1 files changed, 134 insertions, 220 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 34bcc5bc120e..cfa222a91539 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -75,16 +75,6 @@
 #include <asm/irq_regs.h>
 
 /*
- * Scheduler clock - returns current time in nanosec units.
- * This is default implementation.
- * Architectures and sub-architectures can override this.
- */
-unsigned long long __attribute__((weak)) sched_clock(void)
-{
-        return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ);
-}
-
-/*
  * Convert user-nice values [ -20 ... 0 ... 19 ]
  * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
  * and back.
@@ -242,6 +232,12 @@ static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b)
 }
 #endif
 
+/*
+ * sched_domains_mutex serializes calls to arch_init_sched_domains,
+ * detach_destroy_domains and partition_sched_domains.
+ */
+static DEFINE_MUTEX(sched_domains_mutex);
+
 #ifdef CONFIG_GROUP_SCHED
 
 #include <linux/cgroup.h>
@@ -308,9 +304,6 @@ static DEFINE_PER_CPU(struct rt_rq, init_rt_rq) ____cacheline_aligned_in_smp;
  */
 static DEFINE_SPINLOCK(task_group_lock);
 
-/* doms_cur_mutex serializes access to doms_cur[] array */
-static DEFINE_MUTEX(doms_cur_mutex);
-
 #ifdef CONFIG_FAIR_GROUP_SCHED
 #ifdef CONFIG_USER_SCHED
 # define INIT_TASK_GROUP_LOAD   (2*NICE_0_LOAD)
@@ -318,7 +311,13 @@ static DEFINE_MUTEX(doms_cur_mutex);
 # define INIT_TASK_GROUP_LOAD   NICE_0_LOAD
 #endif
 
+/*
+ * A weight of 0, 1 or ULONG_MAX can cause arithmetics problems.
+ * (The default weight is 1024 - so there's no practical
+ *  limitation from this.)
+ */
 #define MIN_SHARES      2
+#define MAX_SHARES      (ULONG_MAX - 1)
 
 static int init_task_group_load = INIT_TASK_GROUP_LOAD;
 #endif
@@ -358,21 +357,9 @@ static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
 #endif
 }
 
-static inline void lock_doms_cur(void)
-{
-        mutex_lock(&doms_cur_mutex);
-}
-
-static inline void unlock_doms_cur(void)
-{
-        mutex_unlock(&doms_cur_mutex);
-}
-
 #else
 
 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
-static inline void lock_doms_cur(void) { }
-static inline void unlock_doms_cur(void) { }
 
 #endif  /* CONFIG_GROUP_SCHED */
 
@@ -560,13 +547,7 @@ struct rq {
         unsigned long next_balance;
         struct mm_struct *prev_mm;
 
-        u64 clock, prev_clock_raw;
-        s64 clock_max_delta;
-
-        unsigned int clock_warps, clock_overflows, clock_underflows;
-        u64 idle_clock;
-        unsigned int clock_deep_idle_events;
-        u64 tick_timestamp;
+        u64 clock;
 
         atomic_t nr_iowait;
 
