defined(__ARCH_WANT_UNLOCKED_CTXSW) - idle->oncpu = 1; -#endif - raw_spin_unlock_irqrestore(&rq->lock, flags); - - /* Set the preempt count _outside_ the spinlocks! */ -#if defined(CONFIG_PREEMPT) - task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0); -#else - task_thread_info(idle)->preempt_count = 0; -#endif - /* - * The idle tasks have their own, simple scheduling class: - */ - idle->sched_class = &idle_sched_class; - ftrace_graph_init_task(idle); -} - -/* - * In a system that switches off the HZ timer nohz_cpu_mask - * indicates which cpus entered this state. This is used - * in the rcu update to wait only for active cpus. For system - * which do not switch off the HZ timer nohz_cpu_mask should - * always be CPU_BITS_NONE. - */ -cpumask_var_t nohz_cpu_mask; - -/* - * Increase the granularity value when there are more CPUs, - * because with more CPUs the 'effective latency' as visible - * to users decreases. But the relationship is not linear, - * so pick a second-best guess by going with the log2 of the - * number of CPUs. - * - * This idea comes from the SD scheduler of Con Kolivas: - */ -static int get_update_sysctl_factor(void) -{ - unsigned int cpus = min_t(int, num_online_cpus(), 8); - unsigned int factor; - - switch (sysctl_sched_tunable_scaling) { - case SCHED_TUNABLESCALING_NONE: - factor = 1; - break; - case SCHED_TUNABLESCALING_LINEAR: - factor = cpus; - break; - case SCHED_TUNABLESCALING_LOG: - default: - factor = 1 + ilog2(cpus); - break; - } - - return factor; -} - -static void update_sysctl(void) -{ - unsigned int factor = get_update_sysctl_factor(); - -#define SET_SYSCTL(name) \ - (sysctl_##name = (factor) * normalized_sysctl_##name) - SET_SYSCTL(sched_min_granularity); - SET_SYSCTL(sched_latency); - SET_SYSCTL(sched_wakeup_granularity); - SET_SYSCTL(sched_shares_ratelimit); -#undef SET_SYSCTL -} - -static inline void sched_init_granularity(void) -{ - update_sysctl(); -} - -#ifdef CONFIG_SMP -/* - * 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; - - /* - * Serialize against TASK_WAKING so that ttwu() and wunt() can - * drop the rq->lock and still rely on ->cpus_allowed. - */ -again: - while (task_is_waking(p)) - cpu_relax(); - rq = task_rq_lock(p, &flags); - if (task_is_waking(p)) { - task_rq_unlock(rq, &flags); - goto again; - } - - if (!cpumask_intersects(new_mask, cpu_active_mask)) { - ret = -EINVAL; - goto out; - } - - if (unlikely((p->flags & PF_THREAD_BOUND) && p != current && - !cpumask_equal(&p->cpus_allowed, new_mask))) { - ret = -EINVAL; - goto out; - } - - if (p->sched_class->set_cpus_allowed) - p->sched_class->set_cpus_allowed(p, new_mask); - else { - cpumask_copy(&p->cpus_allowed, new_mask); - p->rt.nr_cpus_allowed = cpumask_weight(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 (migrate_task(p, dest_cpu)) { - struct migration_arg arg = { p, dest_cpu }; - /* Need help from migration thread: drop lock and wait. */ - task_rq_unlock(rq, &flags); - stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); - tlb_migrate_finish(p->mm); - return 0; - } -out: - task_rq_unlock(rq, &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); - - 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, &p->cpus_allowed)) - goto fail; - - /* - * If we're not on a rq, the next wake-up will ensure we're - * placed properly. - */ - if (p->se.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); - 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 -/* - * Figure out where task on dead CPU should go, use force if necessary. - */ -void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p) -{ - struct rq *rq = cpu_rq(dead_cpu); - int needs_cpu, uninitialized_var(dest_cpu); - unsigned long flags; - - local_irq_save(flags); - - raw_spin_lock(&rq->lock); - needs_cpu = (task_cpu(p) == dead_cpu) && (p->state != TASK_WAKING); - if (needs_cpu) - dest_cpu = select_fallback_rq(dead_cpu, p); - raw_spin_unlock(&rq->lock); - /* - * It can only fail if we race with set_cpus_allowed(), - * in the racer should migrate the task anyway. - */ - if (needs_cpu) - __migrate_task(p, dead_cpu, dest_cpu); - local_irq_restore(flags); -} - -/* - * 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)); - unsigned long flags; - - local_irq_save(flags); - double_rq_lock(rq_src, rq_dest); - rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible; - rq_src->nr_uninterruptible = 0; - double_rq_unlock(rq_src, rq_dest); - local_irq_restore(flags); -} - -/* Run through task list and migrate tasks from the dead cpu. */ -static void migrate_live_tasks(int src_cpu) -{ - struct task_struct *p, *t; - - read_lock(&tasklist_lock); - - do_each_thread(t, p) { - if (p == current) - continue; - - if (task_cpu(p) == src_cpu) - move_task_off_dead_cpu(src_cpu, p); - } while_each_thread(t, p); - - read_unlock(&tasklist_lock); -} - -/* - * Schedules idle task to be the next runnable task on current CPU. - * It does so by boosting its priority to highest possible. - * Used by CPU offline code. - */ -void sched_idle_next(void) -{ - int this_cpu = smp_processor_id(); - struct rq *rq = cpu_rq(this_cpu); - struct task_struct *p = rq->idle; - unsigned long flags; - - /* cpu has to be offline */ - BUG_ON(cpu_online(this_cpu)); - - /* - * Strictly not necessary since rest of the CPUs are stopped by now - * and interrupts disabled on the current cpu. - */ - raw_spin_lock_irqsave(&rq->lock, flags); - - __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); - - activate_task(rq, p, 0); - - raw_spin_unlock_irqrestore(&rq->lock, flags); -} - -/* - * 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); -} - -/* called under rq->lock with disabled interrupts */ -static void migrate_dead(unsigned int dead_cpu, struct task_struct *p) -{ - struct rq *rq = cpu_rq(dead_cpu); - - /* Must be exiting, otherwise would be on tasklist. */ - BUG_ON(!p->exit_state); - - /* Cannot have done final schedule yet: would have vanished. */ - BUG_ON(p->state == TASK_DEAD); - - get_task_struct(p); - - /* - * Drop lock around migration; if someone else moves it, - * that's OK. No task can be added to