vserver 1.9.3
[linux-2.6.git] / kernel / sched.c
index 305f948..f1780c9 100644 (file)
@@ -31,6 +31,7 @@
 #include <linux/kernel_stat.h>
 #include <linux/security.h>
 #include <linux/notifier.h>
+#include <linux/profile.h>
 #include <linux/suspend.h>
 #include <linux/blkdev.h>
 #include <linux/delay.h>
 #include <linux/cpu.h>
 #include <linux/percpu.h>
 #include <linux/kthread.h>
+#include <linux/seq_file.h>
+#include <linux/times.h>
 #include <linux/vserver/sched.h>
 #include <linux/vs_base.h>
+#include <linux/vs_context.h>
+#include <linux/vs_cvirt.h>
 #include <asm/tlb.h>
 
 #include <asm/unistd.h>
@@ -69,8 +74,6 @@
 #define USER_PRIO(p)           ((p)-MAX_RT_PRIO)
 #define TASK_USER_PRIO(p)      USER_PRIO((p)->static_prio)
 #define MAX_USER_PRIO          (USER_PRIO(MAX_PRIO))
-#define AVG_TIMESLICE  (MIN_TIMESLICE + ((MAX_TIMESLICE - MIN_TIMESLICE) *\
-                       (MAX_PRIO-1-NICE_TO_PRIO(0))/(MAX_USER_PRIO - 1)))
 
 /*
  * Some helpers for converting nanosecond timing to jiffy resolution
 /*
  * These are the 'tuning knobs' of the scheduler:
  *
- * Minimum timeslice is 10 msecs, default timeslice is 100 msecs,
- * maximum timeslice is 200 msecs. Timeslices get refilled after
- * they expire.
+ * Minimum timeslice is 5 msecs (or 1 jiffy, whichever is larger),
+ * default timeslice is 100 msecs, maximum timeslice is 800 msecs.
+ * Timeslices get refilled after they expire.
  */
-#define MIN_TIMESLICE          ( 10 * HZ / 1000)
-#define MAX_TIMESLICE          (200 * HZ / 1000)
+#define MIN_TIMESLICE          max(5 * HZ / 1000, 1)
+#define DEF_TIMESLICE          (100 * HZ / 1000)
 #define ON_RUNQUEUE_WEIGHT      30
 #define CHILD_PENALTY           95
 #define PARENT_PENALTY         100
@@ -94,7 +97,7 @@
 #define PRIO_BONUS_RATIO        25
 #define MAX_BONUS              (MAX_USER_PRIO * PRIO_BONUS_RATIO / 100)
 #define INTERACTIVE_DELTA        2
-#define MAX_SLEEP_AVG          (AVG_TIMESLICE * MAX_BONUS)
+#define MAX_SLEEP_AVG          (DEF_TIMESLICE * MAX_BONUS)
 #define STARVATION_LIMIT       (MAX_SLEEP_AVG)
 #define NS_MAX_SLEEP_AVG       (JIFFIES_TO_NS(MAX_SLEEP_AVG))
 #define CREDIT_LIMIT           100
        ((p)->prio < (rq)->curr->prio)
 
 /*
- * BASE_TIMESLICE scales user-nice values [ -20 ... 19 ]
- * to time slice values.
+ * task_timeslice() scales user-nice values [ -20 ... 0 ... 19 ]
+ * to time slice values: [800ms ... 100ms ... 5ms]
  *
  * The higher a thread's priority, the bigger timeslices
  * it gets during one round of execution. But even the lowest
  * priority thread gets MIN_TIMESLICE worth of execution time.
- *
- * task_timeslice() is the interface that is used by the scheduler.
  */
 
-#define BASE_TIMESLICE(p) (MIN_TIMESLICE + \
-               ((MAX_TIMESLICE - MIN_TIMESLICE) * \
-                       (MAX_PRIO-1 - (p)->static_prio) / (MAX_USER_PRIO-1)))
+#define SCALE_PRIO(x, prio) \
+       max(x * (MAX_PRIO - prio) / (MAX_USER_PRIO/2), MIN_TIMESLICE)
 
 static unsigned int task_timeslice(task_t *p)
 {
-       return BASE_TIMESLICE(p);
+       if (p->static_prio < NICE_TO_PRIO(0))
+               return SCALE_PRIO(DEF_TIMESLICE*4, p->static_prio);
+       else
+               return SCALE_PRIO(DEF_TIMESLICE, p->static_prio);
 }
+#define task_hot(p, now, sd) ((long long) ((now) - (p)->last_ran)      \
+                               < (long long) (sd)->cache_hot_time)
+
+enum idle_type
+{
+       IDLE,
+       NOT_IDLE,
+       NEWLY_IDLE,
+       MAX_IDLE_TYPES
+};
 
-#define task_hot(p, now, sd) ((now) - (p)->timestamp < (sd)->cache_hot_time)
+struct sched_domain;
 
 /*
  * These are the runqueue data structures:
@@ -235,12 +248,190 @@ struct runqueue {
        task_t *migration_thread;
        struct list_head migration_queue;
 #endif
+#ifdef CONFIG_VSERVER_HARDCPU
        struct list_head hold_queue;
        int idle_tokens;
+#endif
+
+#ifdef CONFIG_SCHEDSTATS
+       /* latency stats */
+       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_cnt;
+
+       /* schedule() stats */
+       unsigned long sched_noswitch;
+       unsigned long sched_switch;
+       unsigned long sched_cnt;
+       unsigned long sched_goidle;
+
+       /* pull_task() stats */
+       unsigned long pt_gained[MAX_IDLE_TYPES];
+       unsigned long pt_lost[MAX_IDLE_TYPES];
+
+       /* active_load_balance() stats */
+       unsigned long alb_cnt;
+       unsigned long alb_lost;
+       unsigned long alb_gained;
+       unsigned long alb_failed;
+
+       /* try_to_wake_up() stats */
+       unsigned long ttwu_cnt;
+       unsigned long ttwu_attempts;
+       unsigned long ttwu_moved;
+
+       /* wake_up_new_task() stats */
+       unsigned long wunt_cnt;
+       unsigned long wunt_moved;
+
+       /* sched_migrate_task() stats */
+       unsigned long smt_cnt;
+
+       /* sched_balance_exec() stats */
+       unsigned long sbe_cnt;
+#endif
 };
 
 static DEFINE_PER_CPU(struct runqueue, runqueues);
 
+/*
+ * sched-domains (multiprocessor balancing) declarations:
+ */
+#ifdef CONFIG_SMP
+#define SCHED_LOAD_SCALE       128UL   /* increase resolution of load */
+
+#define SD_BALANCE_NEWIDLE     1       /* Balance when about to become idle */
+#define SD_BALANCE_EXEC                2       /* Balance on exec */
+#define SD_WAKE_IDLE           4       /* Wake to idle CPU on task wakeup */
+#define SD_WAKE_AFFINE         8       /* Wake task to waking CPU */
+#define SD_WAKE_BALANCE                16      /* Perform balancing at task wakeup */
+#define SD_SHARE_CPUPOWER      32      /* Domain members share cpu power */
+
+struct sched_group {
+       struct sched_group *next;       /* Must be a circular list */
+       cpumask_t cpumask;
+
+       /*
+        * CPU power of this group, SCHED_LOAD_SCALE being max power for a
+        * single CPU. This should be read only (except for setup). Although
+        * it will need to be written to at cpu hot(un)plug time, perhaps the
+        * cpucontrol semaphore will provide enough exclusion?
+        */
+       unsigned long cpu_power;
+};
+
+struct sched_domain {
+       /* These fields must be setup */
+       struct sched_domain *parent;    /* top domain must be null terminated */
+       struct sched_group *groups;     /* the balancing groups of the domain */
+       cpumask_t span;                 /* span of all CPUs in this domain */
+       unsigned long min_interval;     /* Minimum balance interval ms */
+       unsigned long max_interval;     /* Maximum balance interval ms */
+       unsigned int busy_factor;       /* less balancing by factor if busy */
+       unsigned int imbalance_pct;     /* No balance until over watermark */
+       unsigned long long cache_hot_time; /* Task considered cache hot (ns) */
+       unsigned int cache_nice_tries;  /* Leave cache hot tasks for # tries */
+       unsigned int per_cpu_gain;      /* CPU % gained by adding domain cpus */
+       int flags;                      /* See SD_* */
+
+       /* Runtime fields. */
+       unsigned long last_balance;     /* init to jiffies. units in jiffies */
+       unsigned int balance_interval;  /* initialise to 1. units in ms. */
+       unsigned int nr_balance_failed; /* initialise to 0 */
+
+#ifdef CONFIG_SCHEDSTATS
+       /* load_balance() stats */
+       unsigned long lb_cnt[MAX_IDLE_TYPES];
+       unsigned long lb_failed[MAX_IDLE_TYPES];
+       unsigned long lb_imbalance[MAX_IDLE_TYPES];
+       unsigned long lb_nobusyg[MAX_IDLE_TYPES];
+       unsigned long lb_nobusyq[MAX_IDLE_TYPES];
+
+       /* sched_balance_exec() stats */
+       unsigned long sbe_attempts;
+       unsigned long sbe_pushed;
+
+       /* try_to_wake_up() stats */
+       unsigned long ttwu_wake_affine;
+       unsigned long ttwu_wake_balance;
+#endif
+};
+
+#ifndef ARCH_HAS_SCHED_TUNE
+#ifdef CONFIG_SCHED_SMT
+#define ARCH_HAS_SCHED_WAKE_IDLE
+/* Common values for SMT siblings */
+#define SD_SIBLING_INIT (struct sched_domain) {                \
+       .span                   = CPU_MASK_NONE,        \
+       .parent                 = NULL,                 \
+       .groups                 = NULL,                 \
+       .min_interval           = 1,                    \
+       .max_interval           = 2,                    \
+       .busy_factor            = 8,                    \
+       .imbalance_pct          = 110,                  \
+       .cache_hot_time         = 0,                    \
+       .cache_nice_tries       = 0,                    \
+       .per_cpu_gain           = 25,                   \
+       .flags                  = SD_BALANCE_NEWIDLE    \
+                               | SD_BALANCE_EXEC       \
+                               | SD_WAKE_AFFINE        \
+                               | SD_WAKE_IDLE          \
+                               | SD_SHARE_CPUPOWER,    \
+       .last_balance           = jiffies,              \
+       .balance_interval       = 1,                    \
+       .nr_balance_failed      = 0,                    \
+}
+#endif
+
+/* Common values for CPUs */
+#define SD_CPU_INIT (struct sched_domain) {            \
+       .span                   = CPU_MASK_NONE,        \
+       .parent                 = NULL,                 \
+       .groups                 = NULL,                 \
+       .min_interval           = 1,                    \
+       .max_interval           = 4,                    \
+       .busy_factor            = 64,                   \
+       .imbalance_pct          = 125,                  \
+       .cache_hot_time         = cache_decay_ticks*1000000 ? : (5*1000000/2),\
+       .cache_nice_tries       = 1,                    \
+       .per_cpu_gain           = 100,                  \
+       .flags                  = SD_BALANCE_NEWIDLE    \
+                               | SD_BALANCE_EXEC       \
+                               | SD_WAKE_AFFINE        \
+                               | SD_WAKE_BALANCE,      \
+       .last_balance           = jiffies,              \
+       .balance_interval       = 1,                    \
+       .nr_balance_failed      = 0,                    \
+}
+
+/* Arch can override this macro in processor.h */
+#if defined(CONFIG_NUMA) && !defined(SD_NODE_INIT)
+#define SD_NODE_INIT (struct sched_domain) {           \
+       .span                   = CPU_MASK_NONE,        \
+       .parent                 = NULL,                 \
+       .groups                 = NULL,                 \
+       .min_interval           = 8,                    \
+       .max_interval           = 32,                   \
+       .busy_factor            = 32,                   \
+       .imbalance_pct          = 125,                  \
+       .cache_hot_time         = (10*1000000),         \
+       .cache_nice_tries       = 1,                    \
+       .per_cpu_gain           = 100,                  \
+       .flags                  = SD_BALANCE_EXEC       \
+                               | SD_WAKE_BALANCE,      \
+       .last_balance           = jiffies,              \
+       .balance_interval       = 1,                    \
+       .nr_balance_failed      = 0,                    \
+}
+#endif
+#endif /* ARCH_HAS_SCHED_TUNE */
+#endif
+
+
 #define for_each_domain(cpu, domain) \
        for (domain = cpu_rq(cpu)->sd; domain; domain = domain->parent)
 
