diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/delayacct.c | 2 | ||||
| -rw-r--r-- | kernel/exit.c | 6 | ||||
| -rw-r--r-- | kernel/fork.c | 3 | ||||
| -rw-r--r-- | kernel/ksysfs.c | 8 | ||||
| -rw-r--r-- | kernel/sched.c | 1444 | ||||
| -rw-r--r-- | kernel/sched_debug.c | 282 | ||||
| -rw-r--r-- | kernel/sched_fair.c | 811 | ||||
| -rw-r--r-- | kernel/sched_idletask.c | 8 | ||||
| -rw-r--r-- | kernel/sched_rt.c | 19 | ||||
| -rw-r--r-- | kernel/sched_stats.h | 28 | ||||
| -rw-r--r-- | kernel/sysctl.c | 37 | ||||
| -rw-r--r-- | kernel/user.c | 249 |
12 files changed, 1654 insertions, 1243 deletions
diff --git a/kernel/delayacct.c b/kernel/delayacct.c index 81e69782963..09e9574eeb2 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -119,7 +119,7 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) * No locking available for sched_info (and too expensive to add one) * Mitigate by taking snapshot of values */ - t1 = tsk->sched_info.pcnt; + t1 = tsk->sched_info.pcount; t2 = tsk->sched_info.run_delay; t3 = tsk->sched_info.cpu_time; diff --git a/kernel/exit.c b/kernel/exit.c index 993369ee94d..7f7959de4a8 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -111,6 +111,7 @@ static void __exit_signal(struct task_struct *tsk) */ sig->utime = cputime_add(sig->utime, tsk->utime); sig->stime = cputime_add(sig->stime, tsk->stime); + sig->gtime = cputime_add(sig->gtime, tsk->gtime); sig->min_flt += tsk->min_flt; sig->maj_flt += tsk->maj_flt; sig->nvcsw += tsk->nvcsw; @@ -1242,6 +1243,11 @@ static int wait_task_zombie(struct task_struct *p, int noreap, cputime_add(p->stime, cputime_add(sig->stime, sig->cstime))); + psig->cgtime = + cputime_add(psig->cgtime, + cputime_add(p->gtime, + cputime_add(sig->gtime, + sig->cgtime))); psig->cmin_flt += p->min_flt + sig->min_flt + sig->cmin_flt; psig->cmaj_flt += diff --git a/kernel/fork.c b/kernel/fork.c index 5e67f90a169..3fc3c138391 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -877,6 +877,8 @@ static inline int copy_signal(unsigned long clone_flags, struct task_struct * ts sig->tty_old_pgrp = NULL; sig->utime = sig->stime = sig->cutime = sig->cstime = cputime_zero; + sig->gtime = cputime_zero; + sig->cgtime = cputime_zero; sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0; sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0; sig->inblock = sig->oublock = sig->cinblock = sig->coublock = 0; @@ -1045,6 +1047,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, p->utime = cputime_zero; p->stime = cputime_zero; + p->gtime = cputime_zero; #ifdef CONFIG_TASK_XACCT p->rchar = 0; /* I/O counter: bytes read */ diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c index d0e5c48e18c..6046939d080 100644 --- a/kernel/ksysfs.c +++ b/kernel/ksysfs.c @@ -14,6 +14,7 @@ #include <linux/module.h> #include <linux/init.h> #include <linux/kexec.h> +#include <linux/sched.h> #define KERNEL_ATTR_RO(_name) \ static struct subsys_attribute _name##_attr = __ATTR_RO(_name) @@ -116,6 +117,13 @@ static int __init ksysfs_init(void) ¬es_attr); } + /* + * Create "/sys/kernel/uids" directory and corresponding root user's + * directory under it. + */ + if (!error) + error = uids_kobject_init(); + return error; } diff --git a/kernel/sched.c b/kernel/sched.c index 6c10fa796ca..bba57adb950 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -96,7 +96,7 @@ unsigned long long __attribute__((weak)) sched_clock(void) /* * Some helpers for converting nanosecond timing to jiffy resolution */ -#define NS_TO_JIFFIES(TIME) ((TIME) / (1000000000 / HZ)) +#define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (1000000000 / HZ)) #define JIFFIES_TO_NS(TIME) ((TIME) * (1000000000 / HZ)) #define NICE_0_LOAD SCHED_LOAD_SCALE @@ -105,11 +105,9 @@ unsigned long long __attribute__((weak)) sched_clock(void) /* * These are the 'tuning knobs' of the scheduler: * - * Minimum timeslice is 5 msecs (or 1 jiffy, whichever is larger), - * default timeslice is 100 msecs, maximum timeslice is 800 msecs. + * default timeslice is 100 msecs (used only for SCHED_RR tasks). * Timeslices get refilled after they expire. */ -#define MIN_TIMESLICE max(5 * HZ / 1000, 1) #define DEF_TIMESLICE (100 * HZ / 1000) #ifdef CONFIG_SMP @@ -133,24 +131,6 @@ static inline void sg_inc_cpu_power(struct sched_group *sg, u32 val) } #endif -#define SCALE_PRIO(x, prio) \ - max(x * (MAX_PRIO - prio) / (MAX_USER_PRIO / 2), MIN_TIMESLICE) - -/* - * static_prio_timeslice() scales user-nice values [ -20 ... 0 ... 19 ] - * to time slice values: [800ms ... 100ms ... 5ms] - */ -static unsigned int static_prio_timeslice(int static_prio) -{ - if (static_prio == NICE_TO_PRIO(19)) - return 1; - - if (static_prio < NICE_TO_PRIO(0)) - return SCALE_PRIO(DEF_TIMESLICE * 4, static_prio); - else - return SCALE_PRIO(DEF_TIMESLICE, static_prio); -} - static inline int rt_policy(int policy) { if (unlikely(policy == SCHED_FIFO) || unlikely(policy == SCHED_RR)) @@ -171,31 +151,91 @@ struct rt_prio_array { struct list_head queue[MAX_RT_PRIO]; }; -struct load_stat { - struct load_weight load; - u64 load_update_start, load_update_last; - unsigned long delta_fair, delta_exec, delta_stat; +#ifdef CONFIG_FAIR_GROUP_SCHED + +struct cfs_rq; + +/* task group related information */ +struct task_group { + /* 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; + /* spinlock to serialize modification to shares */ + spinlock_t lock; +}; + +/* Default task group's sched entity on each cpu */ +static DEFINE_PER_CPU(struct sched_entity, init_sched_entity); +/* Default task group's cfs_rq on each cpu */ +static DEFINE_PER_CPU(struct cfs_rq, init_cfs_rq) ____cacheline_aligned_in_smp; + +static struct sched_entity *init_sched_entity_p[NR_CPUS]; +static struct cfs_rq *init_cfs_rq_p[NR_CPUS]; + +/* Default task group. + * Every task in system belong to this group at bootup. + */ +struct task_group init_task_group = { + .se = init_sched_entity_p, + .cfs_rq = init_cfs_rq_p, }; +#ifdef CONFIG_FAIR_USER_SCHED +# define INIT_TASK_GRP_LOAD 2*NICE_0_LOAD +#else +# define INIT_TASK_GRP_LOAD NICE_0_LOAD +#endif + +static int init_task_group_load = INIT_TASK_GRP_LOAD; + +/* return group to which a task belongs */ +static inline struct task_group *task_group(struct task_struct *p) +{ + struct task_group *tg; + +#ifdef CONFIG_FAIR_USER_SCHED + tg = p->user->tg; +#else + tg = &init_task_group; +#endif + + return tg; +} + +/* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ +static inline void set_task_cfs_rq(struct task_struct *p) +{ + p->se.cfs_rq = task_group(p)->cfs_rq[task_cpu(p)]; + p->se.parent = task_group(p)->se[task_cpu(p)]; +} + +#else + +static inline void set_task_cfs_rq(struct task_struct *p) { } + +#endif /* CONFIG_FAIR_GROUP_SCHED */ + /* CFS-related fields in a runqueue */ struct cfs_rq { struct load_weight load; unsigned long nr_running; - s64 fair_clock; u64 exec_clock; - s64 wait_runtime; - u64 sleeper_bonus; - unsigned long wait_runtime_overruns, wait_runtime_underruns; + u64 min_vruntime; struct rb_root tasks_timeline; struct rb_node *rb_leftmost; struct rb_node *rb_load_balance_curr; -#ifdef CONFIG_FAIR_GROUP_SCHED /* '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; + + unsigned long 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 @@ -206,6 +246,8 @@ struct cfs_rq { * list is used during load balance. */ struct list_head leaf_cfs_rq_list; /* Better name : task_cfs_rq_list? */ + struct task_group *tg; /* group that "owns" this runqueue */ + struct rcu_head rcu; #endif }; @@ -237,7 +279,7 @@ struct rq { #ifdef CONFIG_NO_HZ unsigned char in_nohz_recently; #endif - struct load_stat ls; /* capture load from *all* tasks on this cpu */ + struct load_weight load; /* capture load from *all* tasks on this cpu */ unsigned long nr_load_updates; u64 nr_switches; @@ -289,16 +331,19 @@ struct rq { unsigned long yld_exp_empty; unsigned long yld_act_empty; unsigned long yld_both_empty; - unsigned long yld_cnt; + unsigned long yld_count; /* schedule() stats */ unsigned long sched_switch; - unsigned long sched_cnt; + unsigned long sched_count; unsigned long sched_goidle; /* try_to_wake_up() stats */ - unsigned long ttwu_cnt; + unsigned long ttwu_count; unsigned long ttwu_local; + + /* BKL stats */ + unsigned long bkl_count; #endif struct lock_class_key rq_lock_key; }; @@ -383,6 +428,37 @@ static void update_rq_clock(struct rq *rq) #define cpu_curr(cpu) (cpu_rq(cpu)->curr) /* + * 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 + +/* + * Debugging: various feature bits + */ +enum { + SCHED_FEAT_NEW_FAIR_SLEEPERS = 1, + SCHED_FEAT_START_DEBIT = 2, + SCHED_FEAT_TREE_AVG = 4, + SCHED_FEAT_APPROX_AVG = 8, + SCHED_FEAT_WAKEUP_PREEMPT = 16, + SCHED_FEAT_PREEMPT_RESTRICT = 32, +}; + +const_debug unsigned int sysctl_sched_features = + SCHED_FEAT_NEW_FAIR_SLEEPERS *1 | + SCHED_FEAT_START_DEBIT *1 | + SCHED_FEAT_TREE_AVG *0 | + SCHED_FEAT_APPROX_AVG *0 | + SCHED_FEAT_WAKEUP_PREEMPT *1 | + SCHED_FEAT_PREEMPT_RESTRICT *1; + +#define sched_feat(x) (sysctl_sched_features & SCHED_FEAT_##x) + +/* * For kernel-internal use: high-speed (but slightly incorrect) per-cpu * clock constructed from sched_clock(): */ @@ -400,18 +476,7 @@ unsigned long long cpu_clock(int cpu) return now; } - -#ifdef CONFIG_FAIR_GROUP_SCHED -/* Change a task's ->cfs_rq if it moves across CPUs */ -static inline void set_task_cfs_rq(struct task_struct *p) -{ - p->se.cfs_rq = &task_rq(p)->cfs; -} -#else -static inline void set_task_cfs_rq(struct task_struct *p) -{ -} -#endif +EXPORT_SYMBOL_GPL(cpu_clock); #ifndef prepare_arch_switch # define prepare_arch_switch(next) do { } while (0) @@ -497,16 +562,13 @@ static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) static inline struct rq *__task_rq_lock(struct task_struct *p) __acquires(rq->lock) { - struct rq *rq; - -repeat_lock_task: - rq = task_rq(p); - spin_lock(&rq->lock); - if (unlikely(rq != task_rq(p))) { + for (;;) { + struct rq *rq = task_rq(p); + spin_lock(&rq->lock); + if (likely(rq == task_rq(p))) + return rq; spin_unlock(&rq->lock); - goto repeat_lock_task; } - return rq; } /* @@ -519,18 +581,17 @@ static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) { struct rq *rq; -repeat_lock_task: - local_irq_save(*flags); - rq = task_rq(p); - spin_lock(&rq->lock); - if (unlikely(rq != task_rq(p))) { + for (;;) { + local_irq_save(*flags); + rq = task_rq(p); + spin_lock(&rq->lock); + if (likely(rq == task_rq(p))) + return rq; spin_unlock_irqrestore(&rq->lock, *flags); - goto repeat_lock_task; } - return rq; } -static inline void __task_rq_unlock(struct rq *rq) +static void __task_rq_unlock(struct rq *rq) __releases(rq->lock) { spin_unlock(&rq->lock); @@ -545,7 +606,7 @@ static inline void task_rq_unlock(struct rq *rq, unsigned long *flags) /* * this_rq_lock - lock this runqueue and disable interrupts. */ -static inline struct rq *this_rq_lock(void) +static struct rq *this_rq_lock(void) __acquires(rq->lock) { struct rq *rq; @@ -645,19 +706,6 @@ static inline void resched_task(struct task_struct *p) } #endif -static u64 div64_likely32(u64 divident, unsigned long divisor) -{ -#if BITS_PER_LONG == 32 - if (likely(divident <= 0xffffffffULL)) - return (u32)divident / divisor; - do_div(divident, divisor); - - return divident; -#else - return divident / divisor; -#endif -} - #if BITS_PER_LONG == 32 # define WMULT_CONST (~0UL) #else @@ -699,16 +747,14 @@ calc_delta_fair(unsigned long delta_exec, struct load_weight *lw) return calc_delta_mine(delta_exec, NICE_0_LOAD, lw); } -static void update_load_add(struct load_weight *lw, unsigned long inc) +static inline void update_load_add(struct load_weight *lw, unsigned long inc) { lw->weight += inc; - lw->inv_weight = 0; } -static void update_load_sub(struct load_weight *lw, unsigned long dec) +static inline void update_load_sub(struct load_weight *lw, unsigned long dec) { lw->weight -= dec; - lw->inv_weight = 0; } /* @@ -784,29 +830,20 @@ static int balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, int *this_best_prio, struct rq_iterator *iterator); #include "sched_stats.h" -#include "sched_rt.c" -#include "sched_fair.c" #include "sched_idletask.c" +#include "sched_fair.c" +#include "sched_rt.c" #ifdef CONFIG_SCHED_DEBUG # include "sched_debug.c" #endif #define sched_class_highest (&rt_sched_class) -static void __update_curr_load(struct rq *rq, struct load_stat *ls) -{ - if (rq->curr != rq->idle && ls->load.weight) { - ls->delta_exec += ls->delta_stat; - ls->delta_fair += calc_delta_fair(ls->delta_stat, &ls->load); - ls->delta_stat = 0; - } -} - /* * Update delta_exec, delta_fair fields for rq. * * delta_fair clock advances at a rate inversely proportional to - * total load (rq->ls.load.weight) on the runqueue, while + * total load (rq->load.weight) on the runqueue, while * delta_exec advances at the same rate as wall-clock (provided * cpu is not idle). * @@ -814,35 +851,17 @@ static void __update_curr_load(struct rq *rq, struct load_stat *ls) * runqueue over any given interval. This (smoothened) load is used * during load balance. * - * This function is called /before/ updating rq->ls.load + * This function is called /before/ updating rq->load * and when switching tasks. */ -static void update_curr_load(struct rq *rq) -{ - struct load_stat *ls = &rq->ls; - u64 start; - - start = ls->load_update_start; - ls->load_update_start = rq->clock; - ls->delta_stat += rq->clock - start; - /* - * Stagger updates to ls->delta_fair. Very frequent updates - * can be expensive. - */ - if (ls->delta_stat >= sysctl_sched_stat_granularity) - __update_curr_load(rq, ls); -} - static inline void inc_load(struct rq *rq, const struct task_struct *p) { - update_curr_load(rq); - update_load_add(&rq->ls.load, p->se.load.weight); + update_load_add(&rq->load, p->se.load.weight); } static inline void dec_load(struct rq *rq, const struct task_struct *p) { - update_curr_load(rq); - update_load_sub(&rq->ls.load, p->se.load.weight); + update_load_sub(&rq->load, p->se.load.weight); } static void inc_nr_running(struct task_struct *p, struct rq *rq) @@ -859,8 +878,6 @@ static void dec_nr_running(struct task_struct *p, struct rq *rq) static void set_load_weight(struct task_struct *p) { - p->se.wait_runtime = 0; - if (task_has_rt_policy(p)) { p->se.load.weight = prio_to_weight[0] * 2; p->se.load.inv_weight = prio_to_wmult[0] >> 1; @@ -952,20 +969,6 @@ static void activate_task(struct rq *rq, struct task_struct *p, int wakeup) } /* - * activate_idle_task - move idle task to the _front_ of runqueue. - */ -static inline void activate_idle_task(struct task_struct *p, struct rq *rq) -{ - update_rq_clock(rq); - - if (p->state == TASK_UNINTERRUPTIBLE) - rq->nr_uninterruptible--; - - enqueue_task(rq, p, 0); - inc_nr_running(p, rq); -} - -/* * deactivate_task - remove a task from the runqueue. */ static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep) @@ -989,32 +992,50 @@ inline int task_curr(const struct task_struct *p) /* Used instead of source_load when we know the type == 0 */ unsigned long weighted_cpuload(const int cpu) { - return cpu_rq(cpu)->ls.load.weight; + return cpu_rq(cpu)->load.weight; } static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) { #ifdef CONFIG_SMP task_thread_info(p)->cpu = cpu; - set_task_cfs_rq(p); #endif + set_task_cfs_rq(p); } #ifdef CONFIG_SMP +/* + * Is this task likely cache-hot: + */ +static inline int +task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) +{ + s64 delta; + + if (p->sched_class != &fair_sched_class) + return 0; + + if (sysctl_sched_migration_cost == -1) + return 1; + if (sysctl_sched_migration_cost == 0) + return 0; + + delta = now - p->se.exec_start; + + return delta < (s64)sysctl_sched_migration_cost; +} + + void set_task_cpu(struct task_struct *p, unsigned int new_cpu) { int old_cpu = task_cpu(p); struct rq *old_rq = cpu_rq(old_cpu), *new_rq = cpu_rq(new_cpu); - u64 clock_offset, fair_clock_offset; + struct cfs_rq *old_cfsrq = task_cfs_rq(p), + *new_cfsrq = cpu_cfs_rq(old_cfsrq, new_cpu); + u64 clock_offset; clock_offset = old_rq->clock - new_rq->clock; - fair_clock_offset = old_rq->cfs.fair_clock - new_rq->cfs.fair_clock; - - if (p->se.wait_start_fair) - p->se.wait_start_fair -= fair_clock_offset; - if (p->se.sleep_start_fair) - p->se.sleep_start_fair -= fair_clock_offset; #ifdef CONFIG_SCHEDSTATS if (p->se.wait_start) @@ -1023,7 +1044,14 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu) p->se.sleep_start -= clock_offset; if (p->se.block_start) p->se.block_start -= clock_offset; + if (old_cpu != new_cpu) { + schedstat_inc(p, se.nr_migrations); + if (task_hot(p, old_rq->clock, NULL)) + schedstat_inc(p, se.nr_forced2_migrations); + } #endif + p->se.vruntime -= old_cfsrq->min_vruntime - + new_cfsrq->min_vruntime; __set_task_cpu(p, new_cpu); } @@ -1078,69 +1106,71 @@ void wait_task_inactive(struct task_struct *p) int running, on_rq; struct rq *rq; -repeat: - /* - * We do the initial early heuristics without holding - * any task-queue locks at all. We'll only try to get - * the runqueue lock when things look like they will - * work out! - */ - rq = task_rq(p); + for (;;) { + /* + * We do the initial early heuristics without holding + * any task-queue locks at all. We'll only try to get + * the runqueue lock when things look like they will + * work out! + */ + rq = task_rq(p); - /* - * If the task is actively running on another CPU - * still, just relax and busy-wait without holding - * any locks. - * - * NOTE! Since we don't hold any locks, it's not - * even sure that "rq" stays as the right runqueue! - * But we don't care, since "task_running()" will - * return false if the runqueue has changed and p - * is actually now running somewhere else! - */ - while (task_running(rq, p)) - cpu_relax(); + /* + * If the task is actively running on another CPU + * still, just relax and busy-wait without holding + * any locks. + * + * NOTE! Since we don't hold any locks, it's not + * even sure that "rq" stays as the right runqueue! + * But we don't care, since "task_running()" will + * return false if the runqueue has changed and p + * is actually now running somewhere else! + */ + while (task_running(rq, p)) + cpu_relax(); - /* - * Ok, time to look more closely! We need the rq - * lock now, to be *sure*. If we're wrong, we'll - * just go back and repeat. - */ - rq = task_rq_lock(p, &flags); - running = task_running(rq, p); - on_rq = p->se.on_rq; - task_rq_unlock(rq, &flags); + /* + * Ok, time to look more closely! We need the rq + * lock now, to be *sure*. If we're wrong, we'll + * just go back and repeat. + */ + rq = task_rq_lock(p, &flags); + running = task_running(rq, p); + on_rq = p->se.on_rq; + task_rq_unlock(rq, &flags); - /* - * Was it really running after all now that we - * checked with the proper locks actually held? - * - * Oops. Go back and try again.. - */ - if (unlikely(running)) { - cpu_relax(); - goto repeat; - } + /* + * Was it really running after all now that we + * checked with the proper locks actually held? + * + * Oops. Go back and try again.. + */ + if (unlikely(running)) { + cpu_relax(); + continue; + } - /* - * It's not enough that it's not actively running, - * it must be off the runqueue _entirely_, and not - * preempted! - * - * So if it wa still runnable (but just not actively - * running right now), it's preempted, and we should - * yield - it could be a while. - */ - if (unlikely(on_rq)) { - yield(); - goto repeat; - } + /* + * It's not enough that it's not actively running, + * it must be off the runqueue _entirely_, and not + * preempted! + * + * So if it wa still runnable (but just not actively + * running right now), it's preempted, and we should + * yield - it could be a while. + */ + if (unlikely(on_rq)) { + schedule_timeout_uninterruptible(1); + continue; + } - /* - * Ahh, all good. It wasn't running, and it wasn't - * runnable, which means that it will never become - * running in the future either. We're all done! - */ + /* + * Ahh, all good. It wasn't running, and it wasn't + * runnable, which means that it will never become + * running in the future either. We're all done! + */ + break; + } } /*** @@ -1174,7 +1204,7 @@ void kick_process(struct task_struct *p) * We want to under-estimate the load of migration sources, to * balance conservatively. */ -static inline unsigned long source_load(int cpu, int type) +static unsigned long source_load(int cpu, int type) { struct rq *rq = cpu_rq(cpu); unsigned long total = weighted_cpuload(cpu); @@ -1189,7 +1219,7 @@ static inline unsigned long source_load(int cpu, int type) * Return a high guess at the load of a migration-target cpu weighted * according to the scheduling class and "nice" value. */ -static inline unsigned long target_load(int cpu, int type) +static unsigned long target_load(int cpu, int type) { struct rq *rq = cpu_rq(cpu); unsigned long total = weighted_cpuload(cpu); @@ -1231,7 +1261,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu) /* Skip over this group if it has no CPUs allowed */ if (!cpus_intersects(group->cpumask, p->cpus_allowed)) - goto nextgroup; + continue; local_group = cpu_isset(this_cpu, group->cpumask); @@ -1259,9 +1289,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu) min_load = avg_load; idlest = group; } -nextgroup: - group = group->next; - } while (group != sd->groups); + } while (group = group->next, group != sd->groups); if (!idlest || 100*this_load < imbalance*min_load) return NULL; @@ -1393,8 +1421,13 @@ static int wake_idle(int cpu, struct task_struct *p) if (sd->flags & SD_WAKE_IDLE) { cpus_and(tmp, sd->span, p->cpus_allowed); for_each_cpu_mask(i, tmp) { - if (idle_cpu(i)) + if (idle_cpu(i)) { + if (i != task_cpu(p)) { + schedstat_inc(p, + se.nr_wakeups_idle); + } return i; + } } } else { break; @@ -1425,7 +1458,7 @@ static inline int wake_idle(int cpu, struct task_struct *p) */ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) { - int cpu, this_cpu, success = 0; + int cpu, orig_cpu, this_cpu, success = 0; unsigned long flags; long old_state; struct rq *rq; @@ -1444,6 +1477,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) goto out_running; cpu = task_cpu(p); + orig_cpu = cpu; this_cpu = smp_processor_id(); #ifdef CONFIG_SMP @@ -1452,7 +1486,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) new_cpu = cpu; - schedstat_inc(rq, ttwu_cnt); + schedstat_inc(rq, ttwu_count); if (cpu == this_cpu) { schedstat_inc(rq, ttwu_local); goto out_set_cpu; @@ -1487,6 +1521,13 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) unsigned long tl = this_load; unsigned long tl_per_task; + /* + * Attract cache-cold tasks on sync wakeups: + */ + if (sync && !task_hot(p, rq->clock, this_sd)) + goto out_set_cpu; + + schedstat_inc(p, se.nr_wakeups_affine_attempts); tl_per_task = cpu_avg_load_per_task(this_cpu); /* @@ -1506,6 +1547,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) * there is no bad imbalance. */ schedstat_inc(this_sd, ttwu_move_affine); + schedstat_inc(p, se.nr_wakeups_affine); goto out_set_cpu; } } @@ -1517,6 +1559,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) if (this_sd->flags & SD_WAKE_BALANCE) { if (imbalance*this_load <= 100*load) { schedstat_inc(this_sd, ttwu_move_balance); + schedstat_inc(p, se.nr_wakeups_passive); goto out_set_cpu; } } @@ -1542,18 +1585,18 @@ out_set_cpu: out_activate: #endif /* CONFIG_SMP */ + schedstat_inc(p, se.nr_wakeups); + if (sync) + schedstat_inc(p, se.nr_wakeups_sync); + if (orig_cpu != cpu) + schedstat_inc(p, se.nr_wakeups_migrate); + if (cpu == this_cpu) + schedstat_inc(p, se.nr_wakeups_local); + else + schedstat_inc(p, se.nr_wakeups_remote); update_rq_clock(rq); activate_task(rq, p, 1); - /* - * Sync wakeups (i.e. those types of wakeups where the waker - * has indicated that it will leave the CPU in short order) - * don't trigger a preemption, if the woken up task will run on - * this cpu. (in this case the 'I will reschedule' promise of - * the waker guarantees that the freshly woken up task is going - * to be considered on this CPU.) - */ - if (!sync || cpu != this_cpu) - check_preempt_curr(rq, p); + check_preempt_curr(rq, p); success = 1; out_running: @@ -1584,28 +1627,20 @@ int fastcall wake_up_state(struct task_struct *p, unsigned int state) */ static void __sched_fork(struct task_struct *p) { - p->se.wait_start_fair = 0; p->se.exec_start = 0; p->se.sum_exec_runtime = 0; p->se.prev_sum_exec_runtime = 0; - p->se.delta_exec = 0; - p->se.delta_fair_run = 0; - p->se.delta_fair_sleep = 0; - p->se.wait_runtime = 0; - p->se.sleep_start_fair = 0; #ifdef CONFIG_SCHEDSTATS p->se.wait_start = 0; - p->se.sum_wait_runtime = 0; p->se.sum_sleep_runtime = 0; p->se.sleep_start = 0; p->se.block_start = 0; p->se.sleep_max = 0; p->se.block_max = 0; p->se.exec_max = 0; + p->se.slice_max = 0; p->se.wait_max = 0; - p->se.wait_runtime_overruns = 0; - p->se.wait_runtime_underruns = 0; #endif INIT_LIST_HEAD(&p->run_list); @@ -1636,12 +1671,14 @@ void sched_fork(struct task_struct *p, int clone_flags) #ifdef CONFIG_SMP cpu = sched_balance_self(cpu, SD_BALANCE_FORK); #endif - __set_task_cpu(p, cpu); + set_task_cpu(p, cpu); /* * 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 defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) if (likely(sched_info_on())) @@ -1658,12 +1695,6 @@ void sched_fork(struct task_struct *p, int clone_flags) } /* - * After fork, child runs first. (default) If set to 0 then - * parent will (try to) run first. - */ -unsigned int __read_mostly sysctl_sched_child_runs_first = 1; - -/* * wake_up_new_task - wake up a newly created task for the first time. * * This function will do some initial scheduler statistics housekeeping @@ -1674,24 +1705,14 @@ void fastcall wake_up_new_task(struct task_struct *p, unsigned long clone_flags) { unsigned long flags; struct rq *rq; - int this_cpu; rq = task_rq_lock(p, &flags); BUG_ON(p->state != TASK_RUNNING); - this_cpu = smp_processor_id(); /* parent's CPU */ update_rq_clock(rq); p->prio = effective_prio(p); - if (rt_prio(p->prio)) - p->sched_class = &rt_sched_class; - else - p->sched_class = &fair_sched_class; - - if (!p->sched_class->task_new || !sysctl_sched_child_runs_first || - (clone_flags & CLONE_VM) || task_cpu(p) != this_cpu || - !current->se.on_rq) { - + if (!p->sched_class->task_new || !current->se.on_rq || !rq->cfs.curr) { activate_task(rq, p, 0); } else { /* @@ -1800,7 +1821,7 @@ prepare_task_switch(struct rq *rq, struct task_struct *prev, * with the lock held can cause deadlocks; see schedule() for * details.) */ -static inline void finish_task_switch(struct rq *rq, struct task_struct *prev) +static void finish_task_switch(struct rq *rq, struct task_struct *prev) __releases(rq->lock) { struct mm_struct *mm = rq->prev_mm; @@ -1982,42 +2003,10 @@ unsigned long nr_active(void) */ static void update_cpu_load(struct rq *this_rq) { - u64 fair_delta64, exec_delta64, idle_delta64, sample_interval64, tmp64; - unsigned long total_load = this_rq->ls.load.weight; - unsigned long this_load = total_load; - struct load_stat *ls = &this_rq->ls; + unsigned long this_load = this_rq->load.weight; int i, scale; this_rq->nr_load_updates++; - if (unlikely(!(sysctl_sched_features & SCHED_FEAT_PRECISE_CPU_LOAD))) - goto do_avg; - - /* Update delta_fair/delta_exec fields first */ - update_curr_load(this_rq); - - fair_delta64 = ls->delta_fair + 1; - ls->delta_fair = 0; - - exec_delta64 = ls->delta_exec + 1; - ls->delta_exec = 0; - - sample_interval64 = this_rq->clock - ls->load_update_last; - ls->load_update_last = this_rq->clock; - - if ((s64)sample_interval64 < (s64)TICK_NSEC) - sample_interval64 = TICK_NSEC; - - if (exec_delta64 > sample_interval64) - exec_delta64 = sample_interval64; - - idle_delta64 = sample_interval64 - exec_delta64; - - tmp64 = div64_64(SCHED_LOAD_SCALE * exec_delta64, fair_delta64); - tmp64 = div64_64(tmp64 * exec_delta64, sample_interval64); - - this_load = (unsigned long)tmp64; - -do_avg: /* Update our load: */ for (i = 0, scale = 1; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { @@ -2027,7 +2016,13 @@ do_avg: old_load = this_rq->cpu_load[i]; new_load = this_load; - + /* + * Round up the averaging division if load is increasing. This + * prevents us from getting stuck on 9 if the load is 10, for + * example. + */ + if (new_load > old_load) + new_load += scale-1; this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i; } } @@ -2179,13 +2174,38 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu, * 2) cannot be migrated to this CPU due to cpus_allowed, or * 3) are cache-hot on their current CPU. */ - if (!cpu_isset(this_cpu, p->cpus_allowed)) + if (!cpu_isset(this_cpu, p->cpus_allowed)) { + schedstat_inc(p, se.nr_failed_migrations_affine); return 0; + } *all_pinned = 0; - if (task_running(rq, p)) + if (task_running(rq, p)) { + schedstat_inc(p, se.nr_failed_migrations_running); return 0; + } + + /* + * Aggressive migration if: + * 1) task is cache cold, or + * 2) too many balance attempts have failed. + */ + + if (!task_hot(p, rq->clock, sd) || + sd->nr_balance_failed > sd->cache_nice_tries) { +#ifdef CONFIG_SCHEDSTATS + if (task_hot(p, rq->clock, sd)) { + schedstat_inc(sd, lb_hot_gained[idle]); + schedstat_inc(p, se.nr_forced_migrations); + } +#endif + return 1; + } + if (task_hot(p, rq->clock, sd)) { + schedstat_inc(p, se.nr_failed_migrations_hot); + return 0; + } return 1; } @@ -2264,7 +2284,7 @@ static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, struct sched_domain *sd, enum cpu_idle_type idle, int *all_pinned) { - struct sched_class *class = sched_class_highest; + const struct sched_class *class = sched_class_highest; unsigned long total_load_moved = 0; int this_best_prio = this_rq->curr->prio; @@ -2289,7 +2309,7 @@ static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, static int move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, struct sched_domain *sd, enum cpu_idle_type idle) { - struct sched_class *class; + const struct sched_class *class; int this_best_prio = MAX_PRIO; for (class = sched_class_highest; class; class = class->next) @@ -2653,7 +2673,7 @@ static int load_balance(int this_cpu, struct rq *this_rq, !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) sd_idle = 1; - schedstat_inc(sd, lb_cnt[idle]); + schedstat_inc(sd, lb_count[idle]); redo: group = find_busiest_group(sd, this_cpu, &imbalance, idle, &sd_idle, @@ -2806,7 +2826,7 @@ load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd) !