[WATCHDOG] i6300esb.c-WDT_ENABLE-bug
[safe/jmp/linux-2.6] / kernel / sched.c
index 54ce787..2632b81 100644 (file)
@@ -262,7 +262,7 @@ static DEFINE_PER_CPU(struct runqueue, runqueues);
 
 /*
  * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
- * See update_sched_domains: synchronize_kernel for details.
+ * See detach_destroy_domains: synchronize_sched for details.
  *
  * The domain tree of any CPU may only be accessed from within
  * preempt-disabled sections.
@@ -673,7 +673,7 @@ static inline void __activate_idle_task(task_t *p, runqueue_t *rq)
        rq->nr_running++;
 }
 
-static void recalc_task_prio(task_t *p, unsigned long long now)
+static int recalc_task_prio(task_t *p, unsigned long long now)
 {
        /* Caller must always ensure 'now >= p->timestamp' */
        unsigned long long __sleep_time = now - p->timestamp;
@@ -732,7 +732,7 @@ static void recalc_task_prio(task_t *p, unsigned long long now)
                }
        }
 
-       p->prio = effective_prio(p);
+       return effective_prio(p);
 }
 
 /*
@@ -755,7 +755,7 @@ static void activate_task(task_t *p, runqueue_t *rq, int local)
        }
 #endif
 
-       recalc_task_prio(p, now);
+       p->prio = recalc_task_prio(p, now);
 
        /*
         * This checks to make sure it's not an uninterruptible task
@@ -1021,8 +1021,59 @@ static int find_idlest_cpu(struct sched_group *group, int this_cpu)
        return idlest;
 }
 
+/*
+ * sched_balance_self: balance the current task (running on cpu) in domains
+ * that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and
+ * SD_BALANCE_EXEC.
+ *
+ * Balance, ie. select the least loaded group.
+ *
+ * Returns the target CPU number, or the same CPU if no balancing is needed.
+ *
+ * preempt must be disabled.
+ */
+static int sched_balance_self(int cpu, int flag)
+{
+       struct task_struct *t = current;
+       struct sched_domain *tmp, *sd = NULL;
 
-#endif
+       for_each_domain(cpu, tmp)
+               if (tmp->flags & flag)
+                       sd = tmp;
+
+       while (sd) {
+               cpumask_t span;
+               struct sched_group *group;
+               int new_cpu;
+               int weight;
+
+               span = sd->span;
+               group = find_idlest_group(sd, t, cpu);
+               if (!group)
+                       goto nextlevel;
+
+               new_cpu = find_idlest_cpu(group, cpu);
+               if (new_cpu == -1 || new_cpu == cpu)
+                       goto nextlevel;
+
+               /* Now try balancing at a lower domain level */
+               cpu = new_cpu;
+nextlevel:
+               sd = NULL;
+               weight = cpus_weight(span);
+               for_each_domain(cpu, tmp) {
+                       if (weight <= cpus_weight(tmp->span))
+                               break;
+                       if (tmp->flags & flag)
+                               sd = tmp;
+               }
+               /* while loop will break here if sd == NULL */
+       }
+
+       return cpu;
+}
+
+#endif /* CONFIG_SMP */
 
 /*
  * wake_idle() will wake a task on an idle cpu if task->cpu is
@@ -1240,8 +1291,15 @@ int fastcall wake_up_state(task_t *p, unsigned int state)
  * Perform scheduler related setup for a newly forked process p.
  * p is forked by current.
  */
-void fastcall sched_fork(task_t *p)
+void fastcall sched_fork(task_t *p, int clone_flags)
 {
+       int cpu = get_cpu();
+
+#ifdef CONFIG_SMP
+       cpu = sched_balance_self(cpu, SD_BALANCE_FORK);
+#endif
+       set_task_cpu(p, cpu);
+
        /*
         * We mark the process as running here, but have not actually
         * inserted it onto the runqueue yet. This guarantees that
@@ -1282,12 +1340,10 @@ void fastcall sched_fork(task_t *p)
                 * runqueue lock is not a problem.
                 */
                current->time_slice = 1;
-               preempt_disable();
                scheduler_tick();
-               local_irq_enable();
-               preempt_enable();
-       } else
-               local_irq_enable();
+       }
+       local_irq_enable();
+       put_cpu();
 }
 
 /*
@@ -1302,64 +1358,12 @@ void fastcall wake_up_new_task(task_t * p, unsigned long clone_flags)
        unsigned long flags;
        int this_cpu, cpu;
        runqueue_t *rq, *this_rq;
-#ifdef CONFIG_SMP
-       struct sched_domain *tmp, *sd = NULL;
-#endif
 
        rq = task_rq_lock(p, &flags);
        BUG_ON(p->state != TASK_RUNNING);
        this_cpu = smp_processor_id();
        cpu = task_cpu(p);
 