@@ -283,6 +474,104 @@ static inline void task_rq_unlock(runqueue_t *rq, unsigned long *flags)
        spin_unlock_irqrestore(&rq->lock, *flags);
 }
 
+#ifdef CONFIG_SCHEDSTATS
+/*
+ * bump this up when changing the output format or the meaning of an existing
+ * format, so that tools can adapt (or abort)
+ */
+#define SCHEDSTAT_VERSION 10
+
+static int show_schedstat(struct seq_file *seq, void *v)
+{
+       int cpu;
+       enum idle_type itype;
+
+       seq_printf(seq, "version %d\n", SCHEDSTAT_VERSION);
+       seq_printf(seq, "timestamp %lu\n", jiffies);
+       for_each_online_cpu(cpu) {
+               runqueue_t *rq = cpu_rq(cpu);
+#ifdef CONFIG_SMP
+               struct sched_domain *sd;
+               int dcnt = 0;
+#endif
+
+               /* runqueue-specific stats */
+               seq_printf(seq,
+                   "cpu%d %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu "
+                   "%lu %lu %lu %lu %lu %lu %lu %lu %lu %lu",
+                   cpu, rq->yld_both_empty,
+                   rq->yld_act_empty, rq->yld_exp_empty,
+                   rq->yld_cnt, rq->sched_noswitch,
+                   rq->sched_switch, rq->sched_cnt, rq->sched_goidle,
+                   rq->alb_cnt, rq->alb_gained, rq->alb_lost,
+                   rq->alb_failed,
+                   rq->ttwu_cnt, rq->ttwu_moved, rq->ttwu_attempts,
+                   rq->wunt_cnt, rq->wunt_moved,
+                   rq->smt_cnt, rq->sbe_cnt, rq->rq_sched_info.cpu_time,
+                   rq->rq_sched_info.run_delay, rq->rq_sched_info.pcnt);
+
+               for (itype = IDLE; itype < MAX_IDLE_TYPES; itype++)
+                       seq_printf(seq, " %lu %lu", rq->pt_gained[itype],
+                                                   rq->pt_lost[itype]);
+               seq_printf(seq, "\n");
+
+#ifdef CONFIG_SMP
+               /* domain-specific stats */
+               for_each_domain(cpu, sd) {
+                       char mask_str[NR_CPUS];
+
+                       cpumask_scnprintf(mask_str, NR_CPUS, sd->span);
+                       seq_printf(seq, "domain%d %s", dcnt++, mask_str);
+                       for (itype = IDLE; itype < MAX_IDLE_TYPES; itype++) {
+                               seq_printf(seq, " %lu %lu %lu %lu %lu",
+                                   sd->lb_cnt[itype],
+                                   sd->lb_failed[itype],
+                                   sd->lb_imbalance[itype],
+                                   sd->lb_nobusyq[itype],
+                                   sd->lb_nobusyg[itype]);
+                       }
+                       seq_printf(seq, " %lu %lu %lu %lu\n",
+                           sd->sbe_pushed, sd->sbe_attempts,
+                           sd->ttwu_wake_affine, sd->ttwu_wake_balance);
+               }
+#endif
+       }
+       return 0;
+}
+
+static int schedstat_open(struct inode *inode, struct file *file)
+{
+       unsigned int size = PAGE_SIZE * (1 + num_online_cpus() / 32);
+       char *buf = kmalloc(size, GFP_KERNEL);
+       struct seq_file *m;
+       int res;
+
+       if (!buf)
+               return -ENOMEM;
+       res = single_open(file, show_schedstat, NULL);
+       if (!res) {
+               m = file->private_data;
+               m->buf = buf;
+               m->size = size;
+       } else
+               kfree(buf);
+       return res;
+}
+
+struct file_operations proc_schedstat_operations = {
+       .open    = schedstat_open,
+       .read    = seq_read,
+       .llseek  = seq_lseek,
+       .release = single_release,
+};
+
+# define schedstat_inc(rq, field)      rq->field++;
+# define schedstat_add(rq, field, amt) rq->field += amt;
+#else /* !CONFIG_SCHEDSTATS */
+# define schedstat_inc(rq, field)      do { } while (0);
+# define schedstat_add(rq, field, amt) do { } while (0);
+#endif
+
 /*
  * rq_lock - lock a given runqueue and disable interrupts.
  */
@@ -302,6 +591,112 @@ static inline void rq_unlock(runqueue_t *rq)
        spin_unlock_irq(&rq->lock);
 }
 
+#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
+ * tasks, the expired queue will become the active queue after the active
+ * queue is empty, without explicitly dequeuing and requeuing tasks in the
+ * expired queue.  (Interactive tasks may be requeued directly to the
+ * active queue, thus delaying tasks in the expired queue from running;
+ * see scheduler_tick()).
+ *
+ * This function is only called from sched_info_arrive(), rather than
+ * dequeue_task(). Even though a task may be queued and dequeued multiple
+ * times as it is shuffled about, we're really interested in knowing how
+ * long it was from the *first* time it was queued to the time that it
+ * finally hit a cpu.
+ */
+static inline void sched_info_dequeued(task_t *t)
+{
+       t->sched_info.last_queued = 0;
+}
+
+/*
+ * Called when a task finally hits the cpu.  We can now calculate how
+ * long it was waiting to run.  We also note when it began so that we
+ * can keep stats on how long its timeslice is.
+ */
+static inline void sched_info_arrive(task_t *t)
+{
+       unsigned long now = jiffies, diff = 0;
+       struct runqueue *rq = task_rq(t);
+
+       if (t->sched_info.last_queued)
+               diff = now - t->sched_info.last_queued;
+       sched_info_dequeued(t);
+       t->sched_info.run_delay += diff;
+       t->sched_info.last_arrival = now;
+       t->sched_info.pcnt++;
+
+       if (!rq)
+               return;
+
+       rq->rq_sched_info.run_delay += diff;
+       rq->rq_sched_info.pcnt++;
+}
+
+/*
+ * Called when a process is queued into either the active or expired
+ * array.  The time is noted and later used to determine how long we
+ * had to wait for us to reach the cpu.  Since the expired queue will
+ * become the active queue after active queue is empty, without dequeuing
+ * and requeuing any tasks, we are interested in queuing to either. It
+ * is unusual but not impossible for tasks to be dequeued and immediately
+ * requeued in the same or another array: this can happen in sched_yield(),
+ * set_user_nice(), and even load_balance() as it moves tasks from runqueue
+ * to runqueue.
+ *
+ * This function is only called from enqueue_task(), but also only updates
+ * the timestamp if it is already not set.  It's assumed that
+ * sched_info_dequeued() will clear that stamp when appropriate.
+ */
+static inline void sched_info_queued(task_t *t)
+{
+       if (!t->sched_info.last_queued)
+               t->sched_info.last_queued = jiffies;
+}
+
+/*
+ * Called when a process ceases being the active-running process, either
+ * voluntarily or involuntarily.  Now we can calculate how long we ran.
+ */
+static inline void sched_info_depart(task_t *t)
+{
+       struct runqueue *rq = task_rq(t);
+       unsigned long diff = jiffies - t->sched_info.last_arrival;
+
+       t->sched_info.cpu_time += diff;
+
+       if (rq)
+               rq->rq_sched_info.cpu_time += diff;
+}
+
+/*
+ * Called when tasks are switched involuntarily due, typically, to expiring
+ * their time slice.  (This may also be called when switching to or from
+ * the idle task.)  We are only called when prev != next.
+ */
+static inline void sched_info_switch(task_t *prev, task_t *next)
+{
+       struct runqueue *rq = task_rq(prev);
+
+       /*
+        * prev now departs the cpu.  It's not interesting to record
+        * stats about how efficient we were at scheduling the idle
+        * process, however.
+        */
+       if (prev != rq->idle)
+               sched_info_depart(prev);
+
+       if (next != rq->idle)
+               sched_info_arrive(next);
+}
+#else
+#define sched_info_queued(t)           do { } while (0)
+#define sched_info_switch(t, next)     do { } while (0)
+#endif /* CONFIG_SCHEDSTATS */
+
 /*
  * Adding/removing a task to/from a priority array:
  */
@@ -315,6 +710,7 @@ static void dequeue_task(struct task_struct *p, prio_array_t *array)
 
 static void enqueue_task(struct task_struct *p, prio_array_t *array)
 {
+       sched_info_queued(p);
        list_add_tail(&p->run_list, array->queue + p->prio);
        __set_bit(p->prio, array->bitmap);
        array->nr_active++;
@@ -358,7 +754,7 @@ static int effective_prio(task_t *p)
        bonus = CURRENT_BONUS(p) - MAX_BONUS / 2;
 
        prio = p->static_prio - bonus;
-       if (__vx_task_flags(p, VXF_SCHED_PRIO, 0))
+       if (task_vx_flags(p, VXF_SCHED_PRIO, 0))
                prio += effective_vavavoom(p, MAX_USER_PRIO);
 
        if (prio < MAX_RT_PRIO)
@@ -406,7 +802,7 @@ static void recalc_task_prio(task_t *p, unsigned long long now)
                if (p->mm && p->activated != -1 &&
                        sleep_time > INTERACTIVE_SLEEP(p)) {
                                p->sleep_avg = JIFFIES_TO_NS(MAX_SLEEP_AVG -
-                                               AVG_TIMESLICE);
+                                               DEF_TIMESLICE);
                                if (!HIGH_CREDIT(p))
                                        p->interactive_credit++;
                } else {
@@ -506,21 +902,29 @@ static void activate_task(task_t *p, runqueue_t *rq, int local)
        }
        p->timestamp = now;
 
+       vx_activate_task(p);
        __activate_task(p, rq);
 }
 
 /*
  * deactivate_task - remove a task from the runqueue.
  */
-static void deactivate_task(struct task_struct *p, runqueue_t *rq)
+static void __deactivate_task(struct task_struct *p, runqueue_t *rq)
 {
        rq->nr_running--;
        if (p->state == TASK_UNINTERRUPTIBLE)
                rq->nr_uninterruptible++;
        dequeue_task(p, p->array);
+
        p->array = NULL;
 }
 
+static void deactivate_task(struct task_struct *p, runqueue_t *rq)
+{
+       __deactivate_task(p, rq);
+       vx_deactivate_task(p);
+}
+
 /*
  * resched_task - mark a task 'to be rescheduled now'.
  *
@@ -533,7 +937,8 @@ static void resched_task(task_t *p)
 {
        int need_resched, nrpolling;
 