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) sd_idle = 1; - schedstat_inc(sd, lb_cnt[CPU_NEWLY_IDLE]); + schedstat_inc(sd, lb_count[CPU_NEWLY_IDLE]); redo: group = find_busiest_group(sd, this_cpu, &imbalance, CPU_NEWLY_IDLE, &sd_idle, &cpus, NULL); @@ -2940,7 +2960,7 @@ static void active_load_balance(struct rq *busiest_rq, int busiest_cpu) } if (likely(sd)) { - schedstat_inc(sd, alb_cnt); + schedstat_inc(sd, alb_count); if (move_one_task(target_rq, target_cpu, busiest_rq, sd, CPU_IDLE)) @@ -3033,7 +3053,7 @@ static DEFINE_SPINLOCK(balancing); * * Balancing parameters are set up in arch_init_sched_domains. */ -static inline void rebalance_domains(int cpu, enum cpu_idle_type idle) +static void rebalance_domains(int cpu, enum cpu_idle_type idle) { int balance = 1; struct rq *rq = cpu_rq(cpu); @@ -3280,6 +3300,25 @@ void account_user_time(struct task_struct *p, cputime_t cputime) } /* + * Account guest cpu time to a process. + * @p: the process that the cpu time gets accounted to + * @cputime: the cpu time spent in virtual machine since the last update + */ +void account_guest_time(struct task_struct *p, cputime_t cputime) +{ + cputime64_t tmp; + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; + + tmp = cputime_to_cputime64(cputime); + + p->utime = cputime_add(p->utime, cputime); + p->gtime = cputime_add(p->gtime, cputime); + + cpustat->user = cputime64_add(cpustat->user, tmp); + cpustat->guest = cputime64_add(cpustat->guest, tmp); +} + +/* * Account 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() @@ -3292,6 +3331,12 @@ void account_system_time(struct task_struct *p, int hardirq_offset, struct rq *rq = this_rq(); cputime64_t tmp; + if (p->flags & PF_VCPU) { + account_guest_time(p, cputime); + p->flags &= ~PF_VCPU; + return; + } + p->stime = cputime_add(p->stime, cputime); /* Add system time to cpustat. */ @@ -3430,7 +3475,13 @@ static inline void schedule_debug(struct task_struct *prev) profile_hit(SCHED_PROFILING, __builtin_return_address(0)); - schedstat_inc(this_rq(), sched_cnt); + 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 } /* @@ -3439,7 +3490,7 @@ static inline void schedule_debug(struct task_struct *prev) static inline struct task_struct * pick_next_task(struct rq *rq, struct task_struct *prev) { - struct sched_class *class; + const struct sched_class *class; struct task_struct *p; /* @@ -3488,9 +3539,13 @@ need_resched_nonpreemptible: schedule_debug(prev); - spin_lock_irq(&rq->lock); - clear_tsk_need_resched(prev); + /* + * Do the rq-clock update outside the rq lock: + */ + local_irq_disable(); __update_rq_clock(rq); + spin_lock(&rq->lock); + clear_tsk_need_resched(prev); if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { if (unlikely((prev->state & TASK_INTERRUPTIBLE) && @@ -3550,27 +3605,30 @@ asmlinkage void __sched preempt_schedule(void) if (likely(ti->preempt_count || irqs_disabled())) return; -need_resched: - add_preempt_count(PREEMPT_ACTIVE); - /* - * We keep the big kernel semaphore locked, but we - * clear ->lock_depth so that schedule() doesnt - * auto-release the semaphore: - */ + do { + add_preempt_count(PREEMPT_ACTIVE); + + /* + * We keep the big kernel semaphore locked, but we + * clear ->lock_depth so that schedule() doesnt + * auto-release the semaphore: + */ #ifdef CONFIG_PREEMPT_BKL - saved_lock_depth = task->lock_depth; - task->lock_depth = -1; + saved_lock_depth = task->lock_depth; + task->lock_depth = -1; #endif - schedule(); + schedule(); #ifdef CONFIG_PREEMPT_BKL - task->lock_depth = saved_lock_depth; + task->lock_depth = saved_lock_depth; #endif - sub_preempt_count(PREEMPT_ACTIVE); + sub_preempt_count(PREEMPT_ACTIVE); - /* we could miss a preemption opportunity between schedule and now */ - barrier(); - if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) - goto need_resched; + /* + * Check again in case we missed a preemption opportunity + * between schedule and now. + */ + barrier(); + } while (unlikely(test_thread_flag(TIF_NEED_RESCHED))); } EXPORT_SYMBOL(preempt_schedule); @@ -3590,29 +3648,32 @@ asmlinkage void __sched preempt_schedule_irq(void) /* Catch callers which need to be fixed */ BUG_ON(ti->preempt_count || !irqs_disabled()); -need_resched: - add_preempt_count(PREEMPT_ACTIVE); - /* - * We keep the big kernel semaphore locked, but we - * clear ->lock_depth so that schedule() doesnt - * auto-release the semaphore: - */ + do { + add_preempt_count(PREEMPT_ACTIVE); + + /* + * We keep the big kernel semaphore locked, but we + * clear ->lock_depth so that schedule() doesnt + * auto-release the semaphore: + */ #ifdef CONFIG_PREEMPT_BKL - saved_lock_depth = task->lock_depth; - task->lock_depth = -1; + saved_lock_depth = task->lock_depth; + task->lock_depth = -1; #endif - local_irq_enable(); - schedule(); - local_irq_disable(); + local_irq_enable(); + schedule(); + local_irq_disable(); #ifdef CONFIG_PREEMPT_BKL - task->lock_depth = saved_lock_depth; + task->lock_depth = saved_lock_depth; #endif - sub_preempt_count(PREEMPT_ACTIVE); + sub_preempt_count(PREEMPT_ACTIVE); - /* we could miss a preemption opportunity between schedule and now */ - barrier(); - if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) - goto need_resched; + /* + * Check again in case we missed a preemption opportunity + * between schedule and now. + */ + barrier(); + } while (unlikely(test_thread_flag(TIF_NEED_RESCHED))); } #endif /* CONFIG_PREEMPT */ @@ -3636,10 +3697,9 @@ EXPORT_SYMBOL(default_wake_function); static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, int nr_exclusive, int sync, void *key) { - struct list_head *tmp, *next; + wait_queue_t *curr, *next; - list_for_each_safe(tmp, next, &q->task_list) { - wait_queue_t *curr = list_entry(tmp, wait_queue_t, task_list); + list_for_each_entry_safe(curr, next, &q->task_list, task_list) { unsigned flags = curr->flags; if (curr->func(curr, mode, sync, key) && @@ -3729,206 +3789,116 @@ void fastcall complete_all(struct completion *x) } EXPORT_SYMBOL(complete_all); -void fastcall __sched wait_for_completion(struct completion *x) -{ - might_sleep(); - - spin_lock_irq(&x->wait.lock); - if (!x->done) { - DECLARE_WAITQUEUE(wait, current); - - wait.flags |= WQ_FLAG_EXCLUSIVE; - __add_wait_queue_tail(&x->wait, &wait); - do { - __set_current_state(TASK_UNINTERRUPTIBLE); - spin_unlock_irq(&x->wait.lock); - schedule(); - spin_lock_irq(&x->wait.lock); - } while (!x->done); - __remove_wait_queue(&x->wait, &wait); - } - x->done--; - spin_unlock_irq(&x->wait.lock); -} -EXPORT_SYMBOL(wait_for_completion); - -unsigned long fastcall __sched -wait_for_completion_timeout(struct completion *x, unsigned long timeout) +static inline long __sched +do_wait_for_common(struct completion *x, long timeout, int state) { - might_sleep(); - - spin_lock_irq(&x->wait.lock); if (!x->done) { DECLARE_WAITQUEUE(wait, current); wait.flags |= WQ_FLAG_EXCLUSIVE; __add_wait_queue_tail(&x->wait, &wait); do { - __set_current_state(TASK_UNINTERRUPTIBLE); + if (state == TASK_INTERRUPTIBLE && + signal_pending(current)) { + __remove_wait_queue(&x->wait, &wait); + return -ERESTARTSYS; + } + __set_current_state(state); spin_unlock_irq(&x->wait.lock); timeout = schedule_timeout(timeout); spin_lock_irq(&x->wait.lock); if (!timeout) { __remove_wait_queue(&x->wait, &wait); - goto out; + return timeout; } } while (!x->done); __remove_wait_queue(&x->wait, &wait); } x->done--; -out: - spin_unlock_irq(&x->wait.lock); return timeout; } -EXPORT_SYMBOL(wait_for_completion_timeout); -int fastcall __sched wait_for_completion_interruptible(struct completion *x) +static long __sched +wait_for_common(struct completion *x, long timeout, int state) { - int ret = 0; - might_sleep(); spin_lock_irq(&x->wait.lock); - if (!x->done) { - DECLARE_WAITQUEUE(wait, current); - - wait.flags |= WQ_FLAG_EXCLUSIVE; - __add_wait_queue_tail(&x->wait, &wait); - do { - if (signal_pending(current)) { - ret = -ERESTARTSYS; - __remove_wait_queue(&x->wait, &wait); - goto out; - } - __set_current_state(TASK_INTERRUPTIBLE); - spin_unlock_irq(&x->wait.lock); - schedule(); - spin_lock_irq(&x->wait.lock); - } while (!x->done); - __remove_wait_queue(&x->wait, &wait); - } - x->done--; -out: + timeout = do_wait_for_common(x, timeout, state); spin_unlock_irq(&x->wait.lock); + return timeout; +} - return ret; +void fastcall __sched wait_for_completion(struct completion *x) +{ + wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); } -EXPORT_SYMBOL(wait_for_completion_interruptible); +EXPORT_SYMBOL(wait_for_completion); unsigned long fastcall __sched -wait_for_completion_interruptible_timeout(struct completion *x, - unsigned long timeout) +wait_for_completion_timeout(struct completion *x, unsigned long timeout) { - might_sleep(); - - spin_lock_irq(&x->wait.lock); - if (!x->done) { - DECLARE_WAITQUEUE(wait, current); - - wait.flags |= WQ_FLAG_EXCLUSIVE; - __add_wait_queue_tail(&x->wait, &wait); - do { - if (signal_pending(current)) { - timeout = -ERESTARTSYS; - __remove_wait_queue(&x->wait, &wait); - goto out; - } - __set_current_state(TASK_INTERRUPTIBLE); - spin_unlock_irq(&x->wait.lock); - timeout = schedule_timeout(timeout); - spin_lock_irq(&x->wait.lock); - if (!timeout) { - __remove_wait_queue(&x->wait, &wait); - goto out; - } - } while (!x->done); - __remove_wait_queue(&x->wait, &wait); - } - x->done--; -out: - spin_unlock_irq(&x->wait.lock); - return timeout; + return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); } -EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); +EXPORT_SYMBOL(wait_for_completion_timeout); -static inline void -sleep_on_head(wait_queue_head_t *q, wait_queue_t *wait, unsigned long *flags) +int __sched wait_for_completion_interruptible(struct completion *x) { - spin_lock_irqsave(&q->lock, *flags); - __add_wait_queue(q, wait); - spin_unlock(&q->lock); + return wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); } +EXPORT_SYMBOL(wait_for_completion_interruptible); -static inline void -sleep_on_tail(wait_queue_head_t *q, wait_queue_t *wait, unsigned long *flags) +unsigned long fastcall __sched +wait_for_completion_interruptible_timeout(struct completion *x, + unsigned long timeout) { - spin_lock_irq(&q->lock); - __remove_wait_queue(q, wait); - spin_unlock_irqrestore(&q->lock, *flags); + return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); } +EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); -void __sched interruptible_sleep_on(wait_queue_head_t *q) +static long __sched +sleep_on_common(wait_queue_head_t *q, int state, long timeout) { unsigned long flags; wait_queue_t wait; init_waitqueue_entry(&wait, current); - current->state = TASK_INTERRUPTIBLE; + __set_current_state(state); - sleep_on_head(q, &wait, &flags); - schedule(); - sleep_on_tail(q, &wait, &flags); + spin_lock_irqsave(&q->lock, flags); + __add_wait_queue(q, &wait); + spin_unlock(&q->lock); + timeout = schedule_timeout(timeout); + spin_lock_irq(&q->lock); + __remove_wait_queue(q, &wait); + spin_unlock_irqrestore(&q->lock, flags); + + return timeout; +} + +void __sched interruptible_sleep_on(wait_queue_head_t *q) +{ + sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); } EXPORT_SYMBOL(interruptible_sleep_on); long __sched interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) { - unsigned long flags; - wait_queue_t wait; - - init_waitqueue_entry(&wait, current); - - current->state = TASK_INTERRUPTIBLE; - - sleep_on_head(q, &wait, &flags); - timeout = schedule_timeout(timeout); - sleep_on_tail(q, &wait, &flags); - - return timeout; + return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); } EXPORT_SYMBOL(interruptible_sleep_on_timeout); void __sched sleep_on(wait_queue_head_t *q) { - unsigned long flags; - wait_queue_t wait; - - init_waitqueue_entry(&wait, current); - - current->state = TASK_UNINTERRUPTIBLE; - - sleep_on_head(q, &wait, &flags); - schedule(); - sleep_on_tail(q, &wait, &flags); + sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); } EXPORT_SYMBOL(sleep_on); long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) { - unsigned long flags; - wait_queue_t wait; - - init_waitqueue_entry(&wait, current); - - current->state = TASK_UNINTERRUPTIBLE; - - sleep_on_head(q, &wait, &flags); - timeout = schedule_timeout(timeout); - sleep_on_tail(q, &wait, &flags); - - return timeout; + return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); } EXPORT_SYMBOL(sleep_on_timeout); @@ -3947,7 +3917,7 @@ EXPORT_SYMBOL(sleep_on_timeout); void rt_mutex_setprio(struct task_struct *p, int prio) { unsigned long flags; - int oldprio, on_rq; + int oldprio, on_rq, running; struct rq *rq; BUG_ON(prio < 0 || prio > MAX_PRIO); @@ -3957,8 +3927,12 @@ void rt_mutex_setprio(struct task_struct *p, int prio) oldprio = p->prio; on_rq = p->se.on_rq; - if (on_rq) + running = task_running(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; @@ -3968,13 +3942,15 @@ void rt_mutex_setprio(struct task_struct *p, int prio) p->prio = prio; if (on_rq) { + if (running) + p->sched_class->set_curr_task(rq); enqueue_task(rq, p, 0); /* * Reschedule if we are currently running on this runqueue and * our priority decreased, or if we are not currently running on * this runqueue and our priority is higher than the current's */ - if (task_running(rq, p)) { + if (running) { if (p->prio > oldprio) resched_task(rq->curr); } else { @@ -4138,7 +4114,7 @@ struct task_struct *idle_task(int cpu) * find_process_by_pid - find a process with a matching PID value. * @pid: the pid in question. */ -static inline struct task_struct *find_process_by_pid(pid_t pid) +static struct task_struct *find_process_by_pid(pid_t pid) { return pid ? find_task_by_pid(pid) : current; } @@ -4180,7 +4156,7 @@ __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) int sched_setscheduler(struct task_struct *p, int policy, struct sched_param *param) { - int retval, oldprio, oldpolicy = -1, on_rq; + int retval, oldprio, oldpolicy = -1, on_rq, running; unsigned long flags; struct rq *rq; @@ -4262,18 +4238,26 @@ recheck: } update_rq_clock(rq); on_rq = p->se.on_rq; - if (on_rq) + running = task_running(rq, p); + if (on_rq) { deactivate_task(rq, p, 0); + if (running) + p->sched_class->put_prev_task(rq, p); + } + oldprio = p->prio; __setscheduler(rq, p, policy, param->sched_priority); + if (on_rq) { + if (running) + p->sched_class->set_curr_task(rq); activate_task(rq, p, 0); /* * Reschedule if we are currently running on this runqueue and * our priority decreased, or if we are not currently running on * this runqueue and our priority is higher than the current's */ - if (task_running(rq, p)) { + if (running) { if (p->prio > oldprio) resched_task(rq->curr); } else { @@ -4344,10 +4328,10 @@ asmlinkage long sys_sched_setparam(pid_t pid, struct sched_param __user *param) asmlinkage long sys_sched_getscheduler(pid_t pid) { struct task_struct *p; - int retval = -EINVAL; + int retval; if (pid < 0) - goto out_nounlock; + return -EINVAL; retval = -ESRCH; read_lock(&tasklist_lock); @@ -4358,8 +4342,6 @@ asmlinkage long sys_sched_getscheduler(pid_t pid) retval = p->policy; } read_unlock(&tasklist_lock); - -out_nounlock: return retval; } @@ -4372,10 +4354,10 @@ asmlinkage long sys_sched_getparam(pid_t pid, struct sched_param __user *param) { struct sched_param lp; struct task_struct *p; - int retval = -EINVAL; + int retval; if (!param || pid < 0) - goto out_nounlock; + return -EINVAL; read_lock(&tasklist_lock); p = find_process_by_pid(pid); @@ -4395,7 +4377,6 @@ asmlinkage long sys_sched_getparam(pid_t pid, struct sched_param __user *param) */ retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; -out_nounlock: return retval; out_unlock: @@ -4555,8 +4536,8 @@ asmlinkage long sys_sched_yield(void) { struct rq *rq = this_rq_lock(); - schedstat_inc(rq, yld_cnt); - current->sched_class->yield_task(rq, current); + schedstat_inc(rq, yld_count); + current->sched_class->yield_task(rq); /* * Since we are going to call schedule() anyway, there's @@ -4750,11 +4731,12 @@ asmlinkage long sys_sched_rr_get_interval(pid_t pid, struct timespec __user *interval) { struct task_struct *p; - int retval = -EINVAL; + unsigned int time_slice; + int retval; struct timespec t; if (pid < 0) - goto out_nounlock; + return -EINVAL; retval = -ESRCH; read_lock(&tasklist_lock); @@ -4766,12 +4748,24 @@ long sys_sched_rr_get_interval(pid_t pid, struct timespec __user *interval) if (retval) goto out_unlock; - jiffies_to_timespec(p->policy == SCHED_FIFO ? - 0 : static_prio_timeslice(p->static_prio), &t); + if (p->policy == SCHED_FIFO) + time_slice = 0; + else if (p->policy == SCHED_RR) + time_slice = DEF_TIMESLICE; + else { + struct sched_entity *se = &p->se; + unsigned long flags; + struct rq *rq; + + rq = task_rq_lock(p, &flags); + time_slice = NS_TO_JIFFIES(sched_slice(cfs_rq_of(se), se)); + task_rq_unlock(rq, &flags); + } read_unlock(&tasklist_lock); + jiffies_to_timespec(time_slice, &t); retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; -out_nounlock: return