-#ifdef CONFIG_SMP
-       for_each_domain(cpu, tmp)
-               if (tmp->flags & SD_BALANCE_FORK)
-                       sd = tmp;
-
-       if (sd) {
-               cpumask_t span;
-               int new_cpu;
-               struct sched_group *group;
-
-again:
-               schedstat_inc(sd, sbf_cnt);
-               span = sd->span;
-               cpu = task_cpu(p);
-               group = find_idlest_group(sd, p, cpu);
-               if (!group) {
-                       schedstat_inc(sd, sbf_balanced);
-                       goto nextlevel;
-               }
-
-               new_cpu = find_idlest_cpu(group, cpu);
-               if (new_cpu == -1 || new_cpu == cpu) {
-                       schedstat_inc(sd, sbf_balanced);
-                       goto nextlevel;
-               }
-
-               if (cpu_isset(new_cpu, p->cpus_allowed)) {
-                       schedstat_inc(sd, sbf_pushed);
-                       set_task_cpu(p, new_cpu);
-                       task_rq_unlock(rq, &flags);
-                       rq = task_rq_lock(p, &flags);
-                       cpu = task_cpu(p);
-               }
-
-               /* Now try balancing at a lower domain level */
-nextlevel:
-               sd = NULL;
-               for_each_domain(cpu, tmp) {
-                       if (cpus_subset(span, tmp->span))
-                               break;
-                       if (tmp->flags & SD_BALANCE_FORK)
-                               sd = tmp;
-               }
-
-               if (sd)
-                       goto again;
-       }
-
-#endif
        /*
         * We decrease the sleep average of forking parents
         * and children as well, to keep max-interactive tasks
@@ -1474,6 +1478,7 @@ static inline void prepare_task_switch(runqueue_t *rq, task_t *next)
 
 /**
  * finish_task_switch - clean up after a task-switch
+ * @rq: runqueue associated with task-switch
  * @prev: the thread we just switched away from.
  *
  * finish_task_switch must be called after the context switch, paired
@@ -1708,58 +1713,16 @@ out:
 }
 
 /*
- * 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.
+ * sched_exec - execve() is a valuable balancing opportunity, because at
+ * this point the task has the smallest effective memory and cache footprint.
  */
 void sched_exec(void)
 {
-       struct sched_domain *tmp, *sd = NULL;
        int new_cpu, this_cpu = get_cpu();
-
-       for_each_domain(this_cpu, tmp)
-               if (tmp->flags & SD_BALANCE_EXEC)
-                       sd = tmp;
-
-       if (sd) {
-               cpumask_t span;
-               struct sched_group *group;
-again:
-               schedstat_inc(sd, sbe_cnt);
-               span = sd->span;
-               group = find_idlest_group(sd, current, this_cpu);
-               if (!group) {
-                       schedstat_inc(sd, sbe_balanced);
-                       goto nextlevel;
-               }
-               new_cpu = find_idlest_cpu(group, this_cpu);
-               if (new_cpu == -1 || new_cpu == this_cpu) {
-                       schedstat_inc(sd, sbe_balanced);
-                       goto nextlevel;
-               }
-
-               schedstat_inc(sd, sbe_pushed);
-               put_cpu();
-               sched_migrate_task(current, new_cpu);
-
-               /* Now try balancing at a lower domain level */
-               this_cpu = get_cpu();
-nextlevel:
-               sd = NULL;
-               for_each_domain(this_cpu, tmp) {
-                       if (cpus_subset(span, tmp->span))
-                               break;
-                       if (tmp->flags & SD_BALANCE_EXEC)
-                               sd = tmp;
-               }
-
-               if (sd)
-                       goto again;
-       }
-
+       new_cpu = sched_balance_self(this_cpu, SD_BALANCE_EXEC);
        put_cpu();
+       if (new_cpu != this_cpu)
+               sched_migrate_task(current, new_cpu);
 }
 
 /*
@@ -2069,6 +2032,12 @@ static runqueue_t *find_busiest_queue(struct sched_group *group)
 }
 