-       preempt_disable();
+       BUG_ON(!spin_is_locked(&task_rq(p)->lock));
+
        /* minimise the chance of sending an interrupt to poll_idle() */
        nrpolling = test_tsk_thread_flag(p,TIF_POLLING_NRFLAG);
        need_resched = test_and_set_tsk_thread_flag(p,TIF_NEED_RESCHED);
@@ -541,7 +946,6 @@ static void resched_task(task_t *p)
 
        if (!need_resched && !nrpolling && (task_cpu(p) != smp_processor_id()))
                smp_send_reschedule(task_cpu(p));
-       preempt_enable();
 }
 #else
 static inline void resched_task(task_t *p)
@@ -747,6 +1151,7 @@ static int try_to_wake_up(task_t * p, unsigned int state, int sync)
 #endif
 
        rq = task_rq_lock(p, &flags);
+       schedstat_inc(rq, ttwu_cnt);
        old_state = p->state;
        if (!(old_state & state))
                goto out;
@@ -794,23 +1199,35 @@ static int try_to_wake_up(task_t * p, unsigned int state, int sync)
                 */
                imbalance = sd->imbalance_pct + (sd->imbalance_pct - 100) / 2;
 
-               if ( ((sd->flags & SD_WAKE_AFFINE) &&
-                               !task_hot(p, rq->timestamp_last_tick, sd))
-                       || ((sd->flags & SD_WAKE_BALANCE) &&
-                               imbalance*this_load <= 100*load) ) {
+               if ((sd->flags & SD_WAKE_AFFINE) &&
+                               !task_hot(p, rq->timestamp_last_tick, sd)) {
+                       /*
+                        * This domain has SD_WAKE_AFFINE and p is cache cold
+                        * in this domain.
+                        */
+                       if (cpu_isset(cpu, sd->span)) {
+                               schedstat_inc(sd, ttwu_wake_affine);
+                               goto out_set_cpu;
+                       }
+               } else if ((sd->flags & SD_WAKE_BALANCE) &&
+                               imbalance*this_load <= 100*load) {
                        /*
-                        * Now sd has SD_WAKE_AFFINE and p is cache cold in sd
-                        * or sd has SD_WAKE_BALANCE and there is an imbalance
+                        * This domain has SD_WAKE_BALANCE and there is
+                        * an imbalance.
                         */
-                       if (cpu_isset(cpu, sd->span))
+                       if (cpu_isset(cpu, sd->span)) {
+                               schedstat_inc(sd, ttwu_wake_balance);
                                goto out_set_cpu;
+                       }
                }
        }
 
        new_cpu = cpu; /* Could not wake to this_cpu. Wake to cpu instead */
 out_set_cpu:
+       schedstat_inc(rq, ttwu_attempts);
        new_cpu = wake_idle(new_cpu, p);
        if (new_cpu != cpu && cpu_isset(new_cpu, p->cpus_allowed)) {
+               schedstat_inc(rq, ttwu_moved);
                set_task_cpu(p, new_cpu);
                task_rq_unlock(rq, &flags);
                /* might preempt at this point */
@@ -861,7 +1278,7 @@ out:
 
 int fastcall wake_up_process(task_t * p)
 {
-       return try_to_wake_up(p, TASK_STOPPED |
+       return try_to_wake_up(p, TASK_STOPPED | TASK_TRACED |
                                 TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE, 0);
 }
 
@@ -872,6 +1289,11 @@ int fastcall wake_up_state(task_t *p, unsigned int state)
        return try_to_wake_up(p, state, 0);
 }
 
+#ifdef CONFIG_SMP
+static int find_idlest_cpu(struct task_struct *p, int this_cpu,
+                          struct sched_domain *sd);
+#endif
+
 /*
  * Perform scheduler related setup for a newly forked process p.
  * p is forked by current.
@@ -888,6 +1310,9 @@ void fastcall sched_fork(task_t *p)
        INIT_LIST_HEAD(&p->run_list);
        p->array = NULL;
        spin_lock_init(&p->switch_lock);
+#ifdef CONFIG_SCHEDSTATS
+       memset(&p->sched_info, 0, sizeof(p->sched_info));
+#endif
 #ifdef CONFIG_PREEMPT
        /*
         * During context-switch we hold precisely one spinlock, which
@@ -911,7 +1336,7 @@ void fastcall sched_fork(task_t *p)
        p->first_time_slice = 1;
        current->time_slice >>= 1;
        p->timestamp = sched_clock();
-       if (!current->time_slice) {
+       if (unlikely(!current->time_slice)) {
                /*
                 * This case is rare, it happens when the parent has only
                 * a single jiffy left from its timeslice. Taking the
@@ -927,44 +1352,90 @@ void fastcall sched_fork(task_t *p)
 }
 
 /*
- * wake_up_forked_process - wake up a freshly forked process.
+ * wake_up_new_task - wake up a newly created task for the first time.
  *
  * This function will do some initial scheduler statistics housekeeping
- * that must be done for every newly created process.
+ * that must be done for every newly created context, then puts the task
+ * on the runqueue and wakes it.
  */
-void fastcall wake_up_forked_process(task_t * p)
+void fastcall wake_up_new_task(task_t * p, unsigned long clone_flags)
 {
        unsigned long flags;
-       runqueue_t *rq = task_rq_lock(current, &flags);
+       int this_cpu, cpu;
+       runqueue_t *rq, *this_rq;
+
+       rq = task_rq_lock(p, &flags);
+       cpu = task_cpu(p);
+       this_cpu = smp_processor_id();
 
        BUG_ON(p->state != TASK_RUNNING);
 
+       schedstat_inc(rq, wunt_cnt);
        /*
         * We decrease the sleep average of forking parents
         * and children as well, to keep max-interactive tasks
-        * from forking tasks that are max-interactive.
+        * from forking tasks that are max-interactive. The parent
+        * (current) is done further down, under its lock.
         */
-       current->sleep_avg = JIFFIES_TO_NS(CURRENT_BONUS(current) *
-               PARENT_PENALTY / 100 * MAX_SLEEP_AVG / MAX_BONUS);
-
        p->sleep_avg = JIFFIES_TO_NS(CURRENT_BONUS(p) *
                CHILD_PENALTY / 100 * MAX_SLEEP_AVG / MAX_BONUS);
 
        p->interactive_credit = 0;
 
        p->prio = effective_prio(p);
-       set_task_cpu(p, smp_processor_id());
 
-       if (unlikely(!current->array))
+       vx_activate_task(p);
+       if (likely(cpu == this_cpu)) {
+               if (!(clone_flags & CLONE_VM)) {
+                       /*
+                        * The VM isn't cloned, so we're in a good position to
+                        * do child-runs-first in anticipation of an exec. This
+                        * usually avoids a lot of COW overhead.
+                        */
+                       if (unlikely(!current->array))
+                               __activate_task(p, rq);
+                       else {
+                               p->prio = current->prio;
+                               list_add_tail(&p->run_list, &current->run_list);
+                               p->array = current->array;
+                               p->array->nr_active++;
+                               rq->nr_running++;
+                       }
+                       set_need_resched();
+               } else
+                       /* Run child last */
+                       __activate_task(p, rq);
+               /*
+                * We skip the following code due to cpu == this_cpu
+                *
+                *   task_rq_unlock(rq, &flags);
+                *   this_rq = task_rq_lock(current, &flags);
+                */
+               this_rq = rq;
+       } else {
+               this_rq = cpu_rq(this_cpu);
+
+               /*
+                * Not the local CPU - must adjust timestamp. This should
+                * get optimised away in the !CONFIG_SMP case.
+                */
+               p->timestamp = (p->timestamp - this_rq->timestamp_last_tick)
+                                       + rq->timestamp_last_tick;
                __activate_task(p, rq);
-       else {
-               p->prio = current->prio;
-               list_add_tail(&p->run_list, &current->run_list);
-               p->array = current->array;
-               p->array->nr_active++;
-               rq->nr_running++;
+               if (TASK_PREEMPTS_CURR(p, rq))
+                       resched_task(rq->curr);
+
+               schedstat_inc(rq, wunt_moved);
+               /*
+                * Parent and child are on different CPUs, now get the
+                * parent runqueue to update the parent's ->sleep_avg:
+                */
+               task_rq_unlock(rq, &flags);
+               this_rq = task_rq_lock(current, &flags);
        }
-       task_rq_unlock(rq, &flags);
+       current->sleep_avg = JIFFIES_TO_NS(CURRENT_BONUS(current) *
+               PARENT_PENALTY / 100 * MAX_SLEEP_AVG / MAX_BONUS);
+       task_rq_unlock(this_rq, &flags);
 }
 
 /*
@@ -981,18 +1452,16 @@ void fastcall sched_exit(task_t * p)
        unsigned long flags;
        runqueue_t *rq;
 
-       local_irq_save(flags);
-       if (p->first_time_slice) {
-               p->parent->time_slice += p->time_slice;
-               if (unlikely(p->parent->time_slice > MAX_TIMESLICE))
-                       p->parent->time_slice = MAX_TIMESLICE;
-       }
-       local_irq_restore(flags);
        /*
         * If the child was a (relative-) CPU hog then decrease
         * the sleep_avg of the parent as well.
         */
        rq = task_rq_lock(p->parent, &flags);
+       if (p->first_time_slice) {
+               p->parent->time_slice += p->time_slice;
+               if (unlikely(p->parent->time_slice > task_timeslice(p)))
+                       p->parent->time_slice = task_timeslice(p);
+       }
        if (p->sleep_avg < p->parent->sleep_avg)
                p->parent->sleep_avg = p->parent->sleep_avg /
                (EXIT_WEIGHT + 1) * EXIT_WEIGHT + p->sleep_avg /
@@ -1092,7 +1561,7 @@ unsigned long nr_running(void)
 {
        unsigned long i, sum = 0;
 
-       for_each_cpu(i)
+       for_each_online_cpu(i)
                sum += cpu_rq(i)->nr_running;
 
        return sum;
@@ -1128,6 +1597,8 @@ unsigned long nr_iowait(void)
        return sum;
 }
 
+#ifdef CONFIG_SMP
+
 /*
  * double_rq_lock - safely lock two runqueues
  *
@@ -1162,14 +1633,20 @@ static void double_rq_unlock(runqueue_t *rq1, runqueue_t *rq2)
                spin_unlock(&rq2->lock);
 }
 
-enum idle_type
+/*
+ * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
+ */
+static void double_lock_balance(runqueue_t *this_rq, runqueue_t *busiest)
 {
-       IDLE,
-       NOT_IDLE,
-       NEWLY_IDLE,
-};
-
-#ifdef CONFIG_SMP
+       if (unlikely(!spin_trylock(&busiest->lock))) {
+               if (busiest < this_rq) {
+                       spin_unlock(&this_rq->lock);
+                       spin_lock(&busiest->lock);
+                       spin_lock(&this_rq->lock);
+               } else
+                       spin_lock(&busiest->lock);
+       }
+}
 
 /*
  * find_idlest_cpu - find the least busy runqueue.
@@ -1217,89 +1694,6 @@ static int find_idlest_cpu(struct task_struct *p, int this_cpu,
        return this_cpu;
 }
 