@@ -631,82 +612,6 @@ static inline int cpu_of(struct rq *rq)
 #endif
 }
 
-#ifdef CONFIG_NO_HZ
-static inline bool nohz_on(int cpu)
-{
-        return tick_get_tick_sched(cpu)->nohz_mode != NOHZ_MODE_INACTIVE;
-}
-
-static inline u64 max_skipped_ticks(struct rq *rq)
-{
-        return nohz_on(cpu_of(rq)) ? jiffies - rq->last_tick_seen + 2 : 1;
-}
-
-static inline void update_last_tick_seen(struct rq *rq)
-{
-        rq->last_tick_seen = jiffies;
-}
-#else
-static inline u64 max_skipped_ticks(struct rq *rq)
-{
-        return 1;
-}
-
-static inline void update_last_tick_seen(struct rq *rq)
-{
-}
-#endif
-
-/*
- * Update the per-runqueue clock, as finegrained as the platform can give
- * us, but without assuming monotonicity, etc.:
- */
-static void __update_rq_clock(struct rq *rq)
-{
-        u64 prev_raw = rq->prev_clock_raw;
-        u64 now = sched_clock();
-        s64 delta = now - prev_raw;
-        u64 clock = rq->clock;
-
-#ifdef CONFIG_SCHED_DEBUG
-        WARN_ON_ONCE(cpu_of(rq) != smp_processor_id());
-#endif
-        /*
-         * Protect against sched_clock() occasionally going backwards:
-         */
-        if (unlikely(delta < 0)) {
-                clock++;
-                rq->clock_warps++;
-        } else {
-                /*
-                 * Catch too large forward jumps too:
-                 */
-                u64 max_jump = max_skipped_ticks(rq) * TICK_NSEC;
-                u64 max_time = rq->tick_timestamp + max_jump;
-
-                if (unlikely(clock + delta > max_time)) {
-                        if (clock < max_time)
-                                clock = max_time;
-                        else
-                                clock++;
-                        rq->clock_overflows++;
-                } else {
-                        if (unlikely(delta > rq->clock_max_delta))
-                                rq->clock_max_delta = delta;
-                        clock += delta;
-                }
-        }
-
-        rq->prev_clock_raw = now;
-        rq->clock = clock;
-}
-
-static void update_rq_clock(struct rq *rq)
-{
-        if (likely(smp_processor_id() == cpu_of(rq)))
-                __update_rq_clock(rq);
-}
-
 /*
  * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
  * See detach_destroy_domains: synchronize_sched for details.
@@ -722,6 +627,11 @@ static void update_rq_clock(struct rq *rq)
 #define task_rq(p)              cpu_rq(task_cpu(p))
 #define cpu_curr(cpu)           (cpu_rq(cpu)->curr)
 
+static inline void update_rq_clock(struct rq *rq)
+{
+        rq->clock = sched_clock_cpu(cpu_of(rq));
+}
+
 /*
  * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
  */
@@ -757,14 +667,14 @@ const_debug unsigned int sysctl_sched_features =
 #define SCHED_FEAT(name, enabled)       \
         #name ,
 
-__read_mostly char *sched_feat_names[] = {
+static __read_mostly char *sched_feat_names[] = {
 #include "sched_features.h"
         NULL
 };
 
 #undef SCHED_FEAT
 
-int sched_feat_open(struct inode *inode, struct file *filp)
+static int sched_feat_open(struct inode *inode, struct file *filp)
 {
         filp->private_data = inode->i_private;
         return 0;
@@ -899,7 +809,7 @@ static inline u64 global_rt_runtime(void)
         return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
 }
 
-static const unsigned long long time_sync_thresh = 100000;
+unsigned long long time_sync_thresh = 100000;
 
 static DEFINE_PER_CPU(unsigned long long, time_offset);
 static DEFINE_PER_CPU(unsigned long long, prev_cpu_time);
@@ -913,11 +823,14 @@ static DEFINE_PER_CPU(unsigned long long, prev_cpu_time);
 static DEFINE_SPINLOCK(time_sync_lock);
 static unsigned long long prev_global_time;
 
-static unsigned long long __sync_cpu_clock(cycles_t time, int cpu)
+static unsigned long long __sync_cpu_clock(unsigned long long time, int cpu)
 {
-        unsigned long flags;
-
-        spin_lock_irqsave(&time_sync_lock, flags);
+        /*
+         * We want this inlined, to not get tracer function calls
+         * in this critical section:
+         */
+        spin_acquire(&time_sync_lock.dep_map, 0, 0, _THIS_IP_);
+        __raw_spin_lock(&time_sync_lock.raw_lock);
 
         if (time < prev_global_time) {
                 per_cpu(time_offset, cpu) += prev_global_time - time;
@@ -926,7 +839,8 @@ static unsigned long long __sync_cpu_clock(cycles_t time, int cpu)
                 prev_global_time = time;
         }
 
