Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (21 commits)
  sched: Remove forced2_migrations stats
  sched: Fix memory leak in two error corner cases
  sched: Fix build warning in get_update_sysctl_factor()
  sched: Update normalized values on user updates via proc
  sched: Make tunable scaling style configurable
  sched: Fix missing sched tunable recalculation on cpu add/remove
  sched: Fix task priority bug
  sched: cgroup: Implement different treatment for idle shares
  sched: Remove unnecessary RCU exclusion
  sched: Discard some old bits
  sched: Clean up check_preempt_wakeup()
  sched: Move update_curr() in check_preempt_wakeup() to avoid redundant call
  sched: Sanitize fork() handling
  sched: Clean up ttwu() rq locking
  sched: Remove rq->clock coupling from set_task_cpu()
  sched: Consolidate select_task_rq() callers
  sched: Remove sysctl.sched_features
  sched: Protect sched_rr_get_param() access to task->sched_class
  sched: Protect task->cpus_allowed access in sched_getaffinity()
  sched: Fix balance vs hotplug race
  ...

Fixed up conflicts in kernel/sysctl.c (due to sysctl cleanup)

1 files changed, 114 insertions, 104 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index e7f2cfa6a257..ff39cadf621e 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -814,6 +814,7 @@ const_debug unsigned int sysctl_sched_nr_migrate = 32;
  * default: 0.25ms
  */
 unsigned int sysctl_sched_shares_ratelimit = 250000;
+unsigned int normalized_sysctl_sched_shares_ratelimit = 250000;
 
 /*
  * Inject some fuzzyness into changing the per-cpu group shares
@@ -1614,7 +1615,7 @@ static void update_group_shares_cpu(struct task_group *tg, int cpu,
  */
 static int tg_shares_up(struct task_group *tg, void *data)
 {
-        unsigned long weight, rq_weight = 0, shares = 0;
+        unsigned long weight, rq_weight = 0, sum_weight = 0, shares = 0;
         unsigned long *usd_rq_weight;
         struct sched_domain *sd = data;
         unsigned long flags;
@@ -1630,6 +1631,7 @@ static int tg_shares_up(struct task_group *tg, void *data)
                 weight = tg->cfs_rq[i]->load.weight;
                 usd_rq_weight[i] = weight;
 
+                rq_weight += weight;
                 /*
                  * If there are currently no tasks on the cpu pretend there
                  * is one of average load so that when a new task gets to
@@ -1638,10 +1640,13 @@ static int tg_shares_up(struct task_group *tg, void *data)
                 if (!weight)
                         weight = NICE_0_LOAD;
 
-                rq_weight += weight;
+                sum_weight += weight;
                 shares += tg->cfs_rq[i]->shares;
         }
 
+        if (!rq_weight)
+                rq_weight = sum_weight;
+
         if ((!shares && rq_weight) || shares > tg->shares)
                 shares = tg->shares;
 
@@ -1810,6 +1815,22 @@ static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares)
 #endif
 
 static void calc_load_account_active(struct rq *this_rq);
+static void update_sysctl(void);
+static int get_update_sysctl_factor(void);
+
+static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
+{
+        set_task_rq(p, cpu);
+#ifdef CONFIG_SMP
+        /*
+         * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
+         * successfuly executed on another CPU. We must ensure that updates of
+         * per-task data have been completed by this moment.
+         */
+        smp_wmb();
+        task_thread_info(p)->cpu = cpu;
+#endif
+}
 
 #include "sched_stats.h"
 #include "sched_idletask.c"
@@ -1967,20 +1988,6 @@ inline int task_curr(const struct task_struct *p)
         return cpu_curr(task_cpu(p)) == p;
 }
 
-static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
-{
-        set_task_rq(p, cpu);
-#ifdef CONFIG_SMP
-        /*
-         * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
-         * successfuly executed on another CPU. We must ensure that updates of
-         * per-task data have been completed by this moment.
-         */
-        smp_wmb();
-        task_thread_info(p)->cpu = cpu;
-#endif
-}
-
 static inline void check_class_changed(struct rq *rq, struct task_struct *p,
                                        const struct sched_class *prev_class,
                                        int oldprio, int running)
@@ -2060,29 +2067,13 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
 void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
 {
         int old_cpu = task_cpu(p);
-        struct rq *old_rq = cpu_rq(old_cpu), *new_rq = cpu_rq(new_cpu);
         struct cfs_rq *old_cfsrq = task_cfs_rq(p),
                       *new_cfsrq = cpu_cfs_rq(old_cfsrq, new_cpu);
-        u64 clock_offset;
-
-        clock_offset = old_rq->clock - new_rq->clock;
 
         trace_sched_migrate_task(p, new_cpu);
 