-/*
- * wake_up_forked_thread - wake up a freshly forked thread.
- *
- * This function will do some initial scheduler statistics housekeeping
- * that must be done for every newly created context, and it also does
- * runqueue balancing.
- */
-void fastcall wake_up_forked_thread(task_t * p)
-{
-       unsigned long flags;
-       int this_cpu = get_cpu(), cpu;
-       struct sched_domain *tmp, *sd = NULL;
-       runqueue_t *this_rq = cpu_rq(this_cpu), *rq;
-
-       /*
-        * Find the largest domain that this CPU is part of that
-        * is willing to balance on clone:
-        */
-       for_each_domain(this_cpu, tmp)
-               if (tmp->flags & SD_BALANCE_CLONE)
-                       sd = tmp;
-       if (sd)
-               cpu = find_idlest_cpu(p, this_cpu, sd);
-       else
-               cpu = this_cpu;
-
-       local_irq_save(flags);
-lock_again:
-       rq = cpu_rq(cpu);
-       double_rq_lock(this_rq, rq);
-
-       BUG_ON(p->state != TASK_RUNNING);
-
-       /*
-        * We did find_idlest_cpu() unlocked, so in theory
-        * the mask could have changed - just dont migrate
-        * in this case:
-        */
-       if (unlikely(!cpu_isset(cpu, p->cpus_allowed))) {
-               cpu = this_cpu;
-               double_rq_unlock(this_rq, rq);
-               goto lock_again;
-       }
-       /*
-        * We decrease the sleep average of forking parents
-        * and children as well, to keep max-interactive tasks
-        * from forking tasks that are max-interactive.
-        */
-       current->sleep_avg = JIFFIES_TO_NS(CURRENT_BONUS(current) *
-               PARENT_PENALTY / 100 * MAX_SLEEP_AVG / MAX_BONUS);
-
-       p->sleep_avg = JIFFIES_TO_NS(CURRENT_BONUS(p) *
-               CHILD_PENALTY / 100 * MAX_SLEEP_AVG / MAX_BONUS);
-
-       p->interactive_credit = 0;
-
-       p->prio = effective_prio(p);
-       set_task_cpu(p, cpu);
-
-       if (cpu == this_cpu) {
-               if (unlikely(!current->array))
-                       __activate_task(p, rq);
-               else {
-                       p->prio = current->prio;
-                       list_add_tail(&p->run_list, &current->run_list);
-                       p->array = current->array;
-                       p->array->nr_active++;
-                       rq->nr_running++;
-               }
-       } else {
-               /* Not the local CPU - must adjust timestamp */
-               p->timestamp = (p->timestamp - this_rq->timestamp_last_tick)
-                                       + rq->timestamp_last_tick;
-               __activate_task(p, rq);
-               if (TASK_PREEMPTS_CURR(p, rq))
-                       resched_task(rq->curr);
-       }
-
-       double_rq_unlock(this_rq, rq);
-       local_irq_restore(flags);
-       put_cpu();
-}
-
 /*
  * If dest_cpu is allowed for this process, migrate the task to it.
  * This is accomplished by forcing the cpu_allowed mask to only
@@ -1317,6 +1711,7 @@ static void sched_migrate_task(task_t *p, int dest_cpu)
            || unlikely(cpu_is_offline(dest_cpu)))
                goto out;
 
+       schedstat_inc(rq, smt_cnt);
        /* force the process onto the specified CPU */
        if (migrate_task(p, dest_cpu, &req)) {
                /* Need to wait for migration thread (might exit: take ref). */
@@ -1333,17 +1728,18 @@ out:
 }
 
 /*
- * sched_balance_exec(): find the highest-level, exec-balance-capable
+ * sched_exec(): find the highest-level, exec-balance-capable
  * domain and try to migrate the task to the least loaded CPU.
  *
  * execve() is a valuable balancing opportunity, because at this point
  * the task has the smallest effective memory and cache footprint.
  */
-void sched_balance_exec(void)
+void sched_exec(void)
 {
        struct sched_domain *tmp, *sd = NULL;
        int new_cpu, this_cpu = get_cpu();
 
+       schedstat_inc(this_rq(), sbe_cnt);
        /* Prefer the current CPU if there's only this task running */
        if (this_rq()->nr_running <= 1)
                goto out;
@@ -1353,8 +1749,10 @@ void sched_balance_exec(void)
                        sd = tmp;
 
        if (sd) {
+               schedstat_inc(sd, sbe_attempts);
                new_cpu = find_idlest_cpu(current, this_cpu, sd);
                if (new_cpu != this_cpu) {
+                       schedstat_inc(sd, sbe_pushed);
                        put_cpu();
                        sched_migrate_task(current, new_cpu);
                        return;
@@ -1364,21 +1762,6 @@ out:
        put_cpu();
 }
 
-/*
- * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
- */
-static void double_lock_balance(runqueue_t *this_rq, runqueue_t *busiest)
-{
-       if (unlikely(!spin_trylock(&busiest->lock))) {
-               if (busiest < this_rq) {
-                       spin_unlock(&this_rq->lock);
-                       spin_lock(&busiest->lock);
-                       spin_lock(&this_rq->lock);
-               } else
-                       spin_lock(&busiest->lock);
-       }
-}
-
 /*
  * pull_task - move a task from a remote runqueue to the local runqueue.
  * Both runqueues must be locked.
@@ -1493,6 +1876,15 @@ skip_queue:
                idx++;
                goto skip_bitmap;
        }
+
+       /*
+        * Right now, this is the only place pull_task() is called,
+        * so we can safely collect pull_task() stats here rather than
+        * inside pull_task().
+        */
+       schedstat_inc(this_rq, pt_gained[idle]);
+       schedstat_inc(busiest, pt_lost[idle]);
+
        pull_task(busiest, array, tmp, this_rq, dst_array, this_cpu);
        pulled++;
 
@@ -1687,14 +2079,20 @@ static int load_balance(int this_cpu, runqueue_t *this_rq,
        int nr_moved;
 
        spin_lock(&this_rq->lock);
+       schedstat_inc(sd, lb_cnt[idle]);
 
        group = find_busiest_group(sd, this_cpu, &imbalance, idle);
-       if (!group)
+       if (!group) {
+               schedstat_inc(sd, lb_nobusyg[idle]);
                goto out_balanced;
+       }
 
        busiest = find_busiest_queue(group);
-       if (!busiest)
+       if (!busiest) {
+               schedstat_inc(sd, lb_nobusyq[idle]);
                goto out_balanced;
+       }
+
        /*
         * This should be "impossible", but since load
         * balancing is inherently racy and statistical,
@@ -1705,6 +2103,8 @@ static int load_balance(int this_cpu, runqueue_t *this_rq,
                goto out_balanced;
        }
 
+       schedstat_add(sd, lb_imbalance[idle], imbalance);
+
        nr_moved = 0;
        if (busiest->nr_running > 1) {
                /*
@@ -1721,6 +2121,7 @@ static int load_balance(int this_cpu, runqueue_t *this_rq,
        spin_unlock(&this_rq->lock);
 
        if (!nr_moved) {
+               schedstat_inc(sd, lb_failed[idle]);
                sd->nr_balance_failed++;
 
                if (unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2)) {
@@ -1775,19 +2176,27 @@ static int load_balance_newidle(int this_cpu, runqueue_t *this_rq,
        unsigned long imbalance;
        int nr_moved = 0;
 
+       schedstat_inc(sd, lb_cnt[NEWLY_IDLE]);
        group = find_busiest_group(sd, this_cpu, &imbalance, NEWLY_IDLE);
-       if (!group)
+       if (!group) {
+               schedstat_inc(sd, lb_nobusyg[NEWLY_IDLE]);
                goto out;
+       }
 
        busiest = find_busiest_queue(group);
-       if (!busiest || busiest == this_rq)
+       if (!busiest || busiest == this_rq) {
+               schedstat_inc(sd, lb_nobusyq[NEWLY_IDLE]);
                goto out;
+       }
 
        /* Attempt to move tasks */
        double_lock_balance(this_rq, busiest);
 
+       schedstat_add(sd, lb_imbalance[NEWLY_IDLE], imbalance);
        nr_moved = move_tasks(this_rq, this_cpu, busiest,
                                        imbalance, sd, NEWLY_IDLE);
+       if (!nr_moved)
+               schedstat_inc(sd, lb_failed[NEWLY_IDLE]);
 
        spin_unlock(&busiest->lock);
 
@@ -1827,40 +2236,39 @@ static void active_load_balance(runqueue_t *busiest, int busiest_cpu)
        struct sched_group *group, *busy_group;
        int i;
 
+       schedstat_inc(busiest, alb_cnt);
        if (busiest->nr_running <= 1)
                return;
 
        for_each_domain(busiest_cpu, sd)
                if (cpu_isset(busiest->push_cpu, sd->span))
                        break;
-       if (!sd) {
-               WARN_ON(1);
+       if (!sd)
                return;
-       }
 
-       group = sd->groups;
+       group = sd->groups;
        while (!cpu_isset(busiest_cpu, group->cpumask))
-               group = group->next;
-       busy_group = group;
+               group = group->next;
+       busy_group = group;
 
-       group = sd->groups;
-       do {
+       group = sd->groups;
+       do {
                cpumask_t tmp;
                runqueue_t *rq;
                int push_cpu = 0;
 
-               if (group == busy_group)
-                       goto next_group;
+               if (group == busy_group)
+                       goto next_group;
 
                cpus_and(tmp, group->cpumask, cpu_online_map);
                if (!cpus_weight(tmp))
                        goto next_group;
 
-               for_each_cpu_mask(i, tmp) {
+               for_each_cpu_mask(i, tmp) {
                        if (!idle_cpu(i))
                                goto next_group;
-                       push_cpu = i;
-               }
+                       push_cpu = i;
+               }
 
                rq = cpu_rq(push_cpu);
 
@@ -1873,7 +2281,12 @@ static void active_load_balance(runqueue_t *busiest, int busiest_cpu)
                if (unlikely(busiest == rq))
                        goto next_group;
                double_lock_balance(busiest, rq);
-               move_tasks(rq, push_cpu, busiest, 1, sd, IDLE);
+               if (move_tasks(rq, push_cpu, busiest, 1, sd, IDLE)) {
+                       schedstat_inc(busiest, alb_lost);
+                       schedstat_inc(rq, alb_gained);
+               } else {
+                       schedstat_inc(busiest, alb_failed);
+               }
                spin_unlock(&rq->lock);
 next_group:
                group = group->next;
@@ -1945,17 +2358,20 @@ static inline void idle_balance(int cpu, runqueue_t *rq)
 
 static inline int wake_priority_sleeper(runqueue_t *rq)
 {
+       int ret = 0;
 #ifdef CONFIG_SCHED_SMT
+       spin_lock(&rq->lock);
        /*
         * If an SMT sibling task has been put to sleep for priority
         * reasons reschedule the idle task to see if it can now run.
         */
        if (rq->nr_running) {
                resched_task(rq->idle);
-               return 1;
+               ret = 1;
        }
+       spin_unlock(&rq->lock);
 #endif
-       return 0;
+       return ret;
 }
 
 DEFINE_PER_CPU(struct kernel_stat, kstat);
@@ -1991,12 +2407,18 @@ void scheduler_tick(int user_ticks, int sys_ticks)
        struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
        runqueue_t *rq = this_rq();
        task_t *p = current;
+       struct vx_info *vxi = p->vx_info;
 
        rq->timestamp_last_tick = sched_clock();
 
        if (rcu_pending(cpu))
                rcu_check_callbacks(cpu, user_ticks);
 