-        spin_unlock_irqrestore(&time_sync_lock, flags);
+        __raw_spin_unlock(&time_sync_lock.raw_lock);
+        spin_release(&time_sync_lock.dep_map, 1, _THIS_IP_);
 
         return time;
 }
@@ -934,8 +848,6 @@ static unsigned long long __sync_cpu_clock(cycles_t time, int cpu)
 static unsigned long long __cpu_clock(int cpu)
 {
         unsigned long long now;
-        unsigned long flags;
-        struct rq *rq;
 
         /*
          * Only call sched_clock() if the scheduler has already been
@@ -944,11 +856,7 @@ static unsigned long long __cpu_clock(int cpu)
         if (unlikely(!scheduler_running))
                 return 0;
 
-        local_irq_save(flags);
-        rq = cpu_rq(cpu);
-        update_rq_clock(rq);
-        now = rq->clock;
-        local_irq_restore(flags);
+        now = sched_clock_cpu(cpu);
 
         return now;
 }
@@ -960,13 +868,18 @@ static unsigned long long __cpu_clock(int cpu)
 unsigned long long cpu_clock(int cpu)
 {
         unsigned long long prev_cpu_time, time, delta_time;
+        unsigned long flags;
 
+        local_irq_save(flags);
         prev_cpu_time = per_cpu(prev_cpu_time, cpu);
         time = __cpu_clock(cpu) + per_cpu(time_offset, cpu);
         delta_time = time-prev_cpu_time;
 
-        if (unlikely(delta_time > time_sync_thresh))
+        if (unlikely(delta_time > time_sync_thresh)) {
                 time = __sync_cpu_clock(time, cpu);
+                per_cpu(prev_cpu_time, cpu) = time;
+        }
+        local_irq_restore(flags);
 
         return time;
 }
@@ -1117,43 +1030,6 @@ static struct rq *this_rq_lock(void)
         return rq;
 }
 
-/*
- * We are going deep-idle (irqs are disabled):
- */
-void sched_clock_idle_sleep_event(void)
-{
-        struct rq *rq = cpu_rq(smp_processor_id());
-
-        spin_lock(&rq->lock);
-        __update_rq_clock(rq);
-        spin_unlock(&rq->lock);
-        rq->clock_deep_idle_events++;
-}
-EXPORT_SYMBOL_GPL(sched_clock_idle_sleep_event);
-
-/*
- * We just idled delta nanoseconds (called with irqs disabled):
- */
-void sched_clock_idle_wakeup_event(u64 delta_ns)
-{
-        struct rq *rq = cpu_rq(smp_processor_id());
-        u64 now = sched_clock();
-
-        rq->idle_clock += delta_ns;
-        /*
-         * Override the previous timestamp and ignore all
-         * sched_clock() deltas that occured while we idled,
-         * and use the PM-provided delta_ns to advance the
-         * rq clock:
-         */
-        spin_lock(&rq->lock);
-        rq->prev_clock_raw = now;
-        rq->clock += delta_ns;
-        spin_unlock(&rq->lock);
-        touch_softlockup_watchdog();
-}
-EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event);
-
 static void __resched_task(struct task_struct *p, int tif_bit);
 
 static inline void resched_task(struct task_struct *p)
@@ -1189,6 +1065,7 @@ static inline void resched_rq(struct rq *rq)
 enum {
         HRTICK_SET,             /* re-programm hrtick_timer */
         HRTICK_RESET,           /* not a new slice */
+        HRTICK_BLOCK,           /* stop hrtick operations */
 };
 
 /*
@@ -1200,6 +1077,8 @@ static inline int hrtick_enabled(struct rq *rq)
 {
         if (!sched_feat(HRTICK))
                 return 0;
+        if (unlikely(test_bit(HRTICK_BLOCK, &rq->hrtick_flags)))
+                return 0;
         return hrtimer_is_hres_active(&rq->hrtick_timer);
 }
 