retval; + out_unlock: read_unlock(&tasklist_lock); return retval; @@ -4900,32 +4894,6 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu) */ cpumask_t nohz_cpu_mask = CPU_MASK_NONE; -/* - * Increase the granularity value when there are more CPUs, - * because with more CPUs the 'effective latency' as visible - * to users decreases. But the relationship is not linear, - * so pick a second-best guess by going with the log2 of the - * number of CPUs. - * - * This idea comes from the SD scheduler of Con Kolivas: - */ -static inline void sched_init_granularity(void) -{ - unsigned int factor = 1 + ilog2(num_online_cpus()); - const unsigned long limit = 100000000; - - sysctl_sched_min_granularity *= factor; - if (sysctl_sched_min_granularity > limit) - sysctl_sched_min_granularity = limit; - - sysctl_sched_latency *= factor; - if (sysctl_sched_latency > limit) - sysctl_sched_latency = limit; - - sysctl_sched_runtime_limit = sysctl_sched_latency; - sysctl_sched_wakeup_granularity = sysctl_sched_min_granularity / 2; -} - #ifdef CONFIG_SMP /* * This is how migration works: @@ -5103,35 +5071,34 @@ static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p) struct rq *rq; int dest_cpu; -restart: - /* On same node? */ - mask = node_to_cpumask(cpu_to_node(dead_cpu)); - cpus_and(mask, mask, p->cpus_allowed); - dest_cpu = any_online_cpu(mask); - - /* On any allowed CPU? */ - if (dest_cpu == NR_CPUS) - dest_cpu = any_online_cpu(p->cpus_allowed); - - /* No more Mr. Nice Guy. */ - if (dest_cpu == NR_CPUS) { - rq = task_rq_lock(p, &flags); - cpus_setall(p->cpus_allowed); - dest_cpu = any_online_cpu(p->cpus_allowed); - task_rq_unlock(rq, &flags); + do { + /* On same node? */ + mask = node_to_cpumask(cpu_to_node(dead_cpu)); + cpus_and(mask, mask, p->cpus_allowed); + dest_cpu = any_online_cpu(mask); + + /* On any allowed CPU? */ + if (dest_cpu == NR_CPUS) + dest_cpu = any_online_cpu(p->cpus_allowed); + + /* No more Mr. Nice Guy. */ + if (dest_cpu == NR_CPUS) { + rq = task_rq_lock(p, &flags); + cpus_setall(p->cpus_allowed); + dest_cpu = any_online_cpu(p->cpus_allowed); + task_rq_unlock(rq, &flags); - /* - * Don't tell them about moving exiting tasks or - * kernel threads (both mm NULL), since they never - * leave kernel. - */ - if (p->mm && printk_ratelimit()) - printk(KERN_INFO "process %d (%s) no " - "longer affine to cpu%d\n", - p->pid, p->comm, dead_cpu); - } - if (!__migrate_task(p, dead_cpu, dest_cpu)) - goto restart; + /* + * Don't tell them about moving exiting tasks or + * kernel threads (both mm NULL), since they never + * leave kernel. + */ + if (p->mm && printk_ratelimit()) + printk(KERN_INFO "process %d (%s) no " + "longer affine to cpu%d\n", + p->pid, p->comm, dead_cpu); + } + } while (!__migrate_task(p, dead_cpu, dest_cpu)); } /* @@ -5173,6 +5140,20 @@ static void migrate_live_tasks(int src_cpu) } /* + * activate_idle_task - move idle task to the _front_ of runqueue. + */ +static void activate_idle_task(struct task_struct *p, struct rq *rq) +{ + update_rq_clock(rq); + + if (p->state == TASK_UNINTERRUPTIBLE) + rq->nr_uninterruptible--; + + enqueue_task(rq, p, 0); + inc_nr_running(p, rq); +} + +/* * Schedules idle task to be the next runnable task on current CPU. * It does so by boosting its priority to highest possible and adding it to * the _front_ of the runqueue. Used by CPU offline code. @@ -5284,14 +5265,23 @@ static struct ctl_table sd_ctl_root[] = { static struct ctl_table *sd_alloc_ctl_entry(int n) { struct ctl_table *entry = - kmalloc(n * sizeof(struct ctl_table), GFP_KERNEL); - - BUG_ON(!entry); - memset(entry, 0, n * sizeof(struct ctl_table)); + kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); return entry; } +static void sd_free_ctl_entry(struct ctl_table **tablep) +{ + struct ctl_table *entry = *tablep; + + for (entry = *tablep; entry->procname; entry++) + if (entry->child) + sd_free_ctl_entry(&entry->child); + + kfree(*tablep); + *tablep = NULL; +} + static void set_table_entry(struct ctl_table *entry, const char *procname, void *data, int maxlen, @@ -5307,7 +5297,10 @@ set_table_entry(struct ctl_table *entry, static struct ctl_table * sd_alloc_ctl_domain_table(struct sched_domain *sd) { - struct ctl_table *table = sd_alloc_ctl_entry(14); + struct ctl_table *table = sd_alloc_ctl_entry(12); + + if (table == NULL) + return NULL; set_table_entry(&table[0], "min_interval", &sd->min_interval, sizeof(long), 0644, proc_doulongvec_minmax); @@ -5327,11 +5320,12 @@ sd_alloc_ctl_domain_table(struct sched_domain *sd) sizeof(int), 0644, proc_dointvec_minmax); set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, sizeof(int), 0644, proc_dointvec_minmax); - set_table_entry(&table[10], "cache_nice_tries", + set_table_entry(&table[9], "cache_nice_tries", &sd->cache_nice_tries, sizeof(int), 0644, proc_dointvec_minmax); - set_table_entry(&table[12], "flags", &sd->flags, + set_table_entry(&table[10], "flags", &sd->flags, sizeof(int), 0644, proc_dointvec_minmax); + /* &table[11] is terminator */ return table; } @@ -5346,6 +5340,8 @@ static ctl_table *sd_alloc_ctl_cpu_table(int cpu) 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) { @@ -5360,24 +5356,38 @@ static ctl_table *sd_alloc_ctl_cpu_table(int cpu) } static struct ctl_table_header *sd_sysctl_header; -static void init_sched_domain_sysctl(void) +static void register_sched_domain_sysctl(void) { int i, cpu_num = num_online_cpus(); struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); char buf[32]; + if (entry == NULL) + return; + sd_ctl_dir[0].child = entry; - for (i = 0; i < cpu_num; i++, entry++) { + for_each_online_cpu(i) { snprintf(buf, 32, "cpu%d", i); entry->procname = kstrdup(buf, GFP_KERNEL); entry->mode = 0555; entry->child = sd_alloc_ctl_cpu_table(i); + entry++; } sd_sysctl_header = register_sysctl_table(sd_ctl_root); } + +static void unregister_sched_domain_sysctl(void) +{ + unregister_sysctl_table(sd_sysctl_header); + sd_sysctl_header = NULL; + sd_free_ctl_entry(&sd_ctl_dir[0].child); +} #else -static void init_sched_domain_sysctl(void) +static void register_sched_domain_sysctl(void) +{ +} +static void unregister_sched_domain_sysctl(void) { } #endif @@ -5499,8 +5509,7 @@ int __init migration_init(void) int nr_cpu_ids __read_mostly = NR_CPUS; EXPORT_SYMBOL(nr_cpu_ids); -#undef SCHED_DOMAIN_DEBUG -#ifdef SCHED_DOMAIN_DEBUG +#ifdef CONFIG_SCHED_DEBUG static void sched_domain_debug(struct sched_domain *sd, int cpu) { int level = 0; @@ -5558,16 +5567,19 @@ static void sched_domain_debug(struct sched_domain *sd, int cpu) printk("\n"); printk(KERN_ERR "ERROR: domain->cpu_power not " "set\n"); + break; } if (!cpus_weight(group->cpumask)) { printk("\n"); printk(KERN_ERR "ERROR: empty group\n"); + break; } if (cpus_intersects(groupmask, group->cpumask)) { printk("\n"); printk(KERN_ERR "ERROR: repeated CPUs\n"); + break; } cpus_or(groupmask, groupmask, group->cpumask); @@ -5701,7 +5713,7 @@ static int __init isolated_cpu_setup(char *str) return 1; } -__setup ("isolcpus=", isolated_cpu_setup); +__setup("isolcpus=", isolated_cpu_setup); /* * init_sched_build_groups takes the cpumask we wish to span, and a pointer @@ -5930,24 +5942,23 @@ static void init_numa_sched_groups_power(struct sched_group *group_head) if (!sg) return; -next_sg: - for_each_cpu_mask(j, sg->cpumask) { - struct sched_domain *sd; + do { + for_each_cpu_mask(j, sg->cpumask) { + struct sched_domain *sd; - sd = &per_cpu(phys_domains, j); - if (j != first_cpu(sd->groups->cpumask)) { - /* - * Only add "power" once for each - * physical package. - */ - continue; - } + sd = &per_cpu(phys_domains, j); + if (j != first_cpu(sd->groups->cpumask)) { + /* + * Only add "power" once for each + * physical package. + */ + continue; + } - sg_inc_cpu_power(sg, sd->groups->__cpu_power); - } - sg = sg->next; - if (sg != group_head) - goto next_sg; + sg_inc_cpu_power(sg, sd->groups->__cpu_power); + } + sg = sg->next; + } while (sg != group_head); } #endif @@ -6058,7 +6069,7 @@ static int build_sched_domains(const cpumask_t *cpu_map) /* * Allocate the per-node list of sched groups */ - sched_group_nodes = kzalloc(sizeof(struct sched_group *)*MAX_NUMNODES, + sched_group_nodes = kcalloc(MAX_NUMNODES, sizeof(struct sched_group *), GFP_KERNEL); if (!sched_group_nodes) { printk(KERN_WARNING "Can not alloc sched group node list\n"); @@ -6311,6 +6322,8 @@ static int arch_init_sched_domains(const cpumask_t *cpu_map) err = build_sched_domains(&cpu_default_map); + register_sched_domain_sysctl(); + return err; } @@ -6327,6 +6340,8 @@ static void detach_destroy_domains(const cpumask_t *cpu_map) { int i; + unregister_sched_domain_sysctl(); + for_each_cpu_mask(i, *cpu_map) cpu_attach_domain(NULL, i); synchronize_sched(); @@ -6357,6 +6372,8 @@ int partition_sched_domains(cpumask_t *partition1, cpumask_t *partition2) if (!err && !cpus_empty(*partition2)) err = build_sched_domains(partition2); + register_sched_domain_sysctl(); + return err; } @@ -6488,17 +6505,13 @@ void __init sched_init_smp(void) /* XXX: Theoretical race here - CPU may be hotplugged now */ hotcpu_notifier(update_sched_domains, 0); - init_sched_domain_sysctl(); - /* Move init over to a non-isolated CPU */ if (set_cpus_allowed(current, non_isolated_cpus) < 0) BUG(); - sched_init_granularity(); } #else void __init sched_init_smp(void) { - sched_init_granularity(); } #endif /* CONFIG_SMP */ @@ -6512,28 +6525,20 @@ int in_sched_functions(unsigned long addr) && addr < (unsigned long)__sched_text_end); } -static inline void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq) +static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq) { cfs_rq->tasks_timeline = RB_ROOT; - cfs_rq->fair_clock = 1; #ifdef CONFIG_FAIR_GROUP_SCHED cfs_rq->rq = rq; #endif + cfs_rq->min_vruntime = (u64)(-(1LL << 20)); } void __init sched_init(void) { - u64 now = sched_clock(); int highest_cpu = 0; int i, j; - /* - * Link up the scheduling class hierarchy: - */ - rt_sched_class.next = &fair_sched_class; - fair_sched_class.next = &idle_sched_class; - idle_sched_class.next = NULL; - for_each_possible_cpu(i) { struct rt_prio_array *array; struct rq *rq; @@ -6546,10 +6551,28 @@ void __init sched_init(void) init_cfs_rq(&rq->cfs, rq); #ifdef CONFIG_FAIR_GROUP_SCHED INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); - list_add(&rq->cfs.leaf_cfs_rq_list, &rq->leaf_cfs_rq_list); + { + struct cfs_rq *cfs_rq = &per_cpu(init_cfs_rq, i); + struct sched_entity *se = + &per_cpu(init_sched_entity, i); + + init_cfs_rq_p[i] = cfs_rq; + init_cfs_rq(cfs_rq, rq); + cfs_rq->tg = &init_task_group; + list_add(&cfs_rq->leaf_cfs_rq_list, + &rq->leaf_cfs_rq_list); + + init_sched_entity_p[i] = se; + se->cfs_rq = &rq->cfs; + se->my_q = cfs_rq; + se->load.weight = init_task_group_load; + se->load.inv_weight = + div64_64(1ULL<<32, init_task_group_load); + se->parent = NULL; + } + init_task_group.shares = init_task_group_load; + spin_lock_init(&init_task_group.lock); #endif - rq->ls.load_update_last = now; - rq->ls.load_update_start = now; for (j = 0; j < CPU_LOAD_IDX_MAX; j++) rq->cpu_load[j] = 0; @@ -6634,26 +6657,40 @@ EXPORT_SYMBOL(__might_sleep); #endif #ifdef CONFIG_MAGIC_SYSRQ +static void normalize_task(struct rq *rq, struct task_struct *p) +{ + int on_rq; + update_rq_clock(rq); + on_rq = p->se.on_rq; + if (on_rq) + deactivate_task(rq, p, 0); + __setscheduler(rq, p, SCHED_NORMAL, 0); + if (on_rq) { + activate_task(rq, p, 0); + resched_task(rq->curr); + } +} + void normalize_rt_tasks(void) { struct task_struct *g, *p; unsigned long flags; struct rq *rq; - int on_rq; read_lock_irq(&tasklist_lock); do_each_thread(g, p) { - p->se.fair_key = 0; - p->se.wait_runtime = 0; + /* + * Only normalize user tasks: + */ + if (!p->mm) + continue; + p->se.exec_start = 0; - p->se.wait_start_fair = 0; - p->se.sleep_start_fair = 0; #ifdef CONFIG_SCHEDSTATS p->se.wait_start = 0; p->se.sleep_start = 0; p->se.block_start = 0; #endif - task_rq(p)->cfs.fair_clock = 0; task_rq(p)->clock = 0; if (!rt_task(p)) { @@ -6668,26 +6705,9 @@ void normalize_rt_tasks(void) spin_lock_irqsave(&p->pi_lock, flags); rq = __task_rq_lock(p); -#ifdef CONFIG_SMP - /* - * Do not touch the migration thread: - */ - if (p == rq->migration_thread) - goto out_unlock; -#endif - update_rq_clock(rq); - on_rq = p->se.on_rq; - if (on_rq) - deactivate_task(rq, p, 0); - __setscheduler(rq, p, SCHED_NORMAL, 0); - if (on_rq) { - activate_task(rq, p, 0); - resched_task(rq->curr); - } -#ifdef CONFIG_SMP - out_unlock: -#endif + normalize_task(rq, p); + __task_rq_unlock(rq); spin_unlock_irqrestore(&p->pi_lock, flags); } while_each_thread(g, p); @@ -6740,3 +6760,201 @@ void set_curr_task(int cpu, struct task_struct *p) } #endif + +#ifdef CONFIG_FAIR_GROUP_SCHED + +/* allocate runqueue etc for a new task group */ +struct task_group *sched_create_group(void) +{ + struct task_group *tg; + struct cfs_rq *cfs_rq; + struct sched_entity *se; + struct rq *rq; + int i; + + tg = kzalloc(sizeof(*tg), GFP_KERNEL); + if (!tg) + return ERR_PTR(-ENOMEM); + + tg->cfs_rq = kzalloc(sizeof(cfs_rq) * NR_CPUS, GFP_KERNEL); + if (!tg->cfs_rq) + goto err; + tg->se = kzalloc(sizeof(se) * NR_CPUS, GFP_KERNEL); + if (!tg->se) + goto err; + + for_each_possible_cpu(i) { + rq = cpu_rq(i); + + cfs_rq = kmalloc_node(sizeof(struct cfs_rq), GFP_KERNEL, + cpu_to_node(i)); + if (!cfs_rq) + goto err; + + se = kmalloc_node(sizeof(struct sched_entity), GFP_KERNEL, + cpu_to_node(i)); + if (!se) + goto err; + + memset(cfs_rq, 0, sizeof(struct cfs_rq)); + memset(se, 0, sizeof(struct sched_entity)); + + tg->cfs_rq[i] = cfs_rq; + init_cfs_rq(cfs_rq, rq); + cfs_rq->tg = tg; + + tg->se[i] = se; + se->cfs_rq = &rq->cfs; + se->my_q = cfs_rq; + se->load.weight = NICE_0_LOAD; + se->load.inv_weight = div64_64(1ULL<<32, NICE_0_LOAD); + se->parent = NULL; + } + + for_each_possible_cpu(i) { + rq = cpu_rq(i); + cfs_rq = tg->cfs_rq[i]; + list_add_rcu(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list); + } + + tg->shares = NICE_0_LOAD; + spin_lock_init(&tg->lock); + + return tg; + +err: + 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); + kfree(tg); + + return ERR_PTR(-ENOMEM); +} + +/* rcu callback to free various structures associated with a task group */ +static void free_sched_group(struct rcu_head *rhp) +{ + struct cfs_rq *cfs_rq = container_of(rhp, struct cfs_rq, rcu); + struct task_group *tg = cfs_rq->tg; + struct sched_entity *se; + int i; + + /* now it should be safe to free those cfs_rqs */ + for_each_possible_cpu(i) { + cfs_rq = tg->cfs_rq[i]; + kfree(cfs_rq); + + se = tg->se[i]; + kfree(se); + } + + kfree(tg->cfs_rq); + kfree(tg->se); + kfree(tg); +} + +/* Destroy runqueue etc associated with a task group */ +void sched_destroy_group(struct task_group *tg) +{ + struct cfs_rq *cfs_rq; + int i; + + for_each_possible_cpu(i) { + cfs_rq = tg->cfs_rq[i]; + list_del_rcu(&cfs_rq->leaf_cfs_rq_list); + } + + cfs_rq = tg->cfs_rq[0]; + + /* wait for possible concurrent references to cfs_rqs complete */ + call_rcu(&cfs_rq->rcu, free_sched_group); +} + +/* 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); + + if (tsk->sched_class != &fair_sched_class) + goto done; + + update_rq_clock(rq); + + running = task_running(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); + } + + set_task_cfs_rq(tsk); + + if (on_rq) { + if (unlikely(running)) + tsk->sched_class->set_curr_task(rq); + enqueue_task(rq, tsk, 0); + } + +done: + task_rq_unlock(rq, &flags); +} + +static void set_se_shares(struct sched_entity *se, unsigned long shares) +{ + struct cfs_rq *cfs_rq = se->cfs_rq; + struct rq *rq = cfs_rq->rq; + int on_rq; + + spin_lock_irq(&rq->lock); + + on_rq = se->on_rq; + if (on_rq) + dequeue_entity(cfs_rq, se, 0); + + se->load.weight = shares; + se->load.inv_weight = div64_64((1ULL<<32), shares); + + if (on_rq) + enqueue_entity(cfs_rq, se, 0); + + spin_unlock_irq(&rq->lock); +} + +int sched_group_set_shares(struct task_group *tg, unsigned long shares) +{ + int i; + + spin_lock(&tg->lock); + if (tg->shares == shares) + goto done; + + tg->shares = shares; + for_each_possible_cpu(i) + set_se_shares(tg->se[i], shares); + +done: + spin_unlock(&tg->lock); + return 0; +} + +unsigned long sched_group_shares(struct task_group *tg) +{ + return tg->shares; +} + +#endif /* CONFIG_FAIR_GROUP_SCHED */ diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c index c3ee38bd342..a5e517ec07c 100644 --- a/kernel/sched_debug.c +++ b/kernel/sched_debug.c @@ -28,6 +28,31 @@ printk(x); \ } while (0) +/* + * Ease the printing of nsec fields: + */ +static long long nsec_high(long long nsec) +{ + if (nsec < 0) { + nsec = -nsec; + do_div(nsec, 1000000); + return -nsec; + } + do_div(nsec, 1000000); + + return nsec; +} + +static unsigned long nsec_low(long long nsec) +{ + if (nsec < 0) + nsec = -nsec; + + return do_div(nsec, 1000000); +} + +#define SPLIT_NS(x) nsec_high(x), nsec_low(x) + static void print_task(struct seq_file *m, struct rq *rq, struct task_struct *p) { @@ -36,23 +61,19 @@ print_task(struct seq_file *m, struct rq *rq, struct task_struct *p) else SEQ_printf(m, " "); - SEQ_printf(m, "%15s %5d %15Ld %13Ld %13Ld %9Ld %5d ", + SEQ_printf(m, "%15s %5d %9Ld.