]> err.no Git - linux-2.6/blobdiff - kernel/sched.c
Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus
[linux-2.6] / kernel / sched.c
index 6da1fcef725a61023a5b6e7296334921480a5bf4..3f6bd1112900c9bcf5151d25a22b1d3d8dfda29c 100644 (file)
@@ -44,6 +44,7 @@
 #include <linux/vmalloc.h>
 #include <linux/blkdev.h>
 #include <linux/delay.h>
+#include <linux/pid_namespace.h>
 #include <linux/smp.h>
 #include <linux/threads.h>
 #include <linux/timer.h>
@@ -51,6 +52,7 @@
 #include <linux/cpu.h>
 #include <linux/cpuset.h>
 #include <linux/percpu.h>
+#include <linux/cpu_acct.h>
 #include <linux/kthread.h>
 #include <linux/seq_file.h>
 #include <linux/sysctl.h>
@@ -64,6 +66,7 @@
 #include <linux/pagemap.h>
 
 #include <asm/tlb.h>
+#include <asm/irq_regs.h>
 
 /*
  * Scheduler clock - returns current time in nanosec units.
@@ -153,10 +156,15 @@ struct rt_prio_array {
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
 
+#include <linux/cgroup.h>
+
 struct cfs_rq;
 
 /* task group related information */
 struct task_group {
+#ifdef CONFIG_FAIR_CGROUP_SCHED
+       struct cgroup_subsys_state css;
+#endif
        /* schedulable entities of this group on each cpu */
        struct sched_entity **se;
        /* runqueue "owned" by this group on each cpu */
@@ -164,6 +172,7 @@ struct task_group {
        unsigned long shares;
        /* spinlock to serialize modification to shares */
        spinlock_t lock;
+       struct rcu_head rcu;
 };
 
 /* Default task group's sched entity on each cpu */
@@ -197,6 +206,9 @@ static inline struct task_group *task_group(struct task_struct *p)
 
 #ifdef CONFIG_FAIR_USER_SCHED
        tg = p->user->tg;
+#elif defined(CONFIG_FAIR_CGROUP_SCHED)
+       tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id),
+                               struct task_group, css);
 #else
        tg  = &init_task_group;
 #endif
@@ -247,7 +259,6 @@ struct cfs_rq {
         */
        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
 };
 
@@ -332,22 +343,22 @@ struct rq {
        struct sched_info rq_sched_info;
 
        /* sys_sched_yield() stats */
-       unsigned long yld_exp_empty;
-       unsigned long yld_act_empty;
-       unsigned long yld_both_empty;
-       unsigned long yld_count;
+       unsigned int yld_exp_empty;
+       unsigned int yld_act_empty;
+       unsigned int yld_both_empty;
+       unsigned int yld_count;
 
        /* schedule() stats */
-       unsigned long sched_switch;
-       unsigned long sched_count;
-       unsigned long sched_goidle;
+       unsigned int sched_switch;
+       unsigned int sched_count;
+       unsigned int sched_goidle;
 
        /* try_to_wake_up() stats */
-       unsigned long ttwu_count;
-       unsigned long ttwu_local;
+       unsigned int ttwu_count;
+       unsigned int ttwu_local;
 
        /* BKL stats */
-       unsigned long bkl_count;
+       unsigned int bkl_count;
 #endif
        struct lock_class_key rq_lock_key;
 };
@@ -827,11 +838,18 @@ struct rq_iterator {
        struct task_struct *(*next)(void *);
 };
 
-static int balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
-                     unsigned long max_nr_move, unsigned long max_load_move,
-                     struct sched_domain *sd, enum cpu_idle_type idle,
-                     int *all_pinned, unsigned long *load_moved,
-                     int *this_best_prio, struct rq_iterator *iterator);
+#ifdef CONFIG_SMP
+static unsigned long
+balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
+             unsigned long max_load_move, struct sched_domain *sd,
+             enum cpu_idle_type idle, int *all_pinned,
+             int *this_best_prio, struct rq_iterator *iterator);
+
+static int
+iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
+                  struct sched_domain *sd, enum cpu_idle_type idle,
+                  struct rq_iterator *iterator);
+#endif
 
 #include "sched_stats.h"
 #include "sched_idletask.c"
@@ -1875,7 +1893,7 @@ asmlinkage void schedule_tail(struct task_struct *prev)
        preempt_enable();
 #endif
        if (current->set_child_tid)
-               put_user(current->pid, current->set_child_tid);
+               put_user(task_pid_vnr(current), current->set_child_tid);
 }
 
 /*
@@ -2213,17 +2231,17 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
        return 1;
 }
 