this CPU, so iteration is - * fine. - */ - raw_spin_unlock_irq(&rq->lock); - move_task_off_dead_cpu(dead_cpu, p); - raw_spin_lock_irq(&rq->lock); - - put_task_struct(p); -} - -/* release_task() removes task from tasklist, so we won't find dead tasks. */ -static void migrate_dead_tasks(unsigned int dead_cpu) -{ - struct rq *rq = cpu_rq(dead_cpu); - struct task_struct *next; - - for ( ; ; ) { - if (!rq->nr_running) - break; - next = pick_next_task(rq); - if (!next) - break; - next->sched_class->put_prev_task(rq, next); - migrate_dead(dead_cpu, next); - - } -} - -/* - * 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; -} -#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) { - - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: - rq->calc_load_update = calc_load_update; - break; - - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - /* 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_DEAD: - case CPU_DEAD_FROZEN: - migrate_live_tasks(cpu); - /* Idle task back to normal (off runqueue, low prio) */ - raw_spin_lock_irq(&rq->lock); - deactivate_task(rq, rq->idle, 0); - __setscheduler(rq, rq->idle, SCHED_NORMAL, 0); - rq->idle->sched_class = &idle_sched_class; - migrate_dead_tasks(cpu); - raw_spin_unlock_irq(&rq->lock); - migrate_nr_uninterruptible(rq); - BUG_ON(rq->nr_running != 0); - calc_global_load_remove(rq); - break; - - case CPU_DYING: - case CPU_DYING_FROZEN: - /* 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); - } - raw_spin_unlock_irqrestore(&rq->lock, flags); - break; -#endif - } - 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 - -#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->cpu_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->cpu_power != SCHED_LOAD_SCALE) { - printk(KERN_CONT " (cpu_power = %d)", - group->cpu_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) -{ - cpumask_var_t groupmask; - 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); - - if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) { - printk(KERN_DEBUG "Cannot load-balance (out of memory)\n"); - return; - } - - for (;;) { - if (sched_domain_debug_one(sd, cpu, level, groupmask)) - break; - level++; - sd = sd->parent; - if (!sd) - break; - } - free_cpumask_var(groupmask); -} -#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 root_domain *rd) -{ - synchronize_sched(); - - 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) - free_rootdomain(old_rd); -} - -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; -} - -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; -} - -/* - * 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; - - for (tmp = sd; tmp; tmp = tmp->parent) - tmp->span_weight = cpumask_weight(sched_domain_span(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; - } else - tmp = tmp->parent; - } - - if (sd && sd_degenerate(sd)) { - sd = sd->parent; - if (sd) - sd->child = NULL; - } - - sched_domain_debug(sd, cpu); - - rq_attach_root(rq, rd); - rcu_assign_pointer(rq->sd, sd); -} - -/* 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); - -/* - * init_sched_build_groups takes the cpumask we wish to span, and a pointer - * to a function which identifies what group(along with sched group) a CPU - * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids - * (due to the fact that we keep track of groups covered with a struct cpumask). - * - * init_sched_build_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. - */ -static void -init_sched_build_groups(const struct cpumask *span, - const struct cpumask *cpu_map, - int (*group_fn)(int cpu, const struct cpumask *cpu_map, - struct sched_group **sg, - struct cpumask *tmpmask), - struct cpumask *covered, struct cpumask *tmpmask) -{ - struct sched_group *first = NULL, *last = NULL; - int i; - - cpumask_clear(covered); - - for_each_cpu(i, span) { - struct sched_group *sg; - int group = group_fn(i, cpu_map, &sg, tmpmask); - int j; - - if (cpumask_test_cpu(i, covered)) - continue; - - cpumask_clear(sched_group_cpus(sg)); - sg->cpu_power = 0; - - for_each_cpu(j, span) { - if (group_fn(j, cpu_map, NULL, tmpmask) != 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; -} - -#define SD_NODES_PER_DOMAIN 16 - -#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 = 0; - - 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; - } - } - - 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); - - cpumask_or(span, span, cpumask_of_node(next_node)); - } -} -#endif /* CONFIG_NUMA */ - -int sched_smt_power_savings = 0, sched_mc_power_savings = 0; - -/* - * The cpus mask in sched_group and sched_domain hangs off the end. - * - * ( See the the comments in include/linux/sched.h:struct sched_group - * and struct sched_domain. ) - */ -struct static_sched_group { - struct sched_group sg; - DECLARE_BITMAP(cpus, CONFIG_NR_CPUS); -}; - -struct static_sched_domain { - struct sched_domain sd; - DECLARE_BITMAP(span, CONFIG_NR_CPUS); -}; - -struct s_data { -#ifdef CONFIG_NUMA - int sd_allnodes; - cpumask_var_t domainspan; - cpumask_var_t covered; - cpumask_var_t notcovered; -#endif - cpumask_var_t nodemask; - cpumask_var_t this_sibling_map; - cpumask_var_t this_core_map; - cpumask_var_t this_book_map; - cpumask_var_t send_covered; - cpumask_var_t tmpmask; - struct sched_group **sched_group_nodes; - struct root_domain *rd; -}; - -enum s_alloc { - sa_sched_groups = 0, - sa_rootdomain, - sa_tmpmask, - sa_send_covered, - sa_this_book_map, - sa_this_core_map, - sa_this_sibling_map, - sa_nodemask, - sa_sched_group_nodes, -#ifdef CONFIG_NUMA - sa_notcovered, - sa_covered, - sa_domainspan, -#endif - sa_none, -}; - -/* - * SMT sched-domains: - */ -#ifdef CONFIG_SCHED_SMT -static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains); -static DEFINE_PER_CPU(struct static_sched_group, sched_groups); - -static int -cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map, - struct sched_group **sg, struct cpumask *unused) -{ - if (sg) - *sg = &per_cpu(sched_groups, cpu).sg; - return cpu; -} -#endif /* CONFIG_SCHED_SMT */ - -/* - * multi-core sched-domains: - */ -#ifdef CONFIG_SCHED_MC -static DEFINE_PER_CPU(struct static_sched_domain, core_domains); -static DEFINE_PER_CPU(struct static_sched_group, sched_group_core); - -static int -cpu_to_core_group(int cpu, const struct cpumask *cpu_map, - struct sched_group **sg, struct cpumask *mask) -{ - int group; -#ifdef CONFIG_SCHED_SMT - cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); - group = cpumask_first(mask); -#else - group = cpu; -#endif - if (sg) - *sg = &per_cpu(sched_group_core, group).sg; - return group; -} -#endif /* CONFIG_SCHED_MC */ - -/* - * book sched-domains: - */ -#ifdef CONFIG_SCHED_BOOK -static DEFINE_PER_CPU(struct static_sched_domain, book_domains); -static DEFINE_PER_CPU(struct static_sched_group, sched_group_book); - -static int -cpu_to_book_group(int cpu, const struct cpumask *cpu_map, - struct sched_group **sg, struct cpumask *mask) -{ - int group = cpu; -#ifdef CONFIG_SCHED_MC - cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map); - group = cpumask_first(mask); -#elif defined(CONFIG_SCHED_SMT) - cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); - group = cpumask_first(mask); -#endif - if (sg) - *sg = &per_cpu(sched_group_book, group).sg; - return group; -} -#endif /* CONFIG_SCHED_BOOK */ - -static DEFINE_PER_CPU(struct static_sched_domain, phys_domains); -static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys); - -static int -cpu_to_phys_group(int cpu, const struct cpumask *cpu_map, - struct sched_group **sg, struct cpumask *mask) -{ - int group; -#ifdef CONFIG_SCHED_BOOK - cpumask_and(mask, cpu_book_mask(cpu), cpu_map); - group = cpumask_first(mask); -#elif defined(CONFIG_SCHED_MC) - cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map); - group = cpumask_first(mask); -#elif defined(CONFIG_SCHED_SMT) - cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); - group = cpumask_first(mask); -#else - group = cpu; -#endif - if (sg) - *sg = &per_cpu(sched_group_phys, group).sg; - return group; -} - -#ifdef CONFIG_NUMA -/* - * The init_sched_build_groups can't handle what we want to do with node - * groups, so roll our own. Now each node has its own list of groups which - * gets dynamically allocated. - */ -static DEFINE_PER_CPU(struct static_sched_domain, node_domains); -static struct sched_group ***sched_group_nodes_bycpu; - -static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains); -static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes); - -static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map, - struct sched_group **sg, - struct cpumask *nodemask) -{ - int group; - - cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map); - group = cpumask_first(nodemask); - - if (sg) - *sg = &per_cpu(sched_group_allnodes, group).sg; - return group; -} - -static void init_numa_sched_groups_power(struct sched_group *group_head) -{ - struct sched_group *sg = group_head; - int j; - - if (!sg) - return; - do { - for_each_cpu(j, sched_group_cpus(sg)) { - struct sched_domain *sd; - - sd = &per_cpu(phys_domains, j).sd; - if (j != group_first_cpu(sd->groups)) { - /* - * Only add "power" once for each - * physical package. - */ - continue; - } - - sg->cpu_power += sd->groups->cpu_power; - } - sg = sg->next; - } while (sg != group_head); -} - -static int build_numa_sched_groups(struct s_data *d, - const struct cpumask *cpu_map, int num) -{ - struct sched_domain *sd; - struct sched_group *sg, *prev; - int n, j; - - cpumask_clear(d->covered); - cpumask_and(d->nodemask, cpumask_of_node(num), cpu_map); - if (cpumask_empty(d->nodemask)) { - d->sched_group_nodes[num] = NULL; - goto out; - } - - sched_domain_node_span(num, d->domainspan); - cpumask_and(d->domainspan, d->domainspan, cpu_map); - - sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), - GFP_KERNEL, num); - if (!sg) { - printk(KERN_WARNING "Can not alloc domain group for node %d\n", - num); - return -ENOMEM; - } - d->sched_group_nodes[num] = sg; - - for_each_cpu(j, d->nodemask) { - sd = &per_cpu(node_domains, j).sd; - sd->groups = sg; - } - - sg->cpu_power = 0; - cpumask_copy(sched_group_cpus(sg), d->nodemask); - sg->next = sg; - cpumask_or(d->covered, d->covered, d->nodemask); - - prev = sg; - for (j = 0; j < nr_node_ids; j++) { - n = (num + j) % nr_node_ids; - cpumask_complement(d->notcovered, d->covered); - cpumask_and(d->tmpmask, d->notcovered, cpu_map); - cpumask_and(d->tmpmask, d->tmpmask, d->domainspan); - if (cpumask_empty(d->tmpmask)) - break; - cpumask_and(d->tmpmask, d->tmpmask, cpumask_of_node(n)); - if (cpumask_empty(d->tmpmask)) - continue; - sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), - GFP_KERNEL, num); - if (!sg) { - printk(KERN_WARNING - "Can not alloc domain group for node %d\n", j); - return -ENOMEM; - } - sg->cpu_power = 0; - cpumask_copy(sched_group_cpus(sg), d->tmpmask); - sg->next = prev->next; - cpumask_or(d->covered, d->covered, d->tmpmask); - prev->next = sg; - prev = sg; - } -out: - return 0; -} -#endif /* CONFIG_NUMA */ - -#ifdef CONFIG_NUMA -/* Free memory allocated for various sched_group structures */ -static void free_sched_groups(const struct cpumask *cpu_map, - struct cpumask *nodemask) -{ - int cpu, i; - - for_each_cpu(cpu, cpu_map) { - struct sched_group **sched_group_nodes - = sched_group_nodes_bycpu[cpu]; - - if (!sched_group_nodes) - continue; - - for (i = 0; i < nr_node_ids; i++) { - struct sched_group *oldsg, *sg = sched_group_nodes[i]; - - cpumask_and(nodemask, cpumask_of_node(i), cpu_map); - if (cpumask_empty(nodemask)) - continue; - - if (sg == NULL) - continue; - sg = sg->next; -next_sg: - oldsg = sg; - sg = sg->next; - kfree(oldsg); - if (oldsg != sched_group_nodes[i]) - goto next_sg; - } - kfree(sched_group_nodes); - sched_group_nodes_bycpu[cpu] = NULL; - } -} -#else /* !CONFIG_NUMA */ -static void free_sched_groups(const struct cpumask *cpu_map, - struct cpumask *nodemask) -{ -} -#endif /* CONFIG_NUMA */ - -/* - * 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_domain *child; - struct sched_group *group; - long power; - int weight; - - WARN_ON(!sd || !sd->groups); - - if (cpu != group_first_cpu(sd->groups)) - return; - - child = sd->child; - - sd->groups->cpu_power = 0; - - if (!child) { - power = SCHED_LOAD_SCALE; - weight = cpumask_weight(sched_domain_span(sd)); - /* - * SMT siblings share the power of a single core. - * Usually multiple threads get a better yield out of - * that one core than a single thread would have, - * reflect that in sd->smt_gain. - */ - if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { - power *= sd->smt_gain; - power /= weight; - power >>= SCHED_LOAD_SHIFT; - } - sd->groups->cpu_power += power; - return; - } - - /* - * Add cpu_power of each child group to this groups cpu_power. - */ - group = child->groups; - do { - sd->groups->cpu_power += group->cpu_power; - group = group->next; - } while (group != child->groups); -} - -/* - * 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(sd, type) sd_init_##type(sd) - -#define SD_INIT_FUNC(type) \ -static noinline void sd_init_##type(struct sched_domain *sd) \ -{ \ - memset(sd, 0, sizeof(*sd)); \ - *sd = SD_##type##_INIT; \ - sd->level = SD_LV_##type; \ - SD_INIT_NAME(sd, type); \ -} - -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; - -static int __init setup_relax_domain_level(char *str) -{ - unsigned long val; - - val = simple_strtoul(str, NULL, 0); - if (val < SD_LV_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 __free_domain_allocs(struct s_data *d, enum s_alloc what, - const struct cpumask *cpu_map) -{ - switch (what) { - case sa_sched_groups: - free_sched_groups(cpu_map, d->tmpmask); /* fall through */ - d->sched_group_nodes = NULL; - case sa_rootdomain: - free_rootdomain(d->rd); /* fall through */ - case sa_tmpmask: - free_cpumask_var(d->tmpmask); /* fall through */ - case sa_send_covered: - free_cpumask_var(d->send_covered); /* fall through */ - case sa_this_book_map: - free_cpumask_var(d->this_book_map); /* fall through */ - case sa_this_core_map: - free_cpumask_var(d->this_core_map); /* fall through */ - case sa_this_sibling_map: - free_cpumask_var(d->this_sibling_map); /* fall through */ - case sa_nodemask: - free_cpumask_var(d->nodemask); /* fall through */ - case sa_sched_group_nodes: -#ifdef CONFIG_NUMA - kfree(d->sched_group_nodes); /* fall through */ - case sa_notcovered: - free_cpumask_var(d->notcovered); /* fall through */ - case sa_covered: - free_cpumask_var(d->covered); /* fall through */ - case sa_domainspan: - free_cpumask_var(d->domainspan); /* fall through */ -#endif - case sa_none: - break; - } -} - -static enum s_alloc __visit_domain_allocation_hell(struct s_data *d, - const struct cpumask *cpu_map) -{ -#ifdef CONFIG_NUMA - if (!alloc_cpumask_var(&d->domainspan, GFP_KERNEL)) - return sa_none; - if (!alloc_cpumask_var(&d->covered, GFP_KERNEL)) - return sa_domainspan; - if (!alloc_cpumask_var(&d->notcovered, GFP_KERNEL)) - return sa_covered; - /* Allocate the per-node list of sched groups */ - d->sched_group_nodes = kcalloc(nr_node_ids, - sizeof(struct sched_group *), GFP_KERNEL); - if (!d->sched_group_nodes) { - printk(KERN_WARNING "Can not alloc sched group node list\n"); - return sa_notcovered; - } - sched_group_nodes_bycpu[cpumask_first(cpu_map)] = d->sched_group_nodes; -#endif - if (!alloc_cpumask_var(&d->nodemask, GFP_KERNEL)) - return sa_sched_group_nodes; - if (!alloc_cpumask_var(&d->this_sibling_map, GFP_KERNEL)) - return sa_nodemask; - if (!alloc_cpumask_var(&d->this_core_map, GFP_KERNEL)) - return sa_this_sibling_map; - if (!alloc_cpumask_var(&d->this_book_map, GFP_KERNEL)) - return sa_this_core_map; - if (!alloc_cpumask_var(&d->send_covered, GFP_KERNEL)) - return sa_this_book_map; - if (!alloc_cpumask_var(&d->tmpmask, GFP_KERNEL)) - return sa_send_covered; - d->rd = alloc_rootdomain(); - if (!d->rd) { - printk(KERN_WARNING "Cannot alloc root domain\n"); - return sa_tmpmask; - } - return sa_rootdomain; -} - -static struct sched_domain *__build_numa_sched_domains(struct s_data *d, - const struct cpumask *cpu_map, struct sched_domain_attr *attr, int i) -{ - struct sched_domain *sd = NULL; -#ifdef CONFIG_NUMA - struct sched_domain *parent; - - d->sd_allnodes = 0; - if (cpumask_weight(cpu_map) > - SD_NODES_PER_DOMAIN * cpumask_weight(d->nodemask)) { - sd = &per_cpu(allnodes_domains, i).sd; - SD_INIT(sd, ALLNODES); - set_domain_attribute(sd, attr); - cpumask_copy(sched_domain_span(sd), cpu_map); - cpu_to_allnodes_group(i, cpu_map, &sd->groups, d->tmpmask); - d->sd_allnodes = 1; - } - parent = sd; - - sd = &per_cpu(node_domains, i).sd; - SD_INIT(sd, NODE); - set_domain_attribute(sd, attr); - sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd)); - sd->parent = parent; - if (parent) - parent->child = sd; - cpumask_and(sched_domain_span(sd), sched_domain_span(sd), cpu_map); -#endif - return sd; -} - -static struct sched_domain *__build_cpu_sched_domain(struct s_data *d, - const struct cpumask *cpu_map, struct sched_domain_attr *attr, - struct sched_domain *parent, int i) -{ - struct sched_domain *sd; - sd = &per_cpu(phys_domains, i).sd; - SD_INIT(sd, CPU); - set_domain_attribute(sd, attr); - cpumask_copy(sched_domain_span(sd), d->nodemask); - sd->parent = parent; - if (parent) - parent->child = sd; - cpu_to_phys_group(i, cpu_map, &sd->groups, d->tmpmask); - return sd; -} - -static struct sched_domain *__build_book_sched_domain(struct s_data *d, - const struct cpumask *cpu_map, struct sched_domain_attr *attr, - struct sched_domain *parent, int i) -{ - struct sched_domain *sd = parent; -#ifdef CONFIG_SCHED_BOOK - sd = &per_cpu(book_domains, i).sd; - SD_INIT(sd, BOOK); - set_domain_attribute(sd, attr); - cpumask_and(sched_domain_span(sd), cpu_map, cpu_book_mask(i)); - sd->parent = parent; - parent->child = sd; - cpu_to_book_group(i, cpu_map, &sd->groups, d->tmpmask); -#endif - return sd; -} - -static struct sched_domain *__build_mc_sched_domain(struct s_data *d, - const struct cpumask *cpu_map, struct sched_domain_attr *attr, - struct sched_domain *parent, int i) -{ - struct sched_domain *sd = parent; -#ifdef CONFIG_SCHED_MC - sd = &per_cpu(core_domains, i).sd; - SD_INIT(sd, MC); - set_domain_attribute(sd, attr); - cpumask_and(sched_domain_span(sd), cpu_map, cpu_coregroup_mask(i)); - sd->parent = parent; - parent->child = sd; - cpu_to_core_group(i, cpu_map, &sd->groups, d->tmpmask); -#endif - return sd; -} - -static struct sched_domain *__build_smt_sched_domain(struct s_data *d, - const struct cpumask *cpu_map, struct sched_domain_attr *attr, - struct sched_domain *parent, int i) -{ - struct sched_domain *sd = parent; -#ifdef CONFIG_SCHED_SMT - sd = &per_cpu(cpu_domains, i).sd; - SD_INIT(sd, SIBLING); - set_domain_attribute(sd, attr); - cpumask_and(sched_domain_span(sd), cpu_map, topology_thread_cpumask(i)); - sd->parent = parent; - parent->child = sd; - cpu_to_cpu_group(i, cpu_map, &sd->groups, d->tmpmask); -#endif - return sd; -} - -static void build_sched_groups(struct s_data *d, enum sched_domain_level l, - const struct cpumask *cpu_map, int cpu) -{ - switch (l) { -#ifdef CONFIG_SCHED_SMT - case SD_LV_SIBLING: /* set up CPU (sibling) groups */ - cpumask_and(d->this_sibling_map, cpu_map, - topology_thread_cpumask(cpu)); - if (cpu == cpumask_first(d->this_sibling_map)) - init_sched_build_groups(d->this_sibling_map, cpu_map, - &cpu_to_cpu_group, - d->send_covered, d->tmpmask); - break; -#endif -#ifdef CONFIG_SCHED_MC - case SD_LV_MC: /* set up multi-core groups */ - cpumask_and(d->this_core_map, cpu_map, cpu_coregroup_mask(cpu)); - if (cpu == cpumask_first(d->this_core_map)) - init_sched_build_groups(d->this_core_map, cpu_map, - &cpu_to_core_group, - d->send_covered, d->tmpmask); - break; -#endif -#ifdef CONFIG_SCHED_BOOK - case SD_LV_BOOK: /* set up book groups */ - cpumask_and(d->this_book_map, cpu_map, cpu_book_mask(cpu)); - if (cpu == cpumask_first(d->this_book_map)) - init_sched_build_groups(d->this_book_map, cpu_map, - &cpu_to_book_group, - d->send_covered, d->tmpmask); - break; -#endif - case SD_LV_CPU: /* set up physical groups */ - cpumask_and(d->nodemask, cpumask_of_node(cpu), cpu_map); - if (!cpumask_empty(d->nodemask)) - init_sched_build_groups(d->nodemask, cpu_map, - &cpu_to_phys_group, - d->send_covered, d->tmpmask); - break; -#ifdef CONFIG_NUMA - case SD_LV_ALLNODES: - init_sched_build_groups(cpu_map, cpu_map, &cpu_to_allnodes_group, - d->send_covered, d->tmpmask); - break; -#endif - default: - break; - } -} - -/* - * 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 s_data d; - struct sched_domain *sd; - int i; -#ifdef CONFIG_NUMA - d.sd_allnodes = 0; -#endif - - alloc_state = __visit_domain_allocation_hell(&d, cpu_map); - if (alloc_state != sa_rootdomain) - goto error; - alloc_state = sa_sched_groups; - - /* - * Set up domains for cpus specified by the cpu_map. - */ - for_each_cpu(i, cpu_map) { - cpumask_and(d.nodemask, cpumask_of_node(cpu_to_node(i)), - cpu_map); - - sd = __build_numa_sched_domains(&d, cpu_map, attr, i); - sd = __build_cpu_sched_domain(&d, cpu_map, attr, sd, i); - sd = __build_book_sched_domain(&d, cpu_map, attr, sd, i); - sd = __build_mc_sched_domain(&d, cpu_map, attr, sd, i); - sd = __build_smt_sched_domain(&d, cpu_map, attr, sd, i); - } - - for_each_cpu(i, cpu_map) { - build_sched_groups(&d, SD_LV_SIBLING, cpu_map, i); - build_sched_groups(&d, SD_LV_BOOK, cpu_map, i); - build_sched_groups(&d, SD_LV_MC, cpu_map, i); - } - - /* Set up physical groups */ - for (i = 0; i < nr_node_ids; i++) - build_sched_groups(&d, SD_LV_CPU, cpu_map, i); - -#ifdef CONFIG_NUMA - /* Set up node groups */ - if (d.sd_allnodes) - build_sched_groups(&d, SD_LV_ALLNODES, cpu_map, 0); - - for (i = 0; i < nr_node_ids; i++) - if (build_numa_sched_groups(&d, cpu_map, i)) - goto error; -#endif - - /* Calculate CPU power for physical packages and nodes */ -#ifdef CONFIG_SCHED_SMT - for_each_cpu(i, cpu_map) { - sd = &per_cpu(cpu_domains, i).sd; - init_sched_groups_power(i, sd); - } -#endif -#ifdef CONFIG_SCHED_MC - for_each_cpu(i, cpu_map) { - sd = &per_cpu(core_domains, i).sd; - init_sched_groups_power(i, sd); - } -#endif -#ifdef CONFIG_SCHED_BOOK - for_each_cpu(i, cpu_map) { - sd = &per_cpu(book_domains, i).sd; - init_sched_groups_power(i, sd); - } -#endif - - for_each_cpu(i, cpu_map) { - sd = &per_cpu(phys_domains, i).sd; - init_sched_groups_power(i, sd); - } - -#ifdef CONFIG_NUMA - for (i = 0; i < nr_node_ids; i++) - init_numa_sched_groups_power(d.sched_group_nodes[i]); - - if (d.sd_allnodes) { - struct sched_group *sg; - - cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg, - d.tmpmask); - init_numa_sched_groups_power(sg); - } -#endif - - /* Attach the domains */ - for_each_cpu(i, cpu_map) { -#ifdef CONFIG_SCHED_SMT - sd = &per_cpu(cpu_domains, i).sd; -#elif defined(CONFIG_SCHED_MC) - sd = &per_cpu(core_domains, i).sd; -#elif defined(CONFIG_SCHED_BOOK) - sd = &per_cpu(book_domains, i).sd; -#else - sd = &per_cpu(phys_domains, i).sd; -#endif - cpu_attach_domain(sd, d.rd, i); - } - - d.sched_group_nodes = NULL; /* don't free this we still need it */ - __free_domain_allocs(&d, sa_tmpmask, cpu_map); - return 0; - -error: - __free_domain_allocs(&d, alloc_state, cpu_map); - return -ENOMEM; -} - -static int build_sched_domains(const struct cpumask *cpu_map) -{ - return __build_sched_domains(cpu_map, NULL); -} - -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 arch_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]); - register_sched_domain_sysctl(); - - return err; -} - -static void arch_destroy_sched_domains(const struct cpumask *cpu_map, - struct cpumask *tmpmask) -{ - free_sched_groups(cpu_map, tmpmask); -} - -/* - * 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) -{ - /* Save because hotplug lock held. */ - static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS); - int i; - - for_each_cpu(i, cpu_map) - cpu_attach_domain(NULL, &def_root_domain, i); - synchronize_sched(); - arch_destroy_sched_domains(cpu_map, to_cpumask(tmpmask)); -} - -/* 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 arch_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; - - arch_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; - } -} - -static int update_runtime(struct notifier_block *nfb, - unsigned long action, void *hcpu) -{ - int cpu = (int)(long)hcpu; - - switch (action) { - case