%06ld %9Ld %5d ", p->comm, p->pid, - (long long)p->se.fair_key, - (long long)(p->se.fair_key - rq->cfs.fair_clock), - (long long)p->se.wait_runtime, + SPLIT_NS(p->se.vruntime), (long long)(p->nvcsw + p->nivcsw), p->prio); #ifdef CONFIG_SCHEDSTATS - SEQ_printf(m, "%15Ld %15Ld %15Ld %15Ld %15Ld\n", - (long long)p->se.sum_exec_runtime, - (long long)p->se.sum_wait_runtime, - (long long)p->se.sum_sleep_runtime, - (long long)p->se.wait_runtime_overruns, - (long long)p->se.wait_runtime_underruns); + SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld\n", + SPLIT_NS(p->se.vruntime), + SPLIT_NS(p->se.sum_exec_runtime), + SPLIT_NS(p->se.sum_sleep_runtime)); #else - SEQ_printf(m, "%15Ld %15Ld %15Ld %15Ld %15Ld\n", - 0LL, 0LL, 0LL, 0LL, 0LL); + SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld\n", + 0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L); #endif } @@ -62,14 +83,10 @@ static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu) SEQ_printf(m, "\nrunnable tasks:\n" - " task PID tree-key delta waiting" - " switches prio" - " sum-exec sum-wait sum-sleep" - " wait-overrun wait-underrun\n" - "------------------------------------------------------------------" - "----------------" - "------------------------------------------------" - "--------------------------------\n"); + " task PID tree-key switches prio" + " exec-runtime sum-exec sum-sleep\n" + "------------------------------------------------------" + "----------------------------------------------------\n"); read_lock_irq(&tasklist_lock); @@ -83,45 +100,48 @@ static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu) read_unlock_irq(&tasklist_lock); } -static void -print_cfs_rq_runtime_sum(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) +void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) { - s64 wait_runtime_rq_sum = 0; - struct task_struct *p; - struct rb_node *curr; - unsigned long flags; + s64 MIN_vruntime = -1, min_vruntime, max_vruntime = -1, + spread, rq0_min_vruntime, spread0; struct rq *rq = &per_cpu(runqueues, cpu); + struct sched_entity *last; + unsigned long flags; - spin_lock_irqsave(&rq->lock, flags); - curr = first_fair(cfs_rq); - while (curr) { - p = rb_entry(curr, struct task_struct, se.run_node); - wait_runtime_rq_sum += p->se.wait_runtime; - - curr = rb_next(curr); - } - spin_unlock_irqrestore(&rq->lock, flags); - - SEQ_printf(m, " .%-30s: %Ld\n", "wait_runtime_rq_sum", - (long long)wait_runtime_rq_sum); -} - -void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) -{ SEQ_printf(m, "\ncfs_rq\n"); -#define P(x) \ - SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(cfs_rq->x)) - - P(fair_clock); - P(exec_clock); - P(wait_runtime); - P(wait_runtime_overruns); - P(wait_runtime_underruns); - P(sleeper_bonus); -#undef P + SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "exec_clock", + SPLIT_NS(cfs_rq->exec_clock)); - print_cfs_rq_runtime_sum(m, cpu, cfs_rq); + spin_lock_irqsave(&rq->lock, flags); + if (cfs_rq->rb_leftmost) + MIN_vruntime = (__pick_next_entity(cfs_rq))->vruntime; + last = __pick_last_entity(cfs_rq); + if (last) + max_vruntime = last->vruntime; + min_vruntime = rq->cfs.min_vruntime; + rq0_min_vruntime = per_cpu(runqueues, 0).cfs.min_vruntime; + spin_unlock_irqrestore(&rq->lock, flags); + SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "MIN_vruntime", + SPLIT_NS(MIN_vruntime)); + SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "min_vruntime", + SPLIT_NS(min_vruntime)); + SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "max_vruntime", + SPLIT_NS(max_vruntime)); + spread = max_vruntime - MIN_vruntime; + SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "spread", + SPLIT_NS(spread)); + spread0 = min_vruntime - rq0_min_vruntime; + SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "spread0", + SPLIT_NS(spread0)); + SEQ_printf(m, " .%-30s: %ld\n", "nr_running", cfs_rq->nr_running); + SEQ_printf(m, " .%-30s: %ld\n", "load", cfs_rq->load.weight); +#ifdef CONFIG_SCHEDSTATS + SEQ_printf(m, " .%-30s: %ld\n", "bkl_count", + rq->bkl_count); +#endif + SEQ_printf(m, " .%-30s: %ld\n", "nr_spread_over", + cfs_rq->nr_spread_over); } static void print_cpu(struct seq_file *m, int cpu) @@ -141,31 +161,32 @@ static void print_cpu(struct seq_file *m, int cpu) #define P(x) \ SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(rq->x)) +#define PN(x) \ + SEQ_printf(m, " .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rq->x)) P(nr_running); SEQ_printf(m, " .%-30s: %lu\n", "load", - rq->ls.load.weight); - P(ls.delta_fair); - P(ls.delta_exec); + rq->load.weight); P(nr_switches); P(nr_load_updates); P(nr_uninterruptible); SEQ_printf(m, " .%-30s: %lu\n", "jiffies", jiffies); - P(next_balance); + PN(next_balance); P(curr->pid); - P(clock); - P(idle_clock); - P(prev_clock_raw); + PN(clock); + PN(idle_clock); + PN(prev_clock_raw); P(clock_warps); P(clock_overflows); P(clock_deep_idle_events); - P(clock_max_delta); + PN(clock_max_delta); P(cpu_load[0]); P(cpu_load[1]); P(cpu_load[2]); P(cpu_load[3]); P(cpu_load[4]); #undef P +#undef PN print_cfs_stats(m, cpu); @@ -177,12 +198,25 @@ static int sched_debug_show(struct seq_file *m, void *v) u64 now = ktime_to_ns(ktime_get()); int cpu; - SEQ_printf(m, "Sched Debug Version: v0.05-v20, %s %.*s\n", + SEQ_printf(m, "Sched Debug Version: v0.06-v22, %s %.*s\n", init_utsname()->release, (int)strcspn(init_utsname()->version, " "), init_utsname()->version); - SEQ_printf(m, "now at %Lu nsecs\n", (unsigned long long)now); + SEQ_printf(m, "now at %Lu.%06ld msecs\n", SPLIT_NS(now)); + +#define P(x) \ + SEQ_printf(m, " .%-40s: %Ld\n", #x, (long long)(x)) +#define PN(x) \ + SEQ_printf(m, " .%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x)) + PN(sysctl_sched_latency); + PN(sysctl_sched_nr_latency); + PN(sysctl_sched_wakeup_granularity); + PN(sysctl_sched_batch_wakeup_granularity); + PN(sysctl_sched_child_runs_first); + P(sysctl_sched_features); +#undef PN +#undef P for_each_online_cpu(cpu) print_cpu(m, cpu); @@ -202,7 +236,7 @@ static int sched_debug_open(struct inode *inode, struct file *filp) return single_open(filp, sched_debug_show, NULL); } -static struct file_operations sched_debug_fops = { +static const struct file_operations sched_debug_fops = { .open = sched_debug_open, .read = seq_read, .llseek = seq_lseek, @@ -226,6 +260,7 @@ __initcall(init_sched_debug_procfs); void proc_sched_show_task(struct task_struct *p, struct seq_file *m) { + unsigned long nr_switches; unsigned long flags; int num_threads = 1; @@ -237,41 +272,89 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m) rcu_read_unlock(); SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, p->pid, num_threads); - SEQ_printf(m, "----------------------------------------------\n"); + SEQ_printf(m, + "---------------------------------------------------------\n"); +#define __P(F) \ + SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)F) #define P(F) \ - SEQ_printf(m, "%-25s:%20Ld\n", #F, (long long)p->F) + SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)p->F) +#define __PN(F) \ + SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F)) +#define PN(F) \ + SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F)) - P(se.wait_runtime); - P(se.wait_start_fair); - P(se.exec_start); - P(se.sleep_start_fair); - P(se.sum_exec_runtime); + PN(se.exec_start); + PN(se.vruntime); + PN(se.sum_exec_runtime); + + nr_switches = p->nvcsw + p->nivcsw; #ifdef CONFIG_SCHEDSTATS - P(se.wait_start); - P(se.sleep_start); - P(se.block_start); - P(se.sleep_max); - P(se.block_max); - P(se.exec_max); - P(se.wait_max); - P(se.wait_runtime_overruns); - P(se.wait_runtime_underruns); - P(se.sum_wait_runtime); + PN(se.wait_start); + PN(se.sleep_start); + PN(se.block_start); + PN(se.sleep_max); + PN(se.block_max); + PN(se.exec_max); + PN(se.slice_max); + PN(se.wait_max); + P(sched_info.bkl_count); + P(se.nr_migrations); + P(se.nr_migrations_cold); + P(se.nr_failed_migrations_affine); + P(se.nr_failed_migrations_running); + P(se.nr_failed_migrations_hot); + P(se.nr_forced_migrations); + P(se.nr_forced2_migrations); + P(se.nr_wakeups); + P(se.nr_wakeups_sync); + P(se.nr_wakeups_migrate); + P(se.nr_wakeups_local); + P(se.nr_wakeups_remote); + P(se.nr_wakeups_affine); + P(se.nr_wakeups_affine_attempts); + P(se.nr_wakeups_passive); + P(se.nr_wakeups_idle); + + { + u64 avg_atom, avg_per_cpu; + + avg_atom = p->se.sum_exec_runtime; + if (nr_switches) + do_div(avg_atom, nr_switches); + else + avg_atom = -1LL; + + avg_per_cpu = p->se.sum_exec_runtime; + if (p->se.nr_migrations) + avg_per_cpu = div64_64(avg_per_cpu, p->se.nr_migrations); + else + avg_per_cpu = -1LL; + + __PN(avg_atom); + __PN(avg_per_cpu); + } #endif - SEQ_printf(m, "%-25s:%20Ld\n", - "nr_switches", (long long)(p->nvcsw + p->nivcsw)); + __P(nr_switches); + SEQ_printf(m, "%-35s:%21Ld\n", + "nr_voluntary_switches", (long long)p->nvcsw); + SEQ_printf(m, "%-35s:%21Ld\n", + "nr_involuntary_switches", (long long)p->nivcsw); + P(se.load.weight); P(policy); P(prio); +#undef PN +#undef __PN #undef P +#undef __P { u64 t0, t1; t0 = sched_clock(); t1 = sched_clock(); - SEQ_printf(m, "%-25s:%20Ld\n", + SEQ_printf(m, "%-35s:%21Ld\n", "clock-delta", (long long)(t1-t0)); } } @@ -279,9 +362,32 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m) void proc_sched_set_task(struct task_struct *p) { #ifdef CONFIG_SCHEDSTATS - p->se.sleep_max = p->se.block_max = p->se.exec_max = p->se.wait_max = 0; - p->se.wait_runtime_overruns = p->se.wait_runtime_underruns = 0; + p->se.wait_max = 0; + p->se.sleep_max = 0; + p->se.sum_sleep_runtime = 0; + p->se.block_max = 0; + p->se.exec_max = 0; + p->se.slice_max = 0; + p->se.nr_migrations = 0; + p->se.nr_migrations_cold = 0; + p->se.nr_failed_migrations_affine = 0; + p->se.nr_failed_migrations_running = 0; + p->se.nr_failed_migrations_hot = 0; + p->se.nr_forced_migrations = 0; + p->se.nr_forced2_migrations = 0; + p->se.nr_wakeups = 0; + p->se.nr_wakeups_sync = 0; + p->se.nr_wakeups_migrate = 0; + p->se.nr_wakeups_local = 0; + p->se.nr_wakeups_remote = 0; + p->se.nr_wakeups_affine = 0; + p->se.nr_wakeups_affine_attempts = 0; + p->se.nr_wakeups_passive = 0; + p->se.nr_wakeups_idle = 0; + p->sched_info.bkl_count = 0; #endif - p->se.sum_exec_runtime = 0; - p->se.prev_sum_exec_runtime = 0; + p->se.sum_exec_runtime = 0; + p->se.prev_sum_exec_runtime = 0; + p->nvcsw = 0; + p->nivcsw = 0; } diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 67c67a87146..a17b785d700 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -25,22 +25,26 @@ * (default: 20ms, units: nanoseconds) * * NOTE: this latency value is not the same as the concept of - * 'timeslice length' - timeslices in CFS are of variable length. - * (to see the precise effective timeslice length of your workload, - * run vmstat and monitor the context-switches field) + * 'timeslice length' - timeslices in CFS are of variable length + * and have no persistent notion like in traditional, time-slice + * based scheduling concepts. * - * On SMP systems the value of this is multiplied by the log2 of the - * number of CPUs. (i.e. factor 2x on 2-way systems, 3x on 4-way - * systems, 4x on 8-way systems, 5x on 16-way systems, etc.) - * Targeted preemption latency for CPU-bound tasks: + * (to see the precise effective timeslice length of your workload, + * run vmstat and monitor the context-switches (cs) field) */ -unsigned int sysctl_sched_latency __read_mostly = 20000000ULL; +const_debug unsigned int sysctl_sched_latency = 20000000ULL; + +/* + * After fork, child runs first. (default) If set to 0 then + * parent will (try to) run first. + */ +const_debug unsigned int sysctl_sched_child_runs_first = 1; /* * Minimal preemption granularity for CPU-bound tasks: * (default: 2 msec, units: nanoseconds) */ -unsigned int sysctl_sched_min_granularity __read_mostly = 2000000ULL; +const_debug unsigned int sysctl_sched_nr_latency = 20; /* * sys_sched_yield() compat mode @@ -52,52 +56,25 @@ unsigned int __read_mostly sysctl_sched_compat_yield; /* * SCHED_BATCH wake-up granularity. - * (default: 25 msec, units: nanoseconds) + * (default: 10 msec, units: nanoseconds) * * This option delays the preemption effects of decoupled workloads * and reduces their over-scheduling. Synchronous workloads will still * have immediate wakeup/sleep latencies. */ -unsigned int sysctl_sched_batch_wakeup_granularity __read_mostly = 25000000UL; +const_debug unsigned int sysctl_sched_batch_wakeup_granularity = 10000000UL; /* * SCHED_OTHER wake-up granularity. - * (default: 1 msec, units: nanoseconds) + * (default: 10 msec, units: nanoseconds) * * This option delays the preemption effects of decoupled workloads * and reduces their over-scheduling. Synchronous workloads will still * have immediate wakeup/sleep latencies. */ -unsigned int sysctl_sched_wakeup_granularity __read_mostly = 1000000UL; - -unsigned int sysctl_sched_stat_granularity __read_mostly; - -/* - * Initialized in sched_init_granularity() [to 5 times the base granularity]: - */ -unsigned int sysctl_sched_runtime_limit __read_mostly; - -/* - * Debugging: various feature bits - */ -enum { - SCHED_FEAT_FAIR_SLEEPERS = 1, - SCHED_FEAT_SLEEPER_AVG = 2, - SCHED_FEAT_SLEEPER_LOAD_AVG = 4, - SCHED_FEAT_PRECISE_CPU_LOAD = 8, - SCHED_FEAT_START_DEBIT = 16, - SCHED_FEAT_SKIP_INITIAL = 32, -}; +const_debug unsigned int sysctl_sched_wakeup_granularity = 10000000UL; -unsigned int sysctl_sched_features __read_mostly = - SCHED_FEAT_FAIR_SLEEPERS *1 | - SCHED_FEAT_SLEEPER_AVG *0 | - SCHED_FEAT_SLEEPER_LOAD_AVG *1 | - SCHED_FEAT_PRECISE_CPU_LOAD *1 | - SCHED_FEAT_START_DEBIT *1 | - SCHED_FEAT_SKIP_INITIAL *0; - -extern struct sched_class fair_sched_class; +const_debug unsigned int sysctl_sched_migration_cost = 500000UL; /************************************************************** * CFS operations on generic schedulable entities: @@ -111,21 +88,9 @@ static inline struct rq *rq_of(struct cfs_rq *cfs_rq) return cfs_rq->rq; } -/* currently running entity (if any) on this cfs_rq */ -static inline struct sched_entity *cfs_rq_curr(struct cfs_rq *cfs_rq) -{ - return cfs_rq->curr; -} - /* An entity is a task if it doesn't "own" a runqueue */ #define entity_is_task(se) (!se->my_q) -static inline void -set_cfs_rq_curr(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - cfs_rq->curr = se; -} - #else /* CONFIG_FAIR_GROUP_SCHED */ static inline struct rq *rq_of(struct cfs_rq *cfs_rq) @@ -133,21 +98,8 @@ static inline