-static int balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
-                     unsigned long max_nr_move, unsigned long max_load_move,
-                     struct sched_domain *sd, enum cpu_idle_type idle,
-                     int *all_pinned, unsigned long *load_moved,
-                     int *this_best_prio, struct rq_iterator *iterator)
+static unsigned long
+balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
+             unsigned long max_load_move, struct sched_domain *sd,
+             enum cpu_idle_type idle, int *all_pinned,
+             int *this_best_prio, struct rq_iterator *iterator)
 {
        int pulled = 0, pinned = 0, skip_for_load;
        struct task_struct *p;
        long rem_load_move = max_load_move;
 
-       if (max_nr_move == 0 || max_load_move == 0)
+       if (max_load_move == 0)
                goto out;
 
        pinned = 1;
@@ -2256,7 +2274,7 @@ next:
         * We only want to steal up to the prescribed number of tasks
         * and the prescribed amount of weighted load.
         */
-       if (pulled < max_nr_move && rem_load_move > 0) {
+       if (rem_load_move > 0) {
                if (p->prio < *this_best_prio)
                        *this_best_prio = p->prio;
                p = iterator->next(iterator->arg);
@@ -2264,7 +2282,7 @@ next:
        }
 out:
        /*
-        * Right now, this is the only place pull_task() is called,
+        * Right now, this is one of only two places pull_task() is called,
         * so we can safely collect pull_task() stats here rather than
         * inside pull_task().
         */
@@ -2272,8 +2290,8 @@ out:
 
        if (all_pinned)
                *all_pinned = pinned;
-       *load_moved = max_load_move - rem_load_move;
-       return pulled;
+
+       return max_load_move - rem_load_move;
 }
 
 /*
@@ -2295,7 +2313,7 @@ static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
        do {
                total_load_moved +=
                        class->load_balance(this_rq, this_cpu, busiest,
-                               ULONG_MAX, max_load_move - total_load_moved,
+                               max_load_move - total_load_moved,
                                sd, idle, all_pinned, &this_best_prio);
                class = class->next;
        } while (class && max_load_move > total_load_moved);
@@ -2303,6 +2321,32 @@ static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
        return total_load_moved > 0;
 }
 
+static int
+iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
+                  struct sched_domain *sd, enum cpu_idle_type idle,
+                  struct rq_iterator *iterator)
+{
+       struct task_struct *p = iterator->start(iterator->arg);
+       int pinned = 0;
+
+       while (p) {
+               if (can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) {
+                       pull_task(busiest, p, this_rq, this_cpu);
+                       /*
+                        * Right now, this is only the second place pull_task()
+                        * is called, so we can safely collect pull_task()
+                        * stats here rather than inside pull_task().
+                        */
+                       schedstat_inc(sd, lb_gained[idle]);
+
+                       return 1;
+               }
+               p = iterator->next(iterator->arg);
+       }
+
+       return 0;
+}
+
 /*
  * move_one_task tries to move exactly one task from busiest to this_rq, as
  * part of active balancing operations within "domain".
@@ -2314,12 +2358,9 @@ static int move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
                         struct sched_domain *sd, enum cpu_idle_type idle)
 {
        const struct sched_class *class;
-       int this_best_prio = MAX_PRIO;
 
        for (class = sched_class_highest; class; class = class->next)
-               if (class->load_balance(this_rq, this_cpu, busiest,
-                                       1, ULONG_MAX, sd, idle, NULL,
-                                       &this_best_prio))
+               if (class->move_one_task(this_rq, this_cpu, busiest, sd, idle))
                        return 1;
 
        return 0;
@@ -3256,18 +3297,6 @@ static inline void idle_balance(int cpu, struct rq *rq)
 {
 }
 
-/* Avoid "used but not defined" warning on UP */
-static int balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
-                     unsigned long max_nr_move, unsigned long max_load_move,
-                     struct sched_domain *sd, enum cpu_idle_type idle,
-                     int *all_pinned, unsigned long *load_moved,
-                     int *this_best_prio, struct rq_iterator *iterator)
-{
-       *load_moved = 0;
-
-       return 0;
-}
-
 #endif
 
 DEFINE_PER_CPU(struct kernel_stat, kstat);
@@ -3300,16 +3329,19 @@ unsigned long long task_sched_runtime(struct task_struct *p)
 /*
  * Account user cpu time to a process.
  * @p: the process that the cpu time gets accounted to
- * @hardirq_offset: the offset to subtract from hardirq_count()
  * @cputime: the cpu time spent in user space since the last update
  */
 void account_user_time(struct task_struct *p, cputime_t cputime)
 {
        struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
        cputime64_t tmp;
+       struct rq *rq = this_rq();
 
        p->utime = cputime_add(p->utime, cputime);
 
