]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - kernel/sched.c
sched: clarify ifdef tangle
[linux-2.6-omap-h63xx.git] / kernel / sched.c
index 1a5f73c1fcdcd12983c6a2eed9ef66e630dca837..927c9307cd00f17c1c3384477f5f0b4f215f50d7 100644 (file)
@@ -604,9 +604,9 @@ struct rq {
 
 static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
 
-static inline void check_preempt_curr(struct rq *rq, struct task_struct *p)
+static inline void check_preempt_curr(struct rq *rq, struct task_struct *p, int sync)
 {
-       rq->curr->sched_class->check_preempt_curr(rq, p);
+       rq->curr->sched_class->check_preempt_curr(rq, p, sync);
 }
 
 static inline int cpu_of(struct rq *rq)
@@ -1102,7 +1102,7 @@ static void hrtick_start(struct rq *rq, u64 delay)
        hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay), HRTIMER_MODE_REL);
 }
 
-static void init_hrtick(void)
+static inline void init_hrtick(void)
 {
 }
 #endif /* CONFIG_SMP */
@@ -1121,7 +1121,7 @@ static void init_rq_hrtick(struct rq *rq)
        rq->hrtick_timer.function = hrtick;
        rq->hrtick_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;
 }
-#else
+#else  /* CONFIG_SCHED_HRTICK */
 static inline void hrtick_clear(struct rq *rq)
 {
 }
@@ -1133,7 +1133,7 @@ static inline void init_rq_hrtick(struct rq *rq)
 static inline void init_hrtick(void)
 {
 }
-#endif
+#endif /* CONFIG_SCHED_HRTICK */
 
 /*
  * resched_task - mark a task 'to be rescheduled now'.
@@ -1921,11 +1921,8 @@ unsigned long wait_task_inactive(struct task_struct *p, long match_state)
                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;
-               }
+               if (!match_state || p->state == match_state)
+                       ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
                task_rq_unlock(rq, &flags);
 
                /*
@@ -2285,7 +2282,7 @@ out_running:
        trace_mark(kernel_sched_wakeup,
                "pid %d state %ld ## rq %p task %p rq->curr %p",
                p->pid, p->state, rq, p, rq->curr);
-       check_preempt_curr(rq, p);
+       check_preempt_curr(rq, p, sync);
 
        p->state = TASK_RUNNING;
 #ifdef CONFIG_SMP
@@ -2420,7 +2417,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
        trace_mark(kernel_sched_wakeup_new,
                "pid %d state %ld ## rq %p task %p rq->curr %p",
                p->pid, p->state, rq, p, rq->curr);
-       check_preempt_curr(rq, p);
+       check_preempt_curr(rq, p, 0);
 #ifdef CONFIG_SMP
        if (p->sched_class->task_wake_up)
                p->sched_class->task_wake_up(rq, p);
@@ -2880,7 +2877,7 @@ static void pull_task(struct rq *src_rq, struct task_struct *p,
         * 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);
+       check_preempt_curr(this_rq, p, 0);
 }
 
 /*
@@ -4627,6 +4624,15 @@ __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
 }
 EXPORT_SYMBOL_GPL(__wake_up_sync);     /* For internal use only */
 
+/**
+ * complete: - signals a single thread waiting on this completion
+ * @x:  holds the state of this particular completion
+ *
+ * This will wake up a single thread waiting on this completion. Threads will be
+ * awakened in the same order in which they were queued.
+ *
+ * See also complete_all(), wait_for_completion() and related routines.
+ */
 void complete(struct completion *x)
 {
        unsigned long flags;
@@ -4638,6 +4644,12 @@ void complete(struct completion *x)
 }
 EXPORT_SYMBOL(complete);
 
+/**
+ * complete_all: - signals all threads waiting on this completion
+ * @x:  holds the state of this particular completion
+ *
+ * This will wake up all threads waiting on this particular completion event.
+ */
 void complete_all(struct completion *x)
 {
        unsigned long flags;
@@ -4658,10 +4670,7 @@ do_wait_for_common(struct completion *x, long timeout, int state)
                wait.flags |= WQ_FLAG_EXCLUSIVE;
                __add_wait_queue_tail(&x->wait, &wait);
                do {
-                       if ((state == TASK_INTERRUPTIBLE &&
-                            signal_pending(current)) ||
-                           (state == TASK_KILLABLE &&
-                            fatal_signal_pending(current))) {
+                       if (signal_pending_state(state, current)) {
                                timeout = -ERESTARTSYS;
                                break;
                        }
@@ -4689,12 +4698,31 @@ wait_for_common(struct completion *x, long timeout, int state)
        return timeout;
 }
 
+/**
+ * wait_for_completion: - waits for completion of a task
+ * @x:  holds the state of this particular completion
+ *
+ * This waits to be signaled for completion of a specific task. It is NOT
+ * interruptible and there is no timeout.
+ *
+ * See also similar routines (i.e. wait_for_completion_timeout()) with timeout
+ * and interrupt capability. Also see complete().
+ */
 void __sched wait_for_completion(struct completion *x)
 {
        wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
 }
 EXPORT_SYMBOL(wait_for_completion);
 
+/**
+ * wait_for_completion_timeout: - waits for completion of a task (w/timeout)
+ * @x:  holds the state of this particular completion
+ * @timeout:  timeout value in jiffies
+ *
+ * This waits for either a completion of a specific task to be signaled or for a
+ * specified timeout to expire. The timeout is in jiffies. It is not
+ * interruptible.
+ */
 unsigned long __sched
 wait_for_completion_timeout(struct completion *x, unsigned long timeout)
 {
@@ -4702,6 +4730,13 @@ wait_for_completion_timeout(struct completion *x, unsigned long timeout)
 }
 EXPORT_SYMBOL(wait_for_completion_timeout);
 