 /*
+ * Max backoff if we encounter pinned tasks. Pretty arbitrary value, but
+ * so long as it is large enough.
+ */
+#define MAX_PINNED_INTERVAL    512
+
+/*
  * Check this_cpu to ensure it is balanced within domain. Attempt to move
  * tasks if there is an imbalance.
  *
@@ -2080,7 +2049,7 @@ static int load_balance(int this_cpu, runqueue_t *this_rq,
        struct sched_group *group;
        runqueue_t *busiest;
        unsigned long imbalance;
-       int nr_moved, all_pinned;
+       int nr_moved, all_pinned = 0;
        int active_balance = 0;
 
        spin_lock(&this_rq->lock);
@@ -2171,7 +2140,8 @@ out_balanced:
 
        sd->nr_balance_failed = 0;
        /* tune up the balancing interval */
-       if (sd->balance_interval < sd->max_interval)
+       if ((all_pinned && sd->balance_interval < MAX_PINNED_INTERVAL) ||
+                       (sd->balance_interval < sd->max_interval))
                sd->balance_interval *= 2;
 
        return 0;
@@ -2782,7 +2752,7 @@ asmlinkage void __sched schedule(void)
        struct list_head *queue;
        unsigned long long now;
        unsigned long run_time;
-       int cpu, idx;
+       int cpu, idx, new_prio;
 
        /*
         * Test if we are atomic.  Since do_exit() needs to call into
@@ -2904,15 +2874,21 @@ go_idle:
                        delta = delta * (ON_RUNQUEUE_WEIGHT * 128 / 100) / 128;
 
                array = next->array;
-               dequeue_task(next, array);
-               recalc_task_prio(next, next->timestamp + delta);
-               enqueue_task(next, array);
+               new_prio = recalc_task_prio(next, next->timestamp + delta);
+
+               if (unlikely(next->prio != new_prio)) {
+                       dequeue_task(next, array);
+                       next->prio = new_prio;
+                       enqueue_task(next, array);
+               } else
+                       requeue_task(next, array);
        }
        next->activated = 0;
 switch_tasks:
        if (next == rq->idle)
                schedstat_inc(rq, sched_goidle);
        prefetch(next);
+       prefetch_stack(next);
        clear_tsk_need_resched(prev);
        rcu_qsctr_inc(task_cpu(prev));
 
@@ -3404,8 +3380,8 @@ EXPORT_SYMBOL(set_user_nice);
  */
 int can_nice(const task_t *p, const int nice)
 {
-       /* convert nice value [19,-20] to rlimit style value [0,39] */
-       int nice_rlim = 19 - nice;
+       /* convert nice value [19,-20] to rlimit style value [1,40] */
+       int nice_rlim = 20 - nice;
        return (nice_rlim <= p->signal->rlim[RLIMIT_NICE].rlim_cur ||
                capable(CAP_SYS_NICE));
 }
@@ -3474,15 +3450,7 @@ int task_nice(const task_t *p)
 {
        return TASK_NICE(p);
 }
-
-/*
- * The only users of task_nice are binfmt_elf and binfmt_elf32.
- * binfmt_elf is no longer modular, but binfmt_elf32 still is.
- * Therefore, task_nice is needed if there is a compat_mode.
- */
-#ifdef CONFIG_COMPAT
 EXPORT_SYMBOL_GPL(task_nice);
-#endif
 
 /**
  * idle_cpu - is a given cpu idle currently?
@@ -3520,7 +3488,7 @@ static void __setscheduler(struct task_struct *p, int policy, int prio)
        p->policy = policy;
        p->rt_priority = prio;
        if (policy != SCHED_NORMAL)
-               p->prio = MAX_USER_RT_PRIO-1 - p->rt_priority;
+               p->prio = MAX_RT_PRIO-1 - p->rt_priority;
        else
                p->prio = p->static_prio;
 }
@@ -3552,18 +3520,31 @@ recheck:
         * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL is 0.
         */
        if (param->sched_priority < 0 ||
-           param->sched_priority > MAX_USER_RT_PRIO-1)
+           (p->mm &&  param->sched_priority > MAX_USER_RT_PRIO-1) ||
+           (!p->mm && param->sched_priority > MAX_RT_PRIO-1))
                return -EINVAL;
        if ((policy == SCHED_NORMAL) != (param->sched_priority == 0))
                return -EINVAL;
 
-       if ((policy == SCHED_FIFO || policy == SCHED_RR) &&
-           param->sched_priority > p->signal->rlim[RLIMIT_RTPRIO].rlim_cur &&
-           !capable(CAP_SYS_NICE))
-               return -EPERM;
-       if ((current->euid != p->euid) && (current->euid != p->uid) &&
-           !capable(CAP_SYS_NICE))
-               return -EPERM;
+       /*
+        * Allow unprivileged RT tasks to decrease priority:
+        */
+       if (!capable(CAP_SYS_NICE)) {
+               /* can't change policy */
+               if (policy != p->policy &&
+                       !p->signal->rlim[RLIMIT_RTPRIO].rlim_cur)
+                       return -EPERM;
+               /* can't increase priority */
+               if (policy != SCHED_NORMAL &&
+                   param->sched_priority > p->rt_priority &&
+                   param->sched_priority >
+                               p->signal->rlim[RLIMIT_RTPRIO].rlim_cur)
+                       return -EPERM;
+               /* can't change other user's priorities */
+               if ((current->euid != p->euid) &&
+                   (current->euid != p->uid))
+                       return -EPERM;
+       }
 