@@ -1275,14 +1154,70 @@ static enum hrtimer_restart hrtick(struct hrtimer *timer)
         WARN_ON_ONCE(cpu_of(rq) != smp_processor_id());
 
         spin_lock(&rq->lock);
-        __update_rq_clock(rq);
+        update_rq_clock(rq);
         rq->curr->sched_class->task_tick(rq, rq->curr, 1);
         spin_unlock(&rq->lock);
 
         return HRTIMER_NORESTART;
 }
 
-static inline void init_rq_hrtick(struct rq *rq)
+static void hotplug_hrtick_disable(int cpu)
+{
+        struct rq *rq = cpu_rq(cpu);
+        unsigned long flags;
+
+        spin_lock_irqsave(&rq->lock, flags);
+        rq->hrtick_flags = 0;
+        __set_bit(HRTICK_BLOCK, &rq->hrtick_flags);
+        spin_unlock_irqrestore(&rq->lock, flags);
+
+        hrtick_clear(rq);
+}
+
+static void hotplug_hrtick_enable(int cpu)
+{
+        struct rq *rq = cpu_rq(cpu);
+        unsigned long flags;
+
+        spin_lock_irqsave(&rq->lock, flags);
+        __clear_bit(HRTICK_BLOCK, &rq->hrtick_flags);
+        spin_unlock_irqrestore(&rq->lock, flags);
+}
+
+static int
+hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu)
+{
+        int cpu = (int)(long)hcpu;
+
+        switch (action) {
+        case CPU_UP_CANCELED:
+        case CPU_UP_CANCELED_FROZEN:
+        case CPU_DOWN_PREPARE:
+        case CPU_DOWN_PREPARE_FROZEN:
+        case CPU_DEAD:
+        case CPU_DEAD_FROZEN:
+                hotplug_hrtick_disable(cpu);
+                return NOTIFY_OK;
+
+        case CPU_UP_PREPARE:
+        case CPU_UP_PREPARE_FROZEN:
+        case CPU_DOWN_FAILED:
+        case CPU_DOWN_FAILED_FROZEN:
+        case CPU_ONLINE:
+        case CPU_ONLINE_FROZEN:
+                hotplug_hrtick_enable(cpu);
+                return NOTIFY_OK;
+        }
+
+        return NOTIFY_DONE;
+}
+
+static void init_hrtick(void)
+{
+        hotcpu_notifier(hotplug_hrtick, 0);
+}
+
+static void init_rq_hrtick(struct rq *rq)
 {
         rq->hrtick_flags = 0;
         hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
@@ -1319,6 +1254,10 @@ static inline void init_rq_hrtick(struct rq *rq)
 void hrtick_resched(void)
 {
 }
+
+static inline void init_hrtick(void)
+{
+}
 #endif
 
 /*
@@ -1438,8 +1377,8 @@ calc_delta_mine(unsigned long delta_exec, unsigned long weight,
 {
         u64 tmp;
 
-        if (unlikely(!lw->inv_weight))
-                lw->inv_weight = (WMULT_CONST-lw->weight/2) / (lw->weight+1);
+        if (!lw->inv_weight)
+                lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2)/(lw->weight+1);
 
         tmp = (u64)delta_exec * weight;
         /*
@@ -1748,6 +1687,8 @@ __update_group_shares_cpu(struct task_group *tg, struct sched_domain *sd,
 
         if (shares < MIN_SHARES)
                 shares = MIN_SHARES;
+        else if (shares > MAX_SHARES)
+                shares = MAX_SHARES;
 
         __set_se_shares(tg->se[tcpu], shares);
 }
@@ -4339,8 +4280,10 @@ void account_system_time(struct task_struct *p, int hardirq_offset,
         struct rq *rq = this_rq();
         cputime64_t tmp;
 
-        if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0))
-                return account_guest_time(p, cputime);
+        if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) {
+                account_guest_time(p, cputime);
+                return;
+        }
 
         p->stime = cputime_add(p->stime, cputime);
 