+       if (p != rq->idle)
+               cpuacct_charge(p, cputime);
+
        /* Add user time to cpustat. */
        tmp = cputime_to_cputime64(cputime);
        if (TASK_NICE(p) > 0)
@@ -3323,7 +3355,7 @@ void account_user_time(struct task_struct *p, cputime_t cputime)
  * @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)
+static void account_guest_time(struct task_struct *p, cputime_t cputime)
 {
        cputime64_t tmp;
        struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
@@ -3337,6 +3369,16 @@ void account_guest_time(struct task_struct *p, cputime_t cputime)
        cpustat->guest = cputime64_add(cpustat->guest, tmp);
 }
 
+/*
+ * Account scaled user cpu time to a process.
+ * @p: the process that the cpu time gets accounted to
+ * @cputime: the cpu time spent in user space since the last update
+ */
+void account_user_time_scaled(struct task_struct *p, cputime_t cputime)
+{
+       p->utimescaled = cputime_add(p->utimescaled, cputime);
+}
+
 /*
  * Account system cpu time to a process.
  * @p: the process that the cpu time gets accounted to
@@ -3352,7 +3394,6 @@ void account_system_time(struct task_struct *p, int hardirq_offset,
 
        if (p->flags & PF_VCPU) {
                account_guest_time(p, cputime);
-               p->flags &= ~PF_VCPU;
                return;
        }
 
@@ -3364,9 +3405,10 @@ void account_system_time(struct task_struct *p, int hardirq_offset,
                cpustat->irq = cputime64_add(cpustat->irq, tmp);
        else if (softirq_count())
                cpustat->softirq = cputime64_add(cpustat->softirq, tmp);
-       else if (p != rq->idle)
+       else if (p != rq->idle) {
                cpustat->system = cputime64_add(cpustat->system, tmp);
-       else if (atomic_read(&rq->nr_iowait) > 0)
+               cpuacct_charge(p, cputime);
+       } else if (atomic_read(&rq->nr_iowait) > 0)
                cpustat->iowait = cputime64_add(cpustat->iowait, tmp);
        else
                cpustat->idle = cputime64_add(cpustat->idle, tmp);
@@ -3374,6 +3416,17 @@ void account_system_time(struct task_struct *p, int hardirq_offset,
        acct_update_integrals(p);
 }
 
+/*
+ * Account scaled system cpu time to a process.
+ * @p: the process that the cpu time gets accounted to
+ * @hardirq_offset: the offset to subtract from hardirq_count()
+ * @cputime: the cpu time spent in kernel space since the last update
+ */
+void account_system_time_scaled(struct task_struct *p, cputime_t cputime)
+{
+       p->stimescaled = cputime_add(p->stimescaled, cputime);
+}
+
 /*
  * Account for involuntary wait time.
  * @p: the process from which the cpu time has been stolen
@@ -3391,8 +3444,10 @@ void account_steal_time(struct task_struct *p, cputime_t steal)
                        cpustat->iowait = cputime64_add(cpustat->iowait, tmp);
                else
                        cpustat->idle = cputime64_add(cpustat->idle, tmp);
-       } else
+       } else {
                cpustat->steal = cputime64_add(cpustat->steal, tmp);
+               cpuacct_charge(p, -tmp);
+       }
 }
 
 /*
@@ -3471,12 +3526,19 @@ EXPORT_SYMBOL(sub_preempt_count);
  */
 static noinline void __schedule_bug(struct task_struct *prev)
 {
-       printk(KERN_ERR "BUG: scheduling while atomic: %s/0x%08x/%d\n",
-               prev->comm, preempt_count(), prev->pid);
+       struct pt_regs *regs = get_irq_regs();
+
+       printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n",
+               prev->comm, prev->pid, preempt_count());
+
        debug_show_held_locks(prev);
        if (irqs_disabled())
                print_irqtrace_events(prev);
-       dump_stack();
+
+       if (regs)
+               show_regs(regs);
+       else
+               dump_stack();
 }
 
 /*
@@ -3784,7 +3846,7 @@ __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
 }
 EXPORT_SYMBOL_GPL(__wake_up_sync);     /* For internal use only */
 
-void fastcall complete(struct completion *x)
+void complete(struct completion *x)
 {
        unsigned long flags;
 
@@ -3796,7 +3858,7 @@ void fastcall complete(struct completion *x)
 }
 EXPORT_SYMBOL(complete);
 
-void fastcall complete_all(struct completion *x)
+void complete_all(struct completion *x)
 {
        unsigned long flags;
 
@@ -3848,13 +3910,13 @@ wait_for_common(struct completion *x, long timeout, int state)
        return timeout;
 }
 