        retval = security_task_setscheduler(p, policy, param);
        if (retval)
@@ -3900,6 +3881,13 @@ asmlinkage long sys_sched_yield(void)
 
 static inline void __cond_resched(void)
 {
+       /*
+        * The BKS might be reacquired before we have dropped
+        * PREEMPT_ACTIVE, which could trigger a second
+        * cond_resched() call.
+        */
+       if (unlikely(preempt_count()))
+               return;
        do {
                add_preempt_count(PREEMPT_ACTIVE);
                schedule();
@@ -4189,6 +4177,14 @@ void show_state(void)
        read_unlock(&tasklist_lock);
 }
 
+/**
+ * init_idle - set up an idle thread for a given CPU
+ * @idle: task in question
+ * @cpu: cpu the idle task belongs to
+ *
+ * NOTE: this function does not set the idle thread's NEED_RESCHED
+ * flag, to make booting more robust.
+ */
 void __devinit init_idle(task_t *idle, int cpu)
 {
        runqueue_t *rq = cpu_rq(cpu);
@@ -4206,7 +4202,6 @@ void __devinit init_idle(task_t *idle, int cpu)
 #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW)
        idle->oncpu = 1;
 #endif
-       set_tsk_need_resched(idle);
        spin_unlock_irqrestore(&rq->lock, flags);
 
        /* Set the preempt count _outside_ the spinlocks! */
@@ -4350,8 +4345,7 @@ static int migration_thread(void * data)
                struct list_head *head;
                migration_req_t *req;
 
-               if (current->flags & PF_FREEZE)
-                       refrigerator(PF_FREEZE);
+               try_to_freeze();
 
                spin_lock_irq(&rq->lock);
 
@@ -4639,7 +4633,7 @@ int __init migration_init(void)
 #endif
 
 #ifdef CONFIG_SMP
-#define SCHED_DOMAIN_DEBUG
+#undef SCHED_DOMAIN_DEBUG
 #ifdef SCHED_DOMAIN_DEBUG
 static void sched_domain_debug(struct sched_domain *sd, int cpu)
 {
@@ -4732,7 +4726,7 @@ static void sched_domain_debug(struct sched_domain *sd, int cpu)
 #define sched_domain_debug(sd, cpu) {}
 #endif
 
-static int __devinit sd_degenerate(struct sched_domain *sd)
+static int sd_degenerate(struct sched_domain *sd)
 {
        if (cpus_weight(sd->span) == 1)
                return 1;
@@ -4755,7 +4749,7 @@ static int __devinit sd_degenerate(struct sched_domain *sd)
        return 1;
 }
 
-static int __devinit sd_parent_degenerate(struct sched_domain *sd,
+static int sd_parent_degenerate(struct sched_domain *sd,
                                                struct sched_domain *parent)
 {
        unsigned long cflags = sd->flags, pflags = parent->flags;
@@ -4787,7 +4781,7 @@ static int __devinit sd_parent_degenerate(struct sched_domain *sd,
  * Attach the domain 'sd' to 'cpu' as its base domain.  Callers must
  * hold the hotplug lock.
  */
-void __devinit cpu_attach_domain(struct sched_domain *sd, int cpu)
+static void cpu_attach_domain(struct sched_domain *sd, int cpu)
 {
        runqueue_t *rq = cpu_rq(cpu);
        struct sched_domain *tmp;
@@ -4810,7 +4804,7 @@ void __devinit cpu_attach_domain(struct sched_domain *sd, int cpu)
 }
 
 /* cpus with isolated domains */
-cpumask_t __devinitdata cpu_isolated_map = CPU_MASK_NONE;
+static cpumask_t __devinitdata cpu_isolated_map = CPU_MASK_NONE;
 
 /* Setup the mask of cpus configured for isolated domains */
 static int __init isolated_cpu_setup(char *str)
@@ -4838,8 +4832,8 @@ __setup ("isolcpus=", isolated_cpu_setup);
  * covered by the given span, and will set each group's ->cpumask correctly,
  * and ->cpu_power to 0.
  */
-void __devinit init_sched_build_groups(struct sched_group groups[],
-                       cpumask_t span, int (*group_fn)(int cpu))
+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;
@@ -4872,15 +4866,89 @@ void __devinit init_sched_build_groups(struct sched_group groups[],
        last->next = first;
 }
 