+       if (vxi) {
+               vxi->sched.cpu[cpu].user_ticks += user_ticks;
+               vxi->sched.cpu[cpu].sys_ticks += sys_ticks;
+       }
+
        /* note: this timer irq context must be accounted for as well */
        if (hardirq_count() - HARDIRQ_OFFSET) {
                cpustat->irq += sys_ticks;
@@ -2007,15 +2429,20 @@ void scheduler_tick(int user_ticks, int sys_ticks)
        }
 
        if (p == rq->idle) {
-               if (!--rq->idle_tokens && !list_empty(&rq->hold_queue))
-                       set_need_resched();     
-
                if (atomic_read(&rq->nr_iowait) > 0)
                        cpustat->iowait += sys_ticks;
+                       // vx_cpustat_acc(vxi, iowait, cpu, cpustat, sys_ticks);
                else
                        cpustat->idle += sys_ticks;
+                       // vx_cpustat_acc(vxi, idle, cpu, cpustat, sys_ticks);
+
                if (wake_priority_sleeper(rq))
                        goto out;
+
+#ifdef CONFIG_VSERVER_HARDCPU_IDLE
+               if (!--rq->idle_tokens && !list_empty(&rq->hold_queue))
+                       set_need_resched();
+#endif
                rebalance_tick(cpu, rq, IDLE);
                return;
        }
@@ -2038,7 +2465,7 @@ void scheduler_tick(int user_ticks, int sys_ticks)
         * timeslice. This makes it possible for interactive tasks
         * to use up their timeslices at their highest priority levels.
         */
-       if (unlikely(rt_task(p))) {
+       if (rt_task(p)) {
                /*
                 * RR tasks need a special form of timeslice management.
                 * FIFO tasks have no timeslices.
@@ -2104,23 +2531,34 @@ out:
 }
 
 #ifdef CONFIG_SCHED_SMT
-static inline void wake_sleeping_dependent(int cpu, runqueue_t *rq)
+static inline void wake_sleeping_dependent(int this_cpu, runqueue_t *this_rq)
 {
-       int i;
-       struct sched_domain *sd = rq->sd;
+       struct sched_domain *sd = this_rq->sd;
        cpumask_t sibling_map;
+       int i;
 
        if (!(sd->flags & SD_SHARE_CPUPOWER))
                return;
 
+       /*
+        * Unlock the current runqueue because we have to lock in
+        * CPU order to avoid deadlocks. Caller knows that we might
+        * unlock. We keep IRQs disabled.
+        */
+       spin_unlock(&this_rq->lock);
+
        cpus_and(sibling_map, sd->span, cpu_online_map);
-       for_each_cpu_mask(i, sibling_map) {
-               runqueue_t *smt_rq;
 
-               if (i == cpu)
-                       continue;
+       for_each_cpu_mask(i, sibling_map)
+               spin_lock(&cpu_rq(i)->lock);
+       /*
+        * We clear this CPU from the mask. This both simplifies the
+        * inner loop and keps this_rq locked when we exit:
+        */
+       cpu_clear(this_cpu, sibling_map);
 
-               smt_rq = cpu_rq(i);
+       for_each_cpu_mask(i, sibling_map) {
+               runqueue_t *smt_rq = cpu_rq(i);
 
                /*
                 * If an SMT sibling task is sleeping due to priority
@@ -2129,27 +2567,53 @@ static inline void wake_sleeping_dependent(int cpu, runqueue_t *rq)
                if (smt_rq->curr == smt_rq->idle && smt_rq->nr_running)
                        resched_task(smt_rq->idle);
        }
+
+       for_each_cpu_mask(i, sibling_map)
+               spin_unlock(&cpu_rq(i)->lock);
+       /*
+        * We exit with this_cpu's rq still held and IRQs
+        * still disabled:
+        */
 }
 
-static inline int dependent_sleeper(int cpu, runqueue_t *rq, task_t *p)
+static inline int dependent_sleeper(int this_cpu, runqueue_t *this_rq)
 {
-       struct sched_domain *sd = rq->sd;
+       struct sched_domain *sd = this_rq->sd;
        cpumask_t sibling_map;
+       prio_array_t *array;
        int ret = 0, i;
+       task_t *p;
 
        if (!(sd->flags & SD_SHARE_CPUPOWER))
                return 0;
 
+       /*
+        * The same locking rules and details apply as for
+        * wake_sleeping_dependent():
+        */
+       spin_unlock(&this_rq->lock);
        cpus_and(sibling_map, sd->span, cpu_online_map);
-       for_each_cpu_mask(i, sibling_map) {
-               runqueue_t *smt_rq;
-               task_t *smt_curr;
+       for_each_cpu_mask(i, sibling_map)
+               spin_lock(&cpu_rq(i)->lock);
+       cpu_clear(this_cpu, sibling_map);
 
-               if (i == cpu)
-                       continue;
+       /*
+        * Establish next task to be run - it might have gone away because
+        * we released the runqueue lock above:
+        */
+       if (!this_rq->nr_running)
+               goto out_unlock;
+       array = this_rq->active;
+       if (!array->nr_active)
+               array = this_rq->expired;
+       BUG_ON(!array->nr_active);
+
+       p = list_entry(array->queue[sched_find_first_bit(array->bitmap)].next,
+               task_t, run_list);
 
-               smt_rq = cpu_rq(i);
-               smt_curr = smt_rq->curr;
+       for_each_cpu_mask(i, sibling_map) {
+               runqueue_t *smt_rq = cpu_rq(i);
+               task_t *smt_curr = smt_rq->curr;
 
                /*
                 * If a user task with lower static priority than the
@@ -2175,14 +2639,17 @@ static inline int dependent_sleeper(int cpu, runqueue_t *rq, task_t *p)
                        (smt_curr == smt_rq->idle && smt_rq->nr_running))
                                resched_task(smt_curr);
        }
+out_unlock:
+       for_each_cpu_mask(i, sibling_map)
+               spin_unlock(&cpu_rq(i)->lock);
        return ret;
 }
 #else
-static inline void wake_sleeping_dependent(int cpu, runqueue_t *rq)
+static inline void wake_sleeping_dependent(int this_cpu, runqueue_t *this_rq)
 {
 }
 
-static inline int dependent_sleeper(int cpu, runqueue_t *rq, task_t *p)
+static inline int dependent_sleeper(int this_cpu, runqueue_t *this_rq)
 {
        return 0;
 }
@@ -2200,7 +2667,7 @@ asmlinkage void __sched schedule(void)
        struct list_head *queue;
        unsigned long long now;
        unsigned long run_time;
-#ifdef CONFIG_VSERVER_HARDCPU          
+#ifdef CONFIG_VSERVER_HARDCPU
        struct vx_info *vxi;
        int maxidle = -HZ;
 #endif
@@ -2223,7 +2690,17 @@ need_resched:
        prev = current;
        rq = this_rq();
 
+       /*
+        * The idle thread is not allowed to schedule!
+        * Remove this check after it has been exercised a bit.
+        */
+       if (unlikely(current == rq->idle) && current->state != TASK_RUNNING) {
+               printk(KERN_ERR "bad: scheduling from the idle thread!\n");
+               dump_stack();
+       }
+
        release_kernel_lock(prev);
+       schedstat_inc(rq, sched_cnt);
        now = sched_clock();
        if (likely(now - prev->timestamp < NS_MAX_SLEEP_AVG))
                run_time = now - prev->timestamp;
@@ -2254,7 +2731,7 @@ need_resched:
                        deactivate_task(prev, rq);
        }
 
-#ifdef CONFIG_VSERVER_HARDCPU          
+#ifdef CONFIG_VSERVER_HARDCPU
        if (!list_empty(&rq->hold_queue)) {
                struct list_head *l, *n;
                int ret;
@@ -2272,28 +2749,56 @@ need_resched:
                        if (ret > 0) {
                                list_del(&next->run_list);
                                next->state &= ~TASK_ONHOLD;
-                               recalc_task_prio(next, now);
-                               __activate_task(next, rq);
-                               // printk("··· unhold %p\n", next);
+                               // one less waiting
+                               vx_onhold_dec(vxi);
+                               array = rq->expired;
+                               next->prio = MAX_PRIO-1;
+                               enqueue_task(next, array);
+                               rq->nr_running++;
+                               if (next->static_prio < rq->best_expired_prio)
+                                       rq->best_expired_prio = next->static_prio;
+
+                               // printk("··· %8lu unhold %p [%d]\n", jiffies, next, next->prio);
                                break;
                        }
                        if ((ret < 0) && (maxidle < ret))
                                maxidle = ret;
-               }       
+               }
        }
        rq->idle_tokens = -maxidle;
 
 pick_next:
 #endif
+
        cpu = smp_processor_id();
        if (unlikely(!rq->nr_running)) {
+go_idle:
                idle_balance(cpu, rq);
                if (!rq->nr_running) {
                        next = rq->idle;
                        rq->expired_timestamp = 0;
                        wake_sleeping_dependent(cpu, rq);
+                       /*
+                        * wake_sleeping_dependent() might have released
+                        * the runqueue, so break out if we got new
+                        * tasks meanwhile:
+                        */
+                       if (!rq->nr_running)
+                               goto switch_tasks;
+               }
+       } else {
+               if (dependent_sleeper(cpu, rq)) {
+                       schedstat_inc(rq, sched_goidle);
+                       next = rq->idle;
                        goto switch_tasks;
                }
+               /*
+                * dependent_sleeper() releases and reacquires the runqueue
+                * lock, hence go into the idle loop if the rq went
+                * empty meanwhile:
+                */
+               if (unlikely(!rq->nr_running))
+                       goto go_idle;
        }
 
        array = rq->active;
@@ -2301,34 +2806,34 @@ pick_next:
                /*
                 * Switch the active and expired arrays.
                 */
+               schedstat_inc(rq, sched_switch);
                rq->active = rq->expired;
                rq->expired = array;
                array = rq->active;
                rq->expired_timestamp = 0;
                rq->best_expired_prio = MAX_PRIO;
-       }
+       } else
+               schedstat_inc(rq, sched_noswitch);
 
        idx = sched_find_first_bit(array->bitmap);
        queue = array->queue + idx;
        next = list_entry(queue->next, task_t, run_list);
 
-       if (dependent_sleeper(cpu, rq, next)) {
-               next = rq->idle;
-               goto switch_tasks;
-       }
-
-#ifdef CONFIG_VSERVER_HARDCPU          
+#ifdef CONFIG_VSERVER_HARDCPU
        vxi = next->vx_info;
-       if (vxi && __vx_flags(vxi->vx_flags,
-               VXF_SCHED_PAUSE|VXF_SCHED_HARD, 0)) {
+       if (vx_info_flags(vxi, VXF_SCHED_PAUSE|VXF_SCHED_HARD, 0)) {
                int ret = vx_tokens_recalc(vxi);
 
                if (unlikely(ret <= 0)) {
                        if (ret && (rq->idle_tokens > -ret))
                                rq->idle_tokens = -ret;
-                       deactivate_task(next, rq);
+                       __deactivate_task(next, rq);
+                       recalc_task_prio(next, now);
+                       // a new one on hold
+                       vx_onhold_inc(vxi);
+                       next->state |= TASK_ONHOLD;
                        list_add_tail(&next->run_list, &rq->hold_queue);
-                       next->state |= TASK_ONHOLD;                     
+                       //printk("··· %8lu hold   %p [%d]\n", jiffies, next, next->prio);
                        goto pick_next;
                }
        }
@@ -2349,7 +2854,7 @@ pick_next:
 switch_tasks:
        prefetch(next);
        clear_tsk_need_resched(prev);
-       RCU_qsctr(task_cpu(prev))++;
+       rcu_qsctr_inc(task_cpu(prev));
 
        prev->sleep_avg -= run_time;
        if ((long)prev->sleep_avg <= 0) {
@@ -2357,8 +2862,9 @@ switch_tasks:
                if (!(HIGH_CREDIT(prev) || LOW_CREDIT(prev)))
                        prev->interactive_credit--;
        }
-       prev->timestamp = now;
+       prev->timestamp = prev->last_ran = now;
 
+       sched_info_switch(prev, next);
        if (likely(prev != next)) {
                next->timestamp = now;
                rq->nr_switches++;
@@ -2375,7 +2881,7 @@ switch_tasks:
 
        reacquire_kernel_lock(current);
        preempt_enable_no_resched();
-       if (test_thread_flag(TIF_NEED_RESCHED))
+       if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
                goto need_resched;
 }
 