+/**
+ * wait_for_completion_interruptible: - waits for completion of a task (w/intr)
+ * @x:  holds the state of this particular completion
+ *
+ * This waits for completion of a specific task to be signaled. It is
+ * interruptible.
+ */
 int __sched wait_for_completion_interruptible(struct completion *x)
 {
        long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE);
@@ -4711,6 +4746,14 @@ int __sched wait_for_completion_interruptible(struct completion *x)
 }
 EXPORT_SYMBOL(wait_for_completion_interruptible);
 
+/**
+ * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr))
+ * @x:  holds the state of this particular completion
+ * @timeout:  timeout value in jiffies
+ *
+ * This waits for either a completion of a specific task to be signaled or for a
+ * specified timeout to expire. It is interruptible. The timeout is in jiffies.
+ */
 unsigned long __sched
 wait_for_completion_interruptible_timeout(struct completion *x,
                                          unsigned long timeout)
@@ -4719,6 +4762,13 @@ wait_for_completion_interruptible_timeout(struct completion *x,
 }
 EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
 
+/**
+ * wait_for_completion_killable: - waits for completion of a task (killable)
+ * @x:  holds the state of this particular completion
+ *
+ * This waits to be signaled for completion of a specific task. It can be
+ * interrupted by a kill signal.
+ */
 int __sched wait_for_completion_killable(struct completion *x)
 {
        long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE);
@@ -5957,7 +6007,7 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
        set_task_cpu(p, dest_cpu);
        if (on_rq) {
                activate_task(rq_dest, p, 0);
-               check_preempt_curr(rq_dest, p);
+               check_preempt_curr(rq_dest, p, 0);
        }
 done:
        ret = 1;
@@ -7696,24 +7746,27 @@ static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
  * and partition_sched_domains() will fallback to the single partition
  * 'fallback_doms', it also forces the domains to be rebuilt.
  *
+ * If doms_new==NULL it will be replaced with cpu_online_map.
+ * ndoms_new==0 is a special case for destroying existing domains.
+ * It will not create the default domain.
+ *
  * Call with hotplug lock held
  */
 void partition_sched_domains(int ndoms_new, cpumask_t *doms_new,
                             struct sched_domain_attr *dattr_new)
 {
-       int i, j;
+       int i, j, n;
 
        mutex_lock(&sched_domains_mutex);
 
        /* always unregister in case we don't destroy any domains */
        unregister_sched_domain_sysctl();
 
-       if (doms_new == NULL)
-               ndoms_new = 0;
+       n = doms_new ? ndoms_new : 0;
 
        /* Destroy deleted domains */
        for (i = 0; i < ndoms_cur; i++) {
-               for (j = 0; j < ndoms_new; j++) {
+               for (j = 0; j < n; j++) {
                        if (cpus_equal(doms_cur[i], doms_new[j])
                            && dattrs_equal(dattr_cur, i, dattr_new, j))
                                goto match1;
@@ -7726,7 +7779,6 @@ match1:
 
        if (doms_new == NULL) {
                ndoms_cur = 0;
-               ndoms_new = 1;
                doms_new = &fallback_doms;
                cpus_andnot(doms_new[0], cpu_online_map, cpu_isolated_map);
                dattr_new = NULL;
@@ -7763,8 +7815,13 @@ match2:
 int arch_reinit_sched_domains(void)
 {
        get_online_cpus();
+
+       /* Destroy domains first to force the rebuild */
+       partition_sched_domains(0, NULL, NULL);
+
        rebuild_sched_domains();
        put_online_cpus();
+
        return 0;
 }
 
@@ -7848,7 +7905,7 @@ static int update_sched_domains(struct notifier_block *nfb,
        case CPU_ONLINE_FROZEN:
        case CPU_DEAD:
        case CPU_DEAD_FROZEN:
-               partition_sched_domains(0, NULL, NULL);
+               partition_sched_domains(1, NULL, NULL);
                return NOTIFY_OK;
 
        default:
@@ -8235,20 +8292,25 @@ void __might_sleep(char *file, int line)
 #ifdef in_atomic
        static unsigned long prev_jiffy;        /* ratelimiting */
 
-       if ((in_atomic() || irqs_disabled()) &&
-           system_state == SYSTEM_RUNNING && !oops_in_progress) {
-               if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
-                       return;
-               prev_jiffy = jiffies;
-               printk(KERN_ERR "BUG: sleeping function called from invalid"
-                               " context at %s:%d\n", file, line);
-               printk("in_atomic():%d, irqs_disabled():%d\n",
-                       in_atomic(), irqs_disabled());
-               debug_show_held_locks(current);
-               if (irqs_disabled())
-                       print_irqtrace_events(current);
-               dump_stack();
-       }
+       if ((!in_atomic() && !irqs_disabled()) ||
+                   system_state != SYSTEM_RUNNING || oops_in_progress)
+               return;
+       if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
+               return;
+       prev_jiffy = jiffies;
+
+       printk(KERN_ERR
+               "BUG: sleeping function called from invalid context at %s:%d\n",
+                       file, line);
+       printk(KERN_ERR
+               "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n",
+                       in_atomic(), irqs_disabled(),
+                       current->pid, current->comm);
+
+       debug_show_held_locks(current);
+       if (irqs_disabled())
+               print_irqtrace_events(current);
+       dump_stack();
 #endif
 }
 EXPORT_SYMBOL(__might_sleep);