struct rq *rq_of(struct cfs_rq *cfs_rq) return container_of(cfs_rq, struct rq, cfs); } -static inline struct sched_entity *cfs_rq_curr(struct cfs_rq *cfs_rq) -{ - struct rq *rq = rq_of(cfs_rq); - - if (unlikely(rq->curr->sched_class != &fair_sched_class)) - return NULL; - - return &rq->curr->se; -} - #define entity_is_task(se) 1 -static inline void -set_cfs_rq_curr(struct cfs_rq *cfs_rq, struct sched_entity *se) { } - #endif /* CONFIG_FAIR_GROUP_SCHED */ static inline struct task_struct *task_of(struct sched_entity *se) @@ -160,16 +112,38 @@ static inline struct task_struct *task_of(struct sched_entity *se) * Scheduling class tree data structure manipulation methods: */ +static inline u64 max_vruntime(u64 min_vruntime, u64 vruntime) +{ + s64 delta = (s64)(vruntime - min_vruntime); + if (delta > 0) + min_vruntime = vruntime; + + return min_vruntime; +} + +static inline u64 min_vruntime(u64 min_vruntime, u64 vruntime) +{ + s64 delta = (s64)(vruntime - min_vruntime); + if (delta < 0) + min_vruntime = vruntime; + + return min_vruntime; +} + +static inline s64 entity_key(struct cfs_rq *cfs_rq, struct sched_entity *se) +{ + return se->vruntime - cfs_rq->min_vruntime; +} + /* * Enqueue an entity into the rb-tree: */ -static inline void -__enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) +static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) { struct rb_node **link = &cfs_rq->tasks_timeline.rb_node; struct rb_node *parent = NULL; struct sched_entity *entry; - s64 key = se->fair_key; + s64 key = entity_key(cfs_rq, se); int leftmost = 1; /* @@ -182,7 +156,7 @@ __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) * We dont care about collisions. Nodes with * the same key stay together. */ - if (key - entry->fair_key < 0) { + if (key < entity_key(cfs_rq, entry)) { link = &parent->rb_left; } else { link = &parent->rb_right; @@ -199,24 +173,14 @@ __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) rb_link_node(&se->run_node, parent, link); rb_insert_color(&se->run_node, &cfs_rq->tasks_timeline); - update_load_add(&cfs_rq->load, se->load.weight); - cfs_rq->nr_running++; - se->on_rq = 1; - - schedstat_add(cfs_rq, wait_runtime, se->wait_runtime); } -static inline void -__dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) +static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) { if (cfs_rq->rb_leftmost == &se->run_node) cfs_rq->rb_leftmost = rb_next(&se->run_node); - rb_erase(&se->run_node, &cfs_rq->tasks_timeline); - update_load_sub(&cfs_rq->load, se->load.weight); - cfs_rq->nr_running--; - se->on_rq = 0; - schedstat_add(cfs_rq, wait_runtime, -se->wait_runtime); + rb_erase(&se->run_node, &cfs_rq->tasks_timeline); } static inline struct rb_node *first_fair(struct cfs_rq *cfs_rq) @@ -229,118 +193,86 @@ static struct sched_entity *__pick_next_entity(struct cfs_rq *cfs_rq) return rb_entry(first_fair(cfs_rq), struct sched_entity, run_node); } +static inline struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq) +{ + struct rb_node **link = &cfs_rq->tasks_timeline.rb_node; + struct sched_entity *se = NULL; + struct rb_node *parent; + + while (*link) { + parent = *link; + se = rb_entry(parent, struct sched_entity, run_node); + link = &parent->rb_right; + } + + return se; +} + /************************************************************** * Scheduling class statistics methods: */ + /* - * Calculate the preemption granularity needed to schedule every - * runnable task once per sysctl_sched_latency amount of time. - * (down to a sensible low limit on granularity) - * - * For example, if there are 2 tasks running and latency is 10 msecs, - * we switch tasks every 5 msecs. If we have 3 tasks running, we have - * to switch tasks every 3.33 msecs to get a 10 msecs observed latency - * for each task. We do finer and finer scheduling up to until we - * reach the minimum granularity value. - * - * To achieve this we use the following dynamic-granularity rule: + * The idea is to set a period in which each task runs once. * - * gran = lat/nr - lat/nr/nr + * When there are too many tasks (sysctl_sched_nr_latency) we have to stretch + * this period because otherwise the slices get too small. * - * This comes out of the following equations: - * - * kA1 + gran = kB1 - * kB2 + gran = kA2 - * kA2 = kA1 - * kB2 = kB1 - d + d/nr - * lat = d * nr - * - * Where 'k' is key, 'A' is task A (waiting), 'B' is task B (running), - * '1' is start of time, '2' is end of time, 'd' is delay between - * 1 and 2 (during which task B was running), 'nr' is number of tasks - * running, 'lat' is the the period of each task. ('lat' is the - * sched_latency that we aim for.) + * p = (nr <= nl) ? l : l*nr/nl */ -static long -sched_granularity(struct cfs_rq *cfs_rq) +static u64 __sched_period(unsigned long nr_running) { - unsigned int gran = sysctl_sched_latency; - unsigned int nr = cfs_rq->nr_running; + u64 period = sysctl_sched_latency; + unsigned long nr_latency = sysctl_sched_nr_latency; - if (nr > 1) { - gran = gran/nr - gran/nr/nr; - gran = max(gran, sysctl_sched_min_granularity); + if (unlikely(nr_running > nr_latency)) { + period *= nr_running; + do_div(period, nr_latency); } - return gran; + return period; } /* - * We rescale the rescheduling granularity of tasks according to their - * nice level, but only linearly, not exponentially: + * We calculate the wall-time slice from the period by taking a part + * proportional to the weight. + * + * s = p*w/rw */ -static long -niced_granularity(struct sched_entity *curr, unsigned long granularity) +static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se) { - u64 tmp; + u64 slice = __sched_period(cfs_rq->nr_running); - if (likely(curr->load.weight == NICE_0_LOAD)) - return granularity; - /* - * Positive nice levels get the same granularity as nice-0: - */ - if (likely(curr->load.weight < NICE_0_LOAD)) { - tmp = curr->load.weight * (u64)granularity; - return (long) (tmp >> NICE_0_SHIFT); - } - /* - * Negative nice level tasks get linearly finer - * granularity: - */ - tmp = curr->load.inv_weight * (u64)granularity; + slice *= se->load.weight; + do_div(slice, cfs_rq->load.weight); - /* - * It will always fit into 'long': - */ - return (long) (tmp >> (WMULT_SHIFT-NICE_0_SHIFT)); + return slice; } -static inline void -limit_wait_runtime(struct cfs_rq *cfs_rq, struct sched_entity *se) +/* + * We calculate the vruntime slice. + * + * vs = s/w = p/rw + */ +static u64 __sched_vslice(unsigned long rq_weight, unsigned long nr_running) { - long limit = sysctl_sched_runtime_limit; + u64 vslice = __sched_period(nr_running); - /* - * Niced tasks have the same history dynamic range as - * non-niced tasks: - */ - if (unlikely(se->wait_runtime > limit)) { - se->wait_runtime = limit; - schedstat_inc(se, wait_runtime_overruns); - schedstat_inc(cfs_rq, wait_runtime_overruns); - } - if (unlikely(se->wait_runtime < -limit)) { - se->wait_runtime = -limit; - schedstat_inc(se, wait_runtime_underruns); - schedstat_inc(cfs_rq, wait_runtime_underruns); - } + do_div(vslice, rq_weight); + + return vslice; } -static inline void -__add_wait_runtime(struct cfs_rq *cfs_rq, struct sched_entity *se, long delta) +static u64 sched_vslice(struct cfs_rq *cfs_rq) { - se->wait_runtime += delta; - schedstat_add(se, sum_wait_runtime, delta); - limit_wait_runtime(cfs_rq, se); + return __sched_vslice(cfs_rq->load.weight, cfs_rq->nr_running); } -static void -add_wait_runtime(struct cfs_rq *cfs_rq, struct sched_entity *se, long delta) +static u64 sched_vslice_add(struct cfs_rq *cfs_rq, struct sched_entity *se) { - schedstat_add(cfs_rq, wait_runtime, -se->wait_runtime); - __add_wait_runtime(cfs_rq, se, delta); - schedstat_add(cfs_rq, wait_runtime, se->wait_runtime); + return __sched_vslice(cfs_rq->load.weight + se->load.weight, + cfs_rq->nr_running + 1); } /* @@ -348,46 +280,41 @@ add_wait_runtime(struct cfs_rq *cfs_rq, struct sched_entity *se, long delta) * are not in our scheduling class. */ static inline void -__update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr) +__update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr, + unsigned long delta_exec) { - unsigned long delta, delta_exec, delta_fair, delta_mine; - struct load_weight *lw = &cfs_rq->load; - unsigned long load = lw->weight; + unsigned long delta_exec_weighted; + u64 vruntime; - delta_exec = curr->delta_exec; schedstat_set(curr->exec_max, max((u64)delta_exec, curr->exec_max)); curr->sum_exec_runtime += delta_exec; - cfs_rq->exec_clock += delta_exec; - - if (unlikely(!load)) - return; - - delta_fair = calc_delta_fair(delta_exec, lw); - delta_mine = calc_delta_mine(delta_exec, curr->load.weight, lw); - - if (cfs_rq->sleeper_bonus > sysctl_sched_min_granularity) { - delta = min((u64)delta_mine, cfs_rq->sleeper_bonus); - delta = min(delta, (unsigned long)( - (long)sysctl_sched_runtime_limit - curr->wait_runtime)); - cfs_rq->sleeper_bonus -= delta; - delta_mine -= delta; + schedstat_add(cfs_rq, exec_clock, delta_exec); + delta_exec_weighted = delta_exec; + if (unlikely(curr->load.weight != NICE_0_LOAD)) { + delta_exec_weighted = calc_delta_fair(delta_exec_weighted, + &curr->load); } + curr->vruntime += delta_exec_weighted; - cfs_rq->fair_clock += delta_fair; /* - * We executed delta_exec amount of time on the CPU, - * but we were only entitled to delta_mine amount of - * time during that period (if nr_running == 1 then - * the two values are equal) - * [Note: delta_mine - delta_exec is negative]: + * maintain cfs_rq->min_vruntime to be a monotonic increasing + * value tracking the leftmost vruntime in the tree. */ - add_wait_runtime(cfs_rq, curr, delta_mine - delta_exec); + if (first_fair(cfs_rq)) { + vruntime = min_vruntime(curr->vruntime, + __pick_next_entity(cfs_rq)->vruntime); + } else + vruntime = curr->vruntime; + + cfs_rq->min_vruntime = + max_vruntime(cfs_rq->min_vruntime, vruntime); } static void update_curr(struct cfs_rq *cfs_rq) { - struct sched_entity *curr = cfs_rq_curr(cfs_rq); + struct sched_entity *curr = cfs_rq->curr; + u64 now = rq_of(cfs_rq)->clock; unsigned long delta_exec; if (unlikely(!curr)) @@ -398,135 +325,47 @@ static void update_curr(struct cfs_rq *cfs_rq) * since the last time we changed load (this cannot * overflow on 32 bits): */ - delta_exec = (unsigned long)(rq_of(cfs_rq)->clock - curr->exec_start); + delta_exec = (unsigned long)(now - curr->exec_start); - curr->delta_exec += delta_exec; - - if (unlikely(curr->delta_exec > sysctl_sched_stat_granularity)) { - __update_curr(cfs_rq, curr); - curr->delta_exec = 0; - } - curr->exec_start = rq_of(cfs_rq)->clock; + __update_curr(cfs_rq, curr, delta_exec); + curr->exec_start = now; } static inline void update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se) { - se->wait_start_fair = cfs_rq->fair_clock; schedstat_set(se->wait_start, rq_of(cfs_rq)->clock); } /* - * We calculate fair deltas here, so protect against the random effects - * of a multiplication overflow by capping it to the runtime limit: - */ -#if BITS_PER_LONG == 32 -static inline unsigned long -calc_weighted(unsigned long delta, unsigned long weight, int shift) -{ - u64 tmp = (u64)delta * weight >> shift; - - if (unlikely(tmp > sysctl_sched_runtime_limit*2)) - return sysctl_sched_runtime_limit*2; - return tmp; -} -#else -static inline unsigned long -calc_weighted(unsigned long delta, unsigned long weight, int shift) -{ - return delta * weight >> shift; -} -#endif - -/* * Task is being enqueued - update stats: */ static void update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se) { - s64 key; - /* * Are we enqueueing a waiting task? (for current tasks * a dequeue/enqueue event is a NOP) */ - if (se != cfs_rq_curr(cfs_rq)) + if (se != cfs_rq->curr) update_stats_wait_start(cfs_rq, se); - /* - * Update the key: - */ - key = cfs_rq->fair_clock; - - /* - * Optimize the common nice 0 case: - */ - if (likely(se->load.weight == NICE_0_LOAD)) { - key -= se->wait_runtime; - } else { - u64 tmp; - - if (se->wait_runtime < 0) { - tmp = -se->wait_runtime; - key += (tmp * se->load.inv_weight) >> - (WMULT_SHIFT - NICE_0_SHIFT); - } else { - tmp = se->wait_runtime; - key -= (tmp * se->load.inv_weight) >> - (WMULT_SHIFT - NICE_0_SHIFT); - } - } - - se->fair_key = key; -} - -/* - * Note: must be called with a freshly updated rq->fair_clock. - */ -static inline void -__update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - unsigned long delta_fair = se->delta_fair_run; - - schedstat_set(se->wait_max, max(se->wait_max, - rq_of(cfs_rq)->clock - se->wait_start)); - - if (unlikely(se->load.weight != NICE_0_LOAD)) - delta_fair = calc_weighted(delta_fair, se->load.weight, - NICE_0_SHIFT); - - add_wait_runtime(cfs_rq, se, delta_fair); } static void update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se) { - unsigned long delta_fair; - - if (unlikely(!se->wait_start_fair)) - return; - - delta_fair = (unsigned long)min((u64)(2*sysctl_sched_runtime_limit), - (u64)(cfs_rq->fair_clock - se->wait_start_fair)); - - se->delta_fair_run += delta_fair; - if (unlikely(abs(se->delta_fair_run) >= - sysctl_sched_stat_granularity)) { - __update_stats_wait_end(cfs_rq, se); - se->delta_fair_run = 0; - } - - se->wait_start_fair = 0; + schedstat_set(se->wait_max, max(se->wait_max, + rq_of(cfs_rq)->clock - se->wait_start)); schedstat_set(se->wait_start, 0); } static inline void update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se) { - update_curr(cfs_rq); /* * Mark the end of the wait period if dequeueing a * waiting task: */ - if (se != cfs_rq_curr(cfs_rq)) + if (se != cfs_rq->curr) update_stats_wait_end(cfs_rq, se); } @@ -542,79 +381,28 @@ update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se) se->exec_start = rq_of(cfs_rq)->clock; } -/* - * We are descheduling a task - update its stats: - */ -static inline void -update_stats_curr_end(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - se->exec_start = 0; -} - /************************************************** * Scheduling class queueing methods: */ -static void __enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) +static void +account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se) { - unsigned long load = cfs_rq->load.weight, delta_fair; - long prev_runtime; - - /* - * Do not boost sleepers if there's too much bonus 'in flight' - * already: - */ - if (unlikely(cfs_rq->sleeper_bonus > sysctl_sched_runtime_limit)) - return; - - if (sysctl_sched_features & SCHED_FEAT_SLEEPER_LOAD_AVG) - load = rq_of(cfs_rq)->cpu_load[2]; - - delta_fair = se->delta_fair_sleep; - - /* - * Fix up delta_fair with the effect of us running - * during the whole sleep period: - */ - if (sysctl_sched_features & SCHED_FEAT_SLEEPER_AVG) - delta_fair = div64_likely32((u64)delta_fair * load, - load + se->load.weight); - - if (unlikely(se->load.weight != NICE_0_LOAD)) - delta_fair = calc_weighted(delta_fair, se->load.weight, - NICE_0_SHIFT); - - prev_runtime = se->wait_runtime; - __add_wait_runtime(cfs_rq, se, delta_fair); - delta_fair = se->wait_runtime - prev_runtime; + update_load_add(&cfs_rq->load, se->load.weight); + cfs_rq->nr_running++; + se->on_rq = 1; +} - /* - * Track the amount of bonus we've given to sleepers: - */ - cfs_rq->sleeper_bonus += delta_fair; +static void +account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se) +{ + update_load_sub(&cfs_rq->load, se->load.weight); + cfs_rq->nr_running--; + se->on_rq = 0; } static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) { - struct task_struct *tsk = task_of(se); - unsigned long delta_fair; - - if ((entity_is_task(se) && tsk->policy == SCHED_BATCH) || - !