+#define SD_NODES_PER_DOMAIN 16
 
-#ifdef ARCH_HAS_SCHED_DOMAIN
-extern void __devinit arch_init_sched_domains(void);
-extern void __devinit arch_destroy_sched_domains(void);
-#else
+#ifdef CONFIG_NUMA
+/**
+ * find_next_best_node - find the next node to include in a sched_domain
+ * @node: node whose sched_domain we're building
+ * @used_nodes: nodes already in the sched_domain
+ *
+ * Find the next node to include in a given scheduling domain.  Simply
+ * finds the closest node not already in the @used_nodes map.
+ *
+ * Should use nodemask_t.
+ */
+static int find_next_best_node(int node, unsigned long *used_nodes)
+{
+       int i, n, val, min_val, best_node = 0;
+
+       min_val = INT_MAX;
+
+       for (i = 0; i < MAX_NUMNODES; i++) {
+               /* Start at @node */
+               n = (node + i) % MAX_NUMNODES;
+
+               if (!nr_cpus_node(n))
+                       continue;
+
+               /* Skip already used nodes */
+               if (test_bit(n, used_nodes))
+                       continue;
+
+               /* Simple min distance search */
+               val = node_distance(node, n);
+
+               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.
+ */
+static cpumask_t sched_domain_node_span(int node)
+{
+       int i;
+       cpumask_t span, nodemask;
+       DECLARE_BITMAP(used_nodes, MAX_NUMNODES);
+
+       cpus_clear(span);
+       bitmap_zero(used_nodes, MAX_NUMNODES);
+
+       nodemask = node_to_cpumask(node);
+       cpus_or(span, span, nodemask);
+       set_bit(node, used_nodes);
+
+       for (i = 1; i < SD_NODES_PER_DOMAIN; i++) {
+               int next_node = find_next_best_node(node, used_nodes);
+               nodemask = node_to_cpumask(next_node);
+               cpus_or(span, span, nodemask);
+       }
+
+       return span;
+}
+#endif
+
+/*
+ * At the moment, CONFIG_SCHED_SMT is never defined, but leave it in so we
+ * can switch it on easily if needed.
+ */
 #ifdef CONFIG_SCHED_SMT
 static DEFINE_PER_CPU(struct sched_domain, cpu_domains);
 static struct sched_group sched_group_cpus[NR_CPUS];
-static int __devinit cpu_to_cpu_group(int cpu)
+static int cpu_to_cpu_group(int cpu)
 {
        return cpu;
 }
@@ -4888,7 +4956,7 @@ static int __devinit cpu_to_cpu_group(int cpu)
 
 static DEFINE_PER_CPU(struct sched_domain, phys_domains);
 static struct sched_group sched_group_phys[NR_CPUS];
-static int __devinit cpu_to_phys_group(int cpu)
+static int cpu_to_phys_group(int cpu)
 {
 #ifdef CONFIG_SCHED_SMT
        return first_cpu(cpu_sibling_map[cpu]);
@@ -4898,74 +4966,86 @@ static int __devinit cpu_to_phys_group(int cpu)
 }
 
 #ifdef CONFIG_NUMA
-
-static DEFINE_PER_CPU(struct sched_domain, node_domains);
-static struct sched_group sched_group_nodes[MAX_NUMNODES];
-static int __devinit cpu_to_node_group(int cpu)
-{
-       return cpu_to_node(cpu);
-}
-#endif
-
-#if defined(CONFIG_SCHED_SMT) && defined(CONFIG_NUMA)
 /*
- * The domains setup code relies on siblings not spanning
- * multiple nodes. Make sure the architecture has a proper
- * siblings map:
+ * The init_sched_build_groups can't handle what we want to do with node
+ * groups, so roll our own. Now each node has its own list of groups which
+ * gets dynamically allocated.
  */
-static void check_sibling_maps(void)
-{
-       int i, j;
+static DEFINE_PER_CPU(struct sched_domain, node_domains);
+static struct sched_group **sched_group_nodes_bycpu[NR_CPUS];
 
-       for_each_online_cpu(i) {
-               for_each_cpu_mask(j, cpu_sibling_map[i]) {
-                       if (cpu_to_node(i) != cpu_to_node(j)) {
-                               printk(KERN_INFO "warning: CPU %d siblings map "
-                                       "to different node - isolating "
-                                       "them.\n", i);
-                               cpu_sibling_map[i] = cpumask_of_cpu(i);
-                               break;
-                       }
-               }
-       }
+static DEFINE_PER_CPU(struct sched_domain, allnodes_domains);
+static struct sched_group *sched_group_allnodes_bycpu[NR_CPUS];
+
+static int cpu_to_allnodes_group(int cpu)
+{
+       return cpu_to_node(cpu);
 }
 #endif
 