-void fastcall __sched wait_for_completion(struct completion *x)
+void __sched wait_for_completion(struct completion *x)
 {
        wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
 }
 EXPORT_SYMBOL(wait_for_completion);
 
-unsigned long fastcall __sched
+unsigned long __sched
 wait_for_completion_timeout(struct completion *x, unsigned long timeout)
 {
        return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE);
@@ -3870,7 +3932,7 @@ int __sched wait_for_completion_interruptible(struct completion *x)
 }
 EXPORT_SYMBOL(wait_for_completion_interruptible);
 
-unsigned long fastcall __sched
+unsigned long __sched
 wait_for_completion_interruptible_timeout(struct completion *x,
                                          unsigned long timeout)
 {
@@ -4138,7 +4200,7 @@ struct task_struct *idle_task(int cpu)
  */
 static struct task_struct *find_process_by_pid(pid_t pid)
 {
-       return pid ? find_task_by_pid(pid) : current;
+       return pid ? find_task_by_vpid(pid) : current;
 }
 
 /* Actually do priority change: must hold rq lock. */
@@ -4441,8 +4503,21 @@ long sched_setaffinity(pid_t pid, cpumask_t new_mask)
 
        cpus_allowed = cpuset_cpus_allowed(p);
        cpus_and(new_mask, new_mask, cpus_allowed);
+ again:
        retval = set_cpus_allowed(p, new_mask);
 
+       if (!retval) {
+               cpus_allowed = cpuset_cpus_allowed(p);
+               if (!cpus_subset(new_mask, cpus_allowed)) {
+                       /*
+                        * We must have raced with a concurrent cpuset
+                        * update. Just reset the cpus_allowed to the
+                        * cpuset's cpus_allowed
+                        */
+                       new_mask = cpus_allowed;
+                       goto again;
+               }
+       }
 out_unlock:
        put_task_struct(p);
        mutex_unlock(&sched_hotcpu_mutex);
@@ -4801,18 +4876,18 @@ static void show_task(struct task_struct *p)
        unsigned state;
 
        state = p->state ? __ffs(p->state) + 1 : 0;
-       printk("%-13.13s %c", p->comm,
+       printk(KERN_INFO "%-13.13s %c", p->comm,
                state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
 #if BITS_PER_LONG == 32
        if (state == TASK_RUNNING)
-               printk(" running  ");
+               printk(KERN_CONT " running  ");
        else
-               printk(" %08lx ", thread_saved_pc(p));
+               printk(KERN_CONT " %08lx ", thread_saved_pc(p));
 #else
        if (state == TASK_RUNNING)
-               printk("  running task    ");
+               printk(KERN_CONT "  running task    ");
        else
-               printk(" %016lx ", thread_saved_pc(p));
+               printk(KERN_CONT " %016lx ", thread_saved_pc(p));
 #endif
 #ifdef CONFIG_DEBUG_STACK_USAGE
        {
@@ -4822,7 +4897,8 @@ static void show_task(struct task_struct *p)
                free = (unsigned long)n - (unsigned long)end_of_stack(p);
        }
 #endif
-       printk("%5lu %5d %6d\n", free, p->pid, p->parent->pid);
+       printk(KERN_CONT "%5lu %5d %6d\n", free,
+               task_pid_nr(p), task_pid_nr(p->parent));
 
        if (state != TASK_RUNNING)
                show_stack(p, NULL);
@@ -5094,7 +5170,7 @@ static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu)
 }
 
 /*
- * Figure out where task on dead CPU should go, use force if neccessary.
+ * Figure out where task on dead CPU should go, use force if necessary.
  * NOTE: interrupts should be disabled by the caller
  */
 static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
@@ -5116,8 +5192,16 @@ static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
 
                /* No more Mr. Nice Guy. */
                if (dest_cpu == NR_CPUS) {
+                       cpumask_t cpus_allowed = cpuset_cpus_allowed_locked(p);
+                       /*
+                        * Try to stay on the same cpuset, where the
+                        * current cpuset may be a subset of all cpus.
+                        * The cpuset_cpus_allowed_locked() variant of
+                        * cpuset_cpus_allowed() will not block.  It must be
+                        * called within calls to cpuset_lock/cpuset_unlock.
+                        */
                        rq = task_rq_lock(p, &flags);
-                       cpus_setall(p->cpus_allowed);
+                       p->cpus_allowed = cpus_allowed;
                        dest_cpu = any_online_cpu(p->cpus_allowed);
                        task_rq_unlock(rq, &flags);
 