@@ -2688,6 +3194,8 @@ asmlinkage long sys_nice(int increment)
         * and we have a single winner.
         */
        if (increment < 0) {
+               if (vx_flags(VXF_IGNEG_NICE, 0))
+                       return 0;
                if (!capable(CAP_SYS_NICE))
                        return -EPERM;
                if (increment < -40)
@@ -2813,6 +3321,7 @@ static int setscheduler(pid_t pid, int policy, struct sched_param __user *param)
                                policy != SCHED_NORMAL)
                        goto out_unlock;
        }
+       profile_hit(SCHED_PROFILING, __builtin_return_address(0));
 
        /*
         * Valid priorities for SCHED_FIFO and SCHED_RR are
@@ -2843,6 +3352,7 @@ static int setscheduler(pid_t pid, int policy, struct sched_param __user *param)
        oldprio = p->prio;
        __setscheduler(p, policy, lp.sched_priority);
        if (array) {
+               vx_activate_task(p);
                __activate_task(p, task_rq(p));
                /*
                 * Reschedule if we are currently running on this runqueue and
@@ -2953,24 +3463,10 @@ out_unlock:
        return retval;
 }
 
-/**
- * sys_sched_setaffinity - set the cpu affinity of a process
- * @pid: pid of the process
- * @len: length in bytes of the bitmask pointed to by user_mask_ptr
- * @user_mask_ptr: user-space pointer to the new cpu mask
- */
-asmlinkage long sys_sched_setaffinity(pid_t pid, unsigned int len,
-                                     unsigned long __user *user_mask_ptr)
+long sched_setaffinity(pid_t pid, cpumask_t new_mask)
 {
-       cpumask_t new_mask;
-       int retval;
        task_t *p;
-
-       if (len < sizeof(new_mask))
-               return -EINVAL;
-
-       if (copy_from_user(&new_mask, user_mask_ptr, sizeof(new_mask)))
-               return -EFAULT;
+       int retval;
 
        lock_cpu_hotplug();
        read_lock(&tasklist_lock);
@@ -3003,6 +3499,36 @@ out_unlock:
        return retval;
 }
 
+static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len,
+                            cpumask_t *new_mask)
+{
+       if (len < sizeof(cpumask_t)) {
+               memset(new_mask, 0, sizeof(cpumask_t));
+       } else if (len > sizeof(cpumask_t)) {
+               len = sizeof(cpumask_t);
+       }
+       return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0;
+}
+
+/**
+ * sys_sched_setaffinity - set the cpu affinity of a process
+ * @pid: pid of the process
+ * @len: length in bytes of the bitmask pointed to by user_mask_ptr
+ * @user_mask_ptr: user-space pointer to the new cpu mask
+ */
+asmlinkage long sys_sched_setaffinity(pid_t pid, unsigned int len,
+                                     unsigned long __user *user_mask_ptr)
+{
+       cpumask_t new_mask;
+       int retval;
+
+       retval = get_user_cpu_mask(user_mask_ptr, len, &new_mask);
+       if (retval)
+               return retval;
+
+       return sched_setaffinity(pid, new_mask);
+}
+
 /*
  * Represents all cpu's present in the system
  * In systems capable of hotplug, this map could dynamically grow
@@ -3018,24 +3544,11 @@ cpumask_t cpu_online_map = CPU_MASK_ALL;
 cpumask_t cpu_possible_map = CPU_MASK_ALL;
 #endif
 
-/**
- * sys_sched_getaffinity - get the cpu affinity of a process
- * @pid: pid of the process
- * @len: length in bytes of the bitmask pointed to by user_mask_ptr
- * @user_mask_ptr: user-space pointer to hold the current cpu mask
- */
-asmlinkage long sys_sched_getaffinity(pid_t pid, unsigned int len,
-                                     unsigned long __user *user_mask_ptr)
+long sched_getaffinity(pid_t pid, cpumask_t *mask)
 {
-       unsigned int real_len;
-       cpumask_t mask;
        int retval;
        task_t *p;
 
-       real_len = sizeof(mask);
-       if (len < real_len)
-               return -EINVAL;
-
        lock_cpu_hotplug();
        read_lock(&tasklist_lock);
 
@@ -3045,16 +3558,40 @@ asmlinkage long sys_sched_getaffinity(pid_t pid, unsigned int len,
                goto out_unlock;
 
        retval = 0;
-       cpus_and(mask, p->cpus_allowed, cpu_possible_map);
+       cpus_and(*mask, p->cpus_allowed, cpu_possible_map);
 
 out_unlock:
        read_unlock(&tasklist_lock);
        unlock_cpu_hotplug();
        if (retval)
                return retval;
-       if (copy_to_user(user_mask_ptr, &mask, real_len))
+
+       return 0;
+}
+
+/**
+ * sys_sched_getaffinity - get the cpu affinity of a process
+ * @pid: pid of the process
+ * @len: length in bytes of the bitmask pointed to by user_mask_ptr
+ * @user_mask_ptr: user-space pointer to hold the current cpu mask
+ */
+asmlinkage long sys_sched_getaffinity(pid_t pid, unsigned int len,
+                                     unsigned long __user *user_mask_ptr)
+{
+       int ret;
+       cpumask_t mask;
+
+       if (len < sizeof(cpumask_t))
+               return -EINVAL;
+
+       ret = sched_getaffinity(pid, &mask);
+       if (ret < 0)
+               return ret;
+
+       if (copy_to_user(user_mask_ptr, &mask, sizeof(cpumask_t)))
                return -EFAULT;
-       return real_len;
+
+       return sizeof(cpumask_t);
 }
 
 /**
@@ -3070,6 +3607,7 @@ asmlinkage long sys_sched_yield(void)
        prio_array_t *array = current->array;
        prio_array_t *target = rq->expired;
 
+       schedstat_inc(rq, yld_cnt);
        /*
         * We implement yielding by moving the task into the expired
         * queue.
@@ -3077,9 +3615,16 @@ asmlinkage long sys_sched_yield(void)
         * (special rule: RT tasks will just roundrobin in the active
         *  array.)
         */
-       if (unlikely(rt_task(current)))
+       if (rt_task(current))
                target = rq->active;
 
+       if (current->array->nr_active == 1) {
+               schedstat_inc(rq, yld_act_empty);
+               if (!rq->expired->nr_active)
+                       schedstat_inc(rq, yld_both_empty);
+       } else if (!rq->expired->nr_active)
+               schedstat_inc(rq, yld_exp_empty);
+
        dequeue_task(current, array);
        enqueue_task(current, target);
 
@@ -3253,7 +3798,7 @@ static void show_task(task_t * p)
        task_t *relative;
        unsigned state;
        unsigned long free = 0;
-       static const char *stat_nam[] = { "R", "S", "D", "T", "Z", "W" };
+       static const char *stat_nam[] = { "R", "S", "D", "T", "t", "Z", "X" };
 
        printk("%-13.13s ", p->comm);
        state = p->state ? __ffs(p->state) + 1 : 0;
@@ -3330,21 +3875,20 @@ void show_state(void)
 
 void __devinit init_idle(task_t *idle, int cpu)
 {
-       runqueue_t *idle_rq = cpu_rq(cpu), *rq = cpu_rq(task_cpu(idle));
+       runqueue_t *rq = cpu_rq(cpu);
        unsigned long flags;
 
-       local_irq_save(flags);
-       double_rq_lock(idle_rq, rq);
-
-       idle_rq->curr = idle_rq->idle = idle;
-       deactivate_task(idle, rq);
+       idle->sleep_avg = 0;
+       idle->interactive_credit = 0;
        idle->array = NULL;
        idle->prio = MAX_PRIO;
        idle->state = TASK_RUNNING;
        set_task_cpu(idle, cpu);
-       double_rq_unlock(idle_rq, rq);
+
+       spin_lock_irqsave(&rq->lock, flags);
+       rq->curr = rq->idle = idle;
        set_tsk_need_resched(idle);
-       local_irq_restore(flags);
+       spin_unlock_irqrestore(&rq->lock, flags);
 
        /* Set the preempt count _outside_ the spinlocks! */
 #ifdef CONFIG_PREEMPT
@@ -3426,7 +3970,7 @@ EXPORT_SYMBOL_GPL(set_cpus_allowed);
  * Move (not current) task off this cpu, onto dest cpu.  We're doing
  * this because either it can't run here any more (set_cpus_allowed()
  * away from this CPU, or CPU going down), or because we're
- * attempting to rebalance this task on exec (sched_balance_exec).
+ * attempting to rebalance this task on exec (sched_exec).
  *
  * So we race with normal scheduler movements, but that's OK, as long
  * as the task is no longer on this CPU.
@@ -3438,7 +3982,7 @@ static void __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
        if (unlikely(cpu_is_offline(dest_cpu)))
                return;
 
-       rq_src  = cpu_rq(src_cpu);
+       rq_src = cpu_rq(src_cpu);
        rq_dest = cpu_rq(dest_cpu);
 
        double_rq_lock(rq_src, rq_dest);
@@ -3543,49 +4087,52 @@ wait_to_die:
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
-/* migrate_all_tasks - function to migrate all tasks from the dead cpu.  */
-static void migrate_all_tasks(int src_cpu)
+/* Figure out where task on dead CPU should go, use force if neccessary. */
+static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *tsk)
 {
-       struct task_struct *tsk, *t;
        int dest_cpu;
-       unsigned int node;
+       cpumask_t mask;
 
-       write_lock_irq(&tasklist_lock);
+       /* On same node? */
+       mask = node_to_cpumask(cpu_to_node(dead_cpu));
+       cpus_and(mask, mask, tsk->cpus_allowed);
+       dest_cpu = any_online_cpu(mask);
 
-       /* watch out for per node tasks, let's stay on this node */
-       node = cpu_to_node(src_cpu);
+       /* On any allowed CPU? */
+       if (dest_cpu == NR_CPUS)
+               dest_cpu = any_online_cpu(tsk->cpus_allowed);
+
+       /* No more Mr. Nice Guy. */
+       if (dest_cpu == NR_CPUS) {
+               cpus_setall(tsk->cpus_allowed);
+               dest_cpu = any_online_cpu(tsk->cpus_allowed);
+
+               /*
+                * Don't tell them about moving exiting tasks or
+                * kernel threads (both mm NULL), since they never
+                * leave kernel.
+                */
+               if (tsk->mm && printk_ratelimit())
+                       printk(KERN_INFO "process %d (%s) no "
+                              "longer affine to cpu%d\n",
+                              tsk->pid, tsk->comm, dead_cpu);
+       }
+       __migrate_task(tsk, dead_cpu, dest_cpu);
+}
+
+/* Run through task list and migrate tasks from the dead cpu. */
+static void migrate_live_tasks(int src_cpu)
+{
+       struct task_struct *tsk, *t;
+
+       write_lock_irq(&tasklist_lock);
 
        do_each_thread(t, tsk) {
-               cpumask_t mask;
                if (tsk == current)
                        continue;
 