 /*
- * Set up scheduler domains and groups.  Callers must hold the hotplug lock.
+ * Build sched domains for a given set of cpus and attach the sched domains
+ * to the individual cpus
  */
-static void __devinit arch_init_sched_domains(void)
+void build_sched_domains(const cpumask_t *cpu_map)
 {
        int i;
-       cpumask_t cpu_default_map;
+#ifdef CONFIG_NUMA
+       struct sched_group **sched_group_nodes = NULL;
+       struct sched_group *sched_group_allnodes = NULL;
 
-#if defined(CONFIG_SCHED_SMT) && defined(CONFIG_NUMA)
-       check_sibling_maps();
-#endif
        /*
-        * 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.
+        * Allocate the per-node list of sched groups
         */
-       cpus_complement(cpu_default_map, cpu_isolated_map);
-       cpus_and(cpu_default_map, cpu_default_map, cpu_online_map);
+       sched_group_nodes = kmalloc(sizeof(struct sched_group*)*MAX_NUMNODES,
+                                          GFP_ATOMIC);
+       if (!sched_group_nodes) {
+               printk(KERN_WARNING "Can not alloc sched group node list\n");
+               return;
+       }
+       sched_group_nodes_bycpu[first_cpu(*cpu_map)] = sched_group_nodes;
+#endif
 
        /*
-        * Set up domains. Isolated domains just stay on the NULL domain.
+        * Set up domains for cpus specified by the cpu_map.
         */
-       for_each_cpu_mask(i, cpu_default_map) {
+       for_each_cpu_mask(i, *cpu_map) {
                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);
+               cpus_and(nodemask, nodemask, *cpu_map);
 
 #ifdef CONFIG_NUMA
+               if (cpus_weight(*cpu_map)
+                               > SD_NODES_PER_DOMAIN*cpus_weight(nodemask)) {
+                       if (!sched_group_allnodes) {
+                               sched_group_allnodes
+                                       = kmalloc(sizeof(struct sched_group)
+                                                       * MAX_NUMNODES,
+                                                 GFP_KERNEL);
+                               if (!sched_group_allnodes) {
+                                       printk(KERN_WARNING
+                                       "Can not alloc allnodes sched group\n");
+                                       break;
+                               }
+                               sched_group_allnodes_bycpu[i]
+                                               = sched_group_allnodes;
+                       }
+                       sd = &per_cpu(allnodes_domains, i);
+                       *sd = SD_ALLNODES_INIT;
+                       sd->span = *cpu_map;
+                       group = cpu_to_allnodes_group(i);
+                       sd->groups = &sched_group_allnodes[group];
+                       p = sd;
+               } else
+                       p = NULL;
+
                sd = &per_cpu(node_domains, i);
-               group = cpu_to_node_group(i);
                *sd = SD_NODE_INIT;
-               sd->span = cpu_default_map;
-               sd->groups = &sched_group_nodes[group];
+               sd->span = sched_domain_node_span(cpu_to_node(i));
+               sd->parent = p;
+               cpus_and(sd->span, sd->span, *cpu_map);
 #endif
 
                p = sd;
@@ -4982,7 +5062,7 @@ static void __devinit arch_init_sched_domains(void)
                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);
+               cpus_and(sd->span, sd->span, *cpu_map);
                sd->parent = p;
                sd->groups = &sched_group_cpus[group];
 #endif
@@ -4990,9 +5070,9 @@ static void __devinit arch_init_sched_domains(void)
 
 #ifdef CONFIG_SCHED_SMT
        /* Set up CPU (sibling) groups */
-       for_each_online_cpu(i) {
+       for_each_cpu_mask(i, *cpu_map) {
                cpumask_t this_sibling_map = cpu_sibling_map[i];
-               cpus_and(this_sibling_map, this_sibling_map, cpu_default_map);
+               cpus_and(this_sibling_map, this_sibling_map, *cpu_map);
                if (i != first_cpu(this_sibling_map))
                        continue;
 
@@ -5005,7 +5085,7 @@ static void __devinit arch_init_sched_domains(void)
        for (i = 0; i < MAX_NUMNODES; i++) {
                cpumask_t nodemask = node_to_cpumask(i);
 
-               cpus_and(nodemask, nodemask, cpu_default_map);
+               cpus_and(nodemask, nodemask, *cpu_map);
                if (cpus_empty(nodemask))
                        continue;
 
@@ -5015,12 +5095,81 @@ static void __devinit arch_init_sched_domains(void)
 