@@ -5129,7 +5213,7 @@ static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
                        if (p->mm && printk_ratelimit())
                                printk(KERN_INFO "process %d (%s) no "
                                       "longer affine to cpu%d\n",
-                                      p->pid, p->comm, dead_cpu);
+                              task_pid_nr(p), p->comm, dead_cpu);
                }
        } while (!__migrate_task_irq(p, dead_cpu, dest_cpu));
 }
@@ -5236,7 +5320,7 @@ static void migrate_dead(unsigned int dead_cpu, struct task_struct *p)
        struct rq *rq = cpu_rq(dead_cpu);
 
        /* Must be exiting, otherwise would be on tasklist. */
-       BUG_ON(p->exit_state != EXIT_ZOMBIE && p->exit_state != EXIT_DEAD);
+       BUG_ON(!p->exit_state);
 
        /* Cannot have done final schedule yet: would have vanished. */
        BUG_ON(p->state == TASK_DEAD);
@@ -5281,7 +5365,7 @@ static struct ctl_table sd_ctl_dir[] = {
                .procname       = "sched_domain",
                .mode           = 0555,
        },
-       {0,},
+       {0, },
 };
 
 static struct ctl_table sd_ctl_root[] = {
@@ -5291,7 +5375,7 @@ static struct ctl_table sd_ctl_root[] = {
                .mode           = 0555,
                .child          = sd_ctl_dir,
        },
-       {0,},
+       {0, },
 };
 
 static struct ctl_table *sd_alloc_ctl_entry(int n)
@@ -5403,11 +5487,12 @@ static void register_sched_domain_sysctl(void)
        struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
        char buf[32];
 
+       WARN_ON(sd_ctl_dir[0].child);
+       sd_ctl_dir[0].child = entry;
+
        if (entry == NULL)
                return;
 
-       sd_ctl_dir[0].child = entry;
-
        for_each_online_cpu(i) {
                snprintf(buf, 32, "cpu%d", i);
                entry->procname = kstrdup(buf, GFP_KERNEL);
@@ -5415,14 +5500,19 @@ static void register_sched_domain_sysctl(void)
                entry->child = sd_alloc_ctl_cpu_table(i);
                entry++;
        }
+
+       WARN_ON(sd_sysctl_header);
        sd_sysctl_header = register_sysctl_table(sd_ctl_root);
 }
 
+/* may be called multiple times per register */
 static void unregister_sched_domain_sysctl(void)
 {
-       unregister_sysctl_table(sd_sysctl_header);
+       if (sd_sysctl_header)
+               unregister_sysctl_table(sd_sysctl_header);
        sd_sysctl_header = NULL;
-       sd_free_ctl_entry(&sd_ctl_dir[0].child);
+       if (sd_ctl_dir[0].child)
+               sd_free_ctl_entry(&sd_ctl_dir[0].child);
 }
 #else
 static void register_sched_domain_sysctl(void)
@@ -5465,7 +5555,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
 
        case CPU_ONLINE:
        case CPU_ONLINE_FROZEN:
-               /* Strictly unneccessary, as first user will wake it. */
+               /* Strictly unnecessary, as first user will wake it. */
                wake_up_process(cpu_rq(cpu)->migration_thread);
                break;
 
@@ -5483,6 +5573,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
 
        case CPU_DEAD:
        case CPU_DEAD_FROZEN:
+               cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */
                migrate_live_tasks(cpu);
                rq = cpu_rq(cpu);
                kthread_stop(rq->migration_thread);
@@ -5496,6 +5587,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
                rq->idle->sched_class = &idle_sched_class;
                migrate_dead_tasks(cpu);
                spin_unlock_irq(&rq->lock);
+               cpuset_unlock();
                migrate_nr_uninterruptible(rq);
                BUG_ON(rq->nr_running != 0);
 
@@ -5551,101 +5643,101 @@ int nr_cpu_ids __read_mostly = NR_CPUS;
 EXPORT_SYMBOL(nr_cpu_ids);
 
 #ifdef CONFIG_SCHED_DEBUG
-static void sched_domain_debug(struct sched_domain *sd, int cpu)
+
+static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level)
 {
-       int level = 0;
+       struct sched_group *group = sd->groups;
+       cpumask_t groupmask;
+       char str[NR_CPUS];
 
-       if (!sd) {
-               printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu);
-               return;
+       cpumask_scnprintf(str, NR_CPUS, sd->span);
+       cpus_clear(groupmask);
+
+       printk(KERN_DEBUG "%*s domain %d: ", level, "", level);
+
+       if (!(sd->flags & SD_LOAD_BALANCE)) {
+               printk("does not load-balance\n");
+               if (sd->parent)
+                       printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain"
+                                       " has parent");
+               return -1;
        }
 
-       printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu);
+       printk(KERN_CONT "span %s\n", str);
 