CPU_DOWN_PREPARE: - case CPU_DOWN_PREPARE_FROZEN: - disable_runtime(cpu_rq(cpu)); - return NOTIFY_OK; - - case CPU_DOWN_FAILED: - case CPU_DOWN_FAILED_FROZEN: - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - enable_runtime(cpu_rq(cpu)); - 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); - -#if defined(CONFIG_NUMA) - sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **), - GFP_KERNEL); - BUG_ON(sched_group_nodes_bycpu == NULL); -#endif - get_online_cpus(); - mutex_lock(&sched_domains_mutex); - arch_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); -} - -static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq) -{ - cfs_rq->tasks_timeline = RB_ROOT; - INIT_LIST_HEAD(&cfs_rq->tasks); -#ifdef CONFIG_FAIR_GROUP_SCHED - cfs_rq->rq = rq; -#endif - cfs_rq->min_vruntime = (u64)(-(1LL << 20)); -} - -static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq) -{ - struct rt_prio_array *array; - int i; - - array = &rt_rq->active; - for (i = 0; i < MAX_RT_PRIO; i++) { - INIT_LIST_HEAD(array->queue + i); - __clear_bit(i, array->bitmap); - } - /* delimiter for bitsearch: */ - __set_bit(MAX_RT_PRIO, array->bitmap); - -#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED - rt_rq->highest_prio.curr = MAX_RT_PRIO; -#ifdef CONFIG_SMP - rt_rq->highest_prio.next = MAX_RT_PRIO; -#endif -#endif -#ifdef CONFIG_SMP - rt_rq->rt_nr_migratory = 0; - rt_rq->overloaded = 0; - plist_head_init_raw(&rt_rq->pushable_tasks, &rq->lock); -#endif - - rt_rq->rt_time = 0; - rt_rq->rt_throttled = 0; - rt_rq->rt_runtime = 0; - raw_spin_lock_init(&rt_rq->rt_runtime_lock); - -#ifdef CONFIG_RT_GROUP_SCHED - rt_rq->rt_nr_boosted = 0; - rt_rq->rq = rq; -#endif -} - -#ifdef CONFIG_FAIR_GROUP_SCHED -static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, - struct sched_entity *se, int cpu, int add, - struct sched_entity *parent) -{ - struct rq *rq = cpu_rq(cpu); - tg->cfs_rq[cpu] = cfs_rq; - init_cfs_rq(cfs_rq, rq); - cfs_rq->tg = tg; - if (add) - list_add(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list); - - tg->se[cpu] = se; - /* se could be NULL for init_task_group */ - if (!se) - return; - - if (!parent) - se->cfs_rq = &rq->cfs; - else - se->cfs_rq = parent->my_q; - - se->my_q = cfs_rq; - se->load.weight = tg->shares; - se->load.inv_weight = 0; - se->parent = parent; -} -#endif - -#ifdef CONFIG_RT_GROUP_SCHED -static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, - struct sched_rt_entity *rt_se, int cpu, int add, - struct sched_rt_entity *parent) -{ - struct rq *rq = cpu_rq(cpu); - - tg->rt_rq[cpu] = rt_rq; - init_rt_rq(rt_rq, rq); - rt_rq->tg = tg; - rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; - if (add) - list_add(&rt_rq->leaf_rt_rq_list, &rq->leaf_rt_rq_list); - - tg->rt_se[cpu] = rt_se; - if (!rt_se) - return; - - if (!parent) - rt_se->rt_rq = &rq->rt; - else - rt_se->rt_rq = parent->my_q; - - rt_se->my_q = rt_rq; - rt_se->parent = parent; - INIT_LIST_HEAD(&rt_se->run_list); -} -#endif - -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 - init_task_group.se = (struct sched_entity **)ptr; - ptr += nr_cpu_ids * sizeof(void **); - - init_task_group.cfs_rq = (struct cfs_rq **)ptr; - ptr += nr_cpu_ids * sizeof(void **); - -#endif /* CONFIG_FAIR_GROUP_SCHED */ -#ifdef CONFIG_RT_GROUP_SCHED - init_task_group.rt_se = (struct sched_rt_entity **)ptr; - ptr += nr_cpu_ids * sizeof(void **); - - init_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(&init_task_group.rt_bandwidth, - global_rt_period(), global_rt_runtime()); -#endif /* CONFIG_RT_GROUP_SCHED */ - -#ifdef CONFIG_CGROUP_SCHED - list_add(&init_task_group.list, &task_groups); - INIT_LIST_HEAD(&init_task_group.children); - -#endif /* CONFIG_CGROUP_SCHED */ - -#if defined CONFIG_FAIR_GROUP_SCHED && defined CONFIG_SMP - update_shares_data = __alloc_percpu(nr_cpu_ids * sizeof(unsigned long), - __alignof__(unsigned long)); -#endif - 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, rq); - init_rt_rq(&rq->rt, rq); -#ifdef CONFIG_FAIR_GROUP_SCHED - init_task_group.shares = init_task_group_load; - INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); -#ifdef CONFIG_CGROUP_SCHED - /* - * How much cpu bandwidth does init_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 - * init_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 init_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 init_task_group's tasks sit - * directly in rq->cfs (i.e init_task_group->se[] = NULL). - */ - init_tg_cfs_entry(&init_task_group, &rq->cfs, NULL, i, 1, NULL); -#endif -#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); -#ifdef CONFIG_CGROUP_SCHED - init_tg_rt_entry(&init_task_group, &rq->rt, NULL, i, 1, NULL); -#endif -#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_LOAD_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; - init_sched_softirq_csd(&per_cpu(remote_sched_softirq_cb, i)); -#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_SMP - open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); -#endif - -#ifdef CONFIG_RT_MUTEXES - plist_head_init_raw(&init_task.pi_waiters, &init_task.pi_lock); -#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; - - /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */ - zalloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT); -#ifdef CONFIG_SMP -#ifdef CONFIG_NO_HZ - zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT); - alloc_cpumask_var(&nohz.grp_idle_mask, GFP_NOWAIT); - atomic_set(&nohz.load_balancer, nr_cpu_ids); - atomic_set(&nohz.first_pick_cpu, nr_cpu_ids); - atomic_set(&nohz.second_pick_cpu, nr_cpu_ids); -#endif - /* May be allocated at isolcpus cmdline parse time */ - if (cpu_isolated_map == NULL) - zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); -#endif /* SMP */ - - perf_event_init(); - - scheduler_running = 1; -} - -#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP -static inline int preempt_count_equals(int preempt_offset) -{ - int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth(); - - return (nested == PREEMPT_INATOMIC_BASE + preempt_offset); -} - -void __might_sleep(const