@@ -4404,19 +4347,11 @@ void scheduler_tick(void)
         int cpu = smp_processor_id();
         struct rq *rq = cpu_rq(cpu);
         struct task_struct *curr = rq->curr;
-        u64 next_tick = rq->tick_timestamp + TICK_NSEC;
+
+        sched_clock_tick();
 
         spin_lock(&rq->lock);
-        __update_rq_clock(rq);
-        /*
-         * Let rq->clock advance by at least TICK_NSEC:
-         */
-        if (unlikely(rq->clock < next_tick)) {
-                rq->clock = next_tick;
-                rq->clock_underflows++;
-        }
-        rq->tick_timestamp = rq->clock;
-        update_last_tick_seen(rq);
+        update_rq_clock(rq);
         update_cpu_load(rq);
         curr->sched_class->task_tick(rq, curr, 0);
         spin_unlock(&rq->lock);
@@ -4570,7 +4505,7 @@ need_resched_nonpreemptible:
          * Do the rq-clock update outside the rq lock:
          */
         local_irq_disable();
-        __update_rq_clock(rq);
+        update_rq_clock(rq);
         spin_lock(&rq->lock);
         clear_tsk_need_resched(prev);
 
@@ -4595,9 +4530,9 @@ need_resched_nonpreemptible:
         prev->sched_class->put_prev_task(rq, prev);
         next = pick_next_task(rq, prev);
 
-        sched_info_switch(prev, next);
-
         if (likely(prev != next)) {
+                sched_info_switch(prev, next);
+
                 rq->nr_switches++;
                 rq->curr = next;
                 ++*switch_count;
@@ -4632,8 +4567,6 @@ EXPORT_SYMBOL(schedule);
 asmlinkage void __sched preempt_schedule(void)
 {
         struct thread_info *ti = current_thread_info();
-        struct task_struct *task = current;
-        int saved_lock_depth;
 
         /*
          * If there is a non-zero preempt_count or interrupts are disabled,
@@ -4644,16 +4577,7 @@ asmlinkage void __sched preempt_schedule(void)
 
         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:
-                 */
-                saved_lock_depth = task->lock_depth;
-                task->lock_depth = -1;
                 schedule();
-                task->lock_depth = saved_lock_depth;
                 sub_preempt_count(PREEMPT_ACTIVE);
 
                 /*
@@ -4674,26 +4598,15 @@ EXPORT_SYMBOL(preempt_schedule);
 asmlinkage void __sched preempt_schedule_irq(void)
 {
         struct thread_info *ti = current_thread_info();
-        struct task_struct *task = current;
-        int saved_lock_depth;
 
         /* Catch callers which need to be fixed */
         BUG_ON(ti->preempt_count || !irqs_disabled());
 
         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:
-                 */
-                saved_lock_depth = task->lock_depth;
-                task->lock_depth = -1;
                 local_irq_enable();
                 schedule();
                 local_irq_disable();
-                task->lock_depth = saved_lock_depth;
                 sub_preempt_count(PREEMPT_ACTIVE);
 
                 /*
@@ -5612,7 +5525,6 @@ static void __cond_resched(void)
         } while (need_resched());
 }
 
-#if !defined(CONFIG_PREEMPT) || defined(CONFIG_PREEMPT_VOLUNTARY)
 int __sched _cond_resched(void)
 {
         if (need_resched() && !(preempt_count() & PREEMPT_ACTIVE) &&
@@ -5623,7 +5535,6 @@ int __sched _cond_resched(void)
         return 0;
 }
 EXPORT_SYMBOL(_cond_resched);
-#endif
 
 /*
  * cond_resched_lock() - if a reschedule is pending, drop the given lock,
@@ -5918,8 +5829,11 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
         spin_unlock_irqrestore(&rq->lock, flags);
 
         /* Set the preempt count _outside_ the spinlocks! */
+#if defined(CONFIG_PREEMPT)
+        task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0);
+#else
         task_thread_info(idle)->preempt_count = 0;
-
+#endif
         /*
          * The idle tasks have their own, simple scheduling class:
          */
@@ -7755,7 +7669,7 @@ void partition_sched_domains(int ndoms_new, cpumask_t *doms_new,
 {
         int i, j;
 
-        lock_doms_cur();
+        mutex_lock(&sched_domains_mutex);
 
         /* always unregister in case we don't destroy any domains */
         unregister_sched_domain_sysctl();
@@ -7804,7 +7718,7 @@ match2:
 
         register_sched_domain_sysctl();
 