-#ifdef CONFIG_SCHEDSTATS
-        if (p->se.wait_start)
-                p->se.wait_start -= clock_offset;
-        if (p->se.sleep_start)
-                p->se.sleep_start -= clock_offset;
-        if (p->se.block_start)
-                p->se.block_start -= clock_offset;
-#endif
         if (old_cpu != new_cpu) {
                 p->se.nr_migrations++;
-#ifdef CONFIG_SCHEDSTATS
-                if (task_hot(p, old_rq->clock, NULL))
-                        schedstat_inc(p, se.nr_forced2_migrations);
-#endif
                 perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS,
                                      1, 1, NULL, 0);
         }
@@ -2323,6 +2314,14 @@ void task_oncpu_function_call(struct task_struct *p,
         preempt_enable();
 }
 
+#ifdef CONFIG_SMP
+static inline
+int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags)
+{
+        return p->sched_class->select_task_rq(p, sd_flags, wake_flags);
+}
+#endif
+
 /***
  * try_to_wake_up - wake up a thread
  * @p: the to-be-woken-up thread
@@ -2374,17 +2373,14 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
         if (task_contributes_to_load(p))
                 rq->nr_uninterruptible--;
         p->state = TASK_WAKING;
-        task_rq_unlock(rq, &flags);
+        __task_rq_unlock(rq);
 
-        cpu = p->sched_class->select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
-        if (cpu != orig_cpu) {
-                local_irq_save(flags);
-                rq = cpu_rq(cpu);
-                update_rq_clock(rq);
+        cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
+        if (cpu != orig_cpu)
                 set_task_cpu(p, cpu);
-                local_irq_restore(flags);
-        }
-        rq = task_rq_lock(p, &flags);
+
+        rq = __task_rq_lock(p);
+        update_rq_clock(rq);
 
         WARN_ON(p->state != TASK_WAKING);
         cpu = task_cpu(p);
@@ -2499,7 +2495,6 @@ static void __sched_fork(struct task_struct *p)
         p->se.avg_overlap               = 0;
         p->se.start_runtime             = 0;
         p->se.avg_wakeup                = sysctl_sched_wakeup_granularity;
-        p->se.avg_running               = 0;
 
 #ifdef CONFIG_SCHEDSTATS
         p->se.wait_start                        = 0;
@@ -2521,7 +2516,6 @@ static void __sched_fork(struct task_struct *p)
         p->se.nr_failed_migrations_running      = 0;
         p->se.nr_failed_migrations_hot          = 0;
         p->se.nr_forced_migrations              = 0;
-        p->se.nr_forced2_migrations             = 0;
 
         p->se.nr_wakeups                        = 0;
         p->se.nr_wakeups_sync                   = 0;
@@ -2558,7 +2552,6 @@ static void __sched_fork(struct task_struct *p)
 void sched_fork(struct task_struct *p, int clone_flags)
 {
         int cpu = get_cpu();
-        unsigned long flags;
 
         __sched_fork(p);
 
@@ -2592,13 +2585,13 @@ void sched_fork(struct task_struct *p, int clone_flags)
         if (!rt_prio(p->prio))
                 p->sched_class = &fair_sched_class;
 
+        if (p->sched_class->task_fork)
+                p->sched_class->task_fork(p);
+
 #ifdef CONFIG_SMP
-        cpu = p->sched_class->select_task_rq(p, SD_BALANCE_FORK, 0);
+        cpu = select_task_rq(p, SD_BALANCE_FORK, 0);
 #endif
-        local_irq_save(flags);
-        update_rq_clock(cpu_rq(cpu));
         set_task_cpu(p, cpu);
-        local_irq_restore(flags);
 