char *file, int line, int preempt_offset) -{ -#ifdef in_atomic - static unsigned long prev_jiffy; /* ratelimiting */ - - 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(); -#endif -} -EXPORT_SYMBOL(__might_sleep); -#endif - -#ifdef CONFIG_MAGIC_SYSRQ -static void normalize_task(struct rq *rq, struct task_struct *p) -{ - int on_rq; - - on_rq = p->se.on_rq; - if (on_rq) - deactivate_task(rq, p, 0); - __setscheduler(rq, p, SCHED_NORMAL, 0); - if (on_rq) { - activate_task(rq, p, 0); - resched_task(rq->curr); - } -} - -void normalize_rt_tasks(void) -{ - struct task_struct *g, *p; - unsigned long flags; - struct rq *rq; - - 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_FAIR_GROUP_SCHED -static void free_fair_sched_group(struct task_group *tg) -{ - int i; - - for_each_possible_cpu(i) { - if (tg->cfs_rq) - kfree(tg->cfs_rq[i]); - if (tg->se) - kfree(tg->se[i]); - } - - kfree(tg->cfs_rq); - kfree(tg->se); -} - -static -int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) -{ - struct cfs_rq *cfs_rq; - struct sched_entity *se; - struct rq *rq; - int i; - - tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL); - if (!tg->cfs_rq) - goto err; - tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL); - if (!tg->se) - goto err; - - tg->shares = NICE_0_LOAD; - - for_each_possible_cpu(i) { - rq = cpu_rq(i); - - cfs_rq = kzalloc_node(sizeof(struct cfs_rq), - GFP_KERNEL, cpu_to_node(i)); - if (!cfs_rq) - goto err; - - se = kzalloc_node(sizeof(struct sched_entity), - GFP_KERNEL, cpu_to_node(i)); - if (!se) - goto err_free_rq; - - init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]); - } - - return 1; - -err_free_rq: - kfree(cfs_rq); -err: - return 0; -} - -static inline void register_fair_sched_group(struct task_group *tg, int cpu) -{ - list_add_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list, - &cpu_rq(cpu)->leaf_cfs_rq_list); -} - -static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) -{ - list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list); -} -#else /* !CONFG_FAIR_GROUP_SCHED */ -static inline void free_fair_sched_group(struct task_group *tg) -{ -} - -static inline -int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) -{ - return 1; -} - -static inline void register_fair_sched_group(struct task_group *tg, int cpu) -{ -} - -static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) -{ -} -#endif /* CONFIG_FAIR_GROUP_SCHED */ - -#ifdef CONFIG_RT_GROUP_SCHED -static void free_rt_sched_group(struct task_group *tg) -{ - int i; - - destroy_rt_bandwidth(&tg->rt_bandwidth); - - for_each_possible_cpu(i) { - if (tg->rt_rq) - kfree(tg->rt_rq[i]); - if (tg->rt_se) - kfree(tg->rt_se[i]); - } - - kfree(tg->rt_rq); - kfree(tg->rt_se); -} - -static -int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) -{ - struct rt_rq *rt_rq; - struct sched_rt_entity *rt_se; - struct rq *rq; - int i; - - tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL); - if (!tg->rt_rq) - goto err; - tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL); - if (!tg->rt_se) - goto err; - - init_rt_bandwidth(&tg->rt_bandwidth, - ktime_to_ns(def_rt_bandwidth.rt_period), 0); - - for_each_possible_cpu(i) { - rq = cpu_rq(i); - - rt_rq = kzalloc_node(sizeof(struct rt_rq), - GFP_KERNEL, cpu_to_node(i)); - if (!rt_rq) - goto err; - - rt_se = kzalloc_node(sizeof(struct sched_rt_entity), - GFP_KERNEL, cpu_to_node(i)); - if (!rt_se) - goto err_free_rq; - - init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]); - } - - return 1; - -err_free_rq: - kfree(rt_rq); -err: - return 0; -} - -static inline void register_rt_sched_group(struct task_group *tg, int cpu) -{ - list_add_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list, - &cpu_rq(cpu)->leaf_rt_rq_list); -} - -static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) -{ - list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list); -} -#else /* !CONFIG_RT_GROUP_SCHED */ -static inline void free_rt_sched_group(struct task_group *tg) -{ -} - -static inline -int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) -{ - return 1; -} - -static inline void register_rt_sched_group(struct task_group *tg, int cpu) -{ -} - -static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) -{ -} -#endif /* CONFIG_RT_GROUP_SCHED */ - -#ifdef CONFIG_CGROUP_SCHED -static void free_sched_group(struct task_group *tg) -{ - free_fair_sched_group(tg); - free_rt_sched_group(tg); - kfree(tg); -} - -/* allocate runqueue etc for a new task group */ -struct task_group *sched_create_group(struct task_group *parent) -{ - struct task_group *tg; - unsigned long flags; - int i; - - tg = kzalloc(sizeof(*tg), GFP_KERNEL); - if (!tg) - return ERR_PTR(-ENOMEM); - - if (!alloc_fair_sched_group(tg, parent)) - goto err; - - if (!alloc_rt_sched_group(tg, parent)) - goto err; - - spin_lock_irqsave(&task_group_lock, flags); - for_each_possible_cpu(i) { - register_fair_sched_group(tg, i); - register_rt_sched_group(tg, i); - } - list_add_rcu(&tg->list, &task_groups); - - 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; - - spin_lock_irqsave(&task_group_lock, flags); - for_each_possible_cpu(i) { - unregister_fair_sched_group(tg, i); - unregister_rt_sched_group(tg, i); - } - 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->se.