 #ifdef CONFIG_NUMA
        /* Set up node groups */
-       init_sched_build_groups(sched_group_nodes, cpu_default_map,
-                                       &cpu_to_node_group);
+       if (sched_group_allnodes)
+               init_sched_build_groups(sched_group_allnodes, *cpu_map,
+                                       &cpu_to_allnodes_group);
+
+       for (i = 0; i < MAX_NUMNODES; i++) {
+               /* Set up node groups */
+               struct sched_group *sg, *prev;
+               cpumask_t nodemask = node_to_cpumask(i);
+               cpumask_t domainspan;
+               cpumask_t covered = CPU_MASK_NONE;
+               int j;
+
+               cpus_and(nodemask, nodemask, *cpu_map);
+               if (cpus_empty(nodemask)) {
+                       sched_group_nodes[i] = NULL;
+                       continue;
+               }
+
+               domainspan = sched_domain_node_span(i);
+               cpus_and(domainspan, domainspan, *cpu_map);
+
+               sg = kmalloc(sizeof(struct sched_group), GFP_KERNEL);
+               sched_group_nodes[i] = sg;
+               for_each_cpu_mask(j, nodemask) {
+                       struct sched_domain *sd;
+                       sd = &per_cpu(node_domains, j);
+                       sd->groups = sg;
+                       if (sd->groups == NULL) {
+                               /* Turn off balancing if we have no groups */
+                               sd->flags = 0;
+                       }
+               }
+               if (!sg) {
+                       printk(KERN_WARNING
+                       "Can not alloc domain group for node %d\n", i);
+                       continue;
+               }
+               sg->cpu_power = 0;
+               sg->cpumask = nodemask;
+               cpus_or(covered, covered, nodemask);
+               prev = sg;
+
+               for (j = 0; j < MAX_NUMNODES; j++) {
+                       cpumask_t tmp, notcovered;
+                       int n = (i + j) % MAX_NUMNODES;
+
+                       cpus_complement(notcovered, covered);
+                       cpus_and(tmp, notcovered, *cpu_map);
+                       cpus_and(tmp, tmp, domainspan);
+                       if (cpus_empty(tmp))
+                               break;
+
+                       nodemask = node_to_cpumask(n);
+                       cpus_and(tmp, tmp, nodemask);
+                       if (cpus_empty(tmp))
+                               continue;
+
+                       sg = kmalloc(sizeof(struct sched_group), GFP_KERNEL);
+                       if (!sg) {
+                               printk(KERN_WARNING
+                               "Can not alloc domain group for node %d\n", j);
+                               break;
+                       }
+                       sg->cpu_power = 0;
+                       sg->cpumask = tmp;
+                       cpus_or(covered, covered, tmp);
+                       prev->next = sg;
+                       prev = sg;
+               }
+               prev->next = sched_group_nodes[i];
+       }
 #endif
 
        /* Calculate CPU power for physical packages and nodes */
-       for_each_cpu_mask(i, cpu_default_map) {
+       for_each_cpu_mask(i, *cpu_map) {
                int power;
                struct sched_domain *sd;
 #ifdef CONFIG_SCHED_SMT
@@ -5035,16 +5184,48 @@ static void __devinit arch_init_sched_domains(void)
                sd->groups->cpu_power = power;
 
 #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;
+               sd = &per_cpu(allnodes_domains, i);
+               if (sd->groups) {
+                       power = SCHED_LOAD_SCALE + SCHED_LOAD_SCALE *
+                               (cpus_weight(sd->groups->cpumask)-1) / 10;
+                       sd->groups->cpu_power = power;
                }
 #endif
        }
 