 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
         if (likely(sched_info_on()))
@@ -2631,17 +2624,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
         rq = task_rq_lock(p, &flags);
         BUG_ON(p->state != TASK_RUNNING);
         update_rq_clock(rq);
-
-        if (!p->sched_class->task_new || !current->se.on_rq) {
-                activate_task(rq, p, 0);
-        } else {
-                /*
-                 * Let the scheduling class do new task startup
-                 * management (if any):
-                 */
-                p->sched_class->task_new(rq, p);
-                inc_nr_running(rq);
-        }
+        activate_task(rq, p, 0);
         trace_sched_wakeup_new(rq, p, 1);
         check_preempt_curr(rq, p, WF_FORK);
 #ifdef CONFIG_SMP
@@ -3156,7 +3139,7 @@ out:
 void sched_exec(void)
 {
         int new_cpu, this_cpu = get_cpu();
-        new_cpu = current->sched_class->select_task_rq(current, SD_BALANCE_EXEC, 0);
+        new_cpu = select_task_rq(current, SD_BALANCE_EXEC, 0);
         put_cpu();
         if (new_cpu != this_cpu)
                 sched_migrate_task(current, new_cpu);
@@ -3172,10 +3155,6 @@ static void pull_task(struct rq *src_rq, struct task_struct *p,
         deactivate_task(src_rq, p, 0);
         set_task_cpu(p, this_cpu);
         activate_task(this_rq, p, 0);
-        /*
-         * Note that idle threads have a prio of MAX_PRIO, for this test
-         * to be always true for them.
-         */
         check_preempt_curr(this_rq, p, 0);
 }
 
@@ -4134,7 +4113,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
         unsigned long flags;
         struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
 
-        cpumask_copy(cpus, cpu_online_mask);
+        cpumask_copy(cpus, cpu_active_mask);
 
         /*
          * When power savings policy is enabled for the parent domain, idle
@@ -4297,7 +4276,7 @@ load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd)
         int all_pinned = 0;
         struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
 
-        cpumask_copy(cpus, cpu_online_mask);
+        cpumask_copy(cpus, cpu_active_mask);
 
         /*
          * When power savings policy is enabled for the parent domain, idle
@@ -4694,7 +4673,7 @@ int select_nohz_load_balancer(int stop_tick)
                 cpumask_set_cpu(cpu, nohz.cpu_mask);
 
                 /* time for ilb owner also to sleep */
-                if (cpumask_weight(nohz.cpu_mask) == num_online_cpus()) {
+                if (cpumask_weight(nohz.cpu_mask) == num_active_cpus()) {
                         if (atomic_read(&nohz.load_balancer) == cpu)
                                 atomic_set(&nohz.load_balancer, -1);
                         return 0;
@@ -5396,13 +5375,14 @@ static inline void schedule_debug(struct task_struct *prev)
 #endif
 }
 
-static void put_prev_task(struct rq *rq, struct task_struct *p)
+static void put_prev_task(struct rq *rq, struct task_struct *prev)
 {
-        u64 runtime = p->se.sum_exec_runtime - p->se.prev_sum_exec_runtime;
+        if (prev->state == TASK_RUNNING) {
+                u64 runtime = prev->se.sum_exec_runtime;
 
-        update_avg(&p->se.avg_running, runtime);
+                runtime -= prev->se.prev_sum_exec_runtime;
+                runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost);
 
-        if (p->state == TASK_RUNNING) {
                 /*
                  * In order to avoid avg_overlap growing stale when we are
                  * indeed overlapping and hence not getting put to sleep, grow
@@ -5412,12 +5392,9 @@ static void put_prev_task(struct rq *rq, struct task_struct *p)
                  * correlates to the amount of cache footprint a task can
                  * build up.
                  */
-                runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost);
-                update_avg(&p->se.avg_overlap, runtime);
-        } else {
-                update_avg(&p->se.avg_running, 0);
+                update_avg(&prev->se.avg_overlap, runtime);
         }
-        p->sched_class->put_prev_task(rq, p);
+        prev->sched_class->put_prev_task(rq, prev);
 }
 
 /*
@@ -6631,6 +6608,8 @@ SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len,
 long sched_getaffinity(pid_t pid, struct cpumask *mask)
 {
         struct task_struct *p;
+        unsigned long flags;
+        struct rq *rq;
         int retval;
 
         get_online_cpus();
@@ -6645,7 +6624,9 @@ long sched_getaffinity(pid_t pid, struct cpumask *mask)
         if (retval)
                 goto out_unlock;
 