+       if (!cpu_isset(cpu, sd->span)) {
+               printk(KERN_ERR "ERROR: domain->span does not contain "
+                               "CPU%d\n", cpu);
+       }
+       if (!cpu_isset(cpu, group->cpumask)) {
+               printk(KERN_ERR "ERROR: domain->groups does not contain"
+                               " CPU%d\n", cpu);
+       }
+
+       printk(KERN_DEBUG "%*s groups:", level + 1, "");
        do {
-               int i;
-               char str[NR_CPUS];
-               struct sched_group *group = sd->groups;
-               cpumask_t groupmask;
-
-               cpumask_scnprintf(str, NR_CPUS, sd->span);
-               cpus_clear(groupmask);
-
-               printk(KERN_DEBUG);
-               for (i = 0; i < level + 1; i++)
-                       printk(" ");
-               printk("domain %d: ", level);
-
-               if (!(sd->flags & SD_LOAD_BALANCE)) {
-                       printk("does not load-balance\n");
-                       if (sd->parent)
-                               printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain"
-                                               " has parent");
+               if (!group) {
+                       printk("\n");
+                       printk(KERN_ERR "ERROR: group is NULL\n");
                        break;
                }
 
-               printk("span %s\n", str);
+               if (!group->__cpu_power) {
+                       printk(KERN_CONT "\n");
+                       printk(KERN_ERR "ERROR: domain->cpu_power not "
+                                       "set\n");
+                       break;
+               }
 
-               if (!cpu_isset(cpu, sd->span))
-                       printk(KERN_ERR "ERROR: domain->span does not contain "
-                                       "CPU%d\n", cpu);
-               if (!cpu_isset(cpu, group->cpumask))
-                       printk(KERN_ERR "ERROR: domain->groups does not contain"
-                                       " CPU%d\n", cpu);
+               if (!cpus_weight(group->cpumask)) {
+                       printk(KERN_CONT "\n");
+                       printk(KERN_ERR "ERROR: empty group\n");
+                       break;
+               }
 
-               printk(KERN_DEBUG);
-               for (i = 0; i < level + 2; i++)
-                       printk(" ");
-               printk("groups:");
-               do {
-                       if (!group) {
-                               printk("\n");
-                               printk(KERN_ERR "ERROR: group is NULL\n");
-                               break;
-                       }
+               if (cpus_intersects(groupmask, group->cpumask)) {
+                       printk(KERN_CONT "\n");
+                       printk(KERN_ERR "ERROR: repeated CPUs\n");
+                       break;
+               }
 
-                       if (!group->__cpu_power) {
-                               printk("\n");
-                               printk(KERN_ERR "ERROR: domain->cpu_power not "
-                                               "set\n");
-                               break;
-                       }
+               cpus_or(groupmask, groupmask, group->cpumask);
 
-                       if (!cpus_weight(group->cpumask)) {
-                               printk("\n");
-                               printk(KERN_ERR "ERROR: empty group\n");
-                               break;
-                       }
+               cpumask_scnprintf(str, NR_CPUS, group->cpumask);
+               printk(KERN_CONT " %s", str);
 
-                       if (cpus_intersects(groupmask, group->cpumask)) {
-                               printk("\n");
-                               printk(KERN_ERR "ERROR: repeated CPUs\n");
-                               break;
-                       }
+               group = group->next;
+       } while (group != sd->groups);
+       printk(KERN_CONT "\n");
 
-                       cpus_or(groupmask, groupmask, group->cpumask);
+       if (!cpus_equal(sd->span, groupmask))
+               printk(KERN_ERR "ERROR: groups don't span domain->span\n");
 
-                       cpumask_scnprintf(str, NR_CPUS, group->cpumask);
-                       printk(" %s", str);
+       if (sd->parent && !cpus_subset(groupmask, sd->parent->span))
+               printk(KERN_ERR "ERROR: parent span is not a superset "
+                       "of domain->span\n");
+       return 0;
+}
 
-                       group = group->next;
-               } while (group != sd->groups);
-               printk("\n");
+static void sched_domain_debug(struct sched_domain *sd, int cpu)
+{
+       int level = 0;
 
-               if (!cpus_equal(sd->span, groupmask))
-                       printk(KERN_ERR "ERROR: groups don't span "
-                                       "domain->span\n");
+       if (!sd) {
+               printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu);
+               return;
+       }
 
