static inline void finish_lock_switch(runqueue_t *rq, task_t *prev)
{
+#ifdef CONFIG_DEBUG_SPINLOCK
+ /* this is a valid case when another task releases the spinlock */
+ rq->lock.owner = current;
+#endif
spin_unlock_irq(&rq->lock);
}
* Manfred Spraul <manfred@colorfullife.com>
*/
prev_task_flags = prev->flags;
-#ifdef CONFIG_DEBUG_SPINLOCK
- /* this is a valid case when another task releases the spinlock */
- rq->lock.owner = current;
-#endif
finish_arch_switch(prev);
finish_lock_switch(rq, prev);
if (mm)
{
struct sched_group *busiest = NULL, *this = NULL, *group = sd->groups;
unsigned long max_load, avg_load, total_load, this_load, total_pwr;
+ unsigned long max_pull;
int load_idx;
max_load = this_load = total_load = total_pwr = 0;
group = group->next;
} while (group != sd->groups);
- if (!busiest || this_load >= max_load)
+ if (!busiest || this_load >= max_load || max_load <= SCHED_LOAD_SCALE)
goto out_balanced;
avg_load = (SCHED_LOAD_SCALE * total_load) / total_pwr;
* by pulling tasks to us. Be careful of negative numbers as they'll
* appear as very large values with unsigned longs.
*/
+
+ /* Don't want to pull so many tasks that a group would go idle */
+ max_pull = min(max_load - avg_load, max_load - SCHED_LOAD_SCALE);
+
/* How much load to actually move to equalise the imbalance */
- *imbalance = min((max_load - avg_load) * busiest->cpu_power,
+ *imbalance = min(max_pull * busiest->cpu_power,
(avg_load - this_load) * this->cpu_power)
/ SCHED_LOAD_SCALE;
if (unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2)) {
spin_lock(&busiest->lock);
+
+ /* don't kick the migration_thread, if the curr
+ * task on busiest cpu can't be moved to this_cpu
+ */
+ if (!cpu_isset(this_cpu, busiest->curr->cpus_allowed)) {
+ spin_unlock(&busiest->lock);
+ all_pinned = 1;
+ goto out_one_pinned;
+ }
+
if (!busiest->active_balance) {
busiest->active_balance = 1;
busiest->push_cpu = this_cpu;
schedstat_inc(sd, lb_balanced[idle]);
sd->nr_balance_failed = 0;
+
+out_one_pinned:
/* tune up the balancing interval */
if ((all_pinned && sd->balance_interval < MAX_PINNED_INTERVAL) ||
(sd->balance_interval < sd->max_interval))
if (j - sd->last_balance >= interval) {
if (load_balance(this_cpu, this_rq, sd, idle)) {
- /* We've pulled tasks over so either we're no
+ /*
+ * We've pulled tasks over so either we're no
* longer idle, or one of our SMT siblings is
* not idle.
*/
#ifndef CONFIG_SMP
cpumask_t cpu_online_map = CPU_MASK_ALL;
+EXPORT_SYMBOL_GPL(cpu_online_map);
cpumask_t cpu_possible_map = CPU_MASK_ALL;
#endif
}
#endif /* CONFIG_MAGIC_SYSRQ */
+
+#ifdef CONFIG_IA64
+/*
+ * These functions are only useful for the IA64 MCA handling.
+ *
+ * They can only be called when the whole system has been
+ * stopped - every CPU needs to be quiescent, and no scheduling
+ * activity can take place. Using them for anything else would
+ * be a serious bug, and as a result, they aren't even visible
+ * under any other configuration.
+ */
+
+/**
+ * curr_task - return the current task for a given cpu.
+ * @cpu: the processor in question.
+ *
+ * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
+ */
+task_t *curr_task(int cpu)
+{
+ return cpu_curr(cpu);
+}
+
+/**
+ * set_curr_task - set the current task for a given cpu.
+ * @cpu: the processor in question.
+ * @p: the task pointer to set.
+ *
+ * Description: This function must only be used when non-maskable interrupts
+ * are serviced on a separate stack. It allows the architecture to switch the
+ * notion of the current task on a cpu in a non-blocking manner. This function
+ * must be called with all CPU's synchronized, and interrupts disabled, the
+ * and caller must save the original value of the current task (see
+ * curr_task() above) and restore that value before reenabling interrupts and
+ * re-starting the system.
+ *
+ * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
+ */
+void set_curr_task(int cpu, task_t *p)
+{
+ cpu_curr(cpu) = p;
+}
+
+#endif