alpha: move include/asm-alpha to arch/alpha/include/asm
[pandora-kernel.git] / kernel / sched.c
index 0047bd9..95e6ad3 100644 (file)
@@ -600,7 +600,6 @@ struct rq {
        /* BKL stats */
        unsigned int bkl_count;
 #endif
-       struct lock_class_key rq_lock_key;
 };
 
 static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
@@ -834,7 +833,7 @@ static inline u64 global_rt_period(void)
 
 static inline u64 global_rt_runtime(void)
 {
-       if (sysctl_sched_rt_period < 0)
+       if (sysctl_sched_rt_runtime < 0)
                return RUNTIME_INF;
 
        return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
@@ -1867,16 +1866,24 @@ migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req)
 /*
  * wait_task_inactive - wait for a thread to unschedule.
  *
+ * If @match_state is nonzero, it's the @p->state value just checked and
+ * not expected to change.  If it changes, i.e. @p might have woken up,
+ * then return zero.  When we succeed in waiting for @p to be off its CPU,
+ * we return a positive number (its total switch count).  If a second call
+ * a short while later returns the same number, the caller can be sure that
+ * @p has remained unscheduled the whole time.
+ *
  * The caller must ensure that the task *will* unschedule sometime soon,
  * else this function might spin for a *long* time. This function can't
  * be called with interrupts off, or it may introduce deadlock with
  * smp_call_function() if an IPI is sent by the same process we are
  * waiting to become inactive.
  */
-void wait_task_inactive(struct task_struct *p)
+unsigned long wait_task_inactive(struct task_struct *p, long match_state)
 {
        unsigned long flags;
        int running, on_rq;
+       unsigned long ncsw;
        struct rq *rq;
 
        for (;;) {
@@ -1899,8 +1906,11 @@ void wait_task_inactive(struct task_struct *p)
                 * return false if the runqueue has changed and p
                 * is actually now running somewhere else!
                 */
-               while (task_running(rq, p))
+               while (task_running(rq, p)) {
+                       if (match_state && unlikely(p->state != match_state))
+                               return 0;
                        cpu_relax();
+               }
 
                /*
                 * Ok, time to look more closely! We need the rq
@@ -1910,8 +1920,20 @@ void wait_task_inactive(struct task_struct *p)
                rq = task_rq_lock(p, &flags);
                running = task_running(rq, p);
                on_rq = p->se.on_rq;
+               ncsw = 0;
+               if (!match_state || p->state == match_state) {
+                       ncsw = p->nivcsw + p->nvcsw;
+                       if (unlikely(!ncsw))
+                               ncsw = 1;
+               }
                task_rq_unlock(rq, &flags);
 
+               /*
+                * If it changed from the expected state, bail out now.
+                */
+               if (unlikely(!ncsw))
+                       break;
+
                /*
                 * Was it really running after all now that we
                 * checked with the proper locks actually held?
@@ -1944,6 +1966,8 @@ void wait_task_inactive(struct task_struct *p)
                 */
                break;
        }
+
+       return ncsw;
 }
 
 /***
@@ -2734,10 +2758,10 @@ static void double_rq_lock(struct rq *rq1, struct rq *rq2)
        } else {
                if (rq1 < rq2) {
                        spin_lock(&rq1->lock);
-                       spin_lock(&rq2->lock);
+                       spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING);
                } else {
                        spin_lock(&rq2->lock);
-                       spin_lock(&rq1->lock);
+                       spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
                }
        }
        update_rq_clock(rq1);
@@ -2780,14 +2804,21 @@ static int double_lock_balance(struct rq *this_rq, struct rq *busiest)
                if (busiest < this_rq) {
                        spin_unlock(&this_rq->lock);
                        spin_lock(&busiest->lock);
-                       spin_lock(&this_rq->lock);
+                       spin_lock_nested(&this_rq->lock, SINGLE_DEPTH_NESTING);
                        ret = 1;
                } else
-                       spin_lock(&busiest->lock);
+                       spin_lock_nested(&busiest->lock, SINGLE_DEPTH_NESTING);
        }
        return ret;
 }
 
+static void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
+       __releases(busiest->lock)
+{
+       spin_unlock(&busiest->lock);
+       lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
+}
+
 /*
  * If dest_cpu is allowed for this process, migrate the task to it.
  * This is accomplished by forcing the cpu_allowed mask to only
@@ -3612,7 +3643,7 @@ redo:
                ld_moved = move_tasks(this_rq, this_cpu, busiest,
                                        imbalance, sd, CPU_NEWLY_IDLE,
                                        &all_pinned);
-               spin_unlock(&busiest->lock);
+               double_unlock_balance(this_rq, busiest);
 
                if (unlikely(all_pinned)) {
                        cpu_clear(cpu_of(busiest), *cpus);
@@ -3727,7 +3758,7 @@ static void active_load_balance(struct rq *busiest_rq, int busiest_cpu)
                else
                        schedstat_inc(sd, alb_failed);
        }
-       spin_unlock(&target_rq->lock);
+       double_unlock_balance(busiest_rq, target_rq);
 }
 
 #ifdef CONFIG_NO_HZ
@@ -4638,6 +4669,52 @@ int __sched wait_for_completion_killable(struct completion *x)
 }
 EXPORT_SYMBOL(wait_for_completion_killable);
 