+       printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu);
+
+       for (;;) {
+               if (sched_domain_debug_one(sd, cpu, level))
+                       break;
                level++;
                sd = sd->parent;
                if (!sd)
-                       continue;
-
-               if (!cpus_subset(groupmask, sd->span))
-                       printk(KERN_ERR "ERROR: parent span is not a superset "
-                               "of domain->span\n");
-
-       } while (sd);
+                       break;
+       }
 }
 #else
 # define sched_domain_debug(sd, cpu) do { } while (0)
@@ -6346,23 +6438,32 @@ error:
        return -ENOMEM;
 #endif
 }
+
+static cpumask_t *doms_cur;    /* current sched domains */
+static int ndoms_cur;          /* number of sched domains in 'doms_cur' */
+
+/*
+ * Special case: If a kmalloc of a doms_cur partition (array of
+ * cpumask_t) fails, then fallback to a single sched domain,
+ * as determined by the single cpumask_t fallback_doms.
+ */
+static cpumask_t fallback_doms;
+
 /*
  * Set up scheduler domains and groups.  Callers must hold the hotplug lock.
+ * For now this just excludes isolated cpus, but could be used to
+ * exclude other special cases in the future.
  */
 static int arch_init_sched_domains(const cpumask_t *cpu_map)
 {
-       cpumask_t cpu_default_map;
        int err;
 
-       /*
-        * Setup mask for cpus without special case scheduling requirements.
-        * For now this just excludes isolated cpus, but could be used to
-        * exclude other special cases in the future.
-        */
-       cpus_andnot(cpu_default_map, *cpu_map, cpu_isolated_map);
-
-       err = build_sched_domains(&cpu_default_map);
-
+       ndoms_cur = 1;
+       doms_cur = kmalloc(sizeof(cpumask_t), GFP_KERNEL);
+       if (!doms_cur)
+               doms_cur = &fallback_doms;
+       cpus_andnot(*doms_cur, *cpu_map, cpu_isolated_map);
+       err = build_sched_domains(doms_cur);
        register_sched_domain_sysctl();
 
        return err;
@@ -6389,6 +6490,73 @@ static void detach_destroy_domains(const cpumask_t *cpu_map)
        arch_destroy_sched_domains(cpu_map);
 }
 
+/*
+ * Partition sched domains as specified by the 'ndoms_new'
+ * cpumasks in the array doms_new[] of cpumasks.  This compares
+ * doms_new[] to the current sched domain partitioning, doms_cur[].
+ * It destroys each deleted domain and builds each new domain.
+ *
+ * 'doms_new' is an array of cpumask_t's of length 'ndoms_new'.
+ * The masks don't intersect (don't overlap.)  We should setup one
+ * sched domain for each mask.  CPUs not in any of the cpumasks will
+ * not be load balanced.  If the same cpumask appears both in the
+ * current 'doms_cur' domains and in the new 'doms_new', we can leave
+ * it as it is.
+ *
+ * The passed in 'doms_new' should be kmalloc'd.  This routine takes
+ * ownership of it and will kfree it when done with it.  If the caller
+ * failed the kmalloc call, then it can pass in doms_new == NULL,
+ * and partition_sched_domains() will fallback to the single partition
+ * 'fallback_doms'.
+ *
+ * Call with hotplug lock held
+ */
+void partition_sched_domains(int ndoms_new, cpumask_t *doms_new)
+{
+       int i, j;
+
+       /* always unregister in case we don't destroy any domains */
+       unregister_sched_domain_sysctl();
+
+       if (doms_new == NULL) {
+               ndoms_new = 1;
+               doms_new = &fallback_doms;
+               cpus_andnot(doms_new[0], cpu_online_map, cpu_isolated_map);
+       }
+
+       /* Destroy deleted domains */
+       for (i = 0; i < ndoms_cur; i++) {
+               for (j = 0; j < ndoms_new; j++) {
+                       if (cpus_equal(doms_cur[i], doms_new[j]))
+                               goto match1;
+               }
+               /* no match - a current sched domain not in new doms_new[] */
+               detach_destroy_domains(doms_cur + i);
+match1:
+               ;
+       }
+
+       /* Build new domains */
+       for (i = 0; i < ndoms_new; i++) {
+               for (j = 0; j < ndoms_cur; j++) {
+                       if (cpus_equal(doms_new[i], doms_cur[j]))
+                               goto match2;
+               }
+               /* no match - add a new doms_new */
+               build_sched_domains(doms_new + i);
+match2:
+               ;
+       }
+
+       /* Remember the new sched domains */
+       if (doms_cur != &fallback_doms)
+               kfree(doms_cur);
+       doms_cur = doms_new;
+       ndoms_cur = ndoms_new;
+
+       register_sched_domain_sysctl();
+}
+
 #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
 static int arch_reinit_sched_domains(void)
 {
@@ -6851,8 +7019,8 @@ err:
 /* 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 task_group *tg = container_of(rhp, struct task_group, rcu);
+       struct cfs_rq *cfs_rq;
        struct sched_entity *se;
        int i;
 