+        rq = task_rq_lock(p, &flags);
         cpumask_and(mask, &p->cpus_allowed, cpu_online_mask);
+        task_rq_unlock(rq, &flags);
 
 out_unlock:
         read_unlock(&tasklist_lock);
@@ -6883,6 +6864,8 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
 {
         struct task_struct *p;
         unsigned int time_slice;
+        unsigned long flags;
+        struct rq *rq;
         int retval;
         struct timespec t;
 
@@ -6899,7 +6882,9 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
         if (retval)
                 goto out_unlock;
 
-        time_slice = p->sched_class->get_rr_interval(p);
+        rq = task_rq_lock(p, &flags);
+        time_slice = p->sched_class->get_rr_interval(rq, p);
+        task_rq_unlock(rq, &flags);
 
         read_unlock(&tasklist_lock);
         jiffies_to_timespec(time_slice, &t);
@@ -7000,7 +6985,6 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
         __sched_fork(idle);
         idle->se.exec_start = sched_clock();
 
-        idle->prio = idle->normal_prio = MAX_PRIO;
         cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu));
         __set_task_cpu(idle, cpu);
 
@@ -7041,22 +7025,43 @@ cpumask_var_t nohz_cpu_mask;
  *
  * This idea comes from the SD scheduler of Con Kolivas:
  */
-static inline void sched_init_granularity(void)
+static int get_update_sysctl_factor(void)
 {
-        unsigned int factor = 1 + ilog2(num_online_cpus());
-        const unsigned long limit = 200000000;
+        unsigned int cpus = min_t(int, num_online_cpus(), 8);
+        unsigned int factor;
+
+        switch (sysctl_sched_tunable_scaling) {
+        case SCHED_TUNABLESCALING_NONE:
+                factor = 1;
+                break;
+        case SCHED_TUNABLESCALING_LINEAR:
+                factor = cpus;
+                break;
+        case SCHED_TUNABLESCALING_LOG:
+        default:
+                factor = 1 + ilog2(cpus);
+                break;
+        }
 
-        sysctl_sched_min_granularity *= factor;
-        if (sysctl_sched_min_granularity > limit)
-                sysctl_sched_min_granularity = limit;
+        return factor;
+}
 
-        sysctl_sched_latency *= factor;
-        if (sysctl_sched_latency > limit)
-                sysctl_sched_latency = limit;
+static void update_sysctl(void)
+{
+        unsigned int factor = get_update_sysctl_factor();
 
-        sysctl_sched_wakeup_granularity *= factor;
+#define SET_SYSCTL(name) \
+        (sysctl_##name = (factor) * normalized_sysctl_##name)
+        SET_SYSCTL(sched_min_granularity);
+        SET_SYSCTL(sched_latency);
+        SET_SYSCTL(sched_wakeup_granularity);
+        SET_SYSCTL(sched_shares_ratelimit);
+#undef SET_SYSCTL
+}
 
-        sysctl_sched_shares_ratelimit *= factor;
+static inline void sched_init_granularity(void)
+{
+        update_sysctl();
 }
 
 #ifdef CONFIG_SMP
@@ -7093,7 +7098,7 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
         int ret = 0;
 
         rq = task_rq_lock(p, &flags);
-        if (!cpumask_intersects(new_mask, cpu_online_mask)) {
+        if (!cpumask_intersects(new_mask, cpu_active_mask)) {
                 ret = -EINVAL;
                 goto out;
         }
@@ -7115,7 +7120,7 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
         if (cpumask_test_cpu(task_cpu(p), new_mask))
                 goto out;
 
-        if (migrate_task(p, cpumask_any_and(cpu_online_mask, new_mask), &req)) {
+        if (migrate_task(p, cpumask_any_and(cpu_active_mask, new_mask), &req)) {
                 /* Need help from migration thread: drop lock and wait. */
                 struct task_struct *mt = rq->migration_thread;
 
@@ -7269,19 +7274,19 @@ static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
 
 again:
         /* Look for allowed, online CPU in same node. */
-        for_each_cpu_and(dest_cpu, nodemask, cpu_online_mask)
+        for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask)
                 if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed))
                         goto move;
 
         /* Any allowed, online CPU? */
-        dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_online_mask);
+        dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_active_mask);
         if (dest_cpu < nr_cpu_ids)
                 goto move;
 