-        unlock_doms_cur();
+        mutex_unlock(&sched_domains_mutex);
 }
 
 #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
@@ -7813,8 +7727,10 @@ int arch_reinit_sched_domains(void)
         int err;
 
         get_online_cpus();
+        mutex_lock(&sched_domains_mutex);
         detach_destroy_domains(&cpu_online_map);
         err = arch_init_sched_domains(&cpu_online_map);
+        mutex_unlock(&sched_domains_mutex);
         put_online_cpus();
 
         return err;
@@ -7932,13 +7848,16 @@ void __init sched_init_smp(void)
         BUG_ON(sched_group_nodes_bycpu == NULL);
 #endif
         get_online_cpus();
+        mutex_lock(&sched_domains_mutex);
         arch_init_sched_domains(&cpu_online_map);
         cpus_andnot(non_isolated_cpus, cpu_possible_map, cpu_isolated_map);
         if (cpus_empty(non_isolated_cpus))
                 cpu_set(smp_processor_id(), non_isolated_cpus);
+        mutex_unlock(&sched_domains_mutex);
         put_online_cpus();
         /* XXX: Theoretical race here - CPU may be hotplugged now */
         hotcpu_notifier(update_sched_domains, 0);
+        init_hrtick();
 
         /* Move init over to a non-isolated CPU */
         if (set_cpus_allowed_ptr(current, &non_isolated_cpus) < 0)
@@ -8025,7 +7944,7 @@ static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
 
         se->my_q = cfs_rq;
         se->load.weight = tg->shares;
-        se->load.inv_weight = div64_u64(1ULL<<32, se->load.weight);
+        se->load.inv_weight = 0;
         se->parent = parent;
 }
 #endif
@@ -8149,8 +8068,6 @@ void __init sched_init(void)
                 spin_lock_init(&rq->lock);
                 lockdep_set_class(&rq->lock, &rq->rq_lock_key);
                 rq->nr_running = 0;
-                rq->clock = 1;
-                update_last_tick_seen(rq);
                 init_cfs_rq(&rq->cfs, rq);
                 init_rt_rq(&rq->rt, rq);
 #ifdef CONFIG_FAIR_GROUP_SCHED
@@ -8294,6 +8211,7 @@ EXPORT_SYMBOL(__might_sleep);
 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)
@@ -8325,7 +8243,6 @@ void normalize_rt_tasks(void)
                 p->se.sleep_start               = 0;
                 p->se.block_start               = 0;
 #endif
-                task_rq(p)->clock               = 0;
 
                 if (!rt_task(p)) {
                         /*
@@ -8692,7 +8609,7 @@ static void __set_se_shares(struct sched_entity *se, unsigned long shares)
                 dequeue_entity(cfs_rq, se, 0);
 
         se->load.weight = shares;
-        se->load.inv_weight = div64_u64((1ULL<<32), shares);
+        se->load.inv_weight = 0;
 
         if (on_rq)
                 enqueue_entity(cfs_rq, se, 0);
@@ -8722,13 +8639,10 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares)
         if (!tg->se[0])
                 return -EINVAL;
 
-        /*
-         * A weight of 0 or 1 can cause arithmetics problems.
-         * (The default weight is 1024 - so there's no practical
-         *  limitation from this.)
-         */
         if (shares < MIN_SHARES)
                 shares = MIN_SHARES;
+        else if (shares > MAX_SHARES)
+                shares = MAX_SHARES;
 
         mutex_lock(&shares_mutex);
         if (tg->shares == shares)
@@ -8753,7 +8667,7 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares)
                  * force a rebalance
                  */
                 cfs_rq_set_shares(tg->cfs_rq[i], 0);
-                set_se_shares(tg->se[i], shares/nr_cpu_ids);
+                set_se_shares(tg->se[i], shares);
         }
 
         /*
@@ -9072,7 +8986,7 @@ static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft)
 #endif
 
 #ifdef CONFIG_RT_GROUP_SCHED
-static ssize_t cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft,
+static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft,
                                 s64 val)
 {
         return sched_group_set_rt_runtime(cgroup_tg(cgrp), val);