@@ -6873,7 +7041,7 @@ static void free_sched_group(struct rcu_head *rhp)
 /* Destroy runqueue etc associated with a task group */
 void sched_destroy_group(struct task_group *tg)
 {
-       struct cfs_rq *cfs_rq;
+       struct cfs_rq *cfs_rq = NULL;
        int i;
 
        for_each_possible_cpu(i) {
@@ -6881,10 +7049,10 @@ void sched_destroy_group(struct task_group *tg)
                list_del_rcu(&cfs_rq->leaf_cfs_rq_list);
        }
 
-       cfs_rq = tg->cfs_rq[0];
+       BUG_ON(!cfs_rq);
 
        /* wait for possible concurrent references to cfs_rqs complete */
-       call_rcu(&cfs_rq->rcu, free_sched_group);
+       call_rcu(&tg->rcu, free_sched_group);
 }
 
 /* change task's runqueue when it moves between groups.
@@ -6970,3 +7138,127 @@ unsigned long sched_group_shares(struct task_group *tg)
 }
 
 #endif /* CONFIG_FAIR_GROUP_SCHED */
+
+#ifdef CONFIG_FAIR_CGROUP_SCHED
+
+/* return corresponding task_group object of a cgroup */
+static inline struct task_group *cgroup_tg(struct cgroup *cgrp)
+{
+       return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id),
+                           struct task_group, css);
+}
+
+static struct cgroup_subsys_state *
+cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp)
+{
+       struct task_group *tg;
+
+       if (!cgrp->parent) {
+               /* This is early initialization for the top cgroup */
+               init_task_group.css.cgroup = cgrp;
+               return &init_task_group.css;
+       }
+
+       /* we support only 1-level deep hierarchical scheduler atm */
+       if (cgrp->parent->parent)
+               return ERR_PTR(-EINVAL);
+
+       tg = sched_create_group();
+       if (IS_ERR(tg))
+               return ERR_PTR(-ENOMEM);
+
+       /* Bind the cgroup to task_group object we just created */
+       tg->css.cgroup = cgrp;
+
+       return &tg->css;
+}
+
+static void cpu_cgroup_destroy(struct cgroup_subsys *ss,
+                              struct cgroup *cgrp)
+{
+       struct task_group *tg = cgroup_tg(cgrp);
+
+       sched_destroy_group(tg);
+}
+
+static int cpu_cgroup_can_attach(struct cgroup_subsys *ss,
+                            struct cgroup *cgrp, struct task_struct *tsk)
+{
+       /* We don't support RT-tasks being in separate groups */
+       if (tsk->sched_class != &fair_sched_class)
+               return -EINVAL;
+
+       return 0;
+}
+
+static void
+cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
+                       struct cgroup *old_cont, struct task_struct *tsk)
+{
+       sched_move_task(tsk);
+}
+
+static int cpu_shares_write_uint(struct cgroup *cgrp, struct cftype *cftype,
+                               u64 shareval)
+{
+       return sched_group_set_shares(cgroup_tg(cgrp), shareval);
+}
+
+static u64 cpu_shares_read_uint(struct cgroup *cgrp, struct cftype *cft)
+{
+       struct task_group *tg = cgroup_tg(cgrp);
+
+       return (u64) tg->shares;
+}
+
+static u64 cpu_usage_read(struct cgroup *cgrp, struct cftype *cft)
+{
+       struct task_group *tg = cgroup_tg(cgrp);
+       unsigned long flags;
+       u64 res = 0;
+       int i;
+
+       for_each_possible_cpu(i) {
+               /*
+                * Lock to prevent races with updating 64-bit counters
+                * on 32-bit arches.
+                */
+               spin_lock_irqsave(&cpu_rq(i)->lock, flags);
+               res += tg->se[i]->sum_exec_runtime;
+               spin_unlock_irqrestore(&cpu_rq(i)->lock, flags);
+       }
+       /* Convert from ns to ms */
+       do_div(res, 1000000);
+
+       return res;
+}
+
+static struct cftype cpu_files[] = {
+       {
+               .name = "shares",
+               .read_uint = cpu_shares_read_uint,
+               .write_uint = cpu_shares_write_uint,
+       },
+       {
+               .name = "usage",
+               .read_uint = cpu_usage_read,
+       },
+};
+
+static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont)
+{
+       return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files));
+}
+
+struct cgroup_subsys cpu_cgroup_subsys = {
+       .name           = "cpu",
+       .create         = cpu_cgroup_create,
+       .destroy        = cpu_cgroup_destroy,
+       .can_attach     = cpu_cgroup_can_attach,
+       .attach         = cpu_cgroup_attach,
+       .populate       = cpu_cgroup_populate,
+       .subsys_id      = cpu_cgroup_subsys_id,
+       .early_init     = 1,
+};
+
+#endif /* CONFIG_FAIR_CGROUP_SCHED */