         /* No more Mr. Nice Guy. */
         if (dest_cpu >= nr_cpu_ids) {
                 cpuset_cpus_allowed_locked(p, &p->cpus_allowed);
-                dest_cpu = cpumask_any_and(cpu_online_mask, &p->cpus_allowed);
+                dest_cpu = cpumask_any_and(cpu_active_mask, &p->cpus_allowed);
 
                 /*
                  * Don't tell them about moving exiting tasks or
@@ -7310,7 +7315,7 @@ move:
  */
 static void migrate_nr_uninterruptible(struct rq *rq_src)
 {
-        struct rq *rq_dest = cpu_rq(cpumask_any(cpu_online_mask));
+        struct rq *rq_dest = cpu_rq(cpumask_any(cpu_active_mask));
         unsigned long flags;
 
         local_irq_save(flags);
@@ -7563,7 +7568,7 @@ static ctl_table *sd_alloc_ctl_cpu_table(int cpu)
 static struct ctl_table_header *sd_sysctl_header;
 static void register_sched_domain_sysctl(void)
 {
-        int i, cpu_num = num_online_cpus();
+        int i, cpu_num = num_possible_cpus();
         struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
         char buf[32];
 
@@ -7573,7 +7578,7 @@ static void register_sched_domain_sysctl(void)
         if (entry == NULL)
                 return;
 
-        for_each_online_cpu(i) {
+        for_each_possible_cpu(i) {
                 snprintf(buf, 32, "cpu%d", i);
                 entry->procname = kstrdup(buf, GFP_KERNEL);
                 entry->mode = 0555;
@@ -7703,7 +7708,6 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
                 spin_lock_irq(&rq->lock);
                 update_rq_clock(rq);
                 deactivate_task(rq, rq->idle, 0);
-                rq->idle->static_prio = MAX_PRIO;
                 __setscheduler(rq, rq->idle, SCHED_NORMAL, 0);
                 rq->idle->sched_class = &idle_sched_class;
                 migrate_dead_tasks(cpu);
@@ -9099,7 +9103,7 @@ match1:
         if (doms_new == NULL) {
                 ndoms_cur = 0;
                 doms_new = &fallback_doms;
-                cpumask_andnot(doms_new[0], cpu_online_mask, cpu_isolated_map);
+                cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map);
                 WARN_ON_ONCE(dattr_new);
         }
 
@@ -9230,8 +9234,10 @@ static int update_sched_domains(struct notifier_block *nfb,
         switch (action) {
         case CPU_ONLINE:
         case CPU_ONLINE_FROZEN:
-        case CPU_DEAD:
-        case CPU_DEAD_FROZEN:
+        case CPU_DOWN_PREPARE:
+        case CPU_DOWN_PREPARE_FROZEN:
+        case CPU_DOWN_FAILED:
+        case CPU_DOWN_FAILED_FROZEN:
                 partition_sched_domains(1, NULL, NULL);
                 return NOTIFY_OK;
 
@@ -9278,7 +9284,7 @@ void __init sched_init_smp(void)
 #endif
         get_online_cpus();
         mutex_lock(&sched_domains_mutex);
-        arch_init_sched_domains(cpu_online_mask);
+        arch_init_sched_domains(cpu_active_mask);
         cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map);
         if (cpumask_empty(non_isolated_cpus))
                 cpumask_set_cpu(smp_processor_id(), non_isolated_cpus);
@@ -9842,13 +9848,15 @@ int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
                 se = kzalloc_node(sizeof(struct sched_entity),
                                   GFP_KERNEL, cpu_to_node(i));
                 if (!se)
-                        goto err;
+                        goto err_free_rq;
 
                 init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]);
         }
 
         return 1;
 
+ err_free_rq:
+        kfree(cfs_rq);
  err:
         return 0;
 }
@@ -9930,13 +9938,15 @@ int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
                 rt_se = kzalloc_node(sizeof(struct sched_rt_entity),
                                      GFP_KERNEL, cpu_to_node(i));
                 if (!rt_se)
-                        goto err;
+                        goto err_free_rq;
 
                 init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]);
         }
 
         return 1;
 
+ err_free_rq:
+        kfree(rt_rq);
  err:
         return 0;
 }