+#ifdef CONFIG_NUMA
+       for (i = 0; i < MAX_NUMNODES; i++) {
+               struct sched_group *sg = sched_group_nodes[i];
+               int j;
+
+               if (sg == NULL)
+                       continue;
+next_sg:
+               for_each_cpu_mask(j, sg->cpumask) {
+                       struct sched_domain *sd;
+                       int power;
+
+                       sd = &per_cpu(phys_domains, j);
+                       if (j != first_cpu(sd->groups->cpumask)) {
+                               /*
+                                * Only add "power" once for each
+                                * physical package.
+                                */
+                               continue;
+                       }
+                       power = SCHED_LOAD_SCALE + SCHED_LOAD_SCALE *
+                               (cpus_weight(sd->groups->cpumask)-1) / 10;
+
+                       sg->cpu_power += power;
+               }
+               sg = sg->next;
+               if (sg != sched_group_nodes[i])
+                       goto next_sg;
+       }
+#endif
+
        /* Attach the domains */
-       for_each_online_cpu(i) {
+       for_each_cpu_mask(i, *cpu_map) {
                struct sched_domain *sd;
 #ifdef CONFIG_SCHED_SMT
                sd = &per_cpu(cpu_domains, i);
@@ -5054,15 +5235,104 @@ static void __devinit arch_init_sched_domains(void)
                cpu_attach_domain(sd, i);
        }
 }
-
-#ifdef CONFIG_HOTPLUG_CPU
-static void __devinit arch_destroy_sched_domains(void)
+/*
+ * Set up scheduler domains and groups.  Callers must hold the hotplug lock.
+ */
+static void arch_init_sched_domains(const cpumask_t *cpu_map)
 {
-       /* Do nothing: everything is statically allocated. */
+       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_andnot(cpu_default_map, *cpu_map, cpu_isolated_map);
+
+       build_sched_domains(&cpu_default_map);
 }
+
+static void arch_destroy_sched_domains(const cpumask_t *cpu_map)
+{
+#ifdef CONFIG_NUMA
+       int i;
+       int cpu;
+
+       for_each_cpu_mask(cpu, *cpu_map) {
+               struct sched_group *sched_group_allnodes
+                       = sched_group_allnodes_bycpu[cpu];
+               struct sched_group **sched_group_nodes
+                       = sched_group_nodes_bycpu[cpu];
+
+               if (sched_group_allnodes) {
+                       kfree(sched_group_allnodes);
+                       sched_group_allnodes_bycpu[cpu] = NULL;
+               }
+
+               if (!sched_group_nodes)
+                       continue;
+
+               for (i = 0; i < MAX_NUMNODES; i++) {
+                       cpumask_t nodemask = node_to_cpumask(i);
+                       struct sched_group *oldsg, *sg = sched_group_nodes[i];
+
+                       cpus_and(nodemask, nodemask, *cpu_map);
+                       if (cpus_empty(nodemask))
+                               continue;
+
+                       if (sg == NULL)
+                               continue;
+                       sg = sg->next;
+next_sg:
+                       oldsg = sg;
+                       sg = sg->next;
+                       kfree(oldsg);
+                       if (oldsg != sched_group_nodes[i])
+                               goto next_sg;
+               }
+               kfree(sched_group_nodes);
+               sched_group_nodes_bycpu[cpu] = NULL;
+       }
 #endif
+}
 
-#endif /* ARCH_HAS_SCHED_DOMAIN */
+/*
+ * Detach sched domains from a group of cpus specified in cpu_map
+ * These cpus will now be attached to the NULL domain
+ */
+static inline void detach_destroy_domains(const cpumask_t *cpu_map)
+{
+       int i;
+
+       for_each_cpu_mask(i, *cpu_map)
+               cpu_attach_domain(NULL, i);
+       synchronize_sched();
+       arch_destroy_sched_domains(cpu_map);
+}
+
+/*
+ * Partition sched domains as specified by the cpumasks below.
+ * This attaches all cpus from the cpumasks to the NULL domain,
+ * waits for a RCU quiescent period, recalculates sched
+ * domain information and then attaches them back to the
+ * correct sched domains
+ * Call with hotplug lock held
+ */
+void partition_sched_domains(cpumask_t *partition1, cpumask_t *partition2)
+{
+       cpumask_t change_map;
+
+       cpus_and(*partition1, *partition1, cpu_online_map);
+       cpus_and(*partition2, *partition2, cpu_online_map);
+       cpus_or(change_map, *partition1, *partition2);
+
+       /* Detach sched domains from all of the affected cpus */
+       detach_destroy_domains(&change_map);
+       if (!cpus_empty(*partition1))
+               build_sched_domains(partition1);
+       if (!cpus_empty(*partition2))
+               build_sched_domains(partition2);
+}
 
 #ifdef CONFIG_HOTPLUG_CPU
 /*
@@ -5074,15 +5344,10 @@ static void __devinit arch_destroy_sched_domains(void)
 static int update_sched_domains(struct notifier_block *nfb,
                                unsigned long action, void *hcpu)
 {
-       int i;
-
        switch (action) {
        case CPU_UP_PREPARE:
        case CPU_DOWN_PREPARE:
-               for_each_online_cpu(i)
-                       cpu_attach_domain(NULL, i);
-               synchronize_kernel();
-               arch_destroy_sched_domains();
+               detach_destroy_domains(&cpu_online_map);
                return NOTIFY_OK;
 
        case CPU_UP_CANCELED:
@@ -5098,7 +5363,7 @@ static int update_sched_domains(struct notifier_block *nfb,
        }
 
        /* The hotplug lock is already held by cpu_up/cpu_down */
-       arch_init_sched_domains();
+       arch_init_sched_domains(&cpu_online_map);
 
        return NOTIFY_OK;
 }
@@ -5107,7 +5372,7 @@ static int update_sched_domains(struct notifier_block *nfb,
 void __init sched_init_smp(void)
 {
        lock_cpu_hotplug();
-       arch_init_sched_domains();
+       arch_init_sched_domains(&cpu_online_map);
        unlock_cpu_hotplug();
        /* XXX: Theoretical race here - CPU may be hotplugged now */
        hotcpu_notifier(update_sched_domains, 0);