+/**
+ *     try_wait_for_completion - try to decrement a completion without blocking
+ *     @x:     completion structure
+ *
+ *     Returns: 0 if a decrement cannot be done without blocking
+ *              1 if a decrement succeeded.
+ *
+ *     If a completion is being used as a counting completion,
+ *     attempt to decrement the counter without blocking. This
+ *     enables us to avoid waiting if the resource the completion
+ *     is protecting is not available.
+ */
+bool try_wait_for_completion(struct completion *x)
+{
+       int ret = 1;
+
+       spin_lock_irq(&x->wait.lock);
+       if (!x->done)
+               ret = 0;
+       else
+               x->done--;
+       spin_unlock_irq(&x->wait.lock);
+       return ret;
+}
+EXPORT_SYMBOL(try_wait_for_completion);
+
+/**
+ *     completion_done - Test to see if a completion has any waiters
+ *     @x:     completion structure
+ *
+ *     Returns: 0 if there are waiters (wait_for_completion() in progress)
+ *              1 if there are no waiters.
+ *
+ */
+bool completion_done(struct completion *x)
+{
+       int ret = 1;
+
+       spin_lock_irq(&x->wait.lock);
+       if (!x->done)
+               ret = 0;
+       spin_unlock_irq(&x->wait.lock);
+       return ret;
+}
+EXPORT_SYMBOL(completion_done);
+
 static long __sched
 sleep_on_common(wait_queue_head_t *q, int state, long timeout)
 {
@@ -4979,19 +5056,21 @@ recheck:
                        return -EPERM;
        }
 
+       if (user) {
 #ifdef CONFIG_RT_GROUP_SCHED
-       /*
-        * Do not allow realtime tasks into groups that have no runtime
-        * assigned.
-        */
-       if (user
-           && rt_policy(policy) && task_group(p)->rt_bandwidth.rt_runtime == 0)
-               return -EPERM;
+               /*
+                * Do not allow realtime tasks into groups that have no runtime
+                * assigned.
+                */
+               if (rt_policy(policy) && task_group(p)->rt_bandwidth.rt_runtime == 0)
+                       return -EPERM;
 #endif
 
-       retval = security_task_setscheduler(p, policy, param);
-       if (retval)
-               return retval;
+               retval = security_task_setscheduler(p, policy, param);
+               if (retval)
+                       return retval;
+       }
+
        /*
         * make sure no PI-waiters arrive (or leave) while we are
         * changing the priority of the task:
@@ -6389,7 +6468,7 @@ static struct notifier_block __cpuinitdata migration_notifier = {
        .priority = 10
 };
 
-void __init migration_init(void)
+static int __init migration_init(void)
 {
        void *cpu = (void *)(long)smp_processor_id();
        int err;
@@ -6399,7 +6478,10 @@ void __init migration_init(void)
        BUG_ON(err == NOTIFY_BAD);
        migration_call(&migration_notifier, CPU_ONLINE, cpu);
        register_cpu_notifier(&migration_notifier);
+
+       return err;
 }
+early_initcall(migration_init);
 #endif
 
 #ifdef CONFIG_SMP
@@ -7643,34 +7725,34 @@ static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt)
 }
 
 #ifdef CONFIG_SCHED_MC
-static ssize_t sched_mc_power_savings_show(struct sys_device *dev,
-                               struct sysdev_attribute *attr, char *page)
+static ssize_t sched_mc_power_savings_show(struct sysdev_class *class,
+                                          char *page)
 {
        return sprintf(page, "%u\n", sched_mc_power_savings);
 }
-static ssize_t sched_mc_power_savings_store(struct sys_device *dev,
-                                           struct sysdev_attribute *attr,
+static ssize_t sched_mc_power_savings_store(struct sysdev_class *class,
                                            const char *buf, size_t count)
 {
        return sched_power_savings_store(buf, count, 0);
 }
-static SYSDEV_ATTR(sched_mc_power_savings, 0644, sched_mc_power_savings_show,
-                  sched_mc_power_savings_store);
+static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644,
+                        sched_mc_power_savings_show,
+                        sched_mc_power_savings_store);
 #endif
 
 #ifdef CONFIG_SCHED_SMT
-static ssize_t sched_smt_power_savings_show(struct sys_device *dev,
-                               struct sysdev_attribute *attr, char *page)
+static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev,
+                                           char *page)
 {
        return sprintf(page, "%u\n", sched_smt_power_savings);
 }
-static ssize_t sched_smt_power_savings_store(struct sys_device *dev,
-                                            struct sysdev_attribute *attr,
+static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev,
                                             const char *buf, size_t count)
 {
        return sched_power_savings_store(buf, count, 1);
 }
-static SYSDEV_ATTR(sched_smt_power_savings, 0644, sched_smt_power_savings_show,
+static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644,
+                  sched_smt_power_savings_show,
                   sched_smt_power_savings_store);
 #endif
 
@@ -7970,7 +8052,6 @@ void __init sched_init(void)
 
                rq = cpu_rq(i);
                spin_lock_init(&rq->lock);
-               lockdep_set_class(&rq->lock, &rq->rq_lock_key);
                rq->nr_running = 0;
                init_cfs_rq(&rq->cfs, rq);
                init_rt_rq(&rq->rt, rq);