(sysctl_sched_features & SCHED_FEAT_FAIR_SLEEPERS)) - return; - - delta_fair = (unsigned long)min((u64)(2*sysctl_sched_runtime_limit), - (u64)(cfs_rq->fair_clock - se->sleep_start_fair)); - - se->delta_fair_sleep += delta_fair; - if (unlikely(abs(se->delta_fair_sleep) >= - sysctl_sched_stat_granularity)) { - __enqueue_sleeper(cfs_rq, se); - se->delta_fair_sleep = 0; - } - - se->sleep_start_fair = 0; - #ifdef CONFIG_SCHEDSTATS if (se->sleep_start) { u64 delta = rq_of(cfs_rq)->clock - se->sleep_start; @@ -646,6 +434,8 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) * time that the task spent sleeping: */ if (unlikely(prof_on == SLEEP_PROFILING)) { + struct task_struct *tsk = task_of(se); + profile_hits(SLEEP_PROFILING, (void *)get_wchan(tsk), delta >> 20); } @@ -653,27 +443,81 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) #endif } +static void check_spread(struct cfs_rq *cfs_rq, struct sched_entity *se) +{ +#ifdef CONFIG_SCHED_DEBUG + s64 d = se->vruntime - cfs_rq->min_vruntime; + + if (d < 0) + d = -d; + + if (d > 3*sysctl_sched_latency) + schedstat_inc(cfs_rq, nr_spread_over); +#endif +} + +static void +place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) +{ + u64 vruntime; + + vruntime = cfs_rq->min_vruntime; + + if (sched_feat(TREE_AVG)) { + struct sched_entity *last = __pick_last_entity(cfs_rq); + if (last) { + vruntime += last->vruntime; + vruntime >>= 1; + } + } else if (sched_feat(APPROX_AVG) && cfs_rq->nr_running) + vruntime += sched_vslice(cfs_rq)/2; + + if (initial && sched_feat(START_DEBIT)) + vruntime += sched_vslice_add(cfs_rq, se); + + if (!initial) { + if (sched_feat(NEW_FAIR_SLEEPERS) && entity_is_task(se) && + task_of(se)->policy != SCHED_BATCH) + vruntime -= sysctl_sched_latency; + + vruntime = max_t(s64, vruntime, se->vruntime); + } + + se->vruntime = vruntime; + +} + static void enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup) { /* - * Update the fair clock. + * Update run-time statistics of the 'current'. */ update_curr(cfs_rq); - if (wakeup) + if (wakeup) { + place_entity(cfs_rq, se, 0); enqueue_sleeper(cfs_rq, se); + } update_stats_enqueue(cfs_rq, se); - __enqueue_entity(cfs_rq, se); + check_spread(cfs_rq, se); + if (se != cfs_rq->curr) + __enqueue_entity(cfs_rq, se); + account_entity_enqueue(cfs_rq, se); } static void dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep) { + /* + * Update run-time statistics of the 'current'. + */ + update_curr(cfs_rq); + update_stats_dequeue(cfs_rq, se); if (sleep) { - se->sleep_start_fair = cfs_rq->fair_clock; + se->peer_preempt = 0; #ifdef CONFIG_SCHEDSTATS if (entity_is_task(se)) { struct task_struct *tsk = task_of(se); @@ -685,68 +529,66 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep) } #endif } - __dequeue_entity(cfs_rq, se); + + if (se != cfs_rq->curr) + __dequeue_entity(cfs_rq, se); + account_entity_dequeue(cfs_rq, se); } /* * Preempt the current task with a newly woken task if needed: */ static void -__check_preempt_curr_fair(struct cfs_rq *cfs_rq, struct sched_entity *se, - struct sched_entity *curr, unsigned long granularity) +check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr) { - s64 __delta = curr->fair_key - se->fair_key; unsigned long ideal_runtime, delta_exec; - /* - * ideal_runtime is compared against sum_exec_runtime, which is - * walltime, hence do not scale. - */ - ideal_runtime = max(sysctl_sched_latency / cfs_rq->nr_running, - (unsigned long)sysctl_sched_min_granularity); - - /* - * If we executed more than what the latency constraint suggests, - * reduce the rescheduling granularity. This way the total latency - * of how much a task is not scheduled converges to - * sysctl_sched_latency: - */ + ideal_runtime = sched_slice(cfs_rq, curr); delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime; - if (delta_exec > ideal_runtime) - granularity = 0; - - /* - * Take scheduling granularity into account - do not - * preempt the current task unless the best task has - * a larger than sched_granularity fairness advantage: - * - * scale granularity as key space is in fair_clock. - */ - if (__delta > niced_granularity(curr, granularity)) + if (delta_exec > ideal_runtime || + (sched_feat(PREEMPT_RESTRICT) && curr->peer_preempt)) resched_task(rq_of(cfs_rq)->curr); + curr->peer_preempt = 0; } -static inline void +static void set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) { + /* 'current' is not kept within the tree. */ + if (se->on_rq) { + /* + * Any task has to be enqueued before it get to execute on + * a CPU. So account for the time it spent waiting on the + * runqueue. + */ + update_stats_wait_end(cfs_rq, se); + __dequeue_entity(cfs_rq, se); + } + + update_stats_curr_start(cfs_rq, se); + cfs_rq->curr = se; +#ifdef CONFIG_SCHEDSTATS /* - * Any task has to be enqueued before it get to execute on - * a CPU. So account for the time it spent waiting on the - * runqueue. (note, here we rely on pick_next_task() having - * done a put_prev_task_fair() shortly before this, which - * updated rq->fair_clock - used by update_stats_wait_end()) + * Track our maximum slice length, if the CPU's load is at + * least twice that of our own weight (i.e. dont track it + * when there are only lesser-weight tasks around): */ - update_stats_wait_end(cfs_rq, se); - update_stats_curr_start(cfs_rq, se); - set_cfs_rq_curr(cfs_rq, se); + if (rq_of(cfs_rq)->load.weight >= 2*se->load.weight) { + se->slice_max = max(se->slice_max, + se->sum_exec_runtime - se->prev_sum_exec_runtime); + } +#endif se->prev_sum_exec_runtime = se->sum_exec_runtime; } static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq) { - struct sched_entity *se = __pick_next_entity(cfs_rq); + struct sched_entity *se = NULL; - set_next_entity(cfs_rq, se); + if (first_fair(cfs_rq)) { + se = __pick_next_entity(cfs_rq); + set_next_entity(cfs_rq, se); + } return se; } @@ -760,33 +602,24 @@ static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev) if (prev->on_rq) update_curr(cfs_rq); - update_stats_curr_end(cfs_rq, prev); - - if (prev->on_rq) + check_spread(cfs_rq, prev); + if (prev->on_rq) { update_stats_wait_start(cfs_rq, prev); - set_cfs_rq_curr(cfs_rq, NULL); + /* Put 'current' back into the tree. */ + __enqueue_entity(cfs_rq, prev); + } + cfs_rq->curr = NULL; } static void entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr) { - struct sched_entity *next; - /* - * Dequeue and enqueue the task to update its - * position within the tree: + * Update run-time statistics of the 'current'. */ - dequeue_entity(cfs_rq, curr, 0); - enqueue_entity(cfs_rq, curr, 0); - - /* - * Reschedule if another task tops the current one. - */ - next = __pick_next_entity(cfs_rq); - if (next == curr) - return; + update_curr(cfs_rq); - __check_preempt_curr_fair(cfs_rq, next, curr, - sched_granularity(cfs_rq)); + if (cfs_rq->nr_running > 1 || !sched_feat(WAKEUP_PREEMPT)) + check_preempt_tick(cfs_rq, curr); } /************************************************** @@ -821,23 +654,28 @@ static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) */ static inline struct cfs_rq *cpu_cfs_rq(struct cfs_rq *cfs_rq, int this_cpu) { - /* A later patch will take group into account */ - return &cpu_rq(this_cpu)->cfs; + return cfs_rq->tg->cfs_rq[this_cpu]; } /* Iterate thr' all leaf cfs_rq's on a runqueue */ #define for_each_leaf_cfs_rq(rq, cfs_rq) \ list_for_each_entry(cfs_rq, &rq->leaf_cfs_rq_list, leaf_cfs_rq_list) -/* Do the two (enqueued) tasks belong to the same group ? */ -static inline int is_same_group(struct task_struct *curr, struct task_struct *p) +/* Do the two (enqueued) entities belong to the same group ? */ +static inline int +is_same_group(struct sched_entity *se, struct sched_entity *pse) { - if (curr->se.cfs_rq == p->se.cfs_rq) + if (se->cfs_rq == pse->cfs_rq) return 1; return 0; } +static inline struct sched_entity *parent_entity(struct sched_entity *se) +{ + return se->parent; +} + #else /* CONFIG_FAIR_GROUP_SCHED */ #define for_each_sched_entity(se) \ @@ -870,11 +708,17 @@ static inline struct cfs_rq *cpu_cfs_rq(struct cfs_rq *cfs_rq, int this_cpu) #define for_each_leaf_cfs_rq(rq, cfs_rq) \ for (cfs_rq = &rq->cfs; cfs_rq; cfs_rq = NULL) -static inline int is_same_group(struct task_struct *curr, struct task_struct *p) +static inline int +is_same_group(struct sched_entity *se, struct sched_entity *pse) { return 1; } +static inline struct sched_entity *parent_entity(struct sched_entity *se) +{ + return NULL; +} + #endif /* CONFIG_FAIR_GROUP_SCHED */ /* @@ -892,6 +736,7 @@ static void enqueue_task_fair(struct rq *rq, struct task_struct *p, int wakeup) break; cfs_rq = cfs_rq_of(se); enqueue_entity(cfs_rq, se, wakeup); + wakeup = 1; } } @@ -911,6 +756,7 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int sleep) /* Don't dequeue parent if it has other entities besides us */ if (cfs_rq->load.weight) break; + sleep = 1; } } @@ -919,12 +765,10 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int sleep) * * If compat_yield is turned on then we requeue to the end of the tree. */ -static void yield_task_fair(struct rq *rq, struct task_struct *p) +static void yield_task_fair(struct rq *rq) { - struct cfs_rq *cfs_rq = task_cfs_rq(p); - struct rb_node **link = &cfs_rq->tasks_timeline.rb_node; - struct sched_entity *rightmost, *se = &p->se; - struct rb_node *parent; + struct cfs_rq *cfs_rq = task_cfs_rq(rq->curr); + struct sched_entity *rightmost, *se = &rq->curr->se; /* * Are we the only task in the tree? @@ -935,52 +779,39 @@ static void yield_task_fair(struct rq *rq, struct task_struct *p) if (likely(!sysctl_sched_compat_yield)) { __update_rq_clock(rq); /* - * Dequeue and enqueue the task to update its - * position within the tree: + * Update run-time statistics of the 'current'. */ - dequeue_entity(cfs_rq, &p->se, 0); - enqueue_entity(cfs_rq, &p->se, 0); + update_curr(cfs_rq); return; } /* * Find the rightmost entry in the rbtree: */ - do { - parent = *link; - link = &parent->rb_right; - } while (*link); - - rightmost = rb_entry(parent, struct sched_entity, run_node); + rightmost = __pick_last_entity(cfs_rq); /* * Already in the rightmost position? */ - if (unlikely(rightmost == se)) + if (unlikely(rightmost->vruntime < se->vruntime)) return; /* * Minimally necessary key value to be last in the tree: + * Upon rescheduling, sched_class::put_prev_task() will place + * 'current' within the tree based on its new key value. */ - se->fair_key = rightmost->fair_key + 1; - - if (cfs_rq->rb_leftmost == &se->run_node) - cfs_rq->rb_leftmost = rb_next(&se->run_node); - /* - * Relink the task to the rightmost position: - */ - rb_erase(&se->run_node, &cfs_rq->tasks_timeline); - rb_link_node(&se->run_node, parent, link); - rb_insert_color(&se->run_node, &cfs_rq->tasks_timeline); + se->vruntime = rightmost->vruntime + 1; } /* * Preempt the current task with a newly woken task if needed: */ -static void check_preempt_curr_fair(struct rq *rq, struct task_struct *p) +static void check_preempt_wakeup(struct rq *rq, struct task_struct *p) { struct task_struct *curr = rq->curr; struct cfs_rq *cfs_rq = task_cfs_rq(curr); - unsigned long gran; + struct sched_entity *se = &curr->se, *pse = &p->se; + s64 delta, gran; if (unlikely(rt_prio(p->prio))) { update_rq_clock(rq); @@ -988,16 +819,31 @@ static void check_preempt_curr_fair(struct rq *rq, struct task_struct *p) resched_task(curr); return; } - - gran = sysctl_sched_wakeup_granularity; /* - * Batch tasks prefer throughput over latency: + * Batch tasks do not preempt (their preemption is driven by + * the tick): */ if (unlikely(p->policy == SCHED_BATCH)) - gran = sysctl_sched_batch_wakeup_granularity; + return; + + if (sched_feat(WAKEUP_PREEMPT)) { + while (!is_same_group(se, pse)) { + se = parent_entity(se); + pse = parent_entity(pse); + } - if (is_same_group(curr, p)) - __check_preempt_curr_fair(cfs_rq, &p->se, &curr->se, gran); + delta = se->vruntime - pse->vruntime; + gran = sysctl_sched_wakeup_granularity; + if (unlikely(se->load.weight != NICE_0_LOAD)) + gran = calc_delta_fair(gran, &se->load); + + if (delta > gran) { + int now = !sched_feat(PREEMPT_RESTRICT); + + if (now || p->prio < curr->prio || !se->peer_preempt++) + resched_task(curr); + } + } } static struct task_struct *pick_next_task_fair(struct rq *rq) @@ -1041,7 +887,7 @@ static void put_prev_task_fair(struct rq *rq, struct task_struct *prev) * achieve that by always pre-iterating before returning * the current task: */ -static inline struct task_struct * +static struct task_struct * __load_balance_iterator(struct cfs_rq *cfs_rq, struct rb_node *curr) { struct task_struct *p; @@ -1078,7 +924,10 @@ static int cfs_rq_best_prio(struct cfs_rq *cfs_rq) if (!cfs_rq->nr_running) return MAX_PRIO; - curr = __pick_next_entity(cfs_rq); + curr = cfs_rq->curr; + if (!curr) + curr = __pick_next_entity(cfs_rq); + p = task_of(curr); return p->prio; @@ -1153,6 +1002,8 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr) } } +#define swap(a,b) do { typeof(a) tmp = (a); (a) = (b); (b) = tmp; } while (0) + /* * Share the fairness runtime between parent and child, thus the * total amount of pressure for CPU stays equal - new tasks @@ -1163,37 +1014,32 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr) static void task_new_fair(struct rq *rq, struct task_struct *p) { struct cfs_rq *cfs_rq = task_cfs_rq(p); - struct sched_entity *se = &p->se, *curr = cfs_rq_curr(cfs_rq); + struct sched_entity *se = &p->se, *curr = cfs_rq->curr; + int this_cpu = smp_processor_id(); sched_info_queued(p); update_curr(cfs_rq); - update_stats_enqueue(cfs_rq, se); - /* - * Child runs first: we let it run before the parent - * until it reschedules once. We set up the key so that - * it will preempt the parent: - */ - se->fair_key = curr->fair_key - - niced_granularity(curr, sched_granularity(cfs_rq)) - 1; - /* - * The first wait is dominated by the child-runs-first logic, - * so do not credit it with that waiting time yet: - */ - if (sysctl_sched_features & SCHED_FEAT_SKIP_INITIAL) - se->wait_start_fair = 0; + place_entity(cfs_rq, se, 1); - /* - * The statistical average of wait_runtime is about - * -granularity/2, so initialize the task with that: - */ - if (sysctl_sched_features & SCHED_FEAT_START_DEBIT) - se->wait_runtime = -(sched_granularity(cfs_rq) / 2); + if (sysctl_sched_child_runs_first && this_cpu == task_cpu(p) && + curr->vruntime < se->vruntime) { + /* + * Upon rescheduling, sched_class::put_prev_task() will place + * 'current' within the tree based on its new key value. + */ + swap(curr->vruntime, se->vruntime); + } + update_stats_enqueue(cfs_rq, se); + check_spread(cfs_rq, se); + check_spread(cfs_rq, curr); __enqueue_entity(cfs_rq, se); + account_entity_enqueue(cfs_rq, se); + se->peer_preempt = 0; + resched_task(rq->curr); } -#ifdef CONFIG_FAIR_GROUP_SCHED /* Account for a task changing its policy or group. * * This routine is mostly called to set cfs_rq->curr field when a task @@ -1206,21 +1052,17 @@ static void set_curr_task_fair(struct rq *rq) for_each_sched_entity(se) set_next_entity(cfs_rq_of(se), se); } -#else -static void set_curr_task_fair(struct rq *rq) -{ -} -#endif /* * All the scheduling class methods: */ -struct sched_class fair_sched_class __read_mostly = { +static const struct sched_class fair_sched_class = { + .next = &idle_sched_class, .enqueue_task = enqueue_task_fair, .dequeue_task = dequeue_task_fair, .yield_task = yield_task_fair, - .check_preempt_curr = check_preempt_curr_fair, + .check_preempt_curr = check_preempt_wakeup, .pick_next_task = pick_next_task_fair, .put_prev_task = put_prev_task_fair, @@ -1237,6 +1079,9 @@ static void print_cfs_stats(struct seq_file *m, int cpu) { struct cfs_rq *cfs_rq; +#ifdef CONFIG_FAIR_GROUP_SCHED + print_cfs_rq(m, cpu, &cpu_rq(cpu)->cfs); +#endif for_each_leaf_cfs_rq(cpu_rq(cpu), cfs_rq) print_cfs_rq(m, cpu, cfs_rq); } diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c index 3503fb2d9f9..6e2ead41516 100644 --- a/kernel/sched_idletask.c +++ b/kernel/sched_idletask.c @@ -50,10 +50,15 @@ static void task_tick_idle(struct rq *rq, struct task_struct *curr) { } +static void set_curr_task_idle(struct rq *rq) +{ +} + /* * Simple, special scheduling class for the per-CPU idle tasks: */ -static struct sched_class idle_sched_class __read_mostly = { +const struct sched_class idle_sched_class = { + /* .next is NULL */ /* no enqueue/yield_task for idle tasks */ /* dequeue is not valid, we print a debug message there: */ @@ -66,6 +71,7 @@ static struct sched_class idle_sched_class __read_mostly = { .load_balance = load_balance_idle, + .set_curr_task = set_curr_task_idle, .task_tick = task_tick_idle, /* no .task_new for idle tasks */ }; diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 4b87476a02d..d0097a0634e 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -7,7 +7,7 @@ * Update the current task's runtime statistics. Skip current tasks that * are not in our scheduling class. */ -static inline void update_curr_rt(struct rq *rq) +static void update_curr_rt(struct rq *rq) { struct task_struct *curr = rq->curr; u64 delta_exec; @@ -59,9 +59,9 @@ static void requeue_task_rt(struct rq *rq, struct task_struct *p) } static void -yield_task_rt(struct rq *rq, struct task_struct *p) +yield_task_rt(struct rq *rq) { - requeue_task_rt(rq, p); + requeue_task_rt(rq, rq->curr); } /* @@ -206,7 +206,7 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p) if (--p->time_slice) return; - p->time_slice = static_prio_timeslice(p->static_prio); + p->time_slice = DEF_TIMESLICE; /* * Requeue to the end of queue if we are not the only element @@ -218,7 +218,15 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p) } } -static struct sched_class rt_sched_class __read_mostly = { +static void set_curr_task_rt(struct rq *rq) +{ + struct task_struct *p = rq->curr; + + p->se.exec_start = rq->clock; +} + +const struct sched_class rt_sched_class = { + .next = &fair_sched_class, .enqueue_task = enqueue_task_rt, .dequeue_task = dequeue_task_rt, .yield_task = yield_task_rt, @@ -230,5 +238,6 @@ static struct sched_class rt_sched_class __read_mostly = { .load_balance = load_balance_rt, + .set_curr_task = set_curr_task_rt, .task_tick = task_tick_rt, }; diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h index c20a94dda61..1c084842c3e 100644 --- a/kernel/sched_stats.h +++ b/kernel/sched_stats.h @@ -16,18 +16,18 @@ static int show_schedstat(struct seq_file *seq, void *v) struct rq *rq = cpu_rq(cpu); #ifdef CONFIG_SMP struct sched_domain *sd; - int dcnt = 0; + int dcount = 0; #endif /* runqueue-specific stats */ seq_printf(seq, "cpu%d %lu %lu %lu %lu %lu %lu %lu %lu %lu %llu %llu %lu", cpu, rq->yld_both_empty, - rq->yld_act_empty, rq->yld_exp_empty, rq->yld_cnt, - rq->sched_switch, rq->sched_cnt, rq->sched_goidle, - rq->ttwu_cnt, rq->ttwu_local, + rq->yld_act_empty, rq->yld_exp_empty, rq->yld_count, + rq->sched_switch, rq->sched_count, rq->sched_goidle, + rq->ttwu_count, rq->ttwu_local, rq->rq_sched_info.cpu_time, - rq->rq_sched_info.run_delay, rq->rq_sched_info.pcnt); + rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount); seq_printf(seq, "\n"); @@ -39,12 +39,12 @@ static int show_schedstat(struct seq_file *seq, void *v) char mask_str[NR_CPUS]; cpumask_scnprintf(mask_str, NR_CPUS, sd->span); - seq_printf(seq, "domain%d %s", dcnt++, mask_str); + seq_printf(seq, "domain%d %s", dcount++, mask_str); for (itype = CPU_IDLE; itype < CPU_MAX_IDLE_TYPES; itype++) { seq_printf(seq, " %lu %lu %lu %lu %lu %lu %lu " "%lu", - sd->lb_cnt[itype], + sd->lb_count[itype], sd->lb_balanced[itype], sd->lb_failed[itype], sd->lb_imbalance[itype], @@ -55,9 +55,9 @@ static int show_schedstat(struct seq_file *seq, void *v) } seq_printf(seq, " %lu %lu %lu %lu %lu %lu %lu %lu %lu" " %lu %lu %lu\n", - sd->alb_cnt, sd->alb_failed, sd->alb_pushed, - sd->sbe_cnt, sd->sbe_balanced, sd->sbe_pushed, - sd->sbf_cnt, sd->sbf_balanced, sd->sbf_pushed, + sd->alb_count, sd->alb_failed, sd->alb_pushed, + sd->sbe_count, sd->sbe_balanced, sd->sbe_pushed, + sd->sbf_count, sd->sbf_balanced, sd->sbf_pushed, sd->ttwu_wake_remote, sd->ttwu_move_affine, sd->ttwu_move_balance); } @@ -101,7 +101,7 @@ rq_sched_info_arrive(struct rq *rq, unsigned long long delta) { if (rq) { rq->rq_sched_info.run_delay += delta; - rq->rq_sched_info.pcnt++; + rq->rq_sched_info.pcount++; } } @@ -129,7 +129,7 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta) # define schedstat_set(var, val) do { } while (0) #endif -#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) +#ifdef CONFIG_SCHEDSTATS /* * Called when a process is dequeued from the active array and given * the cpu. We should note that with the exception of interactive @@ -164,7 +164,7 @@ static void sched_info_arrive(struct task_struct *t) sched_info_dequeued(t); t->sched_info.run_delay += delta; t->sched_info.last_arrival = now; - t->sched_info.pcnt++; + t->sched_info.pcount++; rq_sched_info_arrive(task_rq(t), delta); } @@ -233,5 +233,5 @@ sched_info_switch(struct task_struct *prev, struct task_struct *next) #else #define sched_info_queued(t) do { } while (0) #define sched_info_switch(t, next) do { } while (0) -#endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */ +#endif /* CONFIG_SCHEDSTATS */ diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 6c97259e863..ec14aa8ac51 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -222,14 +222,11 @@ static ctl_table kern_table[] = { #ifdef CONFIG_SCHED_DEBUG { .ctl_name = CTL_UNNUMBERED, - .procname = "sched_min_granularity_ns", - .data = &sysctl_sched_min_granularity, + .procname = "sched_nr_latency", + .data = &sysctl_sched_nr_latency, .maxlen = sizeof(unsigned int), .mode = 0644, - .proc_handler = &proc_dointvec_minmax, - .strategy = &sysctl_intvec, - .extra1 = &min_sched_granularity_ns, - .extra2 = &max_sched_granularity_ns, + .proc_handler = &proc_dointvec, }, { .ctl_name = CTL_UNNUMBERED, @@ -266,38 +263,24 @@ static ctl_table kern_table[] = { }, { .ctl_name = CTL_UNNUMBERED, - .procname = "sched_stat_granularity_ns", - .data = &sysctl_sched_stat_granularity, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = &proc_dointvec_minmax, - .strategy = &sysctl_intvec, - .extra1 = &min_wakeup_granularity_ns, - .extra2 = &max_wakeup_granularity_ns, - }, - { - .ctl_name = CTL_UNNUMBERED, - .procname = "sched_runtime_limit_ns", - .data = &sysctl_sched_runtime_limit, + .procname = "sched_child_runs_first", + .data = &sysctl_sched_child_runs_first, .maxlen = sizeof(unsigned int), .mode = 0644, - .proc_handler = &proc_dointvec_minmax, - .strategy = &sysctl_intvec, - .extra1 = &min_sched_granularity_ns, - .extra2 = &max_sched_granularity_ns, + .proc_handler = &proc_dointvec, }, { .ctl_name = CTL_UNNUMBERED, - .procname = "sched_child_runs_first", - .data = &sysctl_sched_child_runs_first, + .procname = "sched_features", + .data = &sysctl_sched_features, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = &proc_dointvec, }, { .ctl_name = CTL_UNNUMBERED, - .procname = "sched_features", - .data = &sysctl_sched_features, + .procname = "sched_migration_cost", + .data = &sysctl_sched_migration_cost, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = &proc_dointvec, diff --git a/kernel/user.c b/kernel/user.c index 9ca2848fc35..f0e561e6d08 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -50,12 +50,16 @@ struct user_struct root_user = { .uid_keyring = &root_user_keyring, .session_keyring = &root_session_keyring, #endif +#ifdef CONFIG_FAIR_USER_SCHED + .tg = &init_task_group, +#endif }; /* * These routines must be called with the uidhash spinlock held! */ -static inline void uid_hash_insert(struct user_struct *up, struct hlist_head *hashent) +static inline void uid_hash_insert(struct user_struct *up, + struct hlist_head *hashent) { hlist_add_head(&up->uidhash_node, hashent); } @@ -65,13 +69,14 @@ static inline void uid_hash_remove(struct user_struct *up) hlist_del_init(&up->uidhash_node); } -static inline struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent) +static inline struct user_struct *uid_hash_find(uid_t uid, + struct hlist_head *hashent) { struct user_struct *user; struct hlist_node *h; hlist_for_each_entry(user, h, hashent, uidhash_node) { - if(user->uid == uid) { + if (user->uid == uid) { atomic_inc(&user->__count); return user; } @@ -80,6 +85,203 @@ static inline struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *ha return NULL; } +#ifdef CONFIG_FAIR_USER_SCHED + +static struct kobject uids_kobject; /* represents /sys/kernel/uids directory */ +static DEFINE_MUTEX(uids_mutex); + +static void sched_destroy_user(struct user_struct *up) +{ + sched_destroy_group(up->tg); +} + +static int sched_create_user(struct user_struct *up) +{ + int rc = 0; + + up->tg = sched_create_group(); + if (IS_ERR(up->tg)) + rc = -ENOMEM; + + return rc; +} + +static void sched_switch_user(struct task_struct *p) +{ + sched_move_task(p); +} + +static inline void uids_mutex_lock(void) +{ + mutex_lock(&uids_mutex); +} + +static inline void uids_mutex_unlock(void) +{ + mutex_unlock(&uids_mutex); +} + +/* return cpu shares held by the user */ +ssize_t cpu_shares_show(struct kset *kset, char *buffer) +{ + struct user_struct *up = container_of(kset, struct user_struct, kset); + + return sprintf(buffer, "%lu\n", sched_group_shares(up->tg)); +} + +/* modify cpu shares held by the user */ +ssize_t cpu_shares_store(struct kset *kset, const char *buffer, size_t size) +{ + struct user_struct *up = container_of(kset, struct user_struct, kset); + unsigned long shares; + int rc; + + sscanf(buffer, "%lu", &shares); + + rc = sched_group_set_shares(up->tg, shares); + + return (rc ? rc : size); +} + +static void user_attr_init(struct subsys_attribute *sa, char *name, int mode) +{ + sa->attr.name = name; + sa->attr.mode = mode; + sa->show = cpu_shares_show; + sa->store = cpu_shares_store; +} + +/* Create "/sys/kernel/uids/<uid>" directory and + * "/sys/kernel/uids/<uid>/cpu_share" file for this user. + */ +static int user_kobject_create(struct user_struct *up) +{ + struct kset *kset = &up->kset; + struct kobject *kobj = &kset->kobj; + int error; + + memset(kset, 0, sizeof(struct kset)); + kobj->parent = &uids_kobject; /* create under /sys/kernel/uids dir */ + kobject_set_name(kobj, "%d", up->uid); + kset_init(kset); + user_attr_init(&up->user_attr, "cpu_share", 0644); + + error = kobject_add(kobj); + if (error) + goto done; + + error = sysfs_create_file(kobj, &up->user_attr.attr); + if (error) + kobject_del(kobj); + + kobject_uevent(kobj, KOBJ_ADD); + +done: + return error; +} + +/* create these in sysfs filesystem: + * "/sys/kernel/uids" directory + * "/sys/kernel/uids/0" directory (for root user) + * "/sys/kernel/uids/0/cpu_share" file (for root user) + */ +int __init uids_kobject_init(void) +{ + int error; + + /* create under /sys/kernel dir */ + uids_kobject.parent = &kernel_subsys.kobj; + uids_kobject.kset = &kernel_subsys; + kobject_set_name(&uids_kobject, "uids"); + kobject_init(&uids_kobject); + + error = kobject_add(&uids_kobject); + if (!error) + error = user_kobject_create(&root_user); + + return error; +} + +/* work function to remove sysfs directory for a user and free up + * corresponding structures. + */ +static void remove_user_sysfs_dir(struct work_struct *w) +{ + struct user_struct *up = container_of(w, struct user_struct, work); + struct kobject *kobj = &up->kset.kobj; + unsigned long flags; + int remove_user = 0; + + /* Make uid_hash_remove() + sysfs_remove_file() + kobject_del() + * atomic. + */ + uids_mutex_lock(); + + local_irq_save(flags); + + if (atomic_dec_and_lock(&up->__count, &uidhash_lock)) { + uid_hash_remove(up); + remove_user = 1; + spin_unlock_irqrestore(&uidhash_lock, flags); + } else { + local_irq_restore(flags); + } + + if (!remove_user) + goto done; + + sysfs_remove_file(kobj, &up->user_attr.attr); + kobject_uevent(kobj, KOBJ_REMOVE); + kobject_del(kobj); + + sched_destroy_user(up); + key_put(up->uid_keyring); + key_put(up->session_keyring); + kmem_cache_free(uid_cachep, up); + +done: + uids_mutex_unlock(); +} + +/* IRQs are disabled and uidhash_lock is held upon function entry. + * IRQ state (as stored in flags) is restored and uidhash_lock released + * upon function exit. + */ +static inline void free_user(struct user_struct *up, unsigned long flags) +{ + /* restore back the count */ + atomic_inc(&up->__count); + spin_unlock_irqrestore(&uidhash_lock, flags); + + INIT_WORK(&up->work, remove_user_sysfs_dir); + schedule_work(&up->work); +} + +#else /* CONFIG_FAIR_USER_SCHED */ + +static void sched_destroy_user(struct user_struct *up) { } +static int sched_create_user(struct user_struct *up) { return 0; } +static void sched_switch_user(struct task_struct *p) { } +static inline int user_kobject_create(struct user_struct *up) { return 0; } +static inline void uids_mutex_lock(void) { } +static inline void uids_mutex_unlock(void) { } + +/* IRQs are disabled and uidhash_lock is held upon function entry. + * IRQ state (as stored in flags) is restored and uidhash_lock released + * upon function exit. + */ +static inline void free_user(struct user_struct *up, unsigned long flags) +{ + uid_hash_remove(up); + spin_unlock_irqrestore(&uidhash_lock, flags); + sched_destroy_user(up); + key_put(up->uid_keyring); + key_put(up->session_keyring); + kmem_cache_free(uid_cachep, up); +} + +#endif /* CONFIG_FAIR_USER_SCHED */ + /* * Locate the user_struct for the passed UID. If found, take a ref on it. The * caller must undo that ref with free_uid(). @@ -106,15 +308,10 @@ void free_uid(struct user_struct *up) return; local_irq_save(flags); - if (atomic_dec_and_lock(&up->__count, &uidhash_lock)) { - uid_hash_remove(up); - spin_unlock_irqrestore(&uidhash_lock, flags); - key_put(up->uid_keyring); - key_put(up->session_keyring); - kmem_cache_free(uid_cachep, up); - } else { + if (atomic_dec_and_lock(&up->__count, &uidhash_lock)) + free_user(up, flags); + else local_irq_restore(flags); - } } struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid) @@ -122,6 +319,11 @@ struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid) struct hlist_head *hashent = uidhashentry(ns, uid); struct user_struct *up; + /* Make uid_hash_find() + user_kobject_create() + uid_hash_insert() + * atomic. + */ + uids_mutex_lock(); + spin_lock_irq(&uidhash_lock); up = uid_hash_find(uid, hashent); spin_unlock_irq(&uidhash_lock); @@ -150,6 +352,22 @@ struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid) return NULL; } + if (sched_create_user(new) < 0) { + key_put(new->uid_keyring); + key_put(new->session_keyring); + kmem_cache_free(uid_cachep, new); + return NULL; + } + + if (user_kobject_create(new)) { + sched_destroy_user(new); + key_put(new->uid_keyring); + key_put(new->session_keyring); + kmem_cache_free(uid_cachep, new); + uids_mutex_unlock(); + return NULL; + } + /* * Before adding this, check whether we raced * on adding the same user already.. @@ -157,6 +375,11 @@ struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid) spin_lock_irq(&uidhash_lock); up = uid_hash_find(uid, hashent); if (up) { + /* This case is not possible when CONFIG_FAIR_USER_SCHED + * is defined, since we serialize alloc_uid() using + * uids_mutex. Hence no need to call + * sched_destroy_user() or remove_user_sysfs_dir(). + */ key_put(new->uid_keyring); key_put(new->session_keyring); kmem_cache_free(uid_cachep, new); @@ -167,6 +390,9 @@ struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid) spin_unlock_irq(&uidhash_lock); } + + uids_mutex_unlock(); + return up; } @@ -184,6 +410,7 @@ void switch_uid(struct user_struct *new_user) atomic_dec(&old_user->processes); switch_uid_keyring(new_user); current->user = new_user; + sched_switch_user(current); /* * We need to synchronize with __sigqueue_alloc() |