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, &flags); -} -#endif /* CONFIG_CGROUP_SCHED */ - -#ifdef CONFIG_FAIR_GROUP_SCHED -static void __set_se_shares(struct sched_entity *se, unsigned long shares) -{ - struct cfs_rq *cfs_rq = se->cfs_rq; - int on_rq; - - on_rq = se->on_rq; - if (on_rq) - dequeue_entity(cfs_rq, se, 0); - - se->load.weight = shares; - se->load.inv_weight = 0; - - if (on_rq) - enqueue_entity(cfs_rq, se, 0); -} - -static void set_se_shares(struct sched_entity *se, unsigned long shares) -{ - struct cfs_rq *cfs_rq = se->cfs_rq; - struct rq *rq = cfs_rq->rq; - unsigned long flags; - - raw_spin_lock_irqsave(&rq->lock, flags); - __set_se_shares(se, shares); - raw_spin_unlock_irqrestore(&rq->lock, flags); -} - -static DEFINE_MUTEX(shares_mutex); - -int sched_group_set_shares(struct task_group *tg, unsigned long shares) -{ - int i; - unsigned long flags; - - /* - * We can't change the weight of the root cgroup. - */ - if (!tg->se[0]) - return -EINVAL; - - if (shares < MIN_SHARES) - shares = MIN_SHARES; - else if (shares > MAX_SHARES) - shares = MAX_SHARES; - - mutex_lock(&shares_mutex); - if (tg->shares == shares) - goto done; - - spin_lock_irqsave(&task_group_lock, flags); - for_each_possible_cpu(i) - unregister_fair_sched_group(tg, i); - list_del_rcu(&tg->siblings); - spin_unlock_irqrestore(&task_group_lock, flags); - - /* wait for any ongoing reference to this group to finish */ - synchronize_sched(); - - /* - * Now we are free to modify the group's share on each cpu - * w/o tripping rebalance_share or load_balance_fair. - */ - tg->shares = shares; - for_each_possible_cpu(i) { - /* - * force a rebalance - */ - cfs_rq_set_shares(tg->cfs_rq[i], 0); - set_se_shares(tg->se[i], shares); - } - - /* - * Enable load balance activity on this group, by inserting it back on - * each cpu's rq->leaf_cfs_rq_list. - */ - spin_lock_irqsave(&task_group_lock, flags); - for_each_possible_cpu(i) - register_fair_sched_group(tg, i); - list_add_rcu(&tg->siblings, &tg->parent->children); - spin_unlock_irqrestore(&task_group_lock, flags); -done: - mutex_unlock(&shares_mutex); - return 0; -} - -unsigned long sched_group_shares(struct task_group *tg) -{ - return tg->shares; -} -#endif - -#ifdef CONFIG_RT_GROUP_SCHED -/* - * Ensure that the real time constraints are schedulable. - */ -static DEFINE_MUTEX(rt_constraints_mutex); - -static unsigned long to_ratio(u64 period, u64 runtime) -{ - if (runtime == RUNTIME_INF) - return 1ULL << 20; - - return div64_u64(runtime << 20, period); -} - -/* Must be called with tasklist_lock held */ -static inline int tg_has_rt_tasks(struct task_group *tg) -{ - struct task_struct *g, *p; - - do_each_thread(g, p) { - if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg) - return 1; - } while_each_thread(g, p); - - return 0; -} - -struct rt_schedulable_data { - struct task_group *tg; - u64 rt_period; - u64 rt_runtime; -}; - -static int tg_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) -{ - struct rt_schedulable_data data = { - .tg = tg, - .rt_period = period, - .rt_runtime = runtime, - }; - - return walk_tg_tree(tg_schedulable, tg_nop, &data); -} - -static int tg_set_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_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_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 &init_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 int -cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, - struct task_struct *tsk, bool threadgroup) -{ - int retval = cpu_cgroup_can_attach_task(cgrp, tsk); - if (retval) - return retval; - if (threadgroup) { - struct task_struct *c; - rcu_read_lock(); - list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { - retval = cpu_cgroup_can_attach_task(cgrp, c); - if (retval) { - rcu_read_unlock(); - return retval; - } - } - rcu_read_unlock(); - } - return 0; -} - -static void -cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, - struct cgroup *old_cont, struct task_struct *tsk, - bool threadgroup) -{ - sched_move_task(tsk); - if (threadgroup) { - struct task_struct *c; - rcu_read_lock(); - list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { - sched_move_task(c); - } - rcu_read_unlock(); - } -} - -#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), shareval); -} - -static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) -{ - struct task_group *tg = cgroup_tg(cgrp); - - return (u64) tg->shares; -} -#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_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 = cpu_cgroup_can_attach, - .attach = cpu_cgroup_attach, - .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. - */ -static 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. - */ -static 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 */ - -#ifndef CONFIG_SMP - -void synchronize_sched_expedited(void) -{ - barrier(); -} -EXPORT_SYMBOL_GPL(synchronize_sched_expedited); - -#else /* #ifndef CONFIG_SMP */ - -static atomic_t synchronize_sched_expedited_count = ATOMIC_INIT(0); - -static int synchronize_sched_expedited_cpu_stop(void *data) -{ - /* - * There must be a full memory barrier on each affected CPU - * between the time that try_stop_cpus() is called and the - * time that it returns. - * - * In the current initial implementation of cpu_stop, the - * above condition is already met when the control reaches - * this point and the following smp_mb() is not strictly - * necessary. Do smp_mb() anyway for documentation and - * robustness against future implementation changes. - */ - smp_mb(); /* See above comment block. */ - return 0; -} - -/* - * Wait for an rcu-sched grace period to elapse, but use "big hammer" - * approach to force grace period to end quickly. This consumes - * significant time on all CPUs, and is thus not recommended for - * any sort of common-case code. - * - * Note that it is illegal to call this function while holding any - * lock that is acquired by a CPU-hotplug notifier. Failing to - * observe this restriction will result in deadlock. - */ -void synchronize_sched_expedited(void) -{ - int snap, trycount = 0; - - smp_mb(); /* ensure prior mod happens before capturing snap. */ - snap = atomic_read(&synchronize_sched_expedited_count) + 1; - get_online_cpus(); - while (try_stop_cpus(cpu_online_mask, - synchronize_sched_expedited_cpu_stop, - NULL) == -EAGAIN) { - put_online_cpus(); - if (trycount++ < 10) - udelay(trycount * num_online_cpus()); - else { - synchronize_sched(); - return; - } - if (atomic_read(&synchronize_sched_expedited_count) - snap > 0) { - smp_mb(); /* ensure test happens before caller kfree */ - return; - } - get_online_cpus(); - } - atomic_inc(&synchronize_sched_expedited_count); - smp_mb__after_atomic_inc(); /* ensure post-GP actions seen after GP. */ - put_online_cpus(); -} -EXPORT_SYMBOL_GPL(synchronize_sched_expedited); - -#endif /* #else #ifndef CONFIG_SMP */ |