-               if (task_cpu(tsk) != src_cpu)
-                       continue;
-
-               /* Figure out where this task should go (attempting to
-                * keep it on-node), and check if it can be migrated
-                * as-is.  NOTE that kernel threads bound to more than
-                * one online cpu will be migrated. */
-               mask = node_to_cpumask(node);
-               cpus_and(mask, mask, tsk->cpus_allowed);
-               dest_cpu = any_online_cpu(mask);
-               if (dest_cpu == NR_CPUS)
-                       dest_cpu = any_online_cpu(tsk->cpus_allowed);
-               if (dest_cpu == NR_CPUS) {
-                       cpus_setall(tsk->cpus_allowed);
-                       dest_cpu = any_online_cpu(tsk->cpus_allowed);
-
-                       /* Don't tell them about moving exiting tasks
-                          or kernel threads (both mm NULL), since
-                          they never leave kernel. */
-                       if (tsk->mm && printk_ratelimit())
-                               printk(KERN_INFO "process %d (%s) no "
-                                      "longer affine to cpu%d\n",
-                                      tsk->pid, tsk->comm, src_cpu);
-               }
-
-               __migrate_task(tsk, src_cpu, dest_cpu);
+               if (task_cpu(tsk) == src_cpu)
+                       move_task_off_dead_cpu(src_cpu, tsk);
        } while_each_thread(t, tsk);
 
        write_unlock_irq(&tasklist_lock);
@@ -3616,6 +4163,47 @@ void sched_idle_next(void)
 
        spin_unlock_irqrestore(&rq->lock, flags);
 }
+
+static void migrate_dead(unsigned int dead_cpu, task_t *tsk)
+{
+       struct runqueue *rq = cpu_rq(dead_cpu);
+
+       /* Must be exiting, otherwise would be on tasklist. */
+       BUG_ON(tsk->state != TASK_ZOMBIE && tsk->state != TASK_DEAD);
+
+       /* Cannot have done final schedule yet: would have vanished. */
+       BUG_ON(tsk->flags & PF_DEAD);
+
+       get_task_struct(tsk);
+
+       /*
+        * Drop lock around migration; if someone else moves it,
+        * that's OK.  No task can be added to this CPU, so iteration is
+        * fine.
+        */
+       spin_unlock_irq(&rq->lock);
+       move_task_off_dead_cpu(dead_cpu, tsk);
+       spin_lock_irq(&rq->lock);
+
+       put_task_struct(tsk);
+}
+
+/* release_task() removes task from tasklist, so we won't find dead tasks. */
+static void migrate_dead_tasks(unsigned int dead_cpu)
+{
+       unsigned arr, i;
+       struct runqueue *rq = cpu_rq(dead_cpu);
+
+       for (arr = 0; arr < 2; arr++) {
+               for (i = 0; i < MAX_PRIO; i++) {
+                       struct list_head *list = &rq->arrays[arr].queue[i];
+                       while (!list_empty(list))
+                               migrate_dead(dead_cpu,
+                                            list_entry(list->next, task_t,
+                                                       run_list));
+               }
+       }
+}
 #endif /* CONFIG_HOTPLUG_CPU */
 
 /*
@@ -3655,7 +4243,7 @@ static int migration_call(struct notifier_block *nfb, unsigned long action,
                cpu_rq(cpu)->migration_thread = NULL;
                break;
        case CPU_DEAD:
-               migrate_all_tasks(cpu);
+               migrate_live_tasks(cpu);
                rq = cpu_rq(cpu);
                kthread_stop(rq->migration_thread);
                rq->migration_thread = NULL;
@@ -3664,8 +4252,9 @@ static int migration_call(struct notifier_block *nfb, unsigned long action,
                deactivate_task(rq->idle, rq);
                rq->idle->static_prio = MAX_PRIO;
                __setscheduler(rq->idle, SCHED_NORMAL, 0);
+               migrate_dead_tasks(cpu);
                task_rq_unlock(rq, &flags);
-               BUG_ON(rq->nr_running != 0);
+               BUG_ON(rq->nr_running != 0);
 
                /* No need to migrate the tasks: it was best-effort if
                 * they didn't do lock_cpu_hotplug().  Just wake up
@@ -3680,7 +4269,7 @@ static int migration_call(struct notifier_block *nfb, unsigned long action,
                        complete(&req->done);
                }
                spin_unlock_irq(&rq->lock);
-               break;
+               break;
 #endif
        }
        return NOTIFY_OK;
@@ -3722,7 +4311,7 @@ EXPORT_SYMBOL(kernel_flag);
 
 #ifdef CONFIG_SMP
 /* Attach the domain 'sd' to 'cpu' as its base domain */
-void cpu_attach_domain(struct sched_domain *sd, int cpu)
+static void cpu_attach_domain(struct sched_domain *sd, int cpu)
 {
        migration_req_t req;
        unsigned long flags;
@@ -3753,124 +4342,343 @@ void cpu_attach_domain(struct sched_domain *sd, int cpu)
        unlock_cpu_hotplug();
 }
 
-#ifdef ARCH_HAS_SCHED_DOMAIN
-extern void __init arch_init_sched_domains(void);
-#else
-static struct sched_group sched_group_cpus[NR_CPUS];
+/*
+ * To enable disjoint top-level NUMA domains, define SD_NODES_PER_DOMAIN
+ * in arch code. That defines the number of nearby nodes in a node's top
+ * level scheduling domain.
+ */
+#if defined(CONFIG_NUMA) && defined(SD_NODES_PER_DOMAIN)
+/**
+ * find_next_best_node - find the next node to include in a sched_domain
+ * @node: node whose sched_domain we're building
+ * @used_nodes: nodes already in the sched_domain
+ *
+ * Find the next node to include in a given scheduling domain.  Simply
+ * finds the closest node not already in the @used_nodes map.
+ *
+ * Should use nodemask_t.
+ */
+static int __init find_next_best_node(int node, unsigned long *used_nodes)
+{
+       int i, n, val, min_val, best_node = 0;
+
+       min_val = INT_MAX;
+
+       for (i = 0; i < numnodes; i++) {
+               /* Start at @node */
+               n = (node + i) % numnodes;
+
+               /* Skip already used nodes */
+               if (test_bit(n, used_nodes))
+                       continue;
+
+               /* Simple min distance search */
+               val = node_distance(node, i);
+
+               if (val < min_val) {
+                       min_val = val;
+                       best_node = n;
+               }
+       }
+
+       set_bit(best_node, used_nodes);
+       return best_node;
+}
+
+/**
+ * sched_domain_node_span - get a cpumask for a node's sched_domain
+ * @node: node whose cpumask we're constructing
+ * @size: number of nodes to include in this span
+ *
+ * Given a node, construct a good cpumask for its sched_domain to span.  It
+ * should be one that prevents unnecessary balancing, but also spreads tasks
+ * out optimally.
+ */
+cpumask_t __init sched_domain_node_span(int node)
+{
+       int i;
+       cpumask_t span;
+       DECLARE_BITMAP(used_nodes, MAX_NUMNODES);
+
+       cpus_clear(span);
+       bitmap_zero(used_nodes, MAX_NUMNODES);
+
+       for (i = 0; i < SD_NODES_PER_DOMAIN; i++) {
+               int next_node = find_next_best_node(node, used_nodes);
+               cpumask_t  nodemask;
+
+               nodemask = node_to_cpumask(next_node);
+               cpus_or(span, span, nodemask);
+       }
+
+       return span;
+}
+#else /* CONFIG_NUMA && SD_NODES_PER_DOMAIN */
+cpumask_t __init sched_domain_node_span(int node)
+{
+       return cpu_possible_map;
+}
+#endif /* CONFIG_NUMA && SD_NODES_PER_DOMAIN */
+
+#ifdef CONFIG_SCHED_SMT
 static DEFINE_PER_CPU(struct sched_domain, cpu_domains);
+static struct sched_group sched_group_cpus[NR_CPUS];
+__init static int cpu_to_cpu_group(int cpu)
+{
+       return cpu;
+}
+#endif
+
+static DEFINE_PER_CPU(struct sched_domain, phys_domains);
+static struct sched_group sched_group_phys[NR_CPUS];
+__init static int cpu_to_phys_group(int cpu)
+{
+#ifdef CONFIG_SCHED_SMT
+       return first_cpu(cpu_sibling_map[cpu]);
+#else
+       return cpu;
+#endif
+}
+
 #ifdef CONFIG_NUMA
-static struct sched_group sched_group_nodes[MAX_NUMNODES];
+
 static DEFINE_PER_CPU(struct sched_domain, node_domains);
-static void __init arch_init_sched_domains(void)
+static struct sched_group sched_group_nodes[MAX_NUMNODES];
+__init static int cpu_to_node_group(int cpu)
 {
-       int i;
-       struct sched_group *first_node = NULL, *last_node = NULL;
+       return cpu_to_node(cpu);
+}
+#endif
 
-       /* Set up domains */
-       for_each_cpu(i) {
-               int node = cpu_to_node(i);
-               cpumask_t nodemask = node_to_cpumask(node);
-               struct sched_domain *node_sd = &per_cpu(node_domains, i);
-               struct sched_domain *cpu_sd = &per_cpu(cpu_domains, i);
-
-               *node_sd = SD_NODE_INIT;
-               node_sd->span = cpu_possible_map;
-               node_sd->groups = &sched_group_nodes[cpu_to_node(i)];
-
-               *cpu_sd = SD_CPU_INIT;
-               cpus_and(cpu_sd->span, nodemask, cpu_possible_map);
-               cpu_sd->groups = &sched_group_cpus[i];
-               cpu_sd->parent = node_sd;
-       }
+/* Groups for isolated scheduling domains */
+static struct sched_group sched_group_isolated[NR_CPUS];
 
-       /* Set up groups */
-       for (i = 0; i < MAX_NUMNODES; i++) {
-               cpumask_t tmp = node_to_cpumask(i);
-               cpumask_t nodemask;
-               struct sched_group *first_cpu = NULL, *last_cpu = NULL;
-               struct sched_group *node = &sched_group_nodes[i];
-               int j;
+/* cpus with isolated domains */
+cpumask_t __initdata cpu_isolated_map = CPU_MASK_NONE;
 
-               cpus_and(nodemask, tmp, cpu_possible_map);
+__init static int cpu_to_isolated_group(int cpu)
+{
+       return cpu;
+}
 
-               if (cpus_empty(nodemask))
-                       continue;
+/* Setup the mask of cpus configured for isolated domains */
+static int __init isolated_cpu_setup(char *str)
+{
+       int ints[NR_CPUS], i;
 
-               node->cpumask = nodemask;
-               node->cpu_power = SCHED_LOAD_SCALE * cpus_weight(node->cpumask);
+       str = get_options(str, ARRAY_SIZE(ints), ints);
+       cpus_clear(cpu_isolated_map);
+       for (i = 1; i <= ints[0]; i++)
+               cpu_set(ints[i], cpu_isolated_map);
+       return 1;
+}
 
-               for_each_cpu_mask(j, node->cpumask) {
-                       struct sched_group *cpu = &sched_group_cpus[j];
+__setup ("isolcpus=", isolated_cpu_setup);
 
-                       cpus_clear(cpu->cpumask);
-                       cpu_set(j, cpu->cpumask);
-                       cpu->cpu_power = SCHED_LOAD_SCALE;
+/*
+ * init_sched_build_groups takes an array of groups, the cpumask we wish
+ * to span, and a pointer to a function which identifies what group a CPU
+ * belongs to. The return value of group_fn must be a valid index into the
+ * groups[] array, and must be >= 0 and < NR_CPUS (due to the fact that we
+ * keep track of groups covered with a cpumask_t).
+ *
+ * init_sched_build_groups will build a circular linked list of the groups
+ * covered by the given span, and will set each group's ->cpumask correctly,
+ * and ->cpu_power to 0.
+ */
+__init static void init_sched_build_groups(struct sched_group groups[],
+                       cpumask_t span, int (*group_fn)(int cpu))
+{
+       struct sched_group *first = NULL, *last = NULL;
+       cpumask_t covered = CPU_MASK_NONE;
+       int i;
 
-                       if (!first_cpu)
-                               first_cpu = cpu;
-                       if (last_cpu)
-                               last_cpu->next = cpu;
-                       last_cpu = cpu;
-               }
-               last_cpu->next = first_cpu;
+       for_each_cpu_mask(i, span) {
+               int group = group_fn(i);
+               struct sched_group *sg = &groups[group];
+               int j;
 
-               if (!first_node)
-                       first_node = node;
-               if (last_node)
-                       last_node->next = node;
-               last_node = node;
-       }
-       last_node->next = first_node;
+               if (cpu_isset(i, covered))
+                       continue;
 
-       mb();
-       for_each_cpu(i) {
-               struct sched_domain *cpu_sd = &per_cpu(cpu_domains, i);
-               cpu_attach_domain(cpu_sd, i);
+               sg->cpumask = CPU_MASK_NONE;
+               sg->cpu_power = 0;
+
+               for_each_cpu_mask(j, span) {
+                       if (group_fn(j) != group)
+                               continue;
+
+                       cpu_set(j, covered);
+                       cpu_set(j, sg->cpumask);
+               }
+               if (!first)
+                       first = sg;
+               if (last)
+                       last->next = sg;
+               last = sg;
        }
+       last->next = first;
 }
 
-#else /* !CONFIG_NUMA */
-static void __init arch_init_sched_domains(void)
+__init static void arch_init_sched_domains(void)
 {
        int i;
-       struct sched_group *first_cpu = NULL, *last_cpu = NULL;
+       cpumask_t cpu_default_map;
+
+       /*
+        * 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_complement(cpu_default_map, cpu_isolated_map);
+       cpus_and(cpu_default_map, cpu_default_map, cpu_possible_map);
 
        /* Set up domains */
        for_each_cpu(i) {
-               struct sched_domain *cpu_sd = &per_cpu(cpu_domains, i);
+               int group;
+               struct sched_domain *sd = NULL, *p;
+               cpumask_t nodemask = node_to_cpumask(cpu_to_node(i));
+
+               cpus_and(nodemask, nodemask, cpu_default_map);
+
+               /*
+                * Set up isolated domains.
+                * Unlike those of other cpus, the domains and groups are
+                * single level, and span a single cpu.
+                */
+               if (cpu_isset(i, cpu_isolated_map)) {
+#ifdef CONFIG_SCHED_SMT
+                       sd = &per_cpu(cpu_domains, i);
+#else
+                       sd = &per_cpu(phys_domains, i);
+#endif
+                       group = cpu_to_isolated_group(i);
+                       *sd = SD_CPU_INIT;
+                       cpu_set(i, sd->span);
+                       sd->balance_interval = INT_MAX; /* Don't balance */
+                       sd->flags = 0;                  /* Avoid WAKE_ */
+                       sd->groups = &sched_group_isolated[group];
+                       printk(KERN_INFO "Setting up cpu %d isolated.\n", i);
+                       /* Single level, so continue with next cpu */
+                       continue;
+               }
+
+#ifdef CONFIG_NUMA
+               sd = &per_cpu(node_domains, i);
+               group = cpu_to_node_group(i);
+               *sd = SD_NODE_INIT;
+               /* FIXME: should be multilevel, in arch code */
+               sd->span = sched_domain_node_span(i);
+               cpus_and(sd->span, sd->span, cpu_default_map);
+               sd->groups = &sched_group_nodes[group];
+#endif
 
-               *cpu_sd = SD_CPU_INIT;
-               cpu_sd->span = cpu_possible_map;
-               cpu_sd->groups = &sched_group_cpus[i];
+               p = sd;
+               sd = &per_cpu(phys_domains, i);
+               group = cpu_to_phys_group(i);
+               *sd = SD_CPU_INIT;
+#ifdef CONFIG_NUMA
+               sd->span = nodemask;
+#else
+               sd->span = cpu_possible_map;
+#endif
+               sd->parent = p;
+               sd->groups = &sched_group_phys[group];
+
+#ifdef CONFIG_SCHED_SMT
+               p = sd;
+               sd = &per_cpu(cpu_domains, i);
+               group = cpu_to_cpu_group(i);
+               *sd = SD_SIBLING_INIT;
+               sd->span = cpu_sibling_map[i];
+               cpus_and(sd->span, sd->span, cpu_default_map);
+               sd->parent = p;
+               sd->groups = &sched_group_cpus[group];
+#endif
        }
 
-       /* Set up CPU groups */
-       for_each_cpu_mask(i, cpu_possible_map) {
-               struct sched_group *cpu = &sched_group_cpus[i];
+#ifdef CONFIG_SCHED_SMT
+       /* Set up CPU (sibling) groups */
+       for_each_cpu(i) {
+               cpumask_t this_sibling_map = cpu_sibling_map[i];
+               cpus_and(this_sibling_map, this_sibling_map, cpu_default_map);
+               if (i != first_cpu(this_sibling_map))
+                       continue;
+
+               init_sched_build_groups(sched_group_cpus, this_sibling_map,
+                                               &cpu_to_cpu_group);
+       }
+#endif
+
+       /* Set up isolated groups */
+       for_each_cpu_mask(i, cpu_isolated_map) {
+               cpumask_t mask;
+               cpus_clear(mask);
+               cpu_set(i, mask);
+               init_sched_build_groups(sched_group_isolated, mask,
+                                               &cpu_to_isolated_group);
+       }
+
+#ifdef CONFIG_NUMA
+       /* Set up physical groups */
+       for (i = 0; i < MAX_NUMNODES; i++) {
+               cpumask_t nodemask = node_to_cpumask(i);
+
+               cpus_and(nodemask, nodemask, cpu_default_map);
+               if (cpus_empty(nodemask))
+                       continue;
+
+               init_sched_build_groups(sched_group_phys, nodemask,
+                                               &cpu_to_phys_group);
+       }
+#else
+       init_sched_build_groups(sched_group_phys, cpu_possible_map,
+                                                       &cpu_to_phys_group);
+#endif
+
+#ifdef CONFIG_NUMA
+       /* Set up node groups */
+       init_sched_build_groups(sched_group_nodes, cpu_default_map,
+                                       &cpu_to_node_group);
+#endif
+
+       /* Calculate CPU power for physical packages and nodes */
+       for_each_cpu_mask(i, cpu_default_map) {
+               int power;
+               struct sched_domain *sd;
+#ifdef CONFIG_SCHED_SMT
+               sd = &per_cpu(cpu_domains, i);
+               power = SCHED_LOAD_SCALE;
+               sd->groups->cpu_power = power;
+#endif
 
-               cpus_clear(cpu->cpumask);
-               cpu_set(i, cpu->cpumask);
-               cpu->cpu_power = SCHED_LOAD_SCALE;
+               sd = &per_cpu(phys_domains, i);
+               power = SCHED_LOAD_SCALE + SCHED_LOAD_SCALE *
+                               (cpus_weight(sd->groups->cpumask)-1) / 10;
+               sd->groups->cpu_power = power;
 
-               if (!first_cpu)
-                       first_cpu = cpu;
-               if (last_cpu)
-                       last_cpu->next = cpu;
-               last_cpu = cpu;
+#ifdef CONFIG_NUMA
+               if (i == first_cpu(sd->groups->cpumask)) {
+                       /* Only add "power" once for each physical package. */
+                       sd = &per_cpu(node_domains, i);
+                       sd->groups->cpu_power += power;
+               }
+#endif
        }
-       last_cpu->next = first_cpu;
 
-       mb(); /* domains were modified outside the lock */
+       /* Attach the domains */
        for_each_cpu(i) {
-               struct sched_domain *cpu_sd = &per_cpu(cpu_domains, i);
-               cpu_attach_domain(cpu_sd, i);
+               struct sched_domain *sd;
+#ifdef CONFIG_SCHED_SMT
+               sd = &per_cpu(cpu_domains, i);
+#else
+               sd = &per_cpu(phys_domains, i);
+#endif
+               cpu_attach_domain(sd, i);
        }
 }
 
-#endif /* CONFIG_NUMA */
-#endif /* ARCH_HAS_SCHED_DOMAIN */
-
-#define SCHED_DOMAIN_DEBUG
+#undef SCHED_DOMAIN_DEBUG
 #ifdef SCHED_DOMAIN_DEBUG
 void sched_domain_debug(void)
 {
@@ -3965,8 +4773,9 @@ int in_sched_functions(unsigned long addr)
 {
        /* Linker adds these: start and end of __sched functions */
        extern char __sched_text_start[], __sched_text_end[];
-       return addr >= (unsigned long)__sched_text_start
-               && addr < (unsigned long)__sched_text_end;
+       return in_lock_functions(addr) ||
+               (addr >= (unsigned long)__sched_text_start
+               && addr < (unsigned long)__sched_text_end);
 }
 
 void __init sched_init(void)
@@ -4009,7 +4818,9 @@ void __init sched_init(void)
                rq->migration_thread = NULL;
                INIT_LIST_HEAD(&rq->migration_queue);
 #endif
+#ifdef CONFIG_VSERVER_HARDCPU
                INIT_LIST_HEAD(&rq->hold_queue);
+#endif
                atomic_set(&rq->nr_iowait, 0);
 
                for (j = 0; j < 2; j++) {
@@ -4022,21 +4833,20 @@ void __init sched_init(void)
                        __set_bit(MAX_PRIO, array->bitmap);
                }
        }
-       /*
-        * We have to do a little magic to get the first
-        * thread right in SMP mode.
-        */
-       rq = this_rq();
-       rq->curr = current;
-       rq->idle = current;
-       set_task_cpu(current, smp_processor_id());
-       wake_up_forked_process(current);
 
        /*
         * The boot idle thread does lazy MMU switching as well:
         */
        atomic_inc(&init_mm.mm_count);
        enter_lazy_tlb(&init_mm, current);
+
+       /*
+        * Make us the idle thread. Technically, schedule() should not be
+        * called from this thread, however somewhere below it might be,
+        * but because we are the idle thread, we just pick up running again
+        * when this runqueue becomes "idle".
+        */
+       init_idle(current, smp_processor_id());
 }
 
 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
@@ -4060,49 +4870,3 @@ void __might_sleep(char *file, int line)
 }
 EXPORT_SYMBOL(__might_sleep);
 #endif
-
-
-#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT)
-/*
- * This could be a long-held lock.  If another CPU holds it for a long time,
- * and that CPU is not asked to reschedule then *this* CPU will spin on the
- * lock for a long time, even if *this* CPU is asked to reschedule.
- *
- * So what we do here, in the slow (contended) path is to spin on the lock by
- * hand while permitting preemption.
- *
- * Called inside preempt_disable().
- */
-void __sched __preempt_spin_lock(spinlock_t *lock)
-{
-       if (preempt_count() > 1) {
-               _raw_spin_lock(lock);
-               return;
-       }
-       do {
-               preempt_enable();
-               while (spin_is_locked(lock))
-                       cpu_relax();
-               preempt_disable();
-       } while (!_raw_spin_trylock(lock));
-}
-
-EXPORT_SYMBOL(__preempt_spin_lock);
-
-void __sched __preempt_write_lock(rwlock_t *lock)
-{
-       if (preempt_count() > 1) {
-               _raw_write_lock(lock);
-               return;
-       }
-
-       do {
-               preempt_enable();
-               while (rwlock_is_locked(lock))
-                       cpu_relax();
-               preempt_disable();
-       } while (!_raw_write_trylock(lock));
-}
-
-EXPORT_SYMBOL(__preempt_write_lock);
-#endif /* defined(CONFIG_SMP) && defined(